/**
 * Stripe Checkout Session API
 * Deploy as standalone Node.js server.
 *
 * Environment: STRIPE_SECRET_KEY, FRONTEND_URL
 */

const http = require('http')
const https = require('https')

const STRIPE_SECRET_KEY = process.env.STRIPE_SECRET_KEY
const FRONTEND_URL = process.env.FRONTEND_URL || 'https://git.fdsa.agency'
const PORT = process.env.PORT || 8787

function createCheckoutSession(priceId, mode, email) {
  return new Promise((resolve, reject) => {
    const data = new URLSearchParams({
      mode: mode || 'payment',
      success_url: `${FRONTEND_URL}/checkout/success`,
      cancel_url: `${FRONTEND_URL}/checkout/cancel`,
      allow_promotion_codes: 'true',
      'line_items[0][price]': priceId,
      'line_items[0][quantity]': '1',
    })
    if (email) data.set('customer_email', email)

    const options = {
      hostname: 'api.stripe.com',
      path: '/v1/checkout/sessions',
      method: 'POST',
      headers: {
        'Authorization': `Bearer ${STRIPE_SECRET_KEY}`,
        'Content-Type': 'application/x-www-form-urlencoded',
        'Content-Length': data.toString().length,
      },
    }

    const req = https.request(options, (res) => {
      let body = ''
      res.on('data', chunk => body += chunk)
      res.on('end', () => {
        try { resolve({ status: res.statusCode, body: JSON.parse(body) }) }
        catch { resolve({ status: res.statusCode, body: { error: { message: body } } }) }
      })
    })
    req.on('error', reject)
    req.write(data.toString())
    req.end()
  })
}

const server = http.createServer(async (req, res) => {
  res.setHeader('Access-Control-Allow-Origin', '*')
  res.setHeader('Access-Control-Allow-Methods', 'POST, OPTIONS')
  res.setHeader('Access-Control-Allow-Headers', 'Content-Type')

  // Healthcheck endpoint
  if (req.url === '/health' && req.method === 'GET') {
    res.writeHead(200, { 'Content-Type': 'application/json' })
    res.end(JSON.stringify({ status: 'ok', uptime: process.uptime() }))
    return
  }

  if (req.method === 'OPTIONS') {
    res.writeHead(204)
    res.end()
    return
  }

  if (req.method !== 'POST') {
    res.writeHead(405, { 'Content-Type': 'application/json' })
    res.end(JSON.stringify({ error: 'Method not allowed' }))
    return
  }

  if (!STRIPE_SECRET_KEY) {
    res.writeHead(500, { 'Content-Type': 'application/json' })
    res.end(JSON.stringify({ error: 'Stripe not configured' }))
    return
  }

  let body = ''
  req.on('data', chunk => body += chunk)
  req.on('end', async () => {
    try {
      const { price_id, mode, customer_email } = JSON.parse(body)
      const result = await createCheckoutSession(price_id, mode, customer_email)

      if (result.status === 200) {
        res.writeHead(200, { 'Content-Type': 'application/json' })
        res.end(JSON.stringify({ url: result.body.url, session_id: result.body.id }))
      } else {
        res.writeHead(result.status, { 'Content-Type': 'application/json' })
        res.end(JSON.stringify({ error: result.body.error?.message || 'Stripe error' }))
      }
    } catch (e) {
      res.writeHead(400, { 'Content-Type': 'application/json' })
      res.end(JSON.stringify({ error: e.message }))
    }
  })
})

server.listen(PORT, () => {
  console.log(`Checkout API running on :${PORT}`)
})