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' })
  }

  const verifyRes = await $fetch<any>(
    `https://identitytoolkit.googleapis.com/v1/accounts:lookup?key=${apiKey}`,
    { method: 'POST', body: { idToken } }
  ).catch(() => null)

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

  const fbUser: FirebaseUser = verifyRes.users[0]
  const email = fbUser.email
  const username = fbUser.displayName || email.split('@')[0]
  const userId = fbUser.localId

  const user = await prisma.user.upsert({
    where: { email },
    update: { username },
    create: {
      id: userId,
      email,
      username,
      password: 'firebase-managed',
      role: 'user',
      profile: {
        create: {
          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,
    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
    }
  }
})