// apps/mobile/app/(tabs)/record.tsx
// Recording tab — expo-av + STT pipeline
// Design ref: docs/v3/designs/recording.html

import { useState, useRef } from 'react'
import { View, StyleSheet, ActivityIndicator, ScrollView } from 'react-native'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import { Audio } from 'expo-av'
import Constants from 'expo-constants'
import {
  MetalCard,
  PhosphorText,
  PhysicalButton,
  Led,
  Header,
  WaveBars,
  AppStatusBar,
  d3roNativePalette,
  d3roNativeFonts
} from '@d3ro/ui-native'
import { useI18n } from '@d3ro/i18n'
import { supabase, isSupabaseConfigured } from '../../lib/supabase'

type RecordingState = 'idle' | 'recording' | 'processing' | 'done' | 'error'

export default function RecordScreen(): React.ReactElement {
  const insets = useSafeAreaInsets()
  const { t } = useI18n()
  const [state, setState] = useState<RecordingState>('idle')
  const [transcript, setTranscript] = useState<string>('')
  const [error, setError] = useState<string | null>(null)
  const [duration, setDuration] = useState(0)
  const recordingRef = useRef<Audio.Recording | null>(null)
  const timerRef = useRef<ReturnType<typeof setInterval> | null>(null)

  async function startRecording(): Promise<void> {
    setError(null)
    setTranscript('')
    setDuration(0)

    try {
      const perm = await Audio.requestPermissionsAsync()
      if (perm.status !== 'granted') {
        setError(t('mobile.rec.micDenied'))
        setState('error')
        return
      }

      await Audio.setAudioModeAsync({
        allowsRecordingIOS: true,
        playsInSilentModeIOS: true
      })

      const recording = new Audio.Recording()
      await recording.prepareToRecordAsync(Audio.RecordingOptionsPresets.HIGH_QUALITY)
      await recording.startAsync()
      recordingRef.current = recording
      setState('recording')

      timerRef.current = setInterval(() => {
        setDuration((d) => d + 1)
      }, 1000)
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Failed to start')
      setState('error')
    }
  }

  async function stopRecording(): Promise<void> {
    if (!recordingRef.current) return
    if (timerRef.current) {
      clearInterval(timerRef.current)
      timerRef.current = null
    }
    setState('processing')

    try {
      await recordingRef.current.stopAndUnloadAsync()
      const uri = recordingRef.current.getURI()
      recordingRef.current = null

      if (!uri) throw new Error('No recording URI')

      if (!isSupabaseConfigured()) {
        setError(t('mobile.rec.supabaseNotConfigured'))
        setState('error')
        return
      }

      const { data: { session } } = await supabase.auth.getSession()
      if (!session) {
        setError(t('mobile.rec.loginRequired'))
        setState('error')
        return
      }

      const formData = new FormData()
      formData.append('audio', {
        uri,
        name: 'recording.m4a',
        type: 'audio/m4a'
      } as unknown as Blob)
      formData.append('language_code', 'ko-KR')

      const url = (Constants.expoConfig?.extra?.supabaseUrl as string) ?? ''
      const response = await fetch(`${url}/functions/v1/stt-proxy`, {
        method: 'POST',
        headers: { Authorization: `Bearer ${session.access_token}` },
        body: formData
      })

      if (!response.ok) throw new Error(`STT failed: ${response.status}`)

      const result = (await response.json()) as { transcript: string }
      setTranscript(result.transcript)
      setState('done')
    } catch (e) {
      setError(e instanceof Error ? e.message : 'Unknown error')
      setState('error')
    }
  }

  async function cancelRecording(): Promise<void> {
    if (timerRef.current) {
      clearInterval(timerRef.current)
      timerRef.current = null
    }
    if (recordingRef.current) {
      try { await recordingRef.current.stopAndUnloadAsync() } catch { /* ignore */ }
      recordingRef.current = null
    }
    setState('idle')
    setTranscript('')
    setError(null)
    setDuration(0)
  }

