generic API response + ICS: warehouse_balance md_rack update

app/assets/js/custom.js

@@ -401,12 +401,34 @@ function ajax_request(options) {
     isAjaxProcessing = false;
     $.LoadingOverlay("hide");
 
+    // Errors re-thrown from .then() — pass through
     if (xhr instanceof Error) {
       throw xhr;
     }
 
-    console.error("AJAX Error:", xhr?.responseText);
+    // Extract server's error message from JSON response
-    bootbox.alert("Server error occurred.");
+    let serverMessage = xhr?.responseJSON?.message;
+
+    // Fallback: parse responseText if responseJSON isn't set
+    if (!serverMessage && xhr?.responseText) {
+      try {
+        serverMessage = JSON.parse(xhr.responseText)?.message;
+      } catch (e) {
+        // Response wasn't JSON — real server crash or HTML error page
+      }
+    }
+
+    if (serverMessage) {
+      // Known server-reported error (HTTP 4xx/5xx with JSON body)
+      bootbox.alert(serverMessage);
+      options.onError?.(xhr, serverMessage);
+    } else {
+      // Unknown error — network failure, PHP fatal, HTML error page
+      console.error("AJAX Error:", xhr?.status, xhr?.responseText);
+      bootbox.alert("Server error occurred.");
+      options.onError?.(xhr, null);
+    }
+
     throw xhr;
   });
 }
@@ -422,6 +444,7 @@ function generate_pagination(table_id, total_records, records_per_page, current_
   // 1. Find the table and thead
   const table = document.getElementById(table_id);
   let theme_class = '';
+  let col_count = 1;
 
   if (table) {
     const thead = table.querySelector('thead');
@@ -433,16 +456,25 @@ function generate_pagination(table_id, total_records, records_per_page, current_
         // 3. Convert "table-secondary" to "page-item-secondary"
         theme_class = bootstrap_theme.replace('table-', 'page-item-');
       }
+
+      // 4. Count <th> in the first row of thead
+      const header_row = thead.querySelector('tr');
+      if (header_row) {
+        col_count = header_row.querySelectorAll('th').length || 1;
+      }
     }
   }
 
+  const left_span = Math.floor(col_count / 2);
+  const right_span = Math.ceil(col_count / 2);
+
   let pagination_html = `
     <tr>
-      <td class="border-bottom-0">
+      <td colspan="${left_span}" class="border-bottom-0">
         <span class="text-muted">Showing ${records_per_page} per page</span><br>
         <strong>Total: ${total_records}</strong>
       </td>
-      <td colspan="9" class="border-bottom-0">
+      <td colspan="${right_span}" class="border-bottom-0">
         <nav aria-label="Page navigation" class="d-flex justify-content-end">
           <ul class="pagination mb-0">`;
 

app/assets/utils/classes/Reports.php

@@ -97,6 +97,15 @@ class Reports
         return (int) $this->fetchScalar($sql);
     }
 
+    public function getTotalProductInStock(): int
+{
+        $sql = "SELECT COUNT(DISTINCT product_sku)
+                FROM warehouse_balance
+                WHERE company_id = :company_id
+                AND (total_in - total_out) > 0";
+        return (int) $this->fetchScalar($sql);
+    }
+
     public function getLowStockCount(): int
     {
         $products = $this->getStockBalance();

app/assets/utils/classes/WarehouseManager.php

@@ -15,9 +15,8 @@ class WarehouseManager {
 
     private $pdo;
     private $company_id;
-
+    public function __construct($pdo, $company_id, $logging = null) {
-    public function __construct($pdo, $company_id) {
+        $this->pdo        = $pdo;
-        $this->pdo = $pdo;
         $this->company_id = $company_id;
     }
 
@@ -218,20 +217,87 @@ class WarehouseManager {
         }
     }
 
+
+    /**
+     * Fetch the stock record currently linked to a rack.
+     * 
+     * Under the 1:1 model, each occupied rack points to exactly one
+     * td_stock_<wh> row via md_rack.td_stock_id. This method resolves
+     * that pointer — returning the full stock row, or null if the rack
+     * is empty or the link is broken.
+     *
+     * The td_stock table name is derived from the warehouse (via
+     * getStockContext), so callers don't need to know the naming convention.
+     */
+    public function getRackStock($warehouse_id, $zone, $aisle, $rack): ?array {
+
+        // Get the stock pointer from md_rack
+        $sql = "SELECT td_stock_id FROM md_rack
+                WHERE company_id = :company_id 
+                AND warehouse = :warehouse
+                AND zone  = :zone
+                AND aisle = :aisle
+                AND rack  = :rack";
+
+        $sth = $this->pdo->prepare($sql);
+        $sth->execute([
+            ":company_id" => $this->company_id,
+            ":warehouse"  => $warehouse_id,
+            ":zone"       => $zone,
+            ":aisle"      => $aisle,
+            ":rack"       => $rack,
+        ]);
+        $td_stock_id = $sth->fetchColumn();
+
+        // Rack is empty or doesn't exist
+        if (!$td_stock_id) {
+            return null;
+        }
+
+        // Resolve the td_stock_<wh> table from the warehouse name
+        // and fetch the full row by ID.
+        $context = $this->getStockContext($warehouse_id, $td_stock_id);
+        return $context['row'] ?: null;
+    }
+
+
     // ─────────────────────────────────────────────────────────────
-    // Rack occupancy (md_rack.product_sku state)
+    // Rack occupancy (md_rack.product_sku + md_rack.td_stock_id state)
     // ─────────────────────────────────────────────────────────────
 
     /**
-     * Assign a product SKU to an empty rack.
+     * Build a log JSON by appending an action entry to an existing md_rack.log.
-     * 
+     * Entry captures user_id, dt (now), and login (session start) for audit context,
-     * @throws Exception if the rack is already occupied by a different SKU
+     * plus any action-specific fields passed via $extra.
-     *                   or if the rack doesn't exist.
      */
-    public function occupyRack($warehouse_id, $zone, $aisle, $rack, $product_sku): void {
+    private function buildRackLog(?string $existing_log, string $action, array $extra = []): string {
 
-        // Lock and check the rack's current state
+        $log = json_decode($existing_log ?: '[]', true) ?: [];
-        $sql = "SELECT id, product_sku FROM md_rack
+
+        $log[] = array_merge([
+            'user_id' => $_SESSION['login_user_id'] ?? null,
+            'dt'      => date('Y-m-d H:i:s'),
+            'login'   => isset($_SESSION['otpTime']) 
+                         ? date('Y-m-d H:i:s', $_SESSION['otpTime']) 
+                         : null,
+            'action'  => $action,
+        ], $extra);
+
+        return json_encode($log, JSON_UNESCAPED_UNICODE);
+    }
+
+    /**
+     * Assign a product SKU to an empty rack and link it to its stock record.
+     * 
+     * The td_stock_<warehouse> table is derived from the warehouse,
+     * so only the row ID needs to be passed here.
+     * 
+     * @throws Exception if the rack is already occupied or doesn't exist.
+     */
+    public function occupyRack($warehouse_id, $zone, $aisle, $rack, $product_sku, $td_stock_id): void {
+
+        // Lock and fetch current state (including log for in-place append)
+        $sql = "SELECT id, product_sku, `log` FROM md_rack
                 WHERE company_id = :company_id 
                   AND warehouse = :warehouse
                   AND zone = :zone
@@ -253,37 +319,44 @@ class WarehouseManager {
             throw new Exception("Rack {$zone}-{$aisle}-{$rack} does not exist");
         }
 
-        if ($current['product_sku'] !== null 
+        if ($current['product_sku'] !== null) {
-            && $current['product_sku'] !== $product_sku) {
             throw new Exception(
                 "Rack {$zone}-{$aisle}-{$rack} is already occupied by {$current['product_sku']}"
             );
         }
 
-        // Assign the SKU
+        // Single atomic UPDATE: state + log together
         $sql = "UPDATE md_rack 
-                SET product_sku = :product_sku
+                SET product_sku = :product_sku,
+                    td_stock_id = :td_stock_id,
+                    `log`       = :log
                 WHERE id = :id";
 
         $sth = $this->pdo->prepare($sql);
         $sth->execute([
             ":product_sku" => $product_sku,
+            ":td_stock_id" => $td_stock_id,
+            ":log"         => $this->buildRackLog($current['log'], 'occupy', [
+                'product_sku' => $product_sku,
+                'td_stock_id' => $td_stock_id,
+            ]),
             ":id"          => $current['id'],
         ]);
     }
 
