/**
 * TabataFit Player Screen
 * Thin orchestrator — all UI extracted to src/features/player/
 * FORCE DARK — always uses darkColors regardless of system theme
 */

import React, { useRef, useEffect, useCallback, useState } from 'react'
import {
  View,
  Text,
  StyleSheet,
  Pressable,
  Animated,
  StatusBar,
  useWindowDimensions,
} from 'react-native'
import { useRouter, useLocalSearchParams } from 'expo-router'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import { LinearGradient } from 'expo-linear-gradient'
import { BlurView } from 'expo-blur'
import { useKeepAwake } from 'expo-keep-awake'
import { Icon } from '@/src/shared/components/Icon'
import { useTranslation } from 'react-i18next'

import { useTimer } from '@/src/shared/hooks/useTimer'
import { useHaptics } from '@/src/shared/hooks/useHaptics'
import { useAudio } from '@/src/shared/hooks/useAudio'
import { useMusicPlayer } from '@/src/shared/hooks/useMusicPlayer'
import { useActivityStore } from '@/src/shared/stores'
import { getWorkoutById, getTrainerById, getWorkoutAccentColor } from '@/src/shared/data'
import { useTranslatedWorkout } from '@/src/shared/data/useTranslatedData'
import { useWatchSync } from '@/src/features/watch'

import { track } from '@/src/shared/services/analytics'
import { VideoPlayer } from '@/src/shared/components/VideoPlayer'
import { PHASE_COLORS, GRADIENTS, darkColors } from '@/src/shared/theme'
import { TYPOGRAPHY } from '@/src/shared/constants/typography'
import { SPACING } from '@/src/shared/constants/spacing'
import { RADIUS } from '@/src/shared/constants/borderRadius'

import {
  TimerRing,
  PhaseIndicator,
  ExerciseDisplay,
  RoundIndicator,
  PlayerControls,
  BurnBar,
  StatsOverlay,
  CoachEncouragement,
  NowPlaying,
} from '@/src/features/player'

// ─── Helpers ─────────────────────────────────────────────────────────────────

function formatTime(seconds: number) {
  const mins = Math.floor(seconds / 60)
  const secs = seconds % 60
  return `${mins}:${secs.toString().padStart(2, '0')}`
}

// ─── Main Screen ─────────────────────────────────────────────────────────────

export default function PlayerScreen() {
  useKeepAwake()
  const router = useRouter()
  const { id } = useLocalSearchParams<{ id: string }>()
  const insets = useSafeAreaInsets()
  const haptics = useHaptics()
  const { t } = useTranslation()
  const { width: SCREEN_WIDTH } = useWindowDimensions()
  const addWorkoutResult = useActivityStore((s) => s.addWorkoutResult)

  const colors = darkColors

  const rawWorkout = getWorkoutById(id ?? '1')
  const workout = useTranslatedWorkout(rawWorkout)
  const trainer = rawWorkout ? getTrainerById(rawWorkout.trainerId) : undefined
  const trainerColor = getWorkoutAccentColor(id ?? '1')
  const timer = useTimer(rawWorkout ?? null)
  const audio = useAudio()

  // Music player — synced with workout timer
  const music = useMusicPlayer({
    vibe: workout?.musicVibe ?? 'electronic',
    isPlaying: timer.isRunning && !timer.isPaused,
  })

  const [showControls, setShowControls] = useState(true)
  const [heartRate, setHeartRate] = useState<number | null>(null)

  // Watch sync integration
  const { isAvailable: isWatchAvailable, sendWorkoutState } = useWatchSync({
    onPlay: () => {
      timer.resume()
      track('watch_control_play', { workout_id: workout?.id ?? id })
    },
    onPause: () => {
      timer.pause()
      track('watch_control_pause', { workout_id: workout?.id ?? id })
    },
    onSkip: () => {
      timer.skip()
      haptics.selection()
      track('watch_control_skip', { workout_id: workout?.id ?? id })
    },
    onStop: () => {
      haptics.phaseChange()
      timer.stop()
      router.back()
      track('watch_control_stop', { workout_id: workout?.id ?? id })
    },
    onHeartRateUpdate: (hr: number) => setHeartRate(hr),
  })

  // Animation refs
  const timerScaleAnim = useRef(new Animated.Value(0.8)).current
  const phaseColor = PHASE_COLORS[timer.phase].fill

