import { useState } from 'react';
import { View, Text, Switch, ActivityIndicator } from 'react-native';
import { Ionicons } from '@expo/vector-icons';

type Props = {
  icon: React.ComponentProps<typeof Ionicons>['name'];
  title: string;
  subtitle: string;
  /** Wenn true: zeigt grünen Check statt Switch (Layer ist an). */
  active: boolean;
  /** Aktivierung (zeigt System-Dialog). UI hat nur read-on-flow,
   *  Toggle-off ist nicht hier — passiert nur über Cooldown. */
  onActivate: () => Promise<{ enabled: boolean; error?: string }>;
  /** Optional: Hinweistext unter Subtitle. Wird OBEN angezeigt wenn inactive
   *  (warnung vor Aktivierung) UND UNTEN wenn active+lockedHint (Hinweis
   *  wo man's wieder deaktiviert — bei Family-Controls/Screen-Time z.B.). */
  warning?: string;
  /** Optional: Hinweis-Text wenn active=true (z.B. "Nur in iOS-Settings
   *  deaktivierbar"). Macht die System-managed-Natur klar. */
  lockedHint?: string;
};

export function LayerSwitchCard({ icon, title, subtitle, active, onActivate, warning, lockedHint }: Props) {
  const [busy, setBusy] = useState(false);

  async function handleSwitch(v: boolean) {
    if (!v || active || busy) return;
    setBusy(true);
    try {
      await onActivate();
    } finally {
      setBusy(false);
    }
  }

  const iconBg = active ? '#dcfce7' : '#f5f5f5';
  const iconColor = active ? '#16a34a' : '#737373';
  const borderColor = active ? '#86efac' : '#e5e5e5';
  const cardBg = active ? '#f0fdf4' : '#ffffff';

  return (
    <View
      style={{
        backgroundColor: cardBg,
        borderWidth: 1,
        borderColor,
        borderRadius: 16,
        padding: 14,
      }}
    >
      <View style={{ flexDirection: 'row', alignItems: 'center', gap: 12 }}>
        <View
          style={{
            width: 40,
            height: 40,
            borderRadius: 12,
            backgroundColor: iconBg,
            alignItems: 'center',
            justifyContent: 'center',
          }}
        >
          <Ionicons name={icon} size={20} color={iconColor} />
        </View>
        <View style={{ flex: 1 }}>
          <Text style={{ fontSize: 14, fontFamily: 'Nunito_700Bold', color: '#0a0a0a' }}>
            {title}
          </Text>
          <Text
            style={{
              fontSize: 12,
              fontFamily: 'Nunito_400Regular',
              color: '#525252',
              marginTop: 2,
            }}
          >
            {subtitle}
          </Text>
        </View>

        {busy ? (
          <ActivityIndicator color={iconColor} />
        ) : active ? (
          <Ionicons name="checkmark-circle" size={28} color="#16a34a" />
        ) : (
          <Switch value={false} onValueChange={handleSwitch} trackColor={{ true: '#16a34a' }} />
        )}
      </View>

      {warning && !active && (
        <View
          style={{
            marginTop: 10,
            paddingTop: 10,
            borderTopWidth: 1,
            borderTopColor: 'rgba(0,0,0,0.06)',
            flexDirection: 'row',
            gap: 8,
          }}
        >
          <Ionicons name="information-circle" size={16} color="#525252" />
          <Text
            style={{
              flex: 1,
              fontSize: 11,
              fontFamily: 'Nunito_400Regular',
              color: '#525252',
              lineHeight: 16,
            }}
          >
            {warning}
          </Text>
        </View>
      )}

      {lockedHint && active && (
        <View
          style={{
            marginTop: 10,
            paddingTop: 10,
            borderTopWidth: 1,
            borderTopColor: 'rgba(0,0,0,0.06)',
            flexDirection: 'row',
            gap: 8,
            alignItems: 'flex-start',
          }}
        >
          <Ionicons name="lock-closed" size={14} color="#16a34a" style={{ marginTop: 1 }} />
          <Text
            style={{
              flex: 1,
              fontSize: 11,
              fontFamily: 'Nunito_600SemiBold',
              color: '#16a34a',
              lineHeight: 16,
            }}
          >
            {lockedHint}
          </Text>
        </View>
      )}
    </View>
  );
}