const { createServer } = require('http')
const { parse } = require('url')
const next = require('next')

const dev = process.env.NODE_ENV !== 'production'
const hostname = 'localhost'
const port = parseInt(process.env.PORT || '3000', 10)

const app = next({ dev, hostname, port })
const handle = app.getRequestHandler()

// Run migrations before starting server (only on primary/candidate nodes)
// LiteFS replicas are read-only, so migrations must run on the primary
const isLiteFSReplica = process.env.LITEFS_CANDIDATE === 'false'

if (isLiteFSReplica) {
  console.log('📖 Skipping migrations (LiteFS replica - read-only)')
} else {
  console.log('🔄 Running database migrations...')
  const { migrate } = require('drizzle-orm/better-sqlite3/migrator')
  const { db } = require('./dist/db/index')

  try {
    migrate(db, { migrationsFolder: './drizzle' })
    console.log('✅ Migrations complete')
  } catch (error) {
    console.error('❌ Migration failed:', error)
    process.exit(1)
  }
}

app.prepare().then(() => {
  const server = createServer(async (req, res) => {
    try {
      const parsedUrl = parse(req.url, true)
      await handle(req, res, parsedUrl)
    } catch (err) {
      console.error('Error occurred handling', req.url, err)
      res.statusCode = 500
      res.end('internal server error')
    }
  })

  // Debug: Check upgrade handlers at each stage
  console.log('📊 Stage 1 - After server creation:')
  console.log(`   Upgrade handlers: ${server.listeners('upgrade').length}`)

  // Initialize Socket.IO
  let initializeSocketServer
  try {
    const socketServer = require('./dist/socket-server')
    initializeSocketServer = socketServer.initializeSocketServer
    console.log('✅ Socket server module loaded successfully')
  } catch (error) {
    console.error('❌ Failed to load socket-server module:', error)
    process.exit(1)
  }

  console.log('📊 Stage 2 - Before initializeSocketServer:')
  console.log(`   Upgrade handlers: ${server.listeners('upgrade').length}`)

  initializeSocketServer(server)

  console.log('📊 Stage 3 - After initializeSocketServer:')
  const allHandlers = server.listeners('upgrade')
  console.log(`   Upgrade handlers: ${allHandlers.length}`)
  allHandlers.forEach((handler, i) => {
    console.log(`   [${i}] ${handler.name || 'anonymous'} (length: ${handler.length} params)`)
  })

  // Log all upgrade requests to see handler execution order
  const originalEmit = server.emit.bind(server)
  server.emit = (event, ...args) => {
    if (event === 'upgrade') {
      const req = args[0]
      console.log(`\n🔄 UPGRADE REQUEST: ${req.url}`)
      console.log(`   ${allHandlers.length} handlers will be called`)
    }
    return originalEmit(event, ...args)
  }

  server
    .once('error', (err) => {
      console.error(err)
      process.exit(1)
    })
    .listen(port, () => {
      console.log(`> Ready on http://${hostname}:${port}`)
    })
})