  // ─── Actions ─────────────────────────────────────────────────────────────

  const startTimer = useCallback(() => {
    timer.start()
    haptics.buttonTap()
    if (workout) {
      track('workout_started', {
        workout_id: workout.id,
        workout_title: workout.title,
        duration: workout.duration,
        level: workout.level,
      })
    }
  }, [timer, haptics, workout])

  const togglePause = useCallback(() => {
    const workoutId = workout?.id ?? id ?? ''
    if (timer.isPaused) {
      timer.resume()
      track('workout_resumed', { workout_id: workoutId })
    } else {
      timer.pause()
      track('workout_paused', { workout_id: workoutId })
    }
    haptics.selection()
  }, [timer, haptics, workout, id])

  const stopWorkout = useCallback(() => {
    haptics.phaseChange()
    timer.stop()
    router.back()
  }, [router, timer, haptics])

  const completeWorkout = useCallback(() => {
    haptics.workoutComplete()
    if (workout) {
      track('workout_completed', {
        workout_id: workout.id,
        workout_title: workout.title,
        calories: timer.calories,
        duration: workout.duration,
        rounds: workout.rounds,
      })
      addWorkoutResult({
        id: Date.now().toString(),
        workoutId: workout.id,
        completedAt: Date.now(),
        calories: timer.calories,
        durationMinutes: workout.duration,
        rounds: workout.rounds,
        completionRate: 1,
      })
    }
    router.replace(`/complete/${workout?.id ?? '1'}`)
  }, [router, workout, timer.calories, haptics, addWorkoutResult])

  const handleSkip = useCallback(() => {
    timer.skip()
    haptics.selection()
  }, [timer, haptics])

  const toggleControls = useCallback(() => {
    setShowControls((s) => !s)
  }, [])

  // ─── Animations & side-effects ───────────────────────────────────────────

  // Entrance animation
  useEffect(() => {
    Animated.spring(timerScaleAnim, {
      toValue: 1,
      friction: 6,
      tension: 100,
      useNativeDriver: true,
    }).start()
  }, [])

  // Phase change animation + audio
  useEffect(() => {
    timerScaleAnim.setValue(0.9)
    Animated.spring(timerScaleAnim, {
      toValue: 1,
      friction: 4,
      tension: 150,
      useNativeDriver: true,
    }).start()
    haptics.phaseChange()
    if (timer.phase === 'COMPLETE') {
      audio.workoutComplete()
    } else if (timer.isRunning) {
      audio.phaseStart()
    }
  }, [timer.phase])

  // Countdown beep + haptic for last 3 seconds
  useEffect(() => {
    if (timer.isRunning && timer.timeRemaining <= 3 && timer.timeRemaining > 0) {
      audio.countdownBeep()
      haptics.countdownTick()
    }
  }, [timer.timeRemaining])

  // Sync workout state with Apple Watch
  useEffect(() => {
    if (!isWatchAvailable || !timer.isRunning) return
    sendWorkoutState({
      phase: timer.phase,
      timeRemaining: timer.timeRemaining,
      currentRound: timer.currentRound,
      totalRounds: timer.totalRounds,
      currentExercise: timer.currentExercise,
      nextExercise: timer.nextExercise,
      calories: timer.calories,
      isPaused: timer.isPaused,
      isPlaying: timer.isRunning && !timer.isPaused,
    })
  }, [
    timer.phase, timer.timeRemaining, timer.currentRound,
    timer.totalRounds, timer.currentExercise, timer.nextExercise,
    timer.calories, timer.isPaused, timer.isRunning, isWatchAvailable,
  ])

  // ─── Render ──────────────────────────────────────────────────────────────

  return (
    <View style={styles.container}>
      <StatusBar hidden />

      {/* Background video or gradient fallback */}
      <VideoPlayer
        videoUrl={workout?.videoUrl}
        gradientColors={[colors.bg.base, colors.bg.surface]}
        mode="background"
        isPlaying={timer.isRunning && !timer.isPaused}
        style={StyleSheet.absoluteFill}
      />

      {/* Phase background tint */}
      <View style={[styles.phaseBg, { backgroundColor: phaseColor }]} />