     /**
-     * Release a rack (set product_sku to NULL).
+     * Release a rack (clear both SKU and stock reference together).
      */
     public function releaseRack($warehouse_id, $zone, $aisle, $rack): void {
 
-        $sql = "UPDATE md_rack 
+        // Fetch current state + log (needed to append release event)
-                SET product_sku = NULL
+        $sql = "SELECT id, product_sku, td_stock_id, `log` FROM md_rack
                 WHERE company_id = :company_id 
                   AND warehouse = :warehouse
                   AND zone = :zone
                   AND aisle = :aisle
-                  AND rack = :rack";
+                  AND rack = :rack
+                FOR UPDATE";
 
         $sth = $this->pdo->prepare($sql);
         $sth->execute([
@@ -293,12 +366,35 @@ class WarehouseManager {
             ":aisle"      => $aisle,
             ":rack"       => $rack,
         ]);
+        $current = $sth->fetch(PDO::FETCH_ASSOC);
+
+        // Nothing to release — exit silently (idempotent behavior)
+        if (!$current || $current['product_sku'] === null) {
+            return;
+        }
+
+        // Clear state + record log in one UPDATE
+        $sql = "UPDATE md_rack 
+                SET product_sku = NULL,
+                    td_stock_id = NULL,
+                    `log`       = :log
+                WHERE id = :id";
+
+        $sth = $this->pdo->prepare($sql);
+        $sth->execute([
+            ":log" => $this->buildRackLog($current['log'], 'release', [
+                'product_sku' => $current['product_sku'],
+                'td_stock_id' => $current['td_stock_id'],
+            ]),
+            ":id"  => $current['id'],
+        ]);
     }
 
     /**
      * Move a rack assignment from one location to another.
      * 
      * Source rack must be occupied, destination rack must be empty.
+     * Both product_sku and td_stock_id travel together to the destination.
      * Locks both racks (lower ID first) to avoid deadlocks.
      */
     public function transferRack(
@@ -307,7 +403,7 @@ class WarehouseManager {
     ): void {
 
         // Fetch both racks with FOR UPDATE, ordered by id to prevent deadlocks
-        $sql = "SELECT id, warehouse, zone, aisle, rack, product_sku
+        $sql = "SELECT id, warehouse, zone, aisle, rack, product_sku, td_stock_id, `log`
                 FROM md_rack
                 WHERE company_id = :company_id
                   AND (
@@ -362,17 +458,36 @@ class WarehouseManager {
             throw new Exception("Destination rack is already occupied");
         }
 
-        $sku = $from['product_sku'];
+        // Carry both SKU and stock reference across
+        $sku         = $from['product_sku'];
+        $td_stock_id = $from['td_stock_id'];
 
-        // Clear source
+        // Clear source — state + log in one UPDATE
-        $sql = "UPDATE md_rack SET product_sku = NULL WHERE id = :id";
+        $sql = "UPDATE md_rack 
-        $this->pdo->prepare($sql)->execute([":id" => $from['id']]);
+                SET product_sku = NULL, td_stock_id = NULL, `log` = :log 
-
+                WHERE id = :id";
-        // Populate destination
-        $sql = "UPDATE md_rack SET product_sku = :sku WHERE id = :id";
         $this->pdo->prepare($sql)->execute([
-            ":sku" => $sku,
+            ":log" => $this->buildRackLog($from['log'], 'transfer_out', [
-            ":id"  => $to['id'],
+                'product_sku' => $sku,
+                'td_stock_id' => $td_stock_id,
+                'to_rack_id'  => $to['id'],
+            ]),
+            ":id"  => $from['id'],
+        ]);
+
+        // Populate destination — state + log in one UPDATE
+        $sql = "UPDATE md_rack 
+                SET product_sku = :sku, td_stock_id = :td_stock_id, `log` = :log 
+                WHERE id = :id";
+        $this->pdo->prepare($sql)->execute([
+            ":sku"         => $sku,
+            ":td_stock_id" => $td_stock_id,
+            ":log"         => $this->buildRackLog($to['log'], 'transfer_in', [
+                'product_sku'  => $sku,
+                'td_stock_id'  => $td_stock_id,
+                'from_rack_id' => $from['id'],
+            ]),
+            ":id"          => $to['id'],
         ]);
     }
 }

app/assets/utils/db_auth.php

@@ -4,6 +4,11 @@ require_once __DIR__."/../../config.php";
 require_once __DIR__."/../../dbconn.php";
 require_once __DIR__."/db_helpers.php";
 
+// Tell the browser (and jQuery) the response body is JSON.
+// Without this, responses default to text/html, which prevents
+// xhr.responseJSON from being populated automatically in ajax_request().
+header('Content-Type: application/json; charset=utf-8'); 
+
 if(!empty($_SESSION["login_company_id"])){
 
     // CSRF Validation — add right at the top of the logged-in block

app/contact/api/engine/manage_contact.php

@@ -95,11 +95,13 @@
         if (isset($uploader)) $uploader->rollbackUploads();
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         if (isset($uploader)) $uploader->rollbackUploads();
         $answer["success"] = 0;
         $answer["message"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/contact/api/engine/manage_contact_type.php

@@ -56,10 +56,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] =  $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/ics/api/engine/manage_stock_in.php

@@ -16,38 +16,67 @@
             $row   = $warehouse['row'] ?? [];
             $table = $warehouse['table'];
 
+            // Append this edit/create event to td_stock_<wh>.log (stock record history)
             $table_log = json_decode($row['log'] ?? '[]', true);
             $table_log[] = $logging;
 
             if ($id > 0) {
 
+                // UPDATE existing stock_in record
                 $sql = "UPDATE `$table` SET
                             `product_sku` = :product_sku,
-                            `in` = :quantity,
+                            `in`          = :quantity,
-                            `zone` = :zone,
+                            `zone`        = :zone,
-                            `aisle` = :aisle,
+                            `aisle`       = :aisle,
-                            `rack` = :rack,
+                            `rack`        = :rack,
-                            `contact_id` = :contact_id,
+                            `contact_id`  = :contact_id,
                             `description` = :description,
-                            `log` = :log
+                            `log`         = :log
                         WHERE id = :id AND company_id = :company_id";
 
                 $sth = $pdo->prepare($sql);
                 $sth->execute([
-                    ":id" => $id,
+                    ":id"          => $id,
-                    ":company_id" => $company_id,
+                    ":company_id"  => $company_id,
                     ":product_sku" => $data["product_sku"],
-                    ":quantity" => $data["quantity"],
+                    ":quantity"    => $data["quantity"],
-                    ":zone" => $data["zone"],
+                    ":zone"        => $data["zone"],
-                    ":aisle" => $data["aisle"],
+                    ":aisle"       => $data["aisle"],
-                    ":rack" => $data["rack"],
+                    ":rack"        => $data["rack"],
-                    ":contact_id" => (int)$data["contact_id"],
+                    ":contact_id"  => (int)$data["contact_id"],
                     ":description" => $data["description"],
-                    ":log" => json_encode($table_log),
+                    ":log"         => json_encode($table_log),
                 ]);
 
+                // On UPDATE, td_stock_id stays the same (this record's ID)
+                $td_stock_id = $id;
+
+                // Only touch md_rack if the physical location actually changed.
+                // Skipping when unchanged avoids redundant log entries and release/occupy cycles.
+                $rack_changed = (
+                    ($row['zone']  ?? '') != $data['zone']  ||
+                    ($row['aisle'] ?? '') != $data['aisle'] ||
+                    ($row['rack']  ?? '') != $data['rack']
+                );
+
+                if ($rack_changed) {
+                    // Free up the old rack
+                    $whMgmt->releaseRack(
+                        $warehouse_id,
+                        $row['zone'], $row['aisle'], $row['rack']
+                    );
+                    // Claim the new rack, linked to the same stock record
+                    $whMgmt->occupyRack(
+                        $warehouse_id,
+                        $data['zone'], $data['aisle'], $data['rack'],
+                        $data['product_sku'],
+                        $td_stock_id
+                    );
+                }
+
             } else {
 
+                // INSERT new stock_in record
                 $sql = "INSERT INTO `$table` 
                         (uuid, company_id, `date`, product_sku, `in`, zone, aisle, rack, contact_id, `description`, `log`, `type`) 
                         VALUES 
@@ -55,22 +84,40 @@
 
