import { Ionicons } from '@expo/vector-icons';
import { LinearGradient } from 'expo-linear-gradient';
import React, { useEffect, useRef, useState } from 'react';
import { useTranslation } from 'react-i18next';
import {
    Animated,
    Easing,
    StyleSheet,
    Text,
    View,
    ViewStyle
} from 'react-native';

// 主题色
const THEME_PRIMARY = '#4F5BD5';
const THEME_SECONDARY = '#6B6CFF';
const THEME_SUCCESS = '#22C55E';
const THEME_TEXT_SECONDARY = '#6f7ba7';

export interface WeightProgressBarProps {
  /** 进度值 0-1 */
  progress: number;
  /** 当前体重 */
  currentWeight: number;
  /** 目标体重 */
  targetWeight: number;
  /** 初始体重 */
  initialWeight: number;
  /** 容器样式 */
  style?: ViewStyle;
  /** 是否显示顶部分隔线，默认 true */
  showTopBorder?: boolean;
}

export const WeightProgressBar: React.FC<WeightProgressBarProps> = ({
  progress,
  currentWeight,
  targetWeight,
  initialWeight,
  style,
  showTopBorder = true,
}) => {
  const { t } = useTranslation();
  const animatedProgress = useRef(new Animated.Value(0)).current;
  const [barWidth, setBarWidth] = useState(0);

  const clampedProgress = Math.min(1, Math.max(0, progress));
  const percent = Math.round(clampedProgress * 100);

  // 判断是否有有效数据
  const hasInitialWeight = initialWeight > 0;
  const hasTargetWeight = targetWeight > 0;
  const hasCurrentWeight = currentWeight > 0;
  // 只要有初始体重和当前体重，就可以显示已减重量
  const canShowLost = hasInitialWeight && hasCurrentWeight;
  // 需要有目标体重才能显示距离目标和进度
  const canShowTarget = hasTargetWeight && hasCurrentWeight;

  useEffect(() => {
    // 延迟 500ms 开始动画，避免页面刚进入时卡顿
    const timer = setTimeout(() => {
      Animated.timing(animatedProgress, {
        toValue: clampedProgress,
        duration: 800,
        easing: Easing.out(Easing.cubic),
        useNativeDriver: false,
      }).start();
    }, 800);

    return () => clearTimeout(timer);
  }, [clampedProgress]);

  const fillWidth = animatedProgress.interpolate({
    inputRange: [0, 1],
    outputRange: [0, barWidth],
  });

  const sliderPosition = animatedProgress.interpolate({
    inputRange: [0, 1],
    outputRange: [-12, barWidth - 12],
  });

  const weightLost = initialWeight - currentWeight;
  const weightToGo = currentWeight - targetWeight;

  return (
    <View style={[
      styles.container,
      showTopBorder && styles.topBorder,
      style
    ]}>
      {/* 进度信息 */}
      <View style={styles.infoRow}>
        <View style={styles.infoItem}>
          <Text style={styles.infoLabel}>{t('statistics.components.weight.progress.lost')}</Text>
          <Text style={[styles.infoValue, { color: canShowLost && weightLost >= 0 ? THEME_SUCCESS : (canShowLost ? '#FF6B6B' : THEME_TEXT_SECONDARY) }]}>
            {canShowLost ? `${weightLost >= 0 ? '-' : '+'}${Math.abs(weightLost).toFixed(1)}kg` : '--'}
          </Text>
        </View>
        <View style={styles.percentContainer}>
          <Text style={styles.percentValue}>{percent}</Text>
          <Text style={styles.percentSymbol}>%</Text>
        </View>
        <View style={[styles.infoItem, { alignItems: 'flex-end' }]}>
          <Text style={styles.infoLabel}>{t('statistics.components.weight.progress.toGo')}</Text>
          <Text style={[styles.infoValue, { color: THEME_PRIMARY }]}>
            {canShowTarget ? `${weightToGo > 0 ? weightToGo.toFixed(1) : '0'}kg` : '--'}
          </Text>
        </View>
      </View>

      {/* 进度条 */}
      <View
        style={styles.trackContainer}
        onLayout={(e) => setBarWidth(e.nativeEvent.layout.width)}
      >
        {/* 背景轨道 */}
        <View style={styles.track} />