      {/* Main content */}
      <Pressable style={styles.content} onPress={toggleControls}>
        {/* Header */}
        {showControls && (
          <View style={[styles.header, { paddingTop: insets.top + SPACING[4] }]}>
            <Pressable onPress={stopWorkout} style={styles.closeBtn}>
              <BlurView
                intensity={colors.glass.blurLight}
                tint={colors.glass.blurTint}
                style={StyleSheet.absoluteFill}
              />
              <Icon name="xmark" size={24} tintColor={colors.text.primary} />
            </Pressable>
            <View style={styles.headerCenter}>
              <Text style={styles.title}>{workout?.title ?? 'Workout'}</Text>
              <Text style={styles.subtitle}>
                {t('durationLevel', {
                  duration: workout?.duration ?? 0,
                  level: t(`levels.${(workout?.level ?? 'beginner').toLowerCase()}`),
                })}
              </Text>
            </View>
            <View style={styles.closeBtn} />
          </View>
        )}

        {/* Stats overlay — above timer ring */}
        {showControls && timer.isRunning && !timer.isComplete && (
          <View style={styles.statsContainer}>
            <StatsOverlay
              calories={timer.calories}
              heartRate={heartRate}
              elapsedRounds={timer.currentRound - 1}
              totalRounds={timer.totalRounds}
            />
          </View>
        )}

        {/* Timer ring + inner text */}
        <Animated.View
          style={[styles.timerContainer, { transform: [{ scale: timerScaleAnim }] }]}
        >
          <TimerRing progress={timer.progress} phase={timer.phase} />
          <View style={styles.timerInner}>
            <PhaseIndicator phase={timer.phase} />
            <Text selectable style={styles.timerTime}>
              {formatTime(timer.timeRemaining)}
            </Text>
            <RoundIndicator current={timer.currentRound} total={timer.totalRounds} />
          </View>
        </Animated.View>

        {/* Exercise name + coach encouragement */}
        {!timer.isComplete && (
          <>
            <ExerciseDisplay
              exercise={timer.currentExercise}
              nextExercise={timer.nextExercise}
            />
            <CoachEncouragement
              phase={timer.phase}
              currentRound={timer.currentRound}
              totalRounds={timer.totalRounds}
            />
          </>
        )}

        {/* Complete state */}
        {timer.isComplete && (
          <View style={styles.completeSection}>
            <Text style={styles.completeTitle}>{t('screens:player.workoutComplete')}</Text>
            <Text style={[styles.completeSubtitle, { color: trainerColor }]}>{t('screens:player.greatJob')}</Text>
            <View style={styles.completeStats}>
              <View style={styles.completeStat}>
                <Text selectable style={styles.completeStatValue}>{timer.totalRounds}</Text>
                <Text style={styles.completeStatLabel}>{t('screens:player.rounds')}</Text>
              </View>
              <View style={styles.completeStat}>
                <Text selectable style={styles.completeStatValue}>{timer.calories}</Text>
                <Text style={styles.completeStatLabel}>{t('screens:player.calories')}</Text>
              </View>
              <View style={styles.completeStat}>
                <Text selectable style={styles.completeStatValue}>{workout?.duration ?? 4}</Text>
                <Text style={styles.completeStatLabel}>{t('screens:player.minutes')}</Text>
              </View>
            </View>
          </View>
        )}

        {/* Player controls */}
        {showControls && !timer.isComplete && (
          <View style={[styles.controls, { paddingBottom: insets.bottom + SPACING[6] }]}>
            <PlayerControls
              isRunning={timer.isRunning}
              isPaused={timer.isPaused}
              onStart={startTimer}
              onPause={() => { timer.pause(); haptics.selection(); track('workout_paused', { workout_id: workout?.id ?? id ?? '' }) }}
              onResume={() => { timer.resume(); haptics.selection(); track('workout_resumed', { workout_id: workout?.id ?? id ?? '' }) }}
              onStop={stopWorkout}
              onSkip={handleSkip}
            />
          </View>
        )}

        {/* Complete CTA */}
        {timer.isComplete && (
          <View style={[styles.controls, { paddingBottom: insets.bottom + SPACING[6] }]}>
            <Pressable style={styles.doneButton} onPress={completeWorkout}>
              <LinearGradient
                colors={GRADIENTS.CTA}
                start={{ x: 0, y: 0 }}
                end={{ x: 1, y: 1 }}
                style={StyleSheet.absoluteFill}
              />
              <Text style={styles.doneButtonText}>{t('common:done')}</Text>
            </Pressable>
          </View>
        )}

