import requests
from flask import Flask, request, redirect

app = Flask(__name__)
API_KEY = 'c2m_your_key'
API_URL = 'https://api.crypt2merchant.net'

# 1. Customer clicks "Pay" → create session and redirect
@app.route('/checkout', methods=['POST'])
def checkout():
    session = requests.post(
        f'{API_URL}/api/session',
        headers={'X-Api-Key': API_KEY},
        json={
            'amount_fiat': float(request.form['total']),
            'currency': 'USD',
            'order_id': request.form['order_id'],
            'callback_url': 'https://yoursite.com/paid',
        },
    ).json()

    # 2. Redirect customer to hosted payment page
    return redirect(
        f"{API_URL}/checkout"
        f"?session_id={session['session_id']}"
        f"&address={session['deposit_address']}"
        f"&amount={session['amount_fiat']}"
        f"&currency=USD"
    )

# 3. We call this URL when payment is confirmed
@app.route('/paid')
def paid():
    order_id = request.args.get('order_id')
    txid = request.args.get('txid_out')
    amount = request.args.get('value_coin')

    # TODO: Mark order as paid in your database
    print(f'Order {order_id} paid! USDC: {amount}')

    return 'OK', 200  # Must return 200

<?php
// 1. Create session when customer clicks "Pay"
$ch = curl_init('https://api.crypt2merchant.net/api/session');
curl_setopt_array($ch, [
    CURLOPT_POST => true,
    CURLOPT_RETURNTRANSFER => true,
    CURLOPT_HTTPHEADER => [
        'X-Api-Key: c2m_your_key',
        'Content-Type: application/json',
    ],
    CURLOPT_POSTFIELDS => json_encode([
        'amount_fiat' => 50.00,
        'currency' => 'USD',
        'order_id' => $_POST['order_id'],
        'callback_url' => 'https://yoursite.com/callback.php',
    ]),
]);
$session = json_decode(curl_exec($ch), true);
curl_close($ch);

// 2. Redirect customer to hosted payment page
header('Location: https://api.crypt2merchant.net/checkout'
    . '?session_id=' . $session['session_id']
    . '&address=' . $session['deposit_address']
    . '&amount=' . $session['amount_fiat']
    . '&currency=USD');
exit;

// --- callback.php ---
// 3. We call this URL when payment is confirmed
$session_id = $_GET['session_id'];
$txid = $_GET['txid_out'];
$amount = $_GET['value_coin'];
$order_id = $_GET['order_id'];

// TODO: Mark order as paid in your database

http_response_code(200); // Must return 200

# 1. Create a payment session
curl -X POST https://api.crypt2merchant.net/api/session \
  -H "X-Api-Key: c2m_your_key" \
  -H "Content-Type: application/json" \
  -d '{
    "amount_fiat": 50.00,
    "currency": "USD",
    "order_id": "order-123",
    "callback_url": "https://yoursite.com/callback"
  }'

# Response:
# {
#   "session_id": "7a004150-...",
#   "deposit_address": "0xC690783E...",
#   "amount_fiat": "50.00"
# }

# 2. Redirect customer to:
# https://api.crypt2merchant.net/checkout
#   ?session_id=7a004150-...
#   &address=0xC690783E...
#   &amount=50.00&currency=USD

# 3. When paid, we GET your callback_url with:
#   ?session_id=...&txid_out=...&value_coin=50.00&order_id=order-123
# Your server must return HTTP 200.