import { MoodHistoryCard } from '@/components/MoodHistoryCard';
import { Colors } from '@/constants/Colors';
import { useAppDispatch, useAppSelector } from '@/hooks/redux';
import { useAuthGuard } from '@/hooks/useAuthGuard';
import { useColorScheme } from '@/hooks/useColorScheme';
import {
  fetchMoodHistory,
  fetchMoodStatistics,
  selectMoodLoading,
  selectMoodRecords,
  selectMoodStatistics
} from '@/store/moodSlice';
import dayjs from 'dayjs';
import { LinearGradient } from 'expo-linear-gradient';
import React, { useEffect } from 'react';
import {
  ActivityIndicator,
  SafeAreaView,
  ScrollView,
  StyleSheet,
  Text,
  View,
} from 'react-native';

export default function MoodStatisticsScreen() {
  const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';
  const colorTokens = Colors[theme];
  const { isLoggedIn } = useAuthGuard();
  const dispatch = useAppDispatch();

  // 从 Redux 获取数据
  const moodRecords = useAppSelector(selectMoodRecords);
  const statistics = useAppSelector(selectMoodStatistics);
  const loading = useAppSelector(selectMoodLoading);

  // 获取最近30天的心情数据
  const loadMoodData = async () => {
    if (!isLoggedIn) return;

    try {
      const endDate = dayjs().format('YYYY-MM-DD');
      const startDate = dayjs().subtract(30, 'days').format('YYYY-MM-DD');

      // 并行加载历史记录和统计数据
      await Promise.all([
        dispatch(fetchMoodHistory({ startDate, endDate })),
        dispatch(fetchMoodStatistics({ startDate, endDate }))
      ]);
    } catch (error) {
      console.error('加载心情数据失败:', error);
    }
  };

  useEffect(() => {
    loadMoodData();
  }, [isLoggedIn, dispatch]);

  // 将 moodRecords 转换为数组格式
  const moodCheckins = Object.values(moodRecords).flat();

  // 使用统一的渐变背景色
  const backgroundGradientColors = [colorTokens.backgroundGradientStart, colorTokens.backgroundGradientEnd] as const;

  if (!isLoggedIn) {
    return (
      <View style={styles.container}>
        <LinearGradient
          colors={backgroundGradientColors}
          style={styles.gradientBackground}
          start={{ x: 0, y: 0 }}
          end={{ x: 0, y: 1 }}
        />
        <SafeAreaView style={styles.safeArea}>
          <View style={styles.centerContainer}>
            <Text style={styles.loginPrompt}>请先登录查看心情统计</Text>
          </View>
        </SafeAreaView>
      </View>
    );
  }

  return (
    <View style={styles.container}>
      <LinearGradient
        colors={backgroundGradientColors}
        style={styles.gradientBackground}
        start={{ x: 0, y: 0 }}
        end={{ x: 0, y: 1 }}
      />
      <SafeAreaView style={styles.safeArea}>
        <ScrollView style={styles.scrollView} showsVerticalScrollIndicator={false}>
          <Text style={styles.title}>心情统计</Text>

          {loading.history || loading.statistics ? (
            <View style={styles.loadingContainer}>
              <ActivityIndicator size="large" color={colorTokens.primary} />
              <Text style={styles.loadingText}>加载中...</Text>
            </View>
          ) : (
            <>
              {/* 统计概览 */}
              {statistics && (
                <View style={styles.statsOverview}>
                  <Text style={styles.sectionTitle}>统计概览</Text>
                  <View style={styles.statsGrid}>
                    <View style={styles.statCard}>
                      <Text style={styles.statNumber}>{statistics.totalCheckins}</Text>
                      <Text style={styles.statLabel}>总打卡次数</Text>
                    </View>
                    <View style={styles.statCard}>
                      <Text style={styles.statNumber}>{statistics.averageIntensity.toFixed(1)}</Text>
                      <Text style={styles.statLabel}>平均强度</Text>
                    </View>
                    <View style={styles.statCard}>
                      <Text style={styles.statNumber}>
                        {statistics.mostFrequentMood ? statistics.moodDistribution[statistics.mostFrequentMood] || 0 : 0}
                      </Text>
                      <Text style={styles.statLabel}>最常见心情</Text>
                    </View>
                  </View>
                </View>
              )}