        {/* Burn bar */}
        {showControls && timer.isRunning && !timer.isComplete && (
          <View style={[styles.burnBarContainer, { bottom: insets.bottom + 140 }]}>
            <BlurView
              intensity={colors.glass.blurMedium}
              tint={colors.glass.blurTint}
              style={StyleSheet.absoluteFill}
            />
            <BurnBar currentCalories={timer.calories} avgCalories={workout?.calories ?? 45} />
          </View>
        )}

        {/* Now Playing music pill */}
        {showControls && timer.isRunning && !timer.isComplete && (
          <View style={[styles.nowPlayingContainer, { bottom: insets.bottom + 220 }]}>
            <NowPlaying
              track={music.currentTrack}
              isReady={music.isReady}
              onSkipTrack={music.nextTrack}
            />
          </View>
        )}
      </Pressable>
    </View>
  )
}

// ─── Styles ──────────────────────────────────────────────────────────────────

const colors = darkColors

const styles = StyleSheet.create({
  container: {
    flex: 1,
    backgroundColor: colors.bg.base,
  },
  phaseBg: {
    ...StyleSheet.absoluteFillObject,
    opacity: 0.15,
  },
  content: {
    flex: 1,
  },

  // Header
  header: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: SPACING[4],
  },
  closeBtn: {
    width: 44,
    height: 44,
    borderRadius: 22,
    alignItems: 'center',
    justifyContent: 'center',
    overflow: 'hidden',
    borderWidth: 1,
    borderColor: colors.border.glass,
  },
  headerCenter: {
    alignItems: 'center',
  },
  title: {
    ...TYPOGRAPHY.HEADLINE,
    color: colors.text.primary,
  },
  subtitle: {
    ...TYPOGRAPHY.CAPTION_1,
    color: colors.text.tertiary,
  },

  // Stats overlay
  statsContainer: {
    marginTop: SPACING[4],
    marginHorizontal: SPACING[4],
  },

  // Timer
  timerContainer: {
    alignItems: 'center',
    justifyContent: 'center',
    marginTop: SPACING[6],
  },
  timerInner: {
    position: 'absolute',
    alignItems: 'center',
  },
  timerTime: {
    ...TYPOGRAPHY.TIMER_NUMBER,
    color: colors.text.primary,
    fontVariant: ['tabular-nums'],
  },

  // Controls
  controls: {
    position: 'absolute',
    bottom: 0,
    left: 0,
    right: 0,
    alignItems: 'center',
  },

  // Burn Bar
  burnBarContainer: {
    position: 'absolute',
    left: SPACING[4],
    right: SPACING[4],
    height: 72,
    borderRadius: RADIUS.LG,
    borderCurve: 'continuous',
    overflow: 'hidden',
    borderWidth: 1,
    borderColor: colors.border.glass,
    padding: SPACING[3],
  },

  // Now Playing
  nowPlayingContainer: {
    position: 'absolute',
    left: SPACING[6],
    right: SPACING[6],
  },

  // Complete
  completeSection: {
    alignItems: 'center',
    marginTop: SPACING[8],
  },
  completeTitle: {
    ...TYPOGRAPHY.LARGE_TITLE,
    color: colors.text.primary,
  },
  completeSubtitle: {
    ...TYPOGRAPHY.TITLE_3,
    marginTop: SPACING[1],
  },
  completeStats: {
    flexDirection: 'row',
    marginTop: SPACING[6],
    gap: SPACING[8],
  },
  completeStat: {
    alignItems: 'center',
  },
  completeStatValue: {
    ...TYPOGRAPHY.TITLE_1,
    color: colors.text.primary,
    fontVariant: ['tabular-nums'],
  },
  completeStatLabel: {
    ...TYPOGRAPHY.CAPTION_1,
    color: colors.text.tertiary,
    marginTop: SPACING[1],
  },
  doneButton: {
    width: 200,
    height: 56,
    borderRadius: RADIUS.GLASS_BUTTON,
    borderCurve: 'continuous',
    alignItems: 'center',
    justifyContent: 'center',
    overflow: 'hidden',
    ...colors.shadow.BRAND_GLOW,
  },
  doneButtonText: {
    ...TYPOGRAPHY.BUTTON_MEDIUM,
    color: colors.text.primary,
    letterSpacing: 1,
  },
})