  const formatTime = (s: number): string => {
    const m = Math.floor(s / 60)
    const sec = s % 60
    return `${String(m).padStart(2, '0')}:${String(sec).padStart(2, '0')}`
  }

  const statusLabel =
    state === 'recording' ? t('mobile.rec.recording')
      : state === 'processing' ? t('mobile.rec.processing')
        : state === 'done' ? t('mobile.rec.done')
          : state === 'error' ? t('mobile.rec.error')
            : t('mobile.rec.ready')

  return (
    <ScrollView style={styles.container} contentContainerStyle={styles.content}>
      <Header
        title={state === 'recording' ? t('mobile.rec.session') : t('mobile.rec.title')}
        paddingTop={insets.top}
        rightContent={
          state === 'recording' ? (
            <View style={styles.headerRight}>
              <PhosphorText variant="label" color="amber">
                {formatTime(duration)}
              </PhosphorText>
              <Led color="green" size={6} />
            </View>
          ) : undefined
        }
      />

      {/* Wave Bars */}
      <WaveBars active={state === 'recording'} />

      {/* Transcript Area */}
      <View style={styles.transcriptArea}>
        {state === 'idle' && (
          <PhosphorText
            variant="small"
            color="muted"
            style={styles.initLog}
          >
            {t('mobile.rec.initLog')}
          </PhosphorText>
        )}

        {state === 'processing' && (
          <ActivityIndicator size="large" color={d3roNativePalette.accent.amber} />
        )}

        {transcript !== '' && state === 'done' && (
          <View style={styles.transcriptBox}>
            <PhosphorText variant="body" color="primary">
              {transcript}
            </PhosphorText>
          </View>
        )}

        {error !== null && (
          <View style={styles.errorBox}>
            <PhosphorText variant="small" color="label">
              {error}
            </PhosphorText>
          </View>
        )}
      </View>

      {/* Status Line */}
      {state === 'recording' && (
        <View style={styles.listeningRow}>
          <Led color="amber" size={6} />
          <PhosphorText variant="label" color="amber" style={styles.listeningText}>
            {t('mobile.rec.listening')}
          </PhosphorText>
          <PhosphorText variant="label" color="muted">
            {t('mobile.rec.realtime')}
          </PhosphorText>
        </View>
      )}

      {/* Buttons */}
      <View style={styles.buttons}>
        {(state === 'idle' || state === 'done' || state === 'error') && (
          <PhysicalButton
            label={state === 'done' ? t('mobile.rec.newRecording') : t('mobile.rec.start')}
            variant="primary"
            onPress={() => void startRecording()}
          />
        )}
        {state === 'recording' && (
          <>
            <PhysicalButton
              label={t('mobile.rec.stop')}
              variant="danger"
              onPress={() => void stopRecording()}
            />
            <View style={styles.buttonSpacer} />
            <PhysicalButton
              label={t('mobile.rec.cancel')}
              variant="secondary"
              onPress={() => void cancelRecording()}
            />
          </>
        )}
      </View>

      <AppStatusBar />
    </ScrollView>
  )
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: d3roNativePalette.bg.app },
  content: { paddingBottom: 100 },
  headerRight: { flexDirection: 'row', alignItems: 'center', gap: 8 },
  transcriptArea: {
    minHeight: 160,
    justifyContent: 'center',
    alignItems: 'center',
    paddingHorizontal: 20,
    paddingVertical: 24
  },
  initLog: {
    fontFamily: d3roNativeFonts.mono,
    textAlign: 'center'
  },
  transcriptBox: {
    backgroundColor: d3roNativePalette.bg.inset,
    padding: 12,
    borderRadius: 8,
    width: '100%'
  },
  errorBox: {
    borderWidth: 1,
    borderColor: d3roNativePalette.accent.amber,
    backgroundColor: d3roNativePalette.accent.amberDim,
    padding: 10,
    borderRadius: 6,
    width: '100%'
  },
  listeningRow: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'center',
    gap: 8,
    paddingBottom: 16
  },
  listeningText: { letterSpacing: 2 },
  buttons: { paddingHorizontal: 20, paddingBottom: 16 },
  buttonSpacer: { height: 12 }
})