import React, { useRef } from 'react';
import { View, Text, StyleSheet, Dimensions, ScrollView, TouchableOpacity, Animated } from 'react-native';
import { LinearGradient } from 'expo-linear-gradient';
import { Ionicons } from '@expo/vector-icons';
import { theme } from '../styles/theme';
import { CircularProgress } from './CircularProgress';
import type { FitnessGoal } from '../services/fitnessGoals';

const { width } = Dimensions.get('window');
const CARD_WIDTH = width * 0.8;
const SPACING = 20;

interface GoalCarouselProps {
    goals: FitnessGoal[];
    onGoalPress: (goal: FitnessGoal) => void;
}

export function GoalCarousel({ goals, onGoalPress }: GoalCarouselProps) {
    const scrollX = useRef(new Animated.Value(0)).current;

    if (goals.length === 0) {
        return (
            <View style={styles.emptyContainer}>
                <Text style={styles.emptyText}>No active goals</Text>
            </View>
        );
    }

    return (
        <View>
            <Animated.ScrollView
                horizontal
                showsHorizontalScrollIndicator={false}
                snapToInterval={CARD_WIDTH + SPACING}
                decelerationRate="fast"
                contentContainerStyle={styles.scrollContent}
                onScroll={Animated.event(
                    [{ nativeEvent: { contentOffset: { x: scrollX } } }],
                    { useNativeDriver: true }
                )}
                scrollEventThrottle={16}
            >
                {goals.map((goal, index) => {
                    const inputRange = [
                        (index - 1) * (CARD_WIDTH + SPACING),
                        index * (CARD_WIDTH + SPACING),
                        (index + 1) * (CARD_WIDTH + SPACING),
                    ];

                    const scale = scrollX.interpolate({
                        inputRange,
                        outputRange: [0.9, 1, 0.9],
                        extrapolate: 'clamp',
                    });

                    const opacity = scrollX.interpolate({
                        inputRange,
                        outputRange: [0.7, 1, 0.7],
                        extrapolate: 'clamp',
                    });

                    return (
                        <TouchableOpacity
                            key={goal.id}
                            activeOpacity={0.9}
                            onPress={() => onGoalPress(goal)}
                        >
                            <Animated.View
                                style={[
                                    styles.cardContainer,
                                    { transform: [{ scale }], opacity },
                                ]}
                            >
                                <LinearGradient
                                    colors={['#ffffff', '#f9fafb']}
                                    style={[styles.card, theme.shadows.medium]}
                                >
                                    <View style={styles.cardHeader}>
                                        <View style={styles.iconContainer}>
                                            <LinearGradient
                                                colors={theme.gradients.primary}
                                                style={styles.iconGradient}
                                            >
                                                <Ionicons name="trophy" size={24} color="#fff" />
                                            </LinearGradient>
                                        </View>
                                        <View style={styles.priorityBadge}>
                                            <Text style={styles.priorityText}>{goal.priority.toUpperCase()}</Text>
                                        </View>
                                    </View>

                                    <Text style={styles.title} numberOfLines={1}>{goal.title}</Text>
                                    <Text style={styles.description} numberOfLines={2}>{goal.description}</Text>

                                    <View style={styles.progressContainer}>
                                        <CircularProgress
                                            progress={goal.progress || 0}
                                            size={80}
                                            strokeWidth={8}
                                            color={theme.colors.primary}
                                        />
                                        <View style={styles.progressDetails}>
                                            <Text style={styles.progressValue}>
                                                {goal.currentValue} / {goal.targetValue}
                                            </Text>
                                            <Text style={styles.progressUnit}>{goal.unit}</Text>
                                        </View>
                                    </View>

                                    <View style={styles.footer}>
                                        <Text style={styles.date}>
                                            Target: {goal.targetDate ? new Date(goal.targetDate).toLocaleDateString() : 'No date'}
                                        </Text>
                                    </View>
                                </LinearGradient>
                            </Animated.View>
                        </TouchableOpacity>
                    );
                })}
            </Animated.ScrollView>
        </View>
    );
}

const styles = StyleSheet.create({
    scrollContent: {
        paddingHorizontal: (width - CARD_WIDTH) / 2,
        paddingVertical: 20,
    },
    emptyContainer: {
        height: 200,
        justifyContent: 'center',
        alignItems: 'center',
    },
    emptyText: {
        color: theme.colors.gray500,
        fontSize: 16,
    },
    cardContainer: {
        width: CARD_WIDTH,
        marginRight: SPACING,
    },
    card: {
        borderRadius: 24,
        padding: 24,
        height: 320,
        justifyContent: 'space-between',
        borderWidth: 1,
        borderColor: 'rgba(0,0,0,0.05)',
    },
    cardHeader: {
        flexDirection: 'row',
        justifyContent: 'space-between',
        alignItems: 'flex-start',
        marginBottom: 16,
    },
    iconContainer: {
        shadowColor: theme.colors.primary,
        shadowOffset: { width: 0, height: 4 },
        shadowOpacity: 0.3,
        shadowRadius: 8,
        elevation: 4,
    },
    iconGradient: {
        width: 48,
        height: 48,
        borderRadius: 16,
        justifyContent: 'center',
        alignItems: 'center',
    },
    priorityBadge: {
        backgroundColor: 'rgba(59, 130, 246, 0.1)',
        paddingHorizontal: 12,
        paddingVertical: 6,
        borderRadius: 12,
    },
    priorityText: {
        color: theme.colors.primary,
        fontSize: 12,
        fontWeight: '700',
    },
    title: {
        fontSize: 24,
        fontWeight: '800',
        color: theme.colors.gray900,
        marginBottom: 8,
    },
    description: {
        fontSize: 14,
        color: theme.colors.gray500,
        marginBottom: 24,
        lineHeight: 20,
    },
    progressContainer: {
        flexDirection: 'row',
        alignItems: 'center',
        justifyContent: 'space-between',
        marginBottom: 24,
    },
    progressDetails: {
        alignItems: 'flex-end',
    },
    progressValue: {
        fontSize: 24,
        fontWeight: '700',
        color: theme.colors.gray900,
    },
    progressUnit: {
        fontSize: 14,
        color: theme.colors.gray500,
        fontWeight: '500',
    },
    footer: {
        borderTopWidth: 1,
        borderTopColor: theme.colors.gray100,
        paddingTop: 16,
    },
    date: {
        fontSize: 12,
        color: theme.colors.gray400,
        fontWeight: '500',
    },
});