                 $sth = $pdo->prepare($sql);
                 $sth->execute([
-                    ":uuid" => $uuid,
+                    ":uuid"        => $uuid,
-                    ":company_id" => $company_id,
+                    ":company_id"  => $company_id,
-                    ":date" => date('Y-m-d H:i:s'),
+                    ":date"        => date('Y-m-d H:i:s'),
                     ":product_sku" => $data["product_sku"],
-                    ":quantity" => $data["quantity"],
+                    ":quantity"    => $data["quantity"],
-                    ":zone" => $data["zone"],
+                    ":zone"        => $data["zone"],
-                    ":aisle" => $data["aisle"],
+                    ":aisle"       => $data["aisle"],
-                    ":rack" => $data["rack"],
+                    ":rack"        => $data["rack"],
-                    ":contact_id" => (int)$data["contact_id"],
+                    ":contact_id"  => (int)$data["contact_id"],
                     ":description" => $data["description"],
-                    ":log" => json_encode($table_log),
+                    ":log"         => json_encode($table_log),
                 ]);
+
+                // Grab the newly-generated ID to link the rack
+                $td_stock_id = (int) $pdo->lastInsertId();
+
+                // Link the rack to this new stock record
+                $whMgmt->occupyRack(
+                    $warehouse_id,
+                    $data['zone'], $data['aisle'], $data['rack'],
+                    $data['product_sku'],
+                    $td_stock_id
+                );
             }
 
-            $whMgmt->occupyRack($warehouse_id,$data["zone"],$data["aisle"],$data["rack"],$data["product_sku"]);
+            // Balance adjustment handles both INSERT (delta = full qty) 
-            $whMgmt->adjustBalance('in', $warehouse_id, $data["product_sku"], $row['in'] ?? 0, $data["quantity"]);
+            // and UPDATE (delta = new - old) via the same formula.
+            $whMgmt->adjustBalance(
+                'in', 
+                $warehouse_id, 
+                $data["product_sku"], 
+                $row['in'] ?? 0, 
+                $data["quantity"]
+            );
 
         });
 
@@ -79,10 +126,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/ics/api/engine/manage_stock_out.php

@@ -1,6 +1,5 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
     require '../../../assets/utils/classes/WarehouseManager.php';
 
@@ -16,61 +15,133 @@
             $row   = $warehouse['row'] ?? [];
             $table = $warehouse['table'];
 
+            // Append this edit/create event to td_stock_<wh>.log (stock record history)
             $table_log = json_decode($row['log'] ?? '[]', true);
             $table_log[] = $logging;
 
+            // Look up the source stock record via the rack.
+            // Under 1:1, the rack points to exactly one td_stock_<wh> row.
+            $source_stock = $whMgmt->getRackStock(
+                $warehouse_id, 
+                $data["zone"], 
+                $data["aisle"], 
+                $data["rack"]
+            );
+
+            if (!$source_stock) {
+                throw new Exception(
+                    "Rack {$data['zone']}-{$data['aisle']}-{$data['rack']} is empty — nothing to take out."
+                );
+            }
+
+            // Defensive check — UI cascade should already prevent mismatches
+            if ($source_stock['product_sku'] !== $data["product_sku"]) {
+                throw new Exception(
+                    "Rack holds {$source_stock['product_sku']}, not {$data['product_sku']}."
+                );
+            }
+
+            // Quantity comes from the source stock_in row, NOT user input.
+            // Under 1:1, taking from this rack = taking the full batch.
+            $quantity = (int) $source_stock['in'];
+            $ref_id   = (int) $source_stock['id'];
+
             if ($id > 0) {
 
+                // UPDATE existing stock_out record
                 $sql = "UPDATE `$table` SET
                             `product_sku` = :product_sku,
-                            `out` = :quantity,
+                            `out`         = :quantity,
-                            `zone` = :zone,
+                            `zone`        = :zone,
-                            `aisle` = :aisle,
+                            `aisle`       = :aisle,
-                            `rack` = :rack,
+                            `rack`        = :rack,
-                            `contact_id` = :contact_id,
+                            `contact_id`  = :contact_id,
                             `description` = :description,
-                            `log` = :log
+                            `log`         = :log
                         WHERE id = :id AND company_id = :company_id";
 
                 $sth = $pdo->prepare($sql);
                 $sth->execute([
-                    ":id" => $id,
+                    ":id"          => $id,
-                    ":company_id" => $company_id,
+                    ":company_id"  => $company_id,
                     ":product_sku" => $data["product_sku"],
-                    ":quantity" => $data["quantity"],
+                    ":quantity"    => $quantity,
-                    ":zone" => $data["zone"],
+                    ":zone"        => $data["zone"],
-                    ":aisle" => $data["aisle"],
+                    ":aisle"       => $data["aisle"],
-                    ":rack" => $data["rack"],
+                    ":rack"        => $data["rack"],
-                    ":contact_id" => (int)$data["contact_id"],
+                    ":contact_id"  => (int)$data["contact_id"],
                     ":description" => $data["description"],
-                    ":log" => json_encode($table_log),
+                    ":log"         => json_encode($table_log),
                 ]);
 
+                // Only touch md_rack if the physical location actually changed.
+                $rack_changed = (
+                    ($row['zone']  ?? '') != $data['zone']  ||
+                    ($row['aisle'] ?? '') != $data['aisle'] ||
+                    ($row['rack']  ?? '') != $data['rack']
+                );
+
+                if ($rack_changed) {
+                    // Re-occupy the old rack with the batch it originally held
+                    // (logically: the stock goes back to where it came from)
+                    $whMgmt->occupyRack(
+                        $warehouse_id,
+                        $row['zone'], $row['aisle'], $row['rack'],
+                        $row['product_sku'],
+                        $row['ref_id'] ?? null
+                    );
+
+                    // Release the new rack (the real stock-out action)
+                    $whMgmt->releaseRack(
+                        $warehouse_id,
+                        $data['zone'], $data['aisle'], $data['rack']
+                    );
+                }
+
             } else {
 
+                // INSERT new stock_out record.
+                // ref_id links this stock_out row back to the stock_in batch it consumed.
                 $sql = "INSERT INTO `$table` 
-                        (uuid, company_id, `date`, product_sku, `out`, zone, aisle, rack, contact_id, `description`, `log`, `type`) 
+                        (uuid, company_id, `date`, product_sku, `out`, zone, aisle, rack, 
+                         contact_id, `description`, `log`, `type`, ref_id) 
                         VALUES 
-                        (:uuid, :company_id, :date, :product_sku, :quantity, :zone, :aisle, :rack, :contact_id, :description, :log, 'out')";
+                        (:uuid, :company_id, :date, :product_sku, :quantity, :zone, :aisle, :rack, 
+                         :contact_id, :description, :log, 'out', :ref_id)";
 
                 $sth = $pdo->prepare($sql);
                 $sth->execute([
-                    ":uuid" => $uuid,
+                    ":uuid"        => $uuid,
-                    ":company_id" => $company_id,
+                    ":company_id"  => $company_id,
-                    ":date" => date('Y-m-d H:i:s'),
+                    ":date"        => date('Y-m-d H:i:s'),
                     ":product_sku" => $data["product_sku"],
-                    ":quantity" => $data["quantity"],
+                    ":quantity"    => $quantity,
-                    ":zone" => $data["zone"],
+                    ":zone"        => $data["zone"],
-                    ":aisle" => $data["aisle"],
+                    ":aisle"       => $data["aisle"],
-                    ":rack" => $data["rack"],
+                    ":rack"        => $data["rack"],
-                    ":contact_id" => (int)$data["contact_id"],
+                    ":contact_id"  => (int)$data["contact_id"],
                     ":description" => $data["description"],
-                    ":log" => json_encode($table_log),
+                    ":log"         => json_encode($table_log),
+                    ":ref_id"      => $ref_id,
                 ]);
+
+                // Release the rack — stock is now gone from this location.
+                $whMgmt->releaseRack(
+                    $warehouse_id, 
+                    $data["zone"], $data["aisle"], $data["rack"]
+                );
             }
 
-            $whMgmt->releaseRack($warehouse_id, $data["zone"], $data["aisle"], $data["rack"],$data["product_sku"]);
+            // Balance: total_out increases by delta.
-            $whMgmt->adjustBalance('out', $warehouse_id, $data["product_sku"], $row['out'] ?? 0, $data["quantity"]);
+            //   INSERT: $row['out'] = 0   → delta = full quantity
+            //   UPDATE: $row['out'] = old → delta = new - old
+            $whMgmt->adjustBalance(
+                'out', 
+                $warehouse_id, 
+                $data["product_sku"], 
+                $row['out'] ?? 0, 
+                $quantity
+            );
 
         });
 
