<?php
include_once __DIR__ . '/../config.php'; // ../ goes up one level from supplies/ to the root
include_once __DIR__ . '/../functions.php';
include_once __DIR__ . '/../includes/auth_check.php'; // Ensure user is logged in
// Optional: Add role check if needed, e.g., only supply managers can view details
// requireRole(['admin', 'supply_manager']);

$supply_id = isset($_GET['id']) ? intval($_GET['id']) : 0; // Get supply ID from URL
$supply_info = null;
$batches = []; // Active batches
$inactive_batches = []; // Inactive/Consumed/Expired batches for history
$error_message = '';

if ($supply_id > 0) {
    // --- Fetch supply details ---
    $sql_supply = "SELECT s.*, c.category_name
                   FROM supplies s
                   JOIN categories c ON s.category_id = c.id
                   WHERE s.id = $supply_id";
    $result_supply = mysqli_query($conn, $sql_supply);

    if ($result_supply && mysqli_num_rows($result_supply) > 0) {
        $supply_info = mysqli_fetch_assoc($result_supply);
        mysqli_free_result($result_supply);

        // --- Fetch ALL batches for this supply, order by status then date ---
        $sql_batches = "SELECT sb.*, u.full_name as created_by_name
                        FROM supply_batches sb
                        LEFT JOIN users u ON sb.created_by = u.id
                        WHERE sb.supply_id = $supply_id
                        ORDER BY
                            CASE sb.status
                                WHEN 'active' THEN 1
                                WHEN 'consumed' THEN 2
                                WHEN 'expired' THEN 3
                                ELSE 4
                            END,
                            sb.received_date ASC, sb.id ASC"; // Active first (FIFO), then others
        $result_batches = mysqli_query($conn, $sql_batches);
        if ($result_batches) {
            while ($row = mysqli_fetch_assoc($result_batches)) {
                if ($row['status'] == 'active' && $row['quantity_remaining'] > 0) {
                    $batches[] = $row; // Active and remaining batches
                } else {
                    $inactive_batches[] = $row; // Consumed, expired, or remaining = 0
                }
            }
            mysqli_free_result($result_batches);
        } else {
            $error_message = "เกิดข้อผิดพลาดในการดึงข้อมูล Batch: " . mysqli_error($conn);
        }
    } else {
        $error_message = "ไม่พบข้อมูลพัสดุรหัส ID: $supply_id";
    }
} else {
    // If ID is invalid or not provided, redirect back to the list
    $_SESSION['message'] = 'ไม่ได้ระบุรหัสพัสดุ';
    $_SESSION['message_type'] = 'warning';
    redirect('index.php');
}

$page_title = isset($supply_info['supply_name']) ? "รายละเอียดพัสดุ: " . htmlspecialchars($supply_info['supply_name']) : "รายละเอียดพัสดุ";

// --- Include Header and Sidebar ---
include_once __DIR__ . '/../includes/header.php';
// Assuming supply managers and admins view this page
include_once __DIR__ . '/../includes/sidebar_supply.php';
// mysqli_close($conn); // Close connection later, after displaying messages if any
?>

<div class="container-fluid">
    <h1 class="mt-4"><?php echo $page_title; ?></h1>

     <?php if (isset($_SESSION['message'])): ?>
        <div class="alert alert-<?php echo $_SESSION['message_type']; ?> alert-dismissible fade show" role="alert">
            <?php echo $_SESSION['message']; ?>
            <button type="button" class="btn-close" data-bs-dismiss="alert" aria-label="Close"></button>
        </div>
        <?php unset($_SESSION['message'], $_SESSION['message_type']); ?>
    <?php endif; ?>


