import { Pressable, ScrollView, StyleSheet, Text, View } from 'react-native';
import { useCallback, useEffect, useState } from 'react';
import { useSafeAreaInsets } from 'react-native-safe-area-context';
import AsyncStorage from '@react-native-async-storage/async-storage';

import { getPrayerTimes, cities } from '../../utils/prayerTimeCalculator';
import i18n from '../../i18n';
import Colors from '../../constants/Colors';

type Prayer = {
  name: string;
  time: string;
};

type City = keyof typeof cities;

export default function TabIndex() {
  const colorScheme = 'dark';
  const theme = Colors[colorScheme ?? 'light'];
  const [selectedCity, setSelectedCity] = useState<City>('Makkah');
  const [prayerTimes, setPrayerTimes] = useState<Prayer[]>([]);
  const [nextPrayerName, setNextPrayerName] = useState<string | null>(null);
  const insets = useSafeAreaInsets();

  useEffect(() => {
    const loadSelectedCity = async () => {
      try {
        const city = (await AsyncStorage.getItem('selectedCity')) as City;
        if (city) {
          setSelectedCity(city);
        }
      } catch (error) {
        console.error('Failed to load selected city:', error);
      }
    };

    loadSelectedCity();
  }, []);

  const prayerNameMapping: { [key: string]: string } = {
    fajr: i18n.t('fajr'),
    dhuhr: i18n.t('dhuhr'),
    asr: i18n.t('asr'),
    maghrib: i18n.t('maghrib'),
    isha: i18n.t('isha'),
  };

  const updatePrayerTimes = useCallback(() => {
    const times = getPrayerTimes(selectedCity);
    const prayers: Prayer[] = Object.keys(prayerNameMapping).map((key) => ({
      name: prayerNameMapping[key],
      time: times[key] || '-----',
    }));
    setPrayerTimes(prayers);

    const now = new Date();
    let nextPrayer: Prayer | null = null;

    for (const prayer of prayers) {
      if (prayer.time === '-----') continue;
      const [hours, minutes] = prayer.time.split(':').map(Number);
      const prayerDate = new Date(now.getFullYear(), now.getMonth(), now.getDate(), hours, minutes);
      if (prayerDate > now) {
        nextPrayer = prayer;
        break;
      }
    }

    if (!nextPrayer && prayers.length > 0) {
      const firstPrayer = prayers.find((p) => p.time !== '-----');
      if (firstPrayer) {
        nextPrayer = firstPrayer;
      }
    }

    setNextPrayerName(nextPrayer ? nextPrayer.name : null);
  }, [selectedCity]);

  useEffect(() => {
    updatePrayerTimes();
    const interval = setInterval(updatePrayerTimes, 60000); // Update every minute
    return () => clearInterval(interval);
  }, [updatePrayerTimes]);

  const handleCityChange = async (city: City) => {
    setSelectedCity(city);
    try {
      await AsyncStorage.setItem('selectedCity', city);
    } catch (error) {
      console.error('Failed to save selected city:', error);
    }
  };

  const renderPrayerTime = (prayer: Prayer) => {
    const isNextPrayer = prayer.name === nextPrayerName;
    return (
      <View
        key={prayer.name}
        style={[styles.prayerRow, { backgroundColor: theme.secondary }, isNextPrayer && [styles.nextPrayerRow, { backgroundColor: theme.tint }]]}>
        <View>
          <Text style={[styles.prayerName, { color: theme.text }, isNextPrayer && styles.nextPrayerText]}>
            {prayer.name}
          </Text>
        </View>
        <Text style={[styles.prayerTime, { color: theme.text }, isNextPrayer && styles.nextPrayerTimeText]}>
          {new Date(`1970-01-01T${prayer.time}:00`).toLocaleTimeString('en-US', {
            hour: 'numeric',
            minute: 'numeric',
            hour12: false,
          })}
        </Text>
      </View>
    );
  };

  return (
    <View style={[styles.container, { backgroundColor: theme.background, paddingTop: insets.top }]}>
      <View style={[styles.citySelector, { backgroundColor: theme.background }]}>
        {(Object.keys(cities) as City[]).map((city) => (
          <Pressable
            key={city}
            onPress={() => handleCityChange(city)}
            style={[styles.cityButton, { backgroundColor: theme.secondary }, selectedCity === city && [styles.activeCityButton, { backgroundColor: theme.tint }]]}>
            <Text
              style={[
                styles.cityButtonText,
                { color: theme.text },
                selectedCity === city && styles.activeCityButtonText,
              ]}>
              {i18n.t(city)}
            </Text>
          </Pressable>
        ))}
      </View>
      <ScrollView contentContainerStyle={styles.listContainer}>
        {prayerTimes.map(renderPrayerTime)}
      </ScrollView>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  citySelector: {
    flexDirection: 'row',
    justifyContent: 'center',
    paddingVertical: 20,
    paddingHorizontal: 10,
  },
  cityButton: {
    paddingVertical: 10,
    paddingHorizontal: 25,
    borderRadius: 20,
    marginHorizontal: 5,
  },
  activeCityButton: {},
  cityButtonText: {
    fontSize: 18,
    fontWeight: '500',
  },
  activeCityButtonText: {
    color: '#fff',
  },
  listContainer: {
    paddingHorizontal: 20,
  },
  prayerRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    paddingVertical: 25,
    paddingHorizontal: 20,
    borderRadius: 15,
    marginBottom: 10,
    shadowColor: '#000',
    shadowOffset: {
      width: 0,
      height: 1,
    },
    shadowOpacity: 0.1,
    shadowRadius: 3,
    elevation: 2,
  },
  nextPrayerRow: {},
  prayerName: {
    fontSize: 28,
    fontWeight: '600',
  },
  inCityText: {
    fontSize: 18,
  },
  prayerTime: {
    fontSize: 28,
    fontWeight: 'bold',
  },
  nextPrayerText: {
    color: '#fff',
  },
  nextPrayerTimeText: {
    color: '#fff',
    fontSize: 32,
  },
});