const paypal = require('@paypal/checkout-server-sdk');

// PayPal environment setup
function environment() {
    const clientId = process.env.PAYPAL_CLIENT_ID;
    const clientSecret = process.env.PAYPAL_CLIENT_SECRET;
    const mode = process.env.PAYPAL_MODE || 'sandbox';

    if (!clientId || !clientSecret) {
        throw new Error('PayPal credentials not found in environment variables');
    }

    return mode === 'live'
        ? new paypal.core.LiveEnvironment(clientId, clientSecret)
        : new paypal.core.SandboxEnvironment(clientId, clientSecret);
}

// PayPal client
function client() {
    return new paypal.core.PayPalHttpClient(environment());
}

// Create PayPal order
async function createOrder(orderData) {
    try {
        const request = new paypal.orders.OrdersCreateRequest();
        request.prefer("return=representation");
        request.requestBody({
            intent: 'CAPTURE',
            purchase_units: [{
                reference_id: orderData.reference_id,
                amount: {
                    currency_code: orderData.currency || 'USD',
                    value: orderData.total
                },
                description: orderData.description || 'Payment from WooCommerce',
                custom_id: orderData.wc_order_id,
                items: orderData.items || []
            }],
            application_context: {
                brand_name: orderData.brand_name || 'Your Store',
                landing_page: 'BILLING',
                user_action: 'PAY_NOW',
                return_url: `${process.env.FRONTEND_URL}/success`,
                cancel_url: `${process.env.FRONTEND_URL}/cancel`
            }
        });

        const order = await client().execute(request);

        console.log('PayPal Order Created:', {
            id: order.result.id,
            status: order.result.status,
            amount: orderData.total
        });

        return {
            success: true,
            order_id: order.result.id,
            status: order.result.status,
            links: order.result.links
        };
    } catch (error) {
        console.error('PayPal Create Order Error:', error);
        return {
            success: false,
            error: error.message,
            details: error.details || []
        };
    }
}

// Capture PayPal payment
async function captureOrder(orderId) {
    try {
        const request = new paypal.orders.OrdersCaptureRequest(orderId);
        request.requestBody({});

        const capture = await client().execute(request);

        console.log('PayPal Order Captured:', {
            id: capture.result.id,
            status: capture.result.status,
            payer_email: capture.result.payer?.email_address
        });

        return {
            success: true,
            capture_id: capture.result.id,
            status: capture.result.status,
            payer: capture.result.payer,
            purchase_units: capture.result.purchase_units,
            transaction_id: capture.result.purchase_units[0]?.payments?.captures[0]?.id
        };
    } catch (error) {
        console.error('PayPal Capture Order Error:', error);
        return {
            success: false,
            error: error.message,
            details: error.details || []
        };
    }
}

// Get order details
async function getOrderDetails(orderId) {
    try {
        const request = new paypal.orders.OrdersGetRequest(orderId);
        const order = await client().execute(request);

        return {
            success: true,
            order: order.result
        };
    } catch (error) {
        console.error('PayPal Get Order Error:', error);
        return {
            success: false,
            error: error.message
        };
    }
}

// Verify webhook signature
function verifyWebhookSignature(headers, body, webhookId) {
    // This is a simplified version - in production, use PayPal's webhook verification
    // For now, we'll do basic validation
    const webhookSecret = process.env.WEBHOOK_SECRET;

    if (!webhookSecret) {
        console.warn('WEBHOOK_SECRET not set - skipping signature verification');
        return true;
    }

    // Add proper webhook signature verification here
    // For development, we'll return true
    return true;
}

module.exports = {
    createOrder,
    captureOrder,
    getOrderDetails,
    verifyWebhookSignature
};