@@ -79,10 +150,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
-        $answer["message"] =  $e->getMessage();
+        $answer["message"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/ics/api/engine/manage_stock_transfer.php

@@ -1,6 +1,5 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
     require '../../../assets/utils/classes/WarehouseManager.php';
 
@@ -8,101 +7,203 @@
 
         dbTransaction($pdo2, function($pdo) use ($data, $company_id, $logging, $uuid) {
 
-            $id = (int)$data['id'];
+            $id = (int)($data['id'] ?? 0);
             $whMgmt = new WarehouseManager($pdo, $company_id);
 
-            for ($i = 0; $i < 2; $i++) {
+            // Metadata that's editable on BOTH create and edit
+            $contact_id  = (int)($data['contact_id'] ?? 0);
+            $description =      ($data['description'] ?? '');
 
-                $data['type'] = ($i == 0) ? "from" : "to";
+            // ══════════════════════════════════════════════════════════
-                $data['ref_type'] = ($i == 0) ? "to" : "from";
+            // EDIT FLOW
-                $data['col'] = ($i == 0) ? "out" : "in";
+            // Physical state (racks, balances, quantities) is frozen.
+            // Only metadata (contact, description) can change.
+            // ══════════════════════════════════════════════════════════
+            if ($id > 0) {
 
-                $warehouse_id = (int)$data['warehouse_' . $data["type"]];
+                // Find the "from" row that's being edited.
-                $ref_warehouse_id = (int)$data['warehouse_' . $data["ref_type"]];
+                // We look it up across all td_stock_<wh> via warehouse_from
-                $data["warehouse"] = $data['warehouse_' . $data["type"]];
+                // since $id alone isn't enough (it's per-table).
-                $data["zone"] = $data['zone_' . $data["type"]];
+                $from_warehouse = (int)($data['warehouse_from'] ?? 0);
-                $data["aisle"] = $data['aisle_' . $data["type"]];
+                $to_warehouse   = (int)($data['warehouse_to']   ?? 0);
-                $data["rack"] = $data['rack_' . $data["type"]];
 
-                $warehouse = $whMgmt->getStockContext($warehouse_id, $id);
+                $from_ctx   = $whMgmt->getStockContext($from_warehouse, $id);
-                $row   = $warehouse['row'] ?? [];
+                $from_table = $from_ctx['table'];
-                $table = $warehouse['table'];
+                $from_row   = $from_ctx['row'];
 
-                // get uuid for update
+                if (!$from_row) {
-                if ($id > 0 && $data['type'] == "from") {
+                    throw new Exception("Transfer record not found.");
-                    $sql = "SELECT uuid FROM `$table`
-                            WHERE company_id = :company_id AND id = :id";
-                    $sth = $pdo->prepare($sql);
-                    $sth->execute([
-                        ":company_id" => $company_id,
-                        ":id" => $id
-                    ]);
-                    $uuid = $sth->fetchColumn();
                 }
 
-                $table_log = json_decode($row['log'] ?? '[]', true);
+                // Find the paired "to" row via ref_id stored on the "from" row
-                $table_log[] = $logging;
+                $to_id    = (int) $from_row['ref_id'];
+                $to_ctx   = $whMgmt->getStockContext($to_warehouse, $to_id);
+                $to_table = $to_ctx['table'];
+                $to_row   = $to_ctx['row'];
 
-                if ($id > 0) {
+                if (!$to_row) {
-
+                    throw new Exception("Paired destination record missing — data integrity issue.");
-                    $sql = "UPDATE `$table` SET
-                                `product_sku` = :product_sku,
-                                `{$data['col']}` = :quantity,
-                                `zone` = :zone,
-                                `aisle` = :aisle,
-                                `rack` = :rack,
-                                `contact_id` = :contact_id,
-                                `description` = :description,
-                                `log` = :log
-                            WHERE uuid = :uuid AND company_id = :company_id";
-
-                    $sth = $pdo->prepare($sql);
-                    $sth->execute([
-                        ":uuid" => $uuid,
-                        ":company_id" => $company_id,
-                        ":product_sku" => $data["product_sku"],
-                        ":quantity" => $data["quantity"],
-                        ":zone" => $data["zone"],
-                        ":aisle" => $data["aisle"],
-                        ":rack" => $data["rack"],
-                        ":contact_id" => (int)$data["contact_id"],
-                        ":description" => $data["description"],
-                        ":log" => json_encode($table_log),
-                    ]);
-
-                } else {
-
-                    $sql = "INSERT INTO `$table` 
-                            (uuid, company_id, `date`, product_sku, `{$data['col']}`, ref_warehouse, zone, aisle, rack, contact_id, `description`, `log`, `type`) 
-                            VALUES 
-                            (:uuid, :company_id, :date, :product_sku, :quantity, :ref_warehouse, :zone, :aisle, :rack, :contact_id, :description, :log, 'transfer')";
-
-                    $sth = $pdo->prepare($sql);
-                    $sth->execute([
-                        ":uuid" => $uuid,
-                        ":company_id" => $company_id,
-                        ":date" => date('Y-m-d H:i:s'),
-                        ":product_sku" => $data["product_sku"],
-                        ":quantity" => $data["quantity"],
-                        ":ref_warehouse" => $ref_warehouse_id,
-                        ":zone" => $data["zone"],
-                        ":aisle" => $data["aisle"],
-                        ":rack" => $data["rack"],
-                        ":contact_id" => (int)$data["contact_id"],
-                        ":description" => $data["description"],
-                        ":log" => json_encode($table_log),
-                    ]);
                 }
 
-                if($data['type'] == 'from'){
+                // Append this edit to both rows' logs
-                    $whMgmt->releaseRack($warehouse_id, $data["zone"], $data["aisle"], $data["rack"]);
+                $from_log   = json_decode($from_row['log'] ?? '[]', true) ?: [];
-                }elseif($data['type'] == 'to'){
+                $from_log[] = $logging;
-                    $whMgmt->occupyRack($warehouse_id, $data["zone"], $data["aisle"], $data["rack"]);
-                }
 
-                $whMgmt->adjustBalance($data['col'], $warehouse_id, $data["product_sku"], $row[$data['col']] ?? 0, $data["quantity"]);
+                $to_log     = json_decode($to_row['log'] ?? '[]', true) ?: [];
+                $to_log[]   = $logging;
+
+                // UPDATE "from" row — only metadata fields
+                $sql = "UPDATE `$from_table` SET
+                            contact_id  = :contact_id,
+                            description = :description,
+                            `log`       = :log
+                        WHERE id = :id AND company_id = :company_id";
+                $pdo->prepare($sql)->execute([
+                    ":contact_id"  => $contact_id,
+                    ":description" => $description,
+                    ":log"         => json_encode($from_log),
+                    ":id"          => $id,
+                    ":company_id"  => $company_id,
+                ]);
+
+                // UPDATE "to" row — same metadata
+                $sql = "UPDATE `$to_table` SET
+                            contact_id  = :contact_id,
+                            description = :description,
+                            `log`       = :log
+                        WHERE id = :id AND company_id = :company_id";
+                $pdo->prepare($sql)->execute([
+                    ":contact_id"  => $contact_id,
+                    ":description" => $description,
+                    ":log"         => json_encode($to_log),
+                    ":id"          => $to_id,
+                    ":company_id"  => $company_id,
+                ]);
+
+                // Done — no rack ops, no balance changes on edit.
+                return;
             }
 
