<?php 
    session_start();

    require '../../../assets/utils/db_auth.php';
    require '../../../assets/utils/classes/WarehouseManager.php';

    $id = 0;
    $warehouse_id = (int)$data['warehouse'];

    $whMgmt = new WarehouseManager($pdo2, $company_id);
    $warehouse = $whMgmt->getStockContext($warehouse_id, $id);
    $table = $warehouse['table'];

    
    // ── Always last 12 months ────────────────────────────────────────────
    $now   = new DateTime();
    $start = (clone $now)->modify('-12 months')->format('Y-m-d 00:00:00');
    $end   = $now->format('Y-m-d 23:59:59');
    
    // ── Query: group by month ────────────────────────────────────────────
    $sql = "SELECT
                DATE_FORMAT(a.date, '%b')    AS `label`,
                DATE_FORMAT(a.date, '%Y-%m') AS `sort_key`,
                ROUND(SUM(a.`in`),  2)       AS `stock_in`,
                ROUND(SUM(a.`out`), 2)       AS `stock_out`
            FROM `{$table}` a
            WHERE 
                a.company_id = {$company_id} and 
                a.date      >= '{$start}' and 
                a.date      <= '{$end}'
            GROUP BY `sort_key`, `label`
            ORDER BY `sort_key` ASC";
    
    $sth = $pdo2->prepare($sql);
    $sth->execute();
    $rows = $sth->fetchAll(PDO::FETCH_ASSOC);
    
    // ── Index DB results by sort_key (YYYY-MM) ──────────────────────────
    $dataByMonth = [];
    foreach ($rows as $row) {
        $dataByMonth[$row['sort_key']] = $row;
    }
    
    // ── Always build 12 months, fill zeros where no data ────────────────
    $labels    = [];
    $stock_in  = [];
    $stock_out = [];
    
    for ($i = 11; $i >= 0; $i--) {
        $dt       = (clone $now)->modify("-{$i} months");
        $key      = $dt->format('Y-m');   // e.g. "2025-04"
        $label    = $dt->format('M');     // e.g. "Apr"
    
        $labels[]    = $label;
        $stock_in[]  = isset($dataByMonth[$key]) ? round((float)$dataByMonth[$key]['stock_in'],  2) : 0;
        $stock_out[] = isset($dataByMonth[$key]) ? round((float)$dataByMonth[$key]['stock_out'], 2) : 0;
    }
    
    // ── Response ─────────────────────────────────────────────────────────
    $output = [
        'labels'    => $labels,
        'stock_in'  => $stock_in,
        'stock_out' => $stock_out,
    ];
    
    $answer["output"] = $output;
    $answer["success"] = 1;
    exit(json_encode($answer));

?>