    <?php if ($error_message): ?>
        <div class="alert alert-danger" role="alert">
            <?php echo $error_message; ?>
        </div>
        <a href="index.php" class="btn btn-secondary"><i class="bi bi-arrow-left"></i> กลับไปรายการพัสดุ</a>
    <?php elseif ($supply_info): ?>
        <div class="card mb-4">
            <div class="card-header">
                <i class="bi bi-info-circle me-1"></i>
                ข้อมูลพัสดุ
            </div>
            <div class="card-body">
                <div class="row">
                    <div class="col-md-6">
                        <p><strong>รหัสพัสดุ:</strong> <?php echo htmlspecialchars($supply_info['supply_code']); ?></p>
                        <p><strong>ชื่อพัสดุ:</strong> <?php echo htmlspecialchars($supply_info['supply_name']); ?></p>
                        <p><strong>หมวดหมู่:</strong> <?php echo htmlspecialchars($supply_info['category_name']); ?></p>
                        <p><strong>หน่วยนับ:</strong> <?php echo htmlspecialchars($supply_info['unit']); ?></p>
                        <p><strong>คำอธิบาย:</strong> <?php echo nl2br(htmlspecialchars(isset($supply_info['description']) ? $supply_info['description'] : '-')); ?></p>
                    </div>
                    <div class="col-md-6">
                        <p><strong>จำนวนคงคลังรวม:</strong> <span class="fw-bold fs-5"><?php echo number_format($supply_info['quantity_in_stock']); ?></span></p>
                        <p><strong>จุดสั่งซื้อขั้นต่ำ:</strong> <?php echo number_format($supply_info['min_stock_level']); ?></p>
                        <p><strong>มูลค่าเฉลี่ยต่อหน่วย:</strong> <?php echo number_format($supply_info['average_unit_price'], 2); ?> บาท</p>
                        <p><strong>มูลค่ารวมในคลัง (ประมาณ):</strong> <?php echo number_format($supply_info['total_value'], 2); ?> บาท</p>
                        <p><strong>สถานะพัสดุ:</strong>
                            <?php if ($supply_info['status'] == 'active'): ?>
                                <span class="badge bg-success">ใช้งาน</span>
                            <?php else: ?>
                                <span class="badge bg-secondary">ไม่ใช้งาน</span>
                            <?php endif; ?>
                            <?php if ($supply_info['quantity_in_stock'] <= $supply_info['min_stock_level'] && $supply_info['min_stock_level'] > 0): ?>
                                <span class="badge bg-warning text-dark ms-1">ต่ำกว่าจุดสั่งซื้อ</span>
                            <?php endif; ?>
                        </p>
                    </div>
                </div>
            </div>
        </div>

        <div class="card mb-4">
            <div class="card-header">
                <i class="bi bi-layers-fill me-1"></i>
                รายการ Batch ที่ยังคงเหลือ (เรียงตามลำดับ FIFO ที่จะถูกตัดจ่ายก่อน)
            </div>
            <div class="card-body">
                <div class="table-responsive">
                    <table class="table table-bordered table-sm table-hover">
                        <thead class="table-light">
                            <tr>
                                <th>#</th>
                                <th>หมายเลข Batch</th>
                                <th class="text-end">จำนวนรับเข้า</th>
                                <th class="text-end">จำนวนคงเหลือ</th>
                                <th class="text-end">ราคา/หน่วย (บาท)</th>
                                <th class="text-end">มูลค่าคงเหลือ (บาท)</th>
                                <th>วันที่รับเข้า</th>
                                <th>วันที่หมดอายุ</th>
                                <th>ผู้จำหน่าย</th>
                                <th>เลขที่ใบส่งของ</th>
                                <th>ผู้บันทึก</th>
                                <th>ดำเนินการ</th> </tr>
                        </thead>
                        <tbody>
                            <?php if (!empty($batches)): ?>
                                <?php $batch_counter = 1; ?>
                                <?php foreach ($batches as $batch):
                                    // Check if deletable (nothing consumed)
                                    $can_delete = ($batch['quantity_remaining'] == $batch['quantity_received']);
                                ?>
                                    <tr <?php echo ($batch === $batches[0]) ? 'class="table-info"' : ''; // Highlight next batch ?>>
                                        <td><?php echo $batch_counter++; ?></td>
                                        <td><?php echo htmlspecialchars($batch['batch_no']); ?></td>
                                        <td class="text-end"><?php echo number_format($batch['quantity_received']); ?></td>
                                        <td class="text-end fw-bold"><?php echo number_format($batch['quantity_remaining']); ?></td>
                                        <td class="text-end"><?php echo number_format($batch['unit_price'], 2); ?></td>
                                        <td class="text-end"><?php echo number_format($batch['quantity_remaining'] * $batch['unit_price'], 2); ?></td>
                                        <td><?php echo formatThaiDate($batch['received_date'], true, true); ?></td>
                                        <td><?php echo $batch['expiry_date'] ? formatThaiDate($batch['expiry_date'], false, true) : '-'; ?></td>
                                        <td><?php echo htmlspecialchars(isset($batch['supplier']) ? $batch['supplier'] : '-'); ?></td>
                                        <td><?php echo htmlspecialchars(isset($batch['invoice_no']) ? $batch['invoice_no'] : '-'); ?></td>
                                         <td><?php echo htmlspecialchars(isset($batch['created_by_name']) ? $batch['created_by_name'] : 'N/A'); ?></td>
                                         <td class="text-center"> <a href="batch_edit.php?id=<?php echo $batch['id']; ?>&supply_id=<?php echo $supply_id; ?>" class="btn btn-warning btn-sm" title="แก้ไขข้อมูล Batch (ยกเว้นจำนวน)">
                                                <i class="bi bi-pencil-fill"></i>
                                            </a>
                                            <?php if ($can_delete): ?>
                                                <a href="action_batch_delete.php?id=<?php echo $batch['id']; ?>&supply_id=<?php echo $supply_id; ?>"
                                                   class="btn btn-danger btn-sm"
                                                   title="ลบ Batch (เฉพาะที่ยังไม่ถูกเบิก)"
                                                   onclick="return confirm('ต้องการลบ Batch นี้ใช่หรือไม่? (จะลบได้เฉพาะ Batch ที่ยังไม่มีการเบิกจ่ายเท่านั้น)');">
                                                   <i class="bi bi-trash-fill"></i>
                                                </a>
                                            <?php else: ?>
                                                <button class="btn btn-danger btn-sm" title="ไม่สามารถลบได้ เนื่องจากมีการเบิกจ่ายจาก Batch นี้ไปแล้ว" disabled>
                                                   <i class="bi bi-trash-fill"></i>
                                                </button>
                                            <?php endif; ?>
                                         </td>
                                    </tr>
                                <?php endforeach; ?>
                            <?php else: ?>
                                <tr>
                                    <td colspan="12" class="text-center text-muted">ไม่พบ Batch ที่ยังคงเหลือสำหรับพัสดุนี้</td> </tr>
                            <?php endif; ?>
                        </tbody>
                    </table>
                     <?php if (!empty($batches)): ?>
                         <small class="text-muted"><span class="table-info p-1 rounded">แถบสีฟ้า</span> คือ Batch ที่จะถูกเบิกจ่ายก่อนตามหลัก FIFO</small>
                     <?php endif; ?>
                </div>
            </div>
        </div>

