<?php
session_start();
require '../../../assets/utils/db_auth.php';

$action = $data['action'] ?? '';
$id     = (int)($data['id'] ?? 0);

// ── Generate quotation number ─────────────────────────────────────────────────
function generate_quotation_number(PDO $pdo, int $cid): string {
    $prefix = 'QT-' . date('Ym') . '-';
    $sql = "SELECT quotation_number FROM ac_quotation
            WHERE company_id = :cid AND quotation_number LIKE :prefix
            ORDER BY id DESC LIMIT 1";
    $sth = $pdo->prepare($sql);
    $sth->execute([':cid' => $cid, ':prefix' => $prefix . '%']);
    $last = $sth->fetchColumn();
    $seq  = $last ? ((int)substr($last, -4) + 1) : 1;
    return $prefix . str_pad($seq, 4, '0', STR_PAD_LEFT);
}

// ── Compute totals from items ─────────────────────────────────────────────────
function compute_totals(array $items, float $discount, float $tax): array {
    $subtotal = array_sum(array_map(fn($i) => (float)($i['total_price'] ?? 0), $items));
    $grand    = $subtotal - $discount + $tax;
    return [round($subtotal, 4), round(max(0, $grand), 4)];
}

if ($action === 'create') {

    $items    = json_decode($data['items'] ?? '[]', true) ?: [];
    $discount = (float)($data['discount'] ?? 0);
    $tax      = (float)($data['tax']      ?? 0);
    [$subtotal, $grand] = compute_totals($items, $discount, $tax);

    $qnum = generate_quotation_number($pdo2, $company_id);

    $sql = "INSERT INTO ac_quotation
              (company_id, uuid, quotation_number, contact_id, quotation_date, valid_until,
               status, subtotal, discount, tax, grand_total, items, notes, log, created_at)
            VALUES
              (:cid, :uuid, :qnum, :contact_id, :qdate, :valid_until,
               0, :sub, :disc, :tax, :grand, :items, :notes, :log, NOW())";
    $sth = $pdo2->prepare($sql);
    $sth->execute([
        ':cid'        => $company_id,
        ':uuid'       => $uuid,
        ':qnum'       => $qnum,
        ':contact_id' => (int)($data['contact_id'] ?? 0),
        ':qdate'      => $data['quotation_date']  ?: null,
        ':valid_until'=> $data['valid_until']      ?: null,
        ':sub'        => $subtotal,
        ':disc'       => $discount,
        ':tax'        => $tax,
        ':grand'      => $grand,
        ':items'      => json_encode($items),
        ':notes'      => $data['notes'] ?? '',
        ':log'        => json_encode($logging),
    ]);

    $answer['success'] = 1;
    $answer['message'] = 'Quotation created';
    $answer['new_id']  = (int)$pdo2->lastInsertId();
    $answer['quotation_number'] = $qnum;

} elseif ($action === 'update') {

    if (!$id) { exit(json_encode(['success' => 0, 'message' => 'ID required'])); }

    $items    = json_decode($data['items'] ?? '[]', true) ?: [];
    $discount = (float)($data['discount'] ?? 0);
    $tax      = (float)($data['tax']      ?? 0);
    [$subtotal, $grand] = compute_totals($items, $discount, $tax);

    $sql = "UPDATE ac_quotation SET
              contact_id     = :contact_id,
              quotation_date = :qdate,
              valid_until    = :valid_until,
              subtotal       = :sub,
              discount       = :disc,
              tax            = :tax,
              grand_total    = :grand,
              items          = :items,
              notes          = :notes
            WHERE id = :id AND company_id = :cid AND status = 0";
    $sth = $pdo2->prepare($sql);
    $sth->execute([
        ':contact_id'  => (int)($data['contact_id'] ?? 0),
        ':qdate'       => $data['quotation_date'] ?: null,
        ':valid_until' => $data['valid_until']    ?: null,
        ':sub'         => $subtotal,
        ':disc'        => $discount,
        ':tax'         => $tax,
        ':grand'       => $grand,
        ':items'       => json_encode($items),
        ':notes'       => $data['notes'] ?? '',
        ':id'          => $id,
        ':cid'         => $company_id,
    ]);

    $answer['success'] = 1;
    $answer['message'] = 'Quotation updated';

} else {
    $answer['message'] = 'Unknown action';
}

exit(json_encode($answer));