/**
 * TabataGo Activity Tab
 * Streak, weekly sessions, program history — driven by progressStore.
 */

import { useMemo } from 'react'
import { View, Text, StyleSheet, ScrollView } from 'react-native'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import { useTranslation } from 'react-i18next'
import { Icon } from '@/src/shared/components/Icon'
import { useProgressStore } from '@/src/shared/stores/progressStore'
import { useThemeColors } from '@/src/shared/theme'
import type { ThemeColors } from '@/src/shared/theme/types'
import { TYPOGRAPHY } from '@/src/shared/constants/typography'
import { SPACING, LAYOUT } from '@/src/shared/constants/spacing'
import { RADIUS } from '@/src/shared/constants/borderRadius'
import { GREEN, NAVY, TEXT, BORDER_COLORS } from '@/src/shared/constants/colors'

export default function ActivityScreen() {
  const { t } = useTranslation()
  const insets = useSafeAreaInsets()
  const colors = useThemeColors()
  const styles = useMemo(() => createStyles(colors), [colors])

  const history = useProgressStore(s => s.history)
  const streak = useProgressStore(s => s.streak)
  const weeklyCount = useProgressStore(s => s.getWeeklyCount())
  const completedCount = useProgressStore(s => s.getCompletedCount())

  const totalMinutes = useMemo(
    () => history.reduce((sum, s) => sum + Math.round(s.durationSeconds / 60), 0),
    [history],
  )

  return (
    <ScrollView
      style={styles.container}
      contentContainerStyle={[styles.content, { paddingTop: insets.top + SPACING[4], paddingBottom: insets.bottom + SPACING[6] }]}
      contentInsetAdjustmentBehavior="automatic"
    >
      <Text style={styles.title}>{t('screens:tabs.progression')}</Text>

      {/* Streak hero */}
      <View style={styles.streakHero}>
        <Icon name="flame.fill" size={32} tintColor={GREEN[500]} />
        <Text selectable style={styles.streakCount}>{streak.current}</Text>
        <Text style={styles.streakLabel}>{t('screens:activity.dayStreak')}</Text>
        <Text style={styles.streakRecord}>
          {t('screens:activity.longest')}: {streak.longest}
        </Text>
      </View>

      {/* Stats grid */}
      <View style={styles.grid}>
        <StatCard
          icon="checkmark.circle.fill"
          value={completedCount}
          label={t('screens:programs.completed')}
          color={GREEN[500]}
        />
        <StatCard
          icon="calendar"
          value={weeklyCount}
          label={t('screens:activity.thisWeek')}
          color="#5AC8FA"
        />
        <StatCard
          icon="clock.fill"
          value={totalMinutes}
          label={t('screens:player.minutes')}
          color="#FF6B35"
        />
      </View>

      {/* Recent history */}
      {history.length > 0 && (
        <View style={styles.historySection}>
          <Text style={styles.sectionTitle}>{t('screens:activity.recent')}</Text>
          {history.slice(0, 10).map((session, i) => (
            <View key={i} style={styles.historyRow}>
              <Icon name="checkmark.circle.fill" size={18} tintColor={GREEN[500]} />
              <View style={{ flex: 1 }}>
                <Text style={styles.historyTitle} numberOfLines={1}>{session.programId}</Text>
                <Text style={styles.historyMeta}>
                  {Math.round(session.durationSeconds / 60)} min
                  {' · '}
                  {new Date(session.completedAt).toLocaleDateString()}
                </Text>
              </View>
            </View>
          ))}
        </View>
      )}

      {history.length === 0 && (
        <View style={styles.emptyState}>
          <Text style={styles.emptyTitle}>{t('screens:activity.emptyTitle')}</Text>
          <Text style={styles.emptySubtitle}>{t('screens:activity.emptySubtitle')}</Text>
        </View>
      )}
    </ScrollView>
  )
}

function StatCard({ icon, value, label, color }: { icon: any; value: number; label: string; color: string }) {
  return (
    <View style={cardStyles.card}>
      <Icon name={icon} size={22} tintColor={color} />
      <Text selectable style={cardStyles.value}>{value}</Text>
      <Text style={cardStyles.label}>{label}</Text>
    </View>
  )
}

const cardStyles = StyleSheet.create({
  card: {
    flex: 1,
    alignItems: 'center',
    padding: SPACING[3],
    borderRadius: RADIUS.LG,
    backgroundColor: NAVY[800],
    borderWidth: 1,
    borderColor: BORDER_COLORS.DIM,
    gap: SPACING[1],
    borderCurve: 'continuous',
  },
  value: { ...TYPOGRAPHY.TITLE_2, color: TEXT.PRIMARY, fontVariant: ['tabular-nums'] },
  label: { ...TYPOGRAPHY.CAPTION_2, color: TEXT.TERTIARY, textAlign: 'center' },
})

function createStyles(colors: ThemeColors) {
  return StyleSheet.create({
    container: { flex: 1, backgroundColor: colors.bg.base },
    content: { paddingHorizontal: LAYOUT.SCREEN_PADDING },

    title: { ...TYPOGRAPHY.LARGE_TITLE, color: TEXT.PRIMARY, marginBottom: SPACING[5] },

    streakHero: {
      alignItems: 'center',
      paddingVertical: SPACING[6],
      marginBottom: SPACING[4],
      backgroundColor: NAVY[800],
      borderRadius: RADIUS.XL,
      borderWidth: 1,
      borderColor: BORDER_COLORS.DIM,
      gap: SPACING[1],
    },
    streakCount: { ...TYPOGRAPHY.LARGE_TITLE, color: TEXT.PRIMARY, fontSize: 56, fontVariant: ['tabular-nums'] },
    streakLabel: { ...TYPOGRAPHY.HEADLINE, color: TEXT.SECONDARY },
    streakRecord: { ...TYPOGRAPHY.CAPTION_1, color: TEXT.TERTIARY, marginTop: SPACING[1] },

    grid: { flexDirection: 'row', gap: SPACING[3], marginBottom: SPACING[6] },

    historySection: { gap: SPACING[2] },
    sectionTitle: {
      ...TYPOGRAPHY.CAPTION_1,
      color: TEXT.TERTIARY,
      textTransform: 'uppercase',
      letterSpacing: 0.5,
      marginBottom: SPACING[1],
    },
    historyRow: {
      flexDirection: 'row',
      alignItems: 'center',
      gap: SPACING[3],
      padding: SPACING[3],
      backgroundColor: colors.surface.default.backgroundColor,
      borderRadius: RADIUS.MD,
      borderWidth: 1,
      borderColor: colors.surface.default.borderColor,
    },
    historyTitle: { ...TYPOGRAPHY.SUBHEADLINE, color: TEXT.PRIMARY },
    historyMeta: { ...TYPOGRAPHY.CAPTION_1, color: TEXT.TERTIARY, marginTop: 2 },

    emptyState: { alignItems: 'center', marginTop: SPACING[12], gap: SPACING[2] },
    emptyTitle: { ...TYPOGRAPHY.HEADLINE, color: TEXT.PRIMARY },
    emptySubtitle: { ...TYPOGRAPHY.BODY, color: TEXT.TERTIARY, textAlign: 'center' },
  })
}