<?php
include_once 'config.php';

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

if ($action === 'market_data') {
    // In a real app, this would fetch from Binance or a cache.
    // For now, we'll fetch from our cryptocurrencies table and mix with some dummy data for variety.
    $stmt = db()->query("SELECT * FROM cryptocurrencies WHERE is_active = 1");
    $coins = $stmt->fetchAll();
    
    foreach ($coins as &$coin) {
        // Simple mock: fluctuate price slightly
        $variation = (mt_rand(-100, 100) / 10000); // +/- 1%
        $coin['price'] = (float)$coin['current_price'] * (1 + $variation);
        $coin['change'] = (float)$coin['change_24h'];
    }
    
    header('Content-Type: application/json');
    echo json_encode($coins);
    exit;
}

if ($action === 'submit_order') {
    check_auth();
    $data = json_decode(file_get_contents('php://input'), true);
    
    if (!$data) {
        echo json_encode(['status' => 'error', 'message' => 'Invalid data']);
        exit;
    }
    
    $user_id = $_SESSION['user_id'];
    $account = get_account($user_id);
    
    $symbol = $data['symbol'] ?? 'BTCUSDT';
    $side = $data['side'] ?? 'BUY';
    $trade_type = $data['trade_type'] ?? 'SPOT';
    $order_type = $data['order_type'] ?? 'LIMIT';
    $price = $data['price'] ?? null;
    $amount = (float)($data['amount'] ?? 0);
    $leverage = (int)($data['leverage'] ?? 1);
    
    // Basic validation
    if ($amount <= 0) {
        echo json_encode(['status' => 'error', 'message' => 'Invalid amount']);
        exit;
    }
    
    // Logic for SPOT / CONTRACT balance checks
    // This is a simplified version
    $total_cost = 0;
    if ($trade_type === 'SPOT') {
        if ($side === 'BUY') {
            $exec_price = $price ?: 50000; // Mock price if market
            $total_cost = $amount * $exec_price;
            if ($account['balance'] < $total_cost) {
                echo json_encode(['status' => 'error', 'message' => '余额不足']);
                exit;
            }
        }
    } else {
        // Contract logic
        $total_cost = ($amount * 100) / $leverage;
        if ($account['balance'] < $total_cost) {
            echo json_encode(['status' => 'error', 'message' => '保证金不足']);
            exit;
        }
    }
    
    try {
        $db = db();
        $db->beginTransaction();
        
        // Deduct balance
        $stmt = $db->prepare("UPDATE accounts SET balance = balance - ? WHERE id = ?");
        $stmt->execute([$total_cost, $account['id']]);
        
        // Insert order
        $stmt = $db->prepare("INSERT INTO orders (account_id, symbol, trade_type, side, order_type, price, amount, leverage, status) VALUES (?, ?, ?, ?, ?, ?, ?, ?, 'PENDING')");
        $stmt->execute([$account['id'], $symbol, $trade_type, $side, $order_type, $price, $amount, $leverage]);
        
        $db->commit();
        echo json_encode(['status' => 'success']);
    } catch (Exception $e) {
        $db->rollBack();
        echo json_encode(['status' => 'error', 'message' => $e->getMessage()]);
    }
    exit;
}
?>