import { useThemeColor } from '@/hooks/useThemeColor';
import { BrainCircuit, ChevronDown, ChevronRight } from 'lucide-react-native';
import React, { useEffect, useState } from 'react';
import { StyleSheet, Text, TouchableOpacity, View } from 'react-native';
import Animated, {
    useAnimatedStyle,
    useSharedValue,
    withRepeat,
    withSequence,
    withTiming
} from 'react-native-reanimated';

interface ThinkingBlockProps {
    content: string;
    isComplete: boolean;
    isStreaming?: boolean;
}

export function ThinkingBlock({ content, isComplete, isStreaming }: ThinkingBlockProps) {
    const colors = useThemeColor();
    // Auto-expand while streaming/thinking, auto-collapse when complete
    const [isExpanded, setIsExpanded] = useState(!isComplete);
    
    // Auto collapse when it completes streaming
    useEffect(() => {
        if (isComplete && !isStreaming) {
            setIsExpanded(false);
        } else if (!isComplete && isStreaming) {
            setIsExpanded(true);
        }
    }, [isComplete, isStreaming]);

    // Pulse animation value
    const pulseOpacity = useSharedValue(1);

    useEffect(() => {
        if (!isComplete && isStreaming) {
            pulseOpacity.value = withRepeat(
                withSequence(
                    withTiming(0.4, { duration: 800 }),
                    withTiming(1, { duration: 800 })
                ),
                -1, // infinite
                true // reverse
            );
        } else {
            pulseOpacity.value = withTiming(1, { duration: 300 });
        }
    }, [isComplete, isStreaming, pulseOpacity]);

    const animatedHeaderStyle = useAnimatedStyle(() => {
        return {
            opacity: pulseOpacity.value,
        };
    });

    if (!content && isComplete) {
        return null;
    }

    return (
        <View style={[styles.container, { borderColor: colors.border }]}>
            <TouchableOpacity
                style={styles.header}
                activeOpacity={0.7}
                onPress={() => setIsExpanded(!isExpanded)}
            >
                <Animated.View style={[styles.titleRow, animatedHeaderStyle]}>
                    <BrainCircuit size={16} color={colors.textMuted} />
                    <Text style={[styles.titleText, { color: colors.textMuted }]}>
                        {!isComplete && isStreaming ? 'Pensando...' : 'Processo de Raciocínio'}
                    </Text>
                </Animated.View>
                
                {isExpanded ? (
                    <ChevronDown size={18} color={colors.textMuted} />
                ) : (
                    <ChevronRight size={18} color={colors.textMuted} />
                )}
            </TouchableOpacity>

            {isExpanded && content.length > 0 && (
                <View style={[styles.contentBlock, { borderTopColor: colors.border }]}>
                    <Text style={[styles.contentText, { color: colors.textMuted }]}>
                        {content}
                    </Text>
                </View>
            )}
        </View>
    );
}

const styles = StyleSheet.create({
    container: {
        borderWidth: 1,
        borderRadius: 8,
        marginVertical: 8,
        overflow: 'hidden',
        width: '100%',
    },
    header: {
        flexDirection: 'row',
        alignItems: 'center',
        justifyContent: 'space-between',
        paddingHorizontal: 12,
        paddingVertical: 10,
    },
    titleRow: {
        flexDirection: 'row',
        alignItems: 'center',
        gap: 8,
    },
    titleText: {
        fontSize: 13,
        fontWeight: '600',
    },
    contentBlock: {
        paddingHorizontal: 12,
        paddingVertical: 10,
        borderTopWidth: 1,
    },
    contentText: {
        fontSize: 14,
        lineHeight: 20,
        fontFamily: 'monospace',
    },
});