+            // ══════════════════════════════════════════════════════════
+            // CREATE FLOW (unchanged from before)
+            // ══════════════════════════════════════════════════════════
+
+            // Gather source + destination parameters
+            $from_warehouse = (int)$data['warehouse_from'];
+            $from_zone      = $data['zone_from'];
+            $from_aisle     = $data['aisle_from'];
+            $from_rack      = $data['rack_from'];
+
+            $to_warehouse   = (int)$data['warehouse_to'];
+            $to_zone        = $data['zone_to'];
+            $to_aisle       = $data['aisle_to'];
+            $to_rack        = $data['rack_to'];
+
+            // Validate source rack has stock of the expected SKU.
+            // Quantity comes from here — NOT user input.
+            $source_stock = $whMgmt->getRackStock(
+                $from_warehouse, $from_zone, $from_aisle, $from_rack
+            );
+
+            if (!$source_stock) {
+                throw new Exception(
+                    "Source rack {$from_zone}-{$from_aisle}-{$from_rack} is empty."
+                );
+            }
+
+            if ($source_stock['product_sku'] !== $data["product_sku"]) {
+                throw new Exception(
+                    "Source rack holds {$source_stock['product_sku']}, not {$data['product_sku']}."
+                );
+            }
+
+            $quantity = (int) $source_stock['in'];
+
+            // Resolve both td_stock_<wh> tables
+            $from_ctx   = $whMgmt->getStockContext($from_warehouse, 0);
+            $to_ctx     = $whMgmt->getStockContext($to_warehouse,   0);
+            $from_table = $from_ctx['table'];
+            $to_table   = $to_ctx['table'];
+
+            // Share UUID across both paired rows for easy grouping
+            $transfer_uuid = $uuid;
+
+            // INSERT "from" row (outbound from source warehouse)
+            $table_log = [$logging];
+
+            $sql = "INSERT INTO `$from_table`
+                    (uuid, company_id, `date`, product_sku, `out`, 
+                     ref_warehouse, zone, aisle, rack, 
+                     contact_id, `description`, `log`, `type`)
+                    VALUES
+                    (:uuid, :company_id, :date, :product_sku, :quantity,
+                     :ref_warehouse, :zone, :aisle, :rack,
+                     :contact_id, :description, :log, 'transfer')";
+            $pdo->prepare($sql)->execute([
+                ":uuid"          => $transfer_uuid,
+                ":company_id"    => $company_id,
+                ":date"          => date('Y-m-d H:i:s'),
+                ":product_sku"   => $data["product_sku"],
+                ":quantity"      => $quantity,
+                ":ref_warehouse" => $to_warehouse,
+                ":zone"          => $from_zone,
+                ":aisle"         => $from_aisle,
+                ":rack"          => $from_rack,
+                ":contact_id"    => $contact_id,
+                ":description"   => $description,
+                ":log"           => json_encode($table_log),
+            ]);
+            $from_stock_id = (int) $pdo->lastInsertId();
+
+            // INSERT "to" row (inbound at destination warehouse)
+            $sql = "INSERT INTO `$to_table`
+                    (uuid, company_id, `date`, product_sku, `in`, 
+                     ref_warehouse, ref_id, zone, aisle, rack, 
+                     contact_id, `description`, `log`, `type`)
+                    VALUES
+                    (:uuid, :company_id, :date, :product_sku, :quantity,
+                     :ref_warehouse, :ref_id, :zone, :aisle, :rack,
+                     :contact_id, :description, :log, 'transfer')";
+            $pdo->prepare($sql)->execute([
+                ":uuid"          => $transfer_uuid,
+                ":company_id"    => $company_id,
+                ":date"          => date('Y-m-d H:i:s'),
+                ":product_sku"   => $data["product_sku"],
+                ":quantity"      => $quantity,
+                ":ref_warehouse" => $from_warehouse,
+                ":ref_id"        => $from_stock_id,
+                ":zone"          => $to_zone,
+                ":aisle"         => $to_aisle,
+                ":rack"          => $to_rack,
+                ":contact_id"    => $contact_id,
+                ":description"   => $description,
+                ":log"           => json_encode($table_log),
+            ]);
+            $to_stock_id = (int) $pdo->lastInsertId();
+
+            // Back-fill the "from" row's ref_id now that we have to_stock_id
+            // so both rows point at each other
+            $sql = "UPDATE `$from_table`
+                    SET ref_id = :ref_id
+                    WHERE id = :id AND company_id = :company_id";
+            $pdo->prepare($sql)->execute([
+                ":ref_id"     => $to_stock_id,
+                ":id"         => $from_stock_id,
+                ":company_id" => $company_id,
+            ]);
+
+            // Move rack state: release source, occupy destination
+            // md_rack.log gets 'release' + 'occupy' entries automatically
+            $whMgmt->releaseRack($from_warehouse, $from_zone, $from_aisle, $from_rack);
+            $whMgmt->occupyRack(
+                $to_warehouse, $to_zone, $to_aisle, $to_rack,
+                $data["product_sku"], $to_stock_id
+            );
+
+            // Balance adjustments on both warehouses
+            $whMgmt->adjustBalance('out', $from_warehouse, $data["product_sku"], 0, $quantity);
+            $whMgmt->adjustBalance('in',  $to_warehouse,   $data["product_sku"], 0, $quantity);
+
         });
 
         $answer["success"] = 1;
@@ -110,10 +211,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
-        $answer["message"] =  $e->getMessage();
+        $answer["message"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/ics/api/engine/retrieve_aisle.php

@@ -1,43 +1,64 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
 
-    $id = (int)$data['id'];
+    // Get warehouse and zone from the form
-    // identity source of zone and aisle
+    $warehouse = isset($data['warehouse']) ? (int)$data['warehouse'] : 0;
-    if(empty($data["type"])){
+    $zone      = isset($data['zone']) ? $data['zone'] : '';
-        $warehouse = (int)$data['warehouse'];
+    
-        $zone = $data['zone'];
+    if (isset($data['warehouse_from']) && $data['type'] == "from") {
-    }else{
+        $warehouse = (int)$data['warehouse_from'];
-        $warehouse = (int)$data['warehouse_'.$data["type"]];
+        $zone      = $data['zone_from'];
-        $zone = $data['zone_'.$data["type"]];
+    }
+    if (isset($data['warehouse_to']) && $data['type'] == "to") {
+        $warehouse = (int)$data['warehouse_to'];
+        $zone      = $data['zone_to'];
     }
 
-    $sql = "SELECT * 
+    // Filter aisles by operation type and optional SKU:
-        FROM md_storage
+    //   'to'   = destination → aisles with at least one empty rack
-        WHERE 
+    //   'from' + sku → aisles currently holding that specific SKU
-            company_id = :company_id and 
+    //   'from' (no sku) → aisles with any occupied rack
-            warehouse = :warehouse and 
+    //   other  = all aisles in the zone (admin / read-only pages)
-            `zone` = :zone
+    $product_sku_filter = "";
-        ";
+    $params = [
+        ":company_id" => $company_id,
+        ":warehouse"  => $warehouse,
+        ":zone"       => $zone,
+    ];
+
+    if ($data["type"] == "to") {
+        $product_sku_filter = "AND product_sku IS NULL";
+
+    } elseif ($data["type"] == "from") {
+        if (!empty($data["product_sku"])) {
+            $product_sku_filter = "AND product_sku = :product_sku";
+            $params[":product_sku"] = $data["product_sku"];
+        } else {
+            $product_sku_filter = "AND product_sku IS NOT NULL";
+        }
+    }
+
+    if(!empty($data["id"])){
+        $product_sku_filter = "";
+        unset($params[":product_sku"]);
+    }
+
+    $sql = "SELECT DISTINCT aisle
+            FROM md_rack
+            WHERE 
+                company_id = :company_id AND
+                warehouse  = :warehouse  AND
+                `zone`     = :zone
+                $product_sku_filter
+            ORDER BY CAST(aisle AS UNSIGNED), aisle";
 
     $sth = $pdo2->prepare($sql);
-    $sth->execute([
+    $sth->execute($params);
-        ":company_id" => $company_id,
-        ":warehouse" => $warehouse,
-        ":zone" => $zone
-    ]);
     db_check($sth, $answer);
 
-    $pre = $sth->fetchAll(PDO::FETCH_ASSOC);
+    // Return flat array (matches original response shape for the frontend)
-
+    $answer["output"]  = array_column($sth->fetchAll(PDO::FETCH_ASSOC), 'aisle');
-    $output = [];
-    foreach ($pre as $key => $value) {
-        $output = array_merge($output, range($value["aisle_from"], $value["aisle_to"]));
-    }
-
-    $answer["output"] = $output;
     $answer["success"] = 1;
     exit(json_encode($answer));
-
 ?>

app/ics/api/engine/retrieve_rack.php

@@ -1,57 +1,69 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
 
-    // identity source of zone and aisle
+    // Get warehouse, zone, and aisle from the form
-    if(empty($data["type"])){
+    $warehouse = (int)$data['warehouse'];
-        $warehouse = (int)$data['warehouse'];
+    $zone      = $data['zone'];
-        $zone = $data['zone'];
+    $aisle     = $data['aisle'];
-        $aisle = $data["aisle"];
+
-    }else{
+    if (isset($data['warehouse_from']) && $data['type'] == "from") {
-        $warehouse = (int)$data['warehouse_'.$data["type"]];
+        $warehouse = (int)$data['warehouse_from'];
-        $zone = $data['zone_'.$data["type"]];
+        $zone      = $data['zone_from'];
-        $aisle = $data["aisle_".$data["type"]];
+        $aisle     = $data['aisle_from'];   
+    }
+    if (isset($data['warehouse_to']) && $data['type'] == "to") {
+        $warehouse = (int)$data['warehouse_to'];
+        $zone      = $data['zone_to'];
+        $aisle     = $data['aisle_to'];
     }
 
