/**
 * Settings FormSheet
 * Profile, preferences, premium, legal, reset progress.
 */

import { View, Text, StyleSheet, ScrollView, Pressable, Switch, Alert } from 'react-native'
import { useRouter } from 'expo-router'
import { useSafeAreaInsets } from 'react-native-safe-area-context'
import { useTranslation } from 'react-i18next'

import { Icon, type IconName } from '@/src/shared/components/Icon'
import { useUserStore } from '@/src/shared/stores/userStore'
import { useProgressStore } from '@/src/shared/stores/progressStore'
import { TYPOGRAPHY } from '@/src/shared/constants/typography'
import { SPACING } from '@/src/shared/constants/spacing'
import { RADIUS } from '@/src/shared/constants/borderRadius'
import { TEXT, NAVY, GREEN, BORDER_COLORS } from '@/src/shared/constants/colors'

export default function SettingsScreen() {
  const router = useRouter()
  const insets = useSafeAreaInsets()
  const { t } = useTranslation()

  const profile = useUserStore(s => s.profile)
  const settings = useUserStore(s => s.settings)
  const updateSettings = useUserStore(s => s.updateSettings)
  const resetProgress = useProgressStore(s => s.resetProgress)

  const isPremium = profile.subscription !== 'free'

  const handleResetProgress = () => {
    Alert.alert(
      t('screens:settings.resetTitle'),
      t('screens:settings.resetMessage'),
      [
        { text: t('common:cancel'), style: 'cancel' },
        {
          text: t('screens:settings.resetConfirm'),
          style: 'destructive',
          onPress: () => {
            resetProgress()
          },
        },
      ],
    )
  }

  return (
    <ScrollView
      style={styles.container}
      contentContainerStyle={{ padding: SPACING[5], paddingBottom: insets.bottom + SPACING[8] }}
    >
      <Text style={styles.header}>{t('screens:settings.title')}</Text>

      {/* Profile */}
      <Section title={t('screens:settings.sectionProfile')}>
        <Row label={t('screens:settings.name')} value={profile.name || '—'} />
        <Row
          label={t('screens:settings.subscription')}
          value={isPremium ? t('screens:settings.premium') : t('screens:settings.free')}
          accent={isPremium ? GREEN[500] : undefined}
        />
        {!isPremium && (
          <LinkRow
            icon="sparkles"
            label={t('screens:settings.upgradePremium')}
            onPress={() => router.push('/paywall')}
            accent={GREEN[500]}
          />
        )}
      </Section>

      {/* Preferences */}
      <Section title={t('screens:settings.sectionPrefs')}>
        <SwitchRow
          label={t('screens:settings.haptics')}
          value={settings.haptics}
          onChange={v => updateSettings({ haptics: v })}
        />
        <SwitchRow
          label={t('screens:settings.soundEffects')}
          value={settings.soundEffects}
          onChange={v => updateSettings({ soundEffects: v })}
        />
        <SwitchRow
          label={t('screens:settings.voiceCoaching')}
          value={settings.voiceCoaching}
          onChange={v => updateSettings({ voiceCoaching: v })}
        />
        <SwitchRow
          label={t('screens:settings.music')}
          value={settings.musicEnabled}
          onChange={v => updateSettings({ musicEnabled: v })}
        />
      </Section>

      {/* Legal */}
      <Section title={t('screens:settings.sectionLegal')}>
        <LinkRow icon="doc.text" label={t('screens:settings.terms')} onPress={() => router.push('/terms')} />
        <LinkRow icon="lock.shield" label={t('screens:settings.privacy')} onPress={() => router.push('/privacy')} />
      </Section>

      {/* Danger */}
      <Section title={t('screens:settings.sectionData')}>
        <Pressable onPress={handleResetProgress} style={styles.dangerRow}>
          <Icon name="trash" size={18} tintColor="#FF453A" />
          <Text style={styles.dangerText}>{t('screens:settings.resetProgress')}</Text>
        </Pressable>
      </Section>

      <Text style={styles.version}>{t('screens:settings.version')}</Text>
    </ScrollView>
  )
}

function Section({ title, children }: { title: string; children: React.ReactNode }) {
  return (
    <View style={styles.section}>
      <Text style={styles.sectionTitle}>{title}</Text>
      <View style={styles.sectionBody}>{children}</View>
    </View>
  )
}

function Row({ label, value, accent }: { label: string; value: string; accent?: string }) {
  return (
    <View style={styles.row}>
      <Text style={styles.rowLabel}>{label}</Text>
      <Text style={[styles.rowValue, accent && { color: accent }]}>{value}</Text>
    </View>
  )
}

function SwitchRow({
  label,
  value,
  onChange,
}: {
  label: string
  value: boolean
  onChange: (value: boolean) => void
}) {
  return (
    <View style={styles.row}>
      <Text style={styles.rowLabel}>{label}</Text>
      <Switch value={value} onValueChange={onChange} trackColor={{ true: GREEN[500] }} />
    </View>
  )
}

function LinkRow({
  icon,
  label,
  onPress,
  accent,
}: {
  icon: IconName
  label: string
  onPress: () => void
  accent?: string
}) {
  return (
    <Pressable onPress={onPress} style={styles.row}>
      <View style={styles.linkLeft}>
        <Icon name={icon} size={18} tintColor={accent ?? TEXT.SECONDARY} />
        <Text style={[styles.rowLabel, accent && { color: accent, fontWeight: '600' }]}>{label}</Text>
      </View>
      <Icon name="chevron.right" size={16} tintColor={TEXT.TERTIARY} />
    </Pressable>
  )
}

const styles = StyleSheet.create({
  container: { flex: 1, backgroundColor: NAVY[900] },
  header: { ...TYPOGRAPHY.LARGE_TITLE, color: TEXT.PRIMARY, marginBottom: SPACING[4] },

  section: { marginBottom: SPACING[6] },
  sectionTitle: {
    ...TYPOGRAPHY.CAPTION_1,
    color: TEXT.TERTIARY,
    textTransform: 'uppercase',
    letterSpacing: 0.5,
    marginBottom: SPACING[2],
    paddingHorizontal: SPACING[2],
  },
  sectionBody: {
    backgroundColor: NAVY[800],
    borderRadius: RADIUS.MD,
    borderWidth: 1,
    borderColor: BORDER_COLORS.DIM,
    overflow: 'hidden',
  },

  row: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: SPACING[4],
    paddingVertical: SPACING[3],
    borderBottomWidth: StyleSheet.hairlineWidth,
    borderBottomColor: BORDER_COLORS.DIM,
    gap: SPACING[3],
  },
  rowLabel: { ...TYPOGRAPHY.BODY, color: TEXT.PRIMARY },
  rowValue: { ...TYPOGRAPHY.BODY, color: TEXT.SECONDARY },
  linkLeft: { flexDirection: 'row', alignItems: 'center', gap: SPACING[3] },

  dangerRow: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: SPACING[3],
    paddingHorizontal: SPACING[4],
    paddingVertical: SPACING[3],
  },
  dangerText: { ...TYPOGRAPHY.BODY, color: '#FF453A' },

  version: {
    ...TYPOGRAPHY.CAPTION_1,
    color: TEXT.TERTIARY,
    textAlign: 'center',
    marginTop: SPACING[4],
  },
})