import { generateToken } from '~/server/utils/auth'
import { prisma } from '~/server/utils/prisma'

interface FirebaseUser {
  localId: string
  email: string
  displayName?: string
  photoUrl?: string
}

export default defineEventHandler(async (event) => {
  const body = await readBody(event)
  const { idToken } = body

  if (!idToken) {
    throw createError({ statusCode: 400, message: 'Firebase ID token required' })
  }

  const config = useRuntimeConfig()
  const apiKey = config.firebaseApiKey || config.public.firebaseApiKey

  if (!apiKey) {
    throw createError({ statusCode: 500, message: 'Firebase API key not configured' })
  }

  console.log('[Auth] Received idToken, length:', idToken?.length || 0)
  console.log('[Auth] Using API key (masked):', apiKey ? `${apiKey.slice(0, 6)}...${apiKey.slice(-4)}` : 'EMPTY')

  let verifyRes: any
  try {
    verifyRes = await $fetch<any>(
      `https://identitytoolkit.googleapis.com/v1/accounts:lookup?key=${apiKey}`,
      { method: 'POST', body: { idToken } }
    )
  } catch (err: any) {
    console.error('[Auth] Firebase token verification failed:', err?.data || err?.message || err)
    throw createError({ statusCode: 401, message: 'Invalid Firebase token' })
  }

  if (!verifyRes?.users?.[0]) {
    throw createError({ statusCode: 401, message: 'Invalid Firebase token' })
  }

  const fbUser: FirebaseUser = verifyRes.users[0]
  const email = fbUser.email
  // Очищаем username: заменяем пробелы на дефисы и убираем спецсимволы
  const username = email.split('@')[0].toLowerCase().replace(/\s+/g, '-').replace(/[^a-z0-9-_]/g, '')
  const userId = fbUser.localId

  let user: any
  try {
    user = await prisma.user.upsert({
      where: { email },
      update: { 
        username 
      },
      create: {
        id: userId,
        email,
        username,
        password: 'firebase-managed',
        role: 'user',
        profile: {
          create: {
            displayName: fbUser.displayName || username,
            avatar: fbUser.photoUrl || `https://api.dicebear.com/7.x/avataaars/svg?seed=${userId}`
          }
        }
      },
      include: { 
        profile: true 
      }
    })
  } catch (dbErr: any) {
    console.warn('[Auth] Database offline, creating local dev session for:', email, dbErr.message)
    user = {
      id: userId,
      email,
      username,
      role: 'user',
      profile: {
        displayName: fbUser.displayName || username,
        avatar: fbUser.photoUrl || `https://api.dicebear.com/7.x/avataaars/svg?seed=${userId}`
      }
    }
  }

  const token = generateToken({
    id: user.id,
    email: user.email,
    username: user.username,
    displayName: user.profile?.displayName || user.username,
    role: user.role
  })

  return {
    message: 'Google sign-in successful',
    token,
    user: {
      id: user.id,
      email: user.email,
      username: user.username,
      role: user.role,
      photoUrl: fbUser.photoUrl
    }
  }
})