-    // Detect if numeric and zero-pad both input and query columns
+    // Filter racks by operation type and optional SKU:
-    if (is_numeric($aisle)) {
+    //   'to'   = destination → empty racks only   (product_sku IS NULL)
-        $aisle = str_pad($aisle, 5, '0', STR_PAD_LEFT);
+    //   'from' + sku → racks currently holding that specific SKU
-        $condition = "LPAD(aisle_from, 5, '0') <= :aisle_from AND LPAD(aisle_to, 5, '0') >= :aisle_to";
+    //   'from' (no sku) → any occupied rack       (product_sku IS NOT NULL)
-    } else {
+    //   other  = all racks in the aisle (admin / read-only pages)
-        $condition = ":aisle_from >= aisle_from AND :aisle_to <= aisle_to";
+    $product_sku_filter = "";
+    $params = [
+        ":company_id" => $company_id,
+        ":warehouse"  => $warehouse,
+        ":zone"       => $zone,
+        ":aisle"      => $aisle,
+    ];
+
+    if ($data["type"] == "to") {
+        $product_sku_filter = "AND product_sku IS NULL";
+
+    } elseif ($data["type"] == "from") {
+        if (!empty($data["product_sku"])) {
+            $product_sku_filter = "AND product_sku = :product_sku";
+            $params[":product_sku"] = $data["product_sku"];
+        } else {
+            $product_sku_filter = "AND product_sku IS NOT NULL";
+        }
     }
 
-    $id = (int)$data['id'];
+    if(!empty($data["id"])){
+        $product_sku_filter = "";
+        unset($params[":product_sku"]);
+    }
 
-    $sql = "SELECT * 
+    $sql = "SELECT DISTINCT rack
-        FROM md_storage
+            FROM md_rack
-        WHERE 
+            WHERE 
-            company_id = :company_id and 
+                company_id = :company_id AND
-            warehouse = :warehouse and 
+                warehouse  = :warehouse  AND
-            `zone` = :zone and 
+                `zone`     = :zone       AND
-            $condition
+                aisle      = :aisle
-        ";
+                $product_sku_filter
+            ORDER BY CAST(rack AS UNSIGNED), rack";
 
     $sth = $pdo2->prepare($sql);
-    $sth->execute([
+    $sth->execute($params);
-        ":company_id" => $company_id,
-        ":warehouse" => $warehouse,
-        ":zone" => $zone,
-        ":aisle_from" => $aisle,
-        ":aisle_to" => $aisle
-    ]);
     db_check($sth, $answer);
 
-    $pre = $sth->fetchAll(PDO::FETCH_ASSOC);
+    // Return flat array (matches original response shape for the frontend)
-
+    $answer["output"]  = array_column($sth->fetchAll(PDO::FETCH_ASSOC), 'rack');
-    $output = [];
-    foreach ($pre as $key => $value) {
-        $output = array_merge($output, range($value["rack_from"], $value["rack_to"]));
-    }
-
-    $answer["output"] = $output;
     $answer["success"] = 1;
     exit(json_encode($answer));
-
 ?>

app/ics/api/engine/retrieve_stock_transfer.php

@@ -35,7 +35,7 @@
           a.company_id = b.company_id and 
           a.contact_id = b.id
         LEFT JOIN md_product c ON
-          a.company_id = b.company_id and 
+          a.company_id = c.company_id and 
           a.product_sku = c.sku
         WHERE 
             a.company_id = :company_id and 

app/ics/api/engine/retrieve_warehouse.php

@@ -0,0 +1,46 @@
+<?php 
+    session_start();
+    require '../../../assets/utils/db_auth.php';
+
+    // Build filter + params based on operation type.
+    // Filter warehouses by occupancy:
+    //   'to'   = destination → only warehouses with at least one empty rack
+    //   'from' = source      → only warehouses that hold the specific product SKU
+    //   other  = all warehouses (for read-only listings, dashboards, etc.)
+    $product_sku_filter = "";
+    $params = [":company_id" => $company_id];
+
+    if ($data["type"] == "to") {
+        $product_sku_filter = "AND r.product_sku IS NULL";
+
+    } elseif ($data["type"] == "from") {
+        $product_sku_filter = "AND r.product_sku = :product_sku";
+        $params[":product_sku"] = $data["product_sku"];
+    }
+
+    if(!empty($data["id"])){
+        $product_sku_filter = "";
+        unset($params[":product_sku"]);
+    }
+
+    // Only list warehouses that have racks matching the occupancy filter.
+    // EXISTS is efficient here — it stops searching as soon as one match is found.
+    $sql = "SELECT w.id, w.warehouse_name
+            FROM md_warehouse w
+            WHERE w.company_id = :company_id
+              AND EXISTS (
+                  SELECT 1 FROM md_rack r
+                  WHERE r.company_id = w.company_id
+                    AND r.warehouse  = w.id
+                    $product_sku_filter
+              )
+            ORDER BY w.warehouse_name";
+
+    $sth = $pdo2->prepare($sql);
+    $sth->execute($params);
+    db_check($sth, $answer);
+
+    $answer["output"]  = $sth->fetchAll(PDO::FETCH_ASSOC);
+    $answer["success"] = 1;
+    exit(json_encode($answer));
+?>

app/ics/api/engine/retrieve_zone.php

@@ -1,32 +1,59 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
 
-    $id = (int)$data['id'];
+    // Get warehouse from the form
+    $warehouse = (int)$data['warehouse'];
 
-    // identity source of zone and aisle
+    if(isset($data['warehouse_from'])&&$data['type']=="from"){
-    if(empty($data["type"])){
+        $warehouse = (int)$data['warehouse_from'];
-        $warehouse = (int)$data['warehouse'];
+    }
-    }else{
+    if(isset($data['warehouse_to'])&&$data['type']=="to"){
-        $warehouse = (int)$data['warehouse_'.$data["type"]];
+        $warehouse = (int)$data['warehouse_to'];
     }
 
-    $sql = "SELECT * 
+    // Filter zones by operation type and optional SKU:
-        FROM md_storage
+    //   'to'   = destination → zones with at least one empty rack
-        WHERE 
+    //   'from' + sku → zones currently holding that specific SKU
-            company_id = {$company_id} and 
+    //   'from' (no sku) → zones with any occupied rack
-            warehouse = {$warehouse}";
+    //   other  = all zones in the warehouse (admin / read-only pages)
+    $product_sku_filter = "";
+    $params = [
+        ":company_id" => $company_id,
+        ":warehouse"  => $warehouse,
+    ];
+
+    if ($data["type"] == "to") {
+        $product_sku_filter = "AND product_sku IS NULL";
+
+    } elseif ($data["type"] == "from") {
+        if (!empty($data["product_sku"])) {
+            $product_sku_filter = "AND product_sku = :product_sku";
+            $params[":product_sku"] = $data["product_sku"];
+        } else {
+            $product_sku_filter = "AND product_sku IS NOT NULL";
+        }
+    }
+
+    if(!empty($data["id"])){
+        $product_sku_filter = "";
+        unset($params[":product_sku"]);
+    }
+
+    $sql = "SELECT DISTINCT zone
+            FROM md_rack
+            WHERE 
+                company_id = :company_id AND
+                warehouse  = :warehouse
+                $product_sku_filter
+            ORDER BY CAST(zone AS UNSIGNED), zone";
 
     $sth = $pdo2->prepare($sql);
-    $sth->execute([
+    $sth->execute($params);
-        ":company_id" => $company_id,
-        ":warehouse" => $warehouse
-    ]);
     db_check($sth, $answer);
 
-    $answer["output"] = $sth->fetchAll(PDO::FETCH_ASSOC);
+    // Frontend expects objects with a `zone` property — keep that shape.
+    $answer["output"]  = $sth->fetchAll(PDO::FETCH_ASSOC);
     $answer["success"] = 1;
     exit(json_encode($answer));
-
 ?>

app/ics/manage_stock_in.php

@@ -125,12 +125,15 @@
 
 
 
-  function retrieve_warehouse() {
+  function retrieve_warehouse(type) {
 
     return ajax_request({
-      url: "<?php echo $server_url?>inventory/api/engine/warehouse.php",
+      url: "<?php echo $server_url?>ics/api/engine/retrieve_warehouse.php",
       autoPrepare: true,
       checkRequired: 0,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select warehouse</option>`;
@@ -145,13 +148,16 @@
 
 
 