        <?php if (!empty($inactive_batches)): ?>
        <div class="card mb-4">
            <div class="card-header">
                 <i class="bi bi-clock-history me-1"></i>
                 ประวัติ Batch ที่ใช้หมดแล้ว / หมดอายุ / ไม่ใช้งาน
            </div>
             <div class="card-body">
                <div class="table-responsive" style="max-height: 300px; overflow-y: auto;">
                    <table class="table table-bordered table-sm table-secondary text-muted">
                        <thead class="table-light">
                            <tr>
                                <th>#</th>
                                <th>หมายเลข Batch</th>
                                <th class="text-end">จำนวนรับเข้า</th>
                                <th class="text-end">จำนวนคงเหลือ</th>
                                <th class="text-end">ราคา/หน่วย</th>
                                <th>วันที่รับเข้า</th>
                                <th>สถานะ</th>
                                <th>ผู้บันทึก</th>
                                </tr>
                        </thead>
                        <tbody>
                            <?php $inactive_counter = 1; ?>
                            <?php foreach ($inactive_batches as $batch): ?>
                                <tr>
                                    <td><?php echo $inactive_counter++; ?></td>
                                    <td><?php echo htmlspecialchars($batch['batch_no']); ?></td>
                                    <td class="text-end"><?php echo number_format($batch['quantity_received']); ?></td>
                                    <td class="text-end"><?php echo number_format($batch['quantity_remaining']); ?></td>
                                    <td class="text-end"><?php echo number_format($batch['unit_price'], 2); ?></td>
                                    <td><?php echo formatThaiDate($batch['received_date'], false, true); ?></td>
                                    <td>
                                        <span class="badge bg-<?php echo ($batch['status'] == 'consumed' ? 'secondary' : ($batch['status'] == 'expired' ? 'warning' : 'light text-dark')); ?>">
                                            <?php echo htmlspecialchars($batch['status']); ?>
                                        </span>
                                    </td>
                                    <td><?php echo htmlspecialchars(isset($batch['created_by_name']) ? $batch['created_by_name'] : 'N/A'); ?></td>
                                </tr>
                            <?php endforeach; ?>
                        </tbody>
                    </table>
                </div>
             </div>
        </div>
        <?php endif; ?>


        <a href="index.php" class="btn btn-secondary"><i class="bi bi-arrow-left"></i> กลับไปรายการพัสดุ</a>

    <?php endif; // End check for $supply_info ?>

</div>

<?php
// --- Include Footer ---
include_once __DIR__ . '/../includes/footer.php';
// Close connection here if it wasn't closed before
if (isset($conn) && $conn) {
    mysqli_close($conn);
}
?>