'use client'

// apps/web/src/app/accept-invite/page.tsx
// 팀 초대 수락 페이지 — URL의 ?token=을 team-accept Edge Function으로 전달

import { Suspense, useEffect, useState } from 'react'
import { useRouter, useSearchParams } from 'next/navigation'
import { Box, Stack, Alert, CircularProgress } from '@mui/material'
import { MetalCard, PhosphorText } from '@d3ro/ui/components/ds'
import { d3roPalette } from '@d3ro/ui/theme'
import { getSupabaseBrowserClient, isSupabaseConfigured } from '@/lib/supabase-browser'

type AcceptState = 'loading' | 'success' | 'error' | 'need_login'

// useSearchParams는 Suspense boundary 필요 (Next.js 15 prerender 규칙)
export default function AcceptInvitePage(): React.ReactElement {
  return (
    <Suspense
      fallback={
        <Box
          sx={{
            minHeight: '100vh',
            display: 'flex',
            alignItems: 'center',
            justifyContent: 'center',
            bgcolor: d3roPalette.bg.app
          }}
        >
          <CircularProgress color="warning" />
        </Box>
      }
    >
      <AcceptInviteInner />
    </Suspense>
  )
}

function AcceptInviteInner(): React.ReactElement {
  const router = useRouter()
  const searchParams = useSearchParams()
  const token = searchParams.get('token')
  const [state, setState] = useState<AcceptState>('loading')
  const [message, setMessage] = useState<string>('')
  const [teamId, setTeamId] = useState<string | null>(null)

  useEffect(() => {
    async function run(): Promise<void> {
      if (!token) {
        setState('error')
        setMessage('유효하지 않은 초대 링크입니다 (토큰 누락).')
        return
      }
      if (!isSupabaseConfigured()) {
        setState('error')
        setMessage('Supabase가 설정되지 않았습니다.')
        return
      }

      const supabase = getSupabaseBrowserClient()
      const {
        data: { session }
      } = await supabase.auth.getSession()

      if (!session) {
        setState('need_login')
        setMessage('초대를 수락하려면 먼저 로그인해주세요.')
        // 토큰을 sessionStorage에 저장해두고 로그인 후 돌아오도록
        try {
          sessionStorage.setItem('pending_invite_token', token)
        } catch {
          // storage 차단 시 무시
        }
        return
      }

      try {
        const response = await fetch(
          `${process.env.NEXT_PUBLIC_SUPABASE_URL}/functions/v1/team-accept`,
          {
            method: 'POST',
            headers: {
              Authorization: `Bearer ${session.access_token}`,
              'Content-Type': 'application/json'
            },
            body: JSON.stringify({ token })
          }
        )

        if (!response.ok) {
          const errData = (await response.json()) as { error?: string; message?: string }
          setState('error')
          setMessage(errData.message ?? errData.error ?? `실패: ${response.status}`)
          return
        }

        const data = (await response.json()) as { team_id: string; role: string }
        setTeamId(data.team_id)
        setState('success')
        setMessage(`팀에 가입되었습니다 (${data.role}). 잠시 후 이동합니다...`)

        // 성공 시 3초 후 팀 페이지로
        setTimeout(() => {
          router.replace(`/teams/${data.team_id}`)
        }, 2000)
      } catch (e) {
        setState('error')
        setMessage(e instanceof Error ? e.message : 'Unknown error')
      }
    }
    void run()
  }, [token, router])

  return (
    <Box
      sx={{
        minHeight: '100vh',
        display: 'flex',
        alignItems: 'center',
        justifyContent: 'center',
        bgcolor: d3roPalette.bg.app,
        p: 4
      }}
    >
      <MetalCard sx={{ maxWidth: 480, width: '100%', p: 4 }}>
        <Stack spacing={3} alignItems="center">
          <PhosphorText variant="title">TEAM INVITE</PhosphorText>

          {state === 'loading' && <CircularProgress color="warning" />}

          {state === 'success' && (
            <Alert severity="success" variant="outlined" sx={{ width: '100%' }}>
              {message}
            </Alert>
          )}

          {state === 'error' && (
            <>
              <Alert severity="error" variant="outlined" sx={{ width: '100%' }}>
                {message}
              </Alert>
              <Box
                component="a"
                href="/dashboard"
                sx={{
                  color: d3roPalette.accent.main,
                  textDecoration: 'none',
                  fontSize: 13
                }}
              >
                대시보드로 이동
              </Box>
            </>
          )}

          {state === 'need_login' && (
            <>
              <Alert severity="info" variant="outlined" sx={{ width: '100%' }}>
                {message}
              </Alert>
              <Box
                component="a"
                href="/login"
                sx={{
                  color: d3roPalette.accent.main,
                  textDecoration: 'none',
                  fontSize: 13
                }}
              >
                로그인 페이지로 이동
              </Box>
            </>
          )}

          {teamId && (
            <Box sx={{ color: d3roPalette.text.muted, fontSize: 11 }}>
              Team ID: {teamId}
            </Box>
          )}
        </Stack>
      </MetalCard>
    </Box>
  )
}