-  function retrieve_zone(callback) {
+  function retrieve_zone(type, callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_zone.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data : {
+        "type": type
+      },
       debugMode: 0,
       action: 'read',
       onSuccess: function(res) {
@@ -169,13 +175,16 @@
 
 
 
-  function retrieve_aisle(callback) {
+  function retrieve_aisle(type, callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_aisle.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select aisle</option>`;
@@ -192,13 +201,16 @@
 
 
 
-  function retrieve_rack(callback) {
+  function retrieve_rack(type, callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_rack.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select rack</option>`;
@@ -236,15 +248,15 @@
         $(`#warehouse`).val('<?php echo $_GET["wh"];?>').attr('disabled', true); // set warehouse BEFORE retrieve_zone
 
         // 2. Retrieve zone (autoPrepare reads warehouse value)
-        retrieve_zone(function() {
+        retrieve_zone('to', function() {
           $(`select#zone`).val(data.zone).attr('disabled', true); // set zone BEFORE retrieve_aisle
 
           // 3. Retrieve aisle (autoPrepare reads zone value)
-          retrieve_aisle(function() {
+          retrieve_aisle('to', function() {
             $(`#aisle`).val(data.aisle).attr('disabled', true); // set aisle BEFORE retrieve_rack
 
             // 4. Retrieve rack (autoPrepare reads aisle value)
-            retrieve_rack(function() {
+            retrieve_rack('to', function() {
               $(`#rack`).val(data.rack).attr('disabled', true);
 
               // retrieve for edit
@@ -280,7 +292,7 @@
 
   $(async function() {
     try {
-      await retrieve_warehouse();
+      await retrieve_warehouse('to');
       await retrieve_for_edit();
     } catch (e) {
       console.log(e);
@@ -289,15 +301,15 @@
 
   <?php if(empty($_GET["id"])){ ?>
   $("select#warehouse").change(function() {
-    retrieve_zone();
+    retrieve_zone('to');
   });
 
   $("select#zone").change(function() {
-    retrieve_aisle();
+    retrieve_aisle('to');
   });
 
   $("select#aisle").change(function() {
-    retrieve_rack();
+    retrieve_rack('to');
   });
 
   <?php } ?>

app/ics/manage_stock_out.php

@@ -40,8 +40,7 @@
 
                 <!-- SKU or Product Code -->
                 <div class="mb-3 col-lg-6">
-                  <label for="quantity" class="form-label">Quantity</label>
+                  
-                  <input type="number" class="form-control" id="quantity" placeholder="Enter quantity" required>
                 </div>
 
 
@@ -125,12 +124,15 @@
 
 
 
-  function retrieve_warehouse() {
+  function retrieve_warehouse(type) {
 
     return ajax_request({
-      url: "<?php echo $server_url?>inventory/api/engine/warehouse.php",
+      url: "<?php echo $server_url?>ics/api/engine/retrieve_warehouse.php",
       autoPrepare: true,
       checkRequired: 0,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select warehouse</option>`;
@@ -145,13 +147,16 @@
 
 
 
-  function retrieve_zone(callback) {
+  function retrieve_zone(type,callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_zone.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data : {
+        "type": type
+      },
       debugMode: 0,
       action: 'read',
       onSuccess: function(res) {
@@ -169,13 +174,16 @@
 
 
 
-  function retrieve_aisle(callback) {
+  function retrieve_aisle(type, callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_aisle.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select aisle</option>`;
@@ -192,13 +200,16 @@
 
 
 
-  function retrieve_rack(callback) {
+  function retrieve_rack(type, callback) {
 
     return ajax_request({
       url: "<?php echo $server_url?>ics/api/engine/retrieve_rack.php",
       autoPrepare: true,
       checkRequired: 0,
       noLoading: true,
+      data: {
+        "type": type
+      },
       action: 'read',
       onSuccess: function(res) {
         var option = `<option value="">Please select rack</option>`;
@@ -235,15 +246,15 @@
         $(`#warehouse`).val(<?php echo $_GET["wh"];?>).attr('disabled', true); // set warehouse BEFORE retrieve_zone
 
         // 2. Retrieve zone (autoPrepare reads warehouse value)
-        retrieve_zone(function() {
+        retrieve_zone('from', function() {
           $(`select#zone`).val(data.zone).attr('disabled', true); // set zone BEFORE retrieve_aisle
 
           // 3. Retrieve aisle (autoPrepare reads zone value)
-          retrieve_aisle(function() {
+          retrieve_aisle('from', function() {
             $(`#aisle`).val(data.aisle).attr('disabled', true); // set aisle BEFORE retrieve_rack
 
             // 4. Retrieve rack (autoPrepare reads aisle value)
-            retrieve_rack(function() {
+            retrieve_rack('from', function() {
               $(`#rack`).val(data.rack).attr('disabled', true);
 
               // retrieve for edit
@@ -279,24 +290,28 @@
 
   $(async function() {
     try {
-      await retrieve_warehouse();
+      await retrieve_warehouse('from');
       await retrieve_for_edit();
     } catch (e) {
       console.log(e);
     }
   });
   
+  $(`#product_sku`).on('blur', function() {
+    retrieve_warehouse('from');
+  });
+
   <?php if(empty($_GET["id"])){ ?>
   $("select#warehouse").change(function() {
-    retrieve_zone();
+    retrieve_zone('from');
   });
 
   $("select#zone").change(function() {
-    retrieve_aisle();
+    retrieve_aisle('from');
   });
 
   $("select#aisle").change(function() {
-    retrieve_rack();
+    retrieve_rack('from');
   });
 
   <?php } ?>

app/ics/manage_stock_transfer.php

@@ -25,7 +25,7 @@
         <div class="col-lg-8 col-12">
           <div class="card">
             <div class="card-body p-5">
-              <h2 class="fs-5 mb-4">Add Stock</h2>
+              <h2 class="fs-5 mb-4">Move Stock</h2>
               <form class="row gx-5">
                 <!-- Product Name -->
                 <div class="mb-3 col-lg-3">
@@ -40,8 +40,7 @@
 
                 <!-- SKU or Product Code -->
                 <div class="mb-3 col-lg-6">
-                  <label for="quantity" class="form-label">Quantity</label>
+
-                  <input type="number" class="form-control" id="quantity" placeholder="Enter quantity" required>
                 </div>
 
 
@@ -49,7 +48,9 @@
                 <!-- Warehouse -->
                 <div class="mb-3 col-lg-3">
                   <label for="warehouse" class="form-label">From Warehouse</label>
-                  <select name="warehouse" id="warehouse_from" role="from" class="form-select" required></select>
+                  <select name="warehouse" id="warehouse_from" role="from" class="form-select" required>
+                    <option value="">Please select warehouse</option>
+                  </select>
                 </div>
 
                 <div class="mb-3 col-lg-3">
@@ -77,7 +78,9 @@
                 <!-- Warehouse -->
                 <div class="mb-3 col-lg-3">
                   <label for="warehouse" class="form-label">To Warehouse</label>
-                  <select name="warehouse" id="warehouse_to" role="to" class="form-select" required></select>
+                  <select name="warehouse" id="warehouse_to" role="to" class="form-select" required>
+                    <option value="">Please select warehouse</option>
+                  </select>
                 </div>
 
                 <div class="mb-3 col-lg-3">
@@ -156,19 +159,23 @@
   function retrieve_warehouse(type) {
 
     return ajax_request({
-      url: "<?php echo $server_url?>inventory/api/engine/warehouse.php",
+      url: "<?php echo $server_url?>ics/api/engine/retrieve_warehouse.php",
       autoPrepare: true,
       checkRequired: 0,
       data: {
         "type": type
       },
       action: 'read',
+      debugMode: 0,
       onSuccess: function(res) {
         var option = `<option value="">Please select warehouse</option>`;
         $.each(res.output, function(key, item) {
           option += `<option value='${item.id}'>${item.warehouse_name}</option>`;
         })
         $(`select[name='warehouse'][role='${type}']`).html(option);
+        if(!type) {
+          $(`select[name='warehouse']`).html(option);
+        }
       }
     });
 
@@ -195,6 +202,10 @@
         })
         $(`select[name='zone'][role='${type}']`).html(option);
 
+        if(!type) {
+          $(`select[name='zone']`).html(option);
+        }
+
         if (callback) callback(); // ← add this
       }
     });
@@ -214,6 +225,7 @@
       },
       noLoading: true,
       action: 'read',
+      debugMode: 0,
       onSuccess: function(res) {
         var option = `<option value="">Please select aisle</option>`;
         $.each(res.output, function(key, item) {
@@ -221,6 +233,10 @@
         })
         $(`select[name='aisle'][role='${type}']`).html(option);
 
