import { createError, getQuery, sendRedirect } from 'h3'
import {
  createGoogleAuthorizationUrl,
  createGoogleOAuthState,
  normalizeGoogleOAuthRedirect
} from '../../../utils/google-oauth'
import { requireMemberSession } from '../../../utils/member-auth'

/**
 * Google OAuth 시작 API
 * @param {import('h3').H3Event} event - 요청 이벤트
 * @returns {Promise<void>} Google 인증 화면 리다이렉트
 */
export default defineEventHandler(async (event) => {
  const query = getQuery(event)
  const mode = String(query.mode || 'member')

  if (!['member', 'admin', 'link'].includes(mode)) {
    throw createError({
      statusCode: 400,
      message: 'Google 로그인 모드가 올바르지 않습니다.'
    })
  }

  const redirectTo = normalizeGoogleOAuthRedirect(
    query.redirect,
    mode === 'admin' ? '/admin' : mode === 'link' ? '/settings' : '/'
  )
  let userId = ''

  if (mode === 'link') {
    const session = await requireMemberSession(event)
    userId = session.userId
  }

  const state = createGoogleOAuthState(event, {
    mode,
    redirectTo,
    userId
  })

  return sendRedirect(event, createGoogleAuthorizationUrl(event, state), 302)
})