import { useState } from 'react';
import { Pressable, Switch, Text, View } from 'react-native';
import { SafeAreaView } from 'react-native-safe-area-context';
import Constants from 'expo-constants';
import { apiClient } from '@/api/client';
import { useAuthStore } from '@/stores/auth-store';
import { logError, toUserMessage } from '@/lib/errors';
import { toast } from 'sonner-native';
import type { RootStackScreenProps } from '@/navigation/types';

export function SettingsScreen({
  navigation,
}: RootStackScreenProps<'Settings'>) {
  const user = useAuthStore((s) => s.user);
  const signOut = useAuthStore((s) => s.signOut);
  const isSigningOut = useAuthStore((s) => s.isSigningOut);
  const [emailNotifications, setEmailNotifications] = useState(
    user?.email_notifications_enabled ?? true,
  );
  const version = Constants.expoConfig?.version ?? '—';

  // Optimistic toggle — flip the local + auth-store state immediately, roll
  // back on failure. Mirrors desktop's settings-page handler.
  const handleToggleEmailNotifications = async (checked: boolean) => {
    setEmailNotifications(checked);
    useAuthStore.setState((state) => ({
      user: state.user
        ? { ...state.user, email_notifications_enabled: checked }
        : null,
    }));
    try {
      await apiClient.updateSettings({ email_notifications_enabled: checked });
    } catch (err) {
      setEmailNotifications(!checked);
      useAuthStore.setState((state) => ({
        user: state.user
          ? { ...state.user, email_notifications_enabled: !checked }
          : null,
      }));
      toast.error(toUserMessage(err));
      logError(err, { scope: 'settings.emailNotifications' });
    }
  };

  return (
    <SafeAreaView className="flex-1 bg-background" edges={['top']}>
      <View className="flex-row items-center px-3 py-3 border-b border-border">
        <Pressable onPress={() => navigation.goBack()} className="px-2 py-1">
          <Text className="text-foreground text-2xl">‹</Text>
        </Pressable>
        <Text className="flex-1 text-center text-foreground text-base font-semibold">
          Settings
        </Text>
        <View className="w-8" />
      </View>

      <View className="px-4 py-4">
        <SettingsGroup title="Notifications">
          <View className="flex-row items-center justify-between px-4 py-3">
            <Text className="text-foreground text-base">
              Email notifications
            </Text>
            <Switch
              value={emailNotifications}
              onValueChange={handleToggleEmailNotifications}
            />
          </View>
        </SettingsGroup>

        <SettingsGroup title="About">
          <View className="flex-row items-center justify-between px-4 py-3">
            <Text className="text-foreground text-base">Version</Text>
            <Text className="text-muted-foreground text-base">{version}</Text>
          </View>
        </SettingsGroup>

        <View className="mt-4">
          <Pressable
            onPress={() => void signOut()}
            disabled={isSigningOut}
            className="px-4 py-3 active:bg-accent rounded-xl"
          >
            <Text className="text-destructive text-base font-medium">
              {isSigningOut ? 'Signing out…' : 'Sign out'}
            </Text>
          </Pressable>
        </View>
      </View>
    </SafeAreaView>
  );
}

function SettingsGroup({
  title,
  children,
}: {
  title: string;
  children: React.ReactNode;
}) {
  return (
    <View className="mb-2">
      <Text className="text-muted-foreground text-xs uppercase tracking-wide px-4 pt-4 pb-1">
        {title}
      </Text>
      <View className="bg-muted/40 rounded-xl overflow-hidden">{children}</View>
    </View>
  );
}