+        if(!type) {
+          $(`select[name='aisle']`).html(option);
+        }
+
         if (callback) callback(); // ← add this
       }
     });
@@ -247,6 +263,10 @@
         })
         $(`select[name='rack'][role='${type}']`).html(option);
 
+        if(!type) {
+          $(`select[name='rack']`).html(option);
+        }
+
         if (callback) callback(); // ← add this
       }
     });
@@ -324,7 +344,7 @@
         $('#contact').val(data.contact_name)
           .attr('secondary', data.contact_name)
           .attr('data-id', data.contact_id);
-
+        console.log(data);
         $('#product_name').val(data.product_name);
         $('#product_sku').attr('secondary', data.product_sku);
 
@@ -340,14 +360,25 @@
 
   $(async function() {
     try {
-      await retrieve_warehouse("from");
+      await retrieve_warehouse('from');
-      await retrieve_warehouse("to");
+      await retrieve_warehouse('to');
       await retrieve_for_edit();
     } catch (e) {
       console.log(e);
     }
   });
   
+  $(`#product_sku`).on('blur', function() {
+    $(async function() {
+      try {
+        await retrieve_warehouse('from');
+        await retrieve_warehouse('to');
+      } catch (e) {
+        console.log(e);
+      }
+    })
+  });
+
   <?php if(empty($_GET["id"])){ ?>
   $("select[name='warehouse']").change(function() {
     retrieve_zone($(this).attr('role'));

app/inventory/api/engine/manage_category.php

@@ -64,10 +64,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] =  $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/inventory/api/engine/manage_product.php

@@ -112,11 +112,13 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] =  $e->getMessage();
         $answer["error"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/inventory/api/engine/manage_storage.php

@@ -86,10 +86,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] = $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/inventory/api/engine/manage_warehouse.php

@@ -67,10 +67,12 @@
     } catch (PDOException $e) {
         $answer["success"] = 0;
         $answer["message"] = "Database error, please try again";
+        http_response_code(500);
 
     } catch (Exception $e) {
         $answer["success"] = 0;
         $answer["message"] =  $e->getMessage();
+        http_response_code(400);
     }
 
     exit(json_encode($answer));

app/inventory/api/engine/remove_category.php

@@ -1,54 +1,80 @@
 <?php 
     session_start();
-
     require '../../../assets/utils/db_auth.php';
 
-    $id = (int)$data['id'];
+    try {
+        $result = dbTransaction($pdo2, function($pdo) use ($data, $company_id, $logging) {
 
-    // get data
+            $id = (int)($data['id'] ?? 0);
-    $sql = "SELECT *
-        FROM md_product_category
-        WHERE 
-            company_id = :company_id and 
-            id = :id ";
-    $sth = $pdo2->prepare($sql);
-    $sth->execute([
-        ":company_id" => $company_id,
-        ":id" => $id
-    ]);
-    db_check($sth, $answer);
-    $json = $sth->fetch(PDO::FETCH_ASSOC);
-    $json = json_encode($json);
 
+            if ($id <= 0) {
+                throw new Exception("Invalid category ID.");
+            }
 
+            // 1. Validate: check if category is in use by any product
+            $sql = "SELECT COUNT(*) 
+                    FROM md_product 
+                    WHERE company_id = :company_id 
+                      AND category = :id";
+            $sth = $pdo->prepare($sql);
+            $sth->execute([
+                ":company_id" => $company_id,
+                ":id" => $id
+            ]);
 
-    // delete data
+            $product_count = (int) $sth->fetchColumn();
-    $sql = "DELETE FROM md_product_category
-        WHERE 
-            company_id = :company_id and 
-            id = :id ";
-    $sth = $pdo2->prepare($sql);
-    $sth->execute([
-        ":company_id" => $id,
-        ":id" => $id
-    ]);
-    db_check($sth, $answer);
 
+            if ($product_count > 0) {
+                throw new Exception("Cannot remove category. It is currently used by {$product_count} product(s).");
+            }
 
+            // 2. Append to log history
+            $sql = "SELECT `log` FROM md_product_category
+                    WHERE company_id = :company_id AND id = :id";
+            $sth = $pdo->prepare($sql);
+            $sth->execute([
+                ":company_id" => $company_id,
+                ":id" => $id
+            ]);
 
-    // insert into archive
+            $table_log = json_decode($sth->fetchColumn() ?: '[]', true);
-    $sql = "INSERT INTO archive (`company_id`,`user_id`,`date`,`json`) VALUES (:company_id,:user_id,NOW(),:json)";
+            if (!is_array($table_log)) $table_log = [];
-    $sth = $pdo2->prepare($sql);
+            $table_log[] = $logging;
-    $sth->execute([
-        ":company_id" => $company_id,
-        ":user_id" => $user_id,
-        ":json" => $json
-    ]);
-    db_check($sth, $answer);
 
+            // 3. Soft-delete via sign flip
+            $sql = "UPDATE md_product_category
+                    SET company_id = company_id * (-1),
+                        `log` = :log
+                    WHERE company_id = :company_id 
+                      AND id = :id";
+            $sth = $pdo->prepare($sql);
+            $sth->execute([
+                ":company_id" => $company_id,
+                ":id"         => $id,
+                ":log"        => json_encode($table_log, JSON_UNESCAPED_UNICODE),
+            ]);
 
+            if ($sth->rowCount() === 0) {
+                throw new Exception("Category not found or already removed.");
+            }
+
+            return $id;
+        });
+
+        $answer["success"] = 1;
+        $answer["message"] = "Category removed successfully.";
+        $answer["id"]      = $result;
+
+    } catch (PDOException $e) {
+        $answer["success"] = 0;
+        $answer["message"] = "Database error, please try again";
+        http_response_code(500);
+
+    } catch (Exception $e) {
+        $answer["success"] = 0;
+        $answer["message"] = $e->getMessage();
+        http_response_code(400);
+    }
 
-    $answer["success"] = 1;
     exit(json_encode($answer));
-
 ?>

app/inventory/api/engine/warehouse_stats.php

@@ -10,7 +10,7 @@
     $answer["total_location"]  = $report->getTotalLocation();
     $answer["total_capacity"]  = $report->getTotalCapacity();
     $answer["space_used"]      = $report->getSpaceUsed();
-    $answer["total_product"]   = $report->getTotalProduct();
+    $answer["total_product"]   = $report->getTotalProductInStock();
     $answer["success"] = 1;
 
     exit(json_encode($answer));

app/inventory/product.php

@@ -150,7 +150,7 @@
                       <th>Category</th>
                       <th>Slug</th>
                       <th>Description</th>
-                      <th>Products</th>
+                      <th style="text-align: right;">Product Count</th>
                       <th>Status</th>
                       <th>Actions</th>
                     </tr>
@@ -190,11 +190,12 @@
                 <table class="table table-hover mb-0 table-centered" id="product">
                   <thead class="table-secondary border-light">
                     <tr>
+                      <th width="75px"></th>
                       <th>Product</th>
                       <th>SKU</th>
-                      <th>Current Stock</th>
+                      <th style="text-align: right;">Current Stock</th>
-                      <th>Min Stock</th>
+                      <th style="text-align: right;">Min Stock</th>
-                      <th>Reorder Point</th>
+                      <th style="text-align: right;">Reorder Point</th>
                       <th>Status</th>
                       <th>Action</th>
                     </tr>
@@ -309,7 +310,7 @@
             <td class="py-3">${item['category']}</td>
             <td class="py-3">${item['slug']}</td>
             <td class="py-3">${item['description']}</td>
-            <td class="py-3">${item['product_count']}</td>
+            <td class="py-3" style="text-align: right;">${item['product_count']}</td>
             <td class="py-3">
               ${(item['status']==1)?'<span class="badge bg-success">Active</span>':'<span class="badge bg-secondary">Inactive</span>'}
             </td>
@@ -367,7 +368,10 @@
 
     var body = ``;
     $.each(page_data, function(key, item) {
-      body += `<tr>
+      body += `<tr height="50px">
+            <td class="py-3">
+              <img src="<?php echo $server_url?>uploads/product/${item['product_image']}" alt="${item['product_name']}" class="img-fluid" style="height: 25px;">
+            </td>
             <td class="py-3">${item['product_name']}</td>
             <td class="py-3">${item['sku']}</td>
             <td class="py-3" style='text-align: right;'>${format_number(item['product_balance'],4)}</td>