import React, { useState, useEffect } from 'react';
import { View, Text, FlatList, StyleSheet, TouchableOpacity, Image, ActivityIndicator } from 'react-native';
import { useQuery } from '@tanstack/react-query';
import { Audio } from 'expo-av';
import { Theme } from '../../constants/Theme';
import { Ionicons } from '@expo/vector-icons';
import { SafeAreaView } from 'react-native-safe-area-context';

const API_URL = process.env.EXPO_PUBLIC_API_URL || 'http://216.158.230.94:8001/api/v1';

interface PodcastEpisode {
    id: string;
    title: string;
    description: string;
    audio_url: string;
    published_at: string;
    duration: string;
    image_url: string;
}

interface PodcastFeed {
    title: string;
    description: string;
    image_url: string;
    episodes: PodcastEpisode[];
}

const fetchPodcasts = async (): Promise<PodcastFeed> => {
    const response = await fetch(`${API_URL}/podcast/`);
    if (!response.ok) {
        throw new Error('Network response was not ok');
    }
    return response.json();
};

export default function PodcastsScreen() {
    const { data, isLoading, error } = useQuery({
        queryKey: ['podcasts'],
        queryFn: fetchPodcasts,
    });

    const [sound, setSound] = useState<Audio.Sound | null>(null);
    const [isPlaying, setIsPlaying] = useState(false);
    const [currentEpisodeId, setCurrentEpisodeId] = useState<string | null>(null);

    useEffect(() => {
        return () => {
            if (sound) {
                sound.unloadAsync();
            }
        };
    }, [sound]);

    const playPodcast = async (audioUrl: string, episodeId: string) => {
        try {
            if (sound) {
                await sound.unloadAsync();
            }

            const { sound: newSound } = await Audio.Sound.createAsync(
                { uri: audioUrl },
                { shouldPlay: true }
            );

            setSound(newSound);
            setCurrentEpisodeId(episodeId);
            setIsPlaying(true);

            newSound.setOnPlaybackStatusUpdate((status) => {
                if (status.isLoaded) {
                    setIsPlaying(status.isPlaying);
                    if (status.didJustFinish) {
                        setIsPlaying(false);
                        setCurrentEpisodeId(null);
                    }
                }
            });
        } catch (error) {
            console.error('Error playing sound:', error);
        }
    };

    const pausePodcast = async () => {
        if (sound) {
            await sound.pauseAsync();
            setIsPlaying(false);
        }
    };

    const resumePodcast = async () => {
        if (sound) {
            await sound.playAsync();
            setIsPlaying(true);
        }
    };

    const handlePlayPause = (audioUrl: string, episodeId: string) => {
        if (currentEpisodeId === episodeId) {
            if (isPlaying) {
                pausePodcast();
            } else {
                resumePodcast();
            }
        } else {
            playPodcast(audioUrl, episodeId);
        }
    };

    const renderItem = ({ item }: { item: PodcastEpisode }) => (
        <View style={styles.card}>
            <View style={styles.cardContent}>
                <Image source={{ uri: item.image_url || data?.image_url }} style={styles.thumbnail} />
                <View style={styles.textContainer}>
                    <Text style={styles.episodeTitle} numberOfLines={2}>{item.title}</Text>
                    <Text style={styles.episodeDate}>{new Date(item.published_at).toLocaleDateString()}</Text>
                    <Text style={styles.episodeDuration}>{item.duration}</Text>
                </View>
                <TouchableOpacity
                    style={styles.playButton}
                    onPress={() => handlePlayPause(item.audio_url, item.id)}
                >
                    <Ionicons
                        name={currentEpisodeId === item.id && isPlaying ? "pause-circle" : "play-circle"}
                        size={48}
                        color={Theme.colors.primary}
                    />
                </TouchableOpacity>
            </View>
        </View>
    );

    if (isLoading) {
        return (
            <View style={styles.center}>
                <ActivityIndicator size="large" color={Theme.colors.primary} />
            </View>
        );
    }

    if (error) {
        return (
            <View style={styles.center}>
                <Text style={styles.errorText}>Failed to load podcasts</Text>
            </View>
        );
    }

    return (
        <SafeAreaView style={styles.container} edges={['top']}>
            <FlatList
                data={data?.episodes}
                renderItem={renderItem}
                keyExtractor={(item) => item.id}
                contentContainerStyle={styles.listContent}
                ListHeaderComponent={
                    <View style={styles.header}>
                        <Text style={styles.headerTitle}>Podcasts</Text>
                        <Text style={styles.headerSubtitle}>Listen to the latest episodes</Text>
                    </View>
                }
            />
        </SafeAreaView>
    );
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: Theme.colors.background,
    },
    center: {
        flex: 1,
        justifyContent: 'center',
        alignItems: 'center',
    },
    listContent: {
        padding: Theme.spacing.m,
    },
    header: {
        marginBottom: Theme.spacing.l,
    },
    headerTitle: {
        fontSize: Theme.typography.fontSize.xxl,
        fontFamily: Theme.typography.fontFamily.heading,
        color: Theme.colors.text,
        fontWeight: 'bold',
    },
    headerSubtitle: {
        fontSize: Theme.typography.fontSize.m,
        fontFamily: Theme.typography.fontFamily.body,
        color: Theme.colors.text,
        opacity: 0.7,
    },
    card: {
        backgroundColor: Theme.colors.surface,
        borderRadius: Theme.borderRadius.m,
        padding: Theme.spacing.m,
        marginBottom: Theme.spacing.m,
        ...Theme.shadows.card,
    },
    cardContent: {
        flexDirection: 'row',
        alignItems: 'center',
    },
    thumbnail: {
        width: 60,
        height: 60,
        borderRadius: Theme.borderRadius.s,
        marginRight: Theme.spacing.m,
        backgroundColor: Theme.colors.secondary,
    },
    textContainer: {
        flex: 1,
        marginRight: Theme.spacing.s,
    },
    episodeTitle: {
        fontSize: Theme.typography.fontSize.m,
        fontFamily: Theme.typography.fontFamily.heading,
        color: Theme.colors.text,
        fontWeight: '600',
        marginBottom: 4,
    },
    episodeDate: {
        fontSize: Theme.typography.fontSize.xs,
        fontFamily: Theme.typography.fontFamily.body,
        color: Theme.colors.text,
        opacity: 0.6,
    },
    episodeDuration: {
        fontSize: Theme.typography.fontSize.xs,
        fontFamily: Theme.typography.fontFamily.body,
        color: Theme.colors.text,
        opacity: 0.6,
    },
    playButton: {
        padding: 4,
    },
    errorText: {
        color: Theme.colors.error || 'red',
        fontSize: Theme.typography.fontSize.m,
    },
});