<?php
require_once __DIR__ . '/../db/config.php';

header('Content-Type: application/json');

$action = $_GET['action'] ?? '';

try {
    $pdo = db();

    if ($_SERVER['REQUEST_METHOD'] === 'POST') {
        if ($action === 'create_lpo') {
            $data = json_decode(file_get_contents('php://input'), true);
            
            if (empty($data['supplier_id']) || empty($data['items'])) {
                throw new Exception("Supplier and items are required.");
            }

            $pdo->beginTransaction();

            $stmt = $pdo->prepare("INSERT INTO pharmacy_lpos (supplier_id, lpo_date, status, total_amount, notes) VALUES (?, ?, 'Draft', ?, ?)");
            $stmt->execute([
                $data['supplier_id'],
                $data['lpo_date'] ?? date('Y-m-d'),
                $data['total_amount'] ?? 0,
                $data['notes'] ?? ''
            ]);
            $lpoId = $pdo->lastInsertId();

            $stmtItem = $pdo->prepare("INSERT INTO pharmacy_lpo_items (lpo_id, drug_id, quantity, cost_price, total_cost) VALUES (?, ?, ?, ?, ?)");
            
            foreach ($data['items'] as $item) {
                $stmtItem->execute([
                    $lpoId,
                    $item['drug_id'],
                    $item['quantity'],
                    $item['cost_price'],
                    $item['total_cost']
                ]);
            }

            $pdo->commit();
            echo json_encode(['success' => true, 'message' => 'LPO created successfully']);

        } elseif ($action === 'update_status') {
             $data = json_decode(file_get_contents('php://input'), true);
             if (empty($data['id']) || empty($data['status'])) {
                 throw new Exception("ID and Status are required");
             }
             
             $stmt = $pdo->prepare("UPDATE pharmacy_lpos SET status = ? WHERE id = ?");
             $stmt->execute([$data['status'], $data['id']]);
             
             echo json_encode(['success' => true]);
        }
    } elseif ($_SERVER['REQUEST_METHOD'] === 'GET') {
        if ($action === 'get_lpos') {
            $stmt = $pdo->query("
                SELECT l.*, s.name_en as supplier_name 
                FROM pharmacy_lpos l
                LEFT JOIN suppliers s ON l.supplier_id = s.id
                ORDER BY l.created_at DESC
            ");
            echo json_encode($stmt->fetchAll());

        } elseif ($action === 'get_lpo_details') {
            $id = $_GET['id'] ?? 0;
            $stmt = $pdo->prepare("
                SELECT i.*, d.name_en as drug_name, d.sku 
                FROM pharmacy_lpo_items i
                LEFT JOIN drugs d ON i.drug_id = d.id
                WHERE i.lpo_id = ?
            ");
            $stmt->execute([$id]);
            echo json_encode($stmt->fetchAll());
        
        } elseif ($action === 'get_suppliers') {
            $stmt = $pdo->query("SELECT id, name_en, name_ar FROM suppliers ORDER BY name_en ASC");
            echo json_encode($stmt->fetchAll());
            
        } elseif ($action === 'get_drugs') {
            $stmt = $pdo->query("SELECT id, name_en, name_ar, sku, price FROM drugs ORDER BY name_en ASC");
            echo json_encode($stmt->fetchAll());
        }
    }

} catch (Exception $e) {
    if ($pdo->inTransaction()) {
        $pdo->rollBack();
    }
    http_response_code(500);
    echo json_encode(['error' => $e->getMessage()]);
}