        {/* 填充进度 */}
        <Animated.View style={[styles.fill, { width: fillWidth }]}>
          <LinearGradient
            colors={[THEME_PRIMARY, THEME_SECONDARY]}
            start={{ x: 0, y: 0 }}
            end={{ x: 1, y: 0 }}
            style={StyleSheet.absoluteFillObject}
          />
        </Animated.View>

        {/* 滑块 - 圆角矩形 */}
        <Animated.View style={[styles.slider, { left: sliderPosition }]}>
          <LinearGradient
            colors={['#ffffff', '#f8f9fc']}
            style={styles.sliderInner}
          >
            <View style={styles.sliderLine} />
          </LinearGradient>
        </Animated.View>
      </View>

      {/* 起止标签 */}
      <View style={styles.labelRow}>
        <Text style={styles.labelText}>{hasInitialWeight ? `${initialWeight.toFixed(1)}kg` : '--'}</Text>
        <View style={styles.targetBadge}>
          <Ionicons name="flag" size={10} color={THEME_PRIMARY} />
          <Text style={styles.targetText}>{hasTargetWeight ? `${targetWeight.toFixed(1)}kg` : '--'}</Text>
        </View>
      </View>
    </View>
  );
};

const styles = StyleSheet.create({
  container: {
    marginTop: 12,
    paddingTop: 10,
    marginLeft:12,
    marginRight: 12
  },
  topBorder: {
    borderTopWidth: 1,
    borderTopColor: 'rgba(0,0,0,0.04)',
  },
  infoRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    marginBottom: 8,
  },
  infoItem: {
    flex: 1,
  },
  infoLabel: {
    fontSize: 11,
    color: THEME_TEXT_SECONDARY,
    fontFamily: 'AliRegular',
    marginBottom: 2,
  },
  infoValue: {
    fontSize: 14,
    fontWeight: '700',
    fontFamily: 'AliBold',
  },
  percentContainer: {
    flexDirection: 'row',
    alignItems: 'baseline',
    justifyContent: 'center',
  },
  percentValue: {
    fontSize: 24,
    fontWeight: '800',
    color: THEME_PRIMARY,
    fontFamily: 'AliBold',
  },
  percentSymbol: {
    fontSize: 12,
    fontWeight: '600',
    color: THEME_PRIMARY,
    fontFamily: 'AliBold',
    marginLeft: 2,
  },
  trackContainer: {
    height: 8,
    position: 'relative',
    marginBottom: 8,
  },
  track: {
    position: 'absolute',
    left: 0,
    right: 0,
    top: 0,
    bottom: 0,
    backgroundColor: '#E8EAF0',
    borderRadius: 4,
  },
  fill: {
    position: 'absolute',
    left: 0,
    top: 0,
    bottom: 0,
    borderRadius: 4,
    overflow: 'hidden',
  },
  slider: {
    position: 'absolute',
    top: -8,
    width: 24,
    height: 24,
    borderRadius: 8,
    shadowColor: THEME_PRIMARY,
    shadowOffset: { width: 0, height: 3 },
    shadowOpacity: 0.35,
    shadowRadius: 6,
    elevation: 6,
  },
  sliderInner: {
    width: '100%',
    height: '100%',
    borderRadius: 8,
    alignItems: 'center',
    justifyContent: 'center',
    borderWidth: 2.5,
    borderColor: THEME_PRIMARY,
  },
  sliderLine: {
    width: 8,
    height: 3,
    borderRadius: 1.5,
    backgroundColor: THEME_PRIMARY,
  },
  labelRow: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
  },
  labelText: {
    fontSize: 11,
    color: THEME_TEXT_SECONDARY,
    fontFamily: 'AliRegular',
  },
  targetBadge: {
    flexDirection: 'row',
    alignItems: 'center',
    backgroundColor: 'rgba(79, 91, 213, 0.1)',
    paddingHorizontal: 8,
    paddingVertical: 3,
    borderRadius: 10,
    gap: 4,
  },
  targetText: {
    fontSize: 11,
    color: THEME_PRIMARY,
    fontWeight: '600',
    fontFamily: 'AliBold',
  },
});

export default WeightProgressBar;