<?php
session_start();
header("Access-Control-Allow-Origin: *");
header("Access-Control-Allow-Methods: GET, POST");
header("Access-Control-Allow-Headers: Content-Type");
header("Content-Type: application/json; charset=UTF-8");

require_once 'db.php';

$action = $_GET['action'] ?? '';

// ১. লগইন প্রসেস
if ($action === 'login') {
    $data = json_decode(file_get_contents("php://input"), true);
    $username = $data['username'] ?? '';
    $password = $data['password'] ?? '';

    $stmt = $conn->prepare("SELECT * FROM users WHERE username = ?");
    $stmt->bind_param("s", $username);
    $stmt->execute();
    $result = $stmt->get_result();
    $user = $result->fetch_assoc();

    if ($user && password_verify($password, $user['password'])) {
        $_SESSION['user_id'] = $user['id'];
        $_SESSION['username'] = $user['username'];
        $_SESSION['role'] = $user['role'];

        echo json_encode([
            "status" => "success",
            "user" => ["username" => $user['username'], "role" => $user['role']]
        ]);
    } else {
        echo json_encode(["status" => "error", "message" => "ভুল ইউজারনেম বা পাসওয়ার্ড!"]);
    }
    exit;
}

// সেসন চেক
if (!isset($_SESSION['user_id']) && $action !== 'login') {
    echo json_encode(["status" => "unauthorized"]);
    exit;
}

// ২. লগআউট
if ($action === 'logout') {
    session_destroy();
    echo json_encode(["status" => "success"]);
    exit;
}

// ৩. নতুন ইউজার যোগ করা (Admin Only)
if ($action === 'add_user') {
    if ($_SESSION['role'] !== 'admin') {
        echo json_encode(["status" => "error", "message" => "শুধুমাত্র এডমিন নতুন ইউজার যোগ করতে পারবেন।"]);
        exit;
    }

    $data = json_decode(file_get_contents("php://input"), true);
    $newUser = $data['username'];
    $newPass = password_hash($data['password'], PASSWORD_BCRYPT);
    $newRole = $data['role'] ?? 'staff';

    $stmt = $conn->prepare("INSERT INTO users (username, password, role) VALUES (?, ?, ?)");
    $stmt->bind_param("sss", $newUser, $newPass, $newRole);

    if ($stmt->execute()) {
        echo json_encode(["status" => "success"]);
    } else {
        echo json_encode(["status" => "error", "message" => "ইউজারনেমটি আগে থেকেই রয়েছে!"]);
    }
    exit;
}

// ৪. কাস্টমার ও ব্যালেন্স ডাটা লোড
if ($action === 'get_all') {
    $custResult = $conn->query("SELECT * FROM customers ORDER BY created_at DESC");
    $customers = [];

    while ($row = $custResult->fetch_assoc()) {
        $custId = $row['id'];
        $histResult = $conn->query("SELECT entry_id as entryId, type, amount, details, files, timestamp FROM history WHERE cust_id = '$custId' ORDER BY id ASC");
        $history = [];
        
        while ($hRow = $histResult->fetch_assoc()) {
            $hRow['files'] = json_decode($hRow['files']) ?? [];
            $history[] = $hRow;
        }
        $row['history'] = $history;
        $customers[] = $row;
    }

    $settResult = $conn->query("SELECT cash, wallet FROM settings WHERE id=1");
    $settings = $settResult->fetch_assoc();

    echo json_encode([
        "status" => "success",
        "currentUser" => ["username" => $_SESSION['username'], "role" => $_SESSION['role']],
        "customers" => $customers,
        "cash" => (float)($settings['cash'] ?? 0),
        "wallet" => (float)($settings['wallet'] ?? 0)
    ]);
    exit;
}

// ৫. কাস্টমার সেভ / আপডেট
if ($action === 'save_customer') {
    $data = json_decode(file_get_contents("php://input"), true);
    
    $stmt = $conn->prepare("INSERT INTO customers (id, name, phone, acc, aadhar, address) VALUES (?, ?, ?, ?, ?, ?) ON DUPLICATE KEY UPDATE name=?, phone=?, acc=?, aadhar=?, address=?");
    $stmt->bind_param("sssssssssss", $data['id'], $data['name'], $data['phone'], $data['acc'], $data['aadhar'], $data['address'], $data['name'], $data['phone'], $data['acc'], $data['aadhar'], $data['address']);
    $stmt->execute();

    if (isset($data['history']) && count($data['history']) > 0) {
        $first = $data['history'][0];
        $filesJson = json_encode($first['files'] ?? []);
        $hStmt = $conn->prepare("INSERT IGNORE INTO history (entry_id, cust_id, type, amount, details, files, timestamp) VALUES (?, ?, ?, ?, ?, ?, ?)");
        $hStmt->bind_param("sssssss", $first['entryId'], $data['id'], $first['type'], $first['amount'], $first['details'], $filesJson, $first['timestamp']);
        $hStmt->execute();
    }

    echo json_encode(["status" => "success"]);
    exit;
}

// ৬. ট্রানজাকশন সেভ করা
if ($action === 'save_transaction') {
    $data = json_decode(file_get_contents("php://input"), true);
    
    $filesJson = json_encode($data['files'] ?? []);
    $stmt = $conn->prepare("INSERT INTO history (entry_id, cust_id, type, amount, details, files, timestamp) VALUES (?, ?, ?, ?, ?, ?, ?)");
    $stmt->bind_param("sssssss", $data['entryId'], $data['custId'], $data['type'], $data['amount'], $data['details'], $filesJson, $data['timestamp']);
    $stmt->execute();

    $conn->query("UPDATE settings SET cash = '{$data['newCash']}', wallet = '{$data['newWallet']}' WHERE id=1");

    echo json_encode(["status" => "success"]);
    exit;
}

// ৭. ক্যাশ ও ওয়ালেট সেটিং আপডেট
if ($action === 'save_settings') {
    $data = json_decode(file_get_contents("php://input"), true);
    $conn->query("UPDATE settings SET cash = '{$data['cash']}', wallet = '{$data['wallet']}' WHERE id=1");
    echo json_encode(["status" => "success"]);
    exit;
}

// ৮. টাইমলাইন হিস্ট্রি মোছা
if ($action === 'delete_history') {
    $entryId = $_GET['entry_id'] ?? '';
    $stmt = $conn->prepare("DELETE FROM history WHERE entry_id = ?");
    $stmt->bind_param("s", $entryId);
    $stmt->execute();
    echo json_encode(["status" => "success"]);
    exit;
}
?>