              {/* 心情历史记录 */}
              <MoodHistoryCard
                moodCheckins={moodCheckins}
                title="最近30天心情记录"
              />

              {/* 心情分布 */}
              {statistics && (
                <View style={styles.distributionContainer}>
                  <Text style={styles.sectionTitle}>心情分布</Text>
                  <View style={styles.distributionList}>
                    {Object.entries(statistics.moodDistribution)
                      .sort(([, a], [, b]) => b - a)
                      .map(([moodType, count]) => (
                        <View key={moodType} style={styles.distributionItem}>
                          <Text style={styles.moodType}>{moodType}</Text>
                          <View style={styles.countContainer}>
                            <Text style={styles.count}>{count}</Text>
                            <Text style={styles.percentage}>
                              ({((count / statistics.totalCheckins) * 100).toFixed(1)}%)
                            </Text>
                          </View>
                        </View>
                      ))}
                  </View>
                </View>
              )}
            </>
          )}
        </ScrollView>
      </SafeAreaView>
    </View>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  gradientBackground: {
    position: 'absolute',
    left: 0,
    right: 0,
    top: 0,
    bottom: 0,
  },
  safeArea: {
    flex: 1,
  },
  scrollView: {
    flex: 1,
    paddingHorizontal: 20,
  },
  centerContainer: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
  },
  loginPrompt: {
    fontSize: 16,
    color: '#666',
    textAlign: 'center',
  },
  title: {
    fontSize: 28,
    fontWeight: '800',
    color: '#192126',
    marginTop: 24,
    marginBottom: 24,
  },
  loadingContainer: {
    flex: 1,
    justifyContent: 'center',
    alignItems: 'center',
    paddingVertical: 60,
  },
  loadingText: {
    fontSize: 16,
    color: '#666',
    marginTop: 16,
  },
  sectionTitle: {
    fontSize: 20,
    fontWeight: '700',
    color: '#192126',
    marginBottom: 16,
  },
  statsOverview: {
    marginBottom: 24,
  },
  statsGrid: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    gap: 12,
  },
  statCard: {
    flex: 1,
    backgroundColor: '#FFFFFF',
    borderRadius: 16,
    padding: 20,
    alignItems: 'center',
    shadowColor: '#000',
    shadowOffset: {
      width: 0,
      height: 2,
    },
    shadowOpacity: 0.1,
    shadowRadius: 3.84,
    elevation: 5,
  },
  statNumber: {
    fontSize: 24,
    fontWeight: '800',
    color: '#192126',
    marginBottom: 8,
  },
  statLabel: {
    fontSize: 14,
    color: '#6B7280',
    textAlign: 'center',
  },
  distributionContainer: {
    backgroundColor: '#FFFFFF',
    borderRadius: 16,
    padding: 16,
    marginBottom: 24,
    shadowColor: '#000',
    shadowOffset: {
      width: 0,
      height: 2,
    },
    shadowOpacity: 0.1,
    shadowRadius: 3.84,
    elevation: 5,
  },
  distributionList: {
    gap: 12,
  },
  distributionItem: {
    flexDirection: 'row',
    justifyContent: 'space-between',
    alignItems: 'center',
    paddingVertical: 8,
  },
  moodType: {
    fontSize: 16,
    fontWeight: '500',
    color: '#192126',
  },
  countContainer: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 8,
  },
  count: {
    fontSize: 16,
    fontWeight: '600',
    color: '#192126',
  },
  percentage: {
    fontSize: 14,
    color: '#6B7280',
  },
});