import CreateGoalModal from '@/components/CreateGoalModal';
import { TaskCard } from '@/components/TaskCard';
import { TaskFilterTabs, TaskFilterType } from '@/components/TaskFilterTabs';
import { TaskProgressCard } from '@/components/TaskProgressCard';
import { Colors } from '@/constants/Colors';
import { useAppDispatch, useAppSelector } from '@/hooks/redux';
import { useColorScheme } from '@/hooks/useColorScheme';
import { clearErrors, createGoal } from '@/store/goalsSlice';
import { clearErrors as clearTaskErrors, completeTask, fetchTasks, loadMoreTasks, skipTask } from '@/store/tasksSlice';
import { CreateGoalRequest, TaskListItem } from '@/types/goals';
import MaterialIcons from '@expo/vector-icons/MaterialIcons';
import { useFocusEffect } from '@react-navigation/native';
import dayjs from 'dayjs';
import { LinearGradient } from 'expo-linear-gradient';
import { useRouter } from 'expo-router';
import React, { useCallback, useEffect, useState } from 'react';
import { Alert, FlatList, Image, RefreshControl, SafeAreaView, StatusBar, StyleSheet, Text, TouchableOpacity, View } from 'react-native';

export default function GoalsScreen() {
  const theme = (useColorScheme() ?? 'light') as 'light' | 'dark';
  const colorTokens = Colors[theme];
  const dispatch = useAppDispatch();
  const router = useRouter();

  // Redux状态
  const {
    tasks,
    tasksLoading,
    tasksError,
    tasksPagination,
    completeLoading,
    completeError,
    skipLoading,
    skipError,
  } = useAppSelector((state) => state.tasks);

  const {
    createLoading,
    createError
  } = useAppSelector((state) => state.goals);

  const [showCreateModal, setShowCreateModal] = useState(false);
  const [refreshing, setRefreshing] = useState(false);
  const [selectedFilter, setSelectedFilter] = useState<TaskFilterType>('all');

  // 页面聚焦时重新加载数据
  useFocusEffect(
    useCallback(() => {
      console.log('useFocusEffect - loading tasks');
      loadTasks();
    }, [dispatch])
  );

  // 加载任务列表
  const loadTasks = async () => {
    try {
      await dispatch(fetchTasks({
        startDate: dayjs().startOf('day').toISOString(),
        endDate: dayjs().endOf('day').toISOString(),
      })).unwrap();
    } catch (error) {
      console.error('Failed to load tasks:', error);
    }
  };

  // 下拉刷新
  const onRefresh = async () => {
    setRefreshing(true);
    try {
      await loadTasks();
    } finally {
      setRefreshing(false);
    }
  };

  // 加载更多任务
  const handleLoadMoreTasks = async () => {
    if (tasksPagination.hasMore && !tasksLoading) {
      try {
        await dispatch(loadMoreTasks()).unwrap();
      } catch (error) {
        console.error('Failed to load more tasks:', error);
      }
    }
  };

  // 处理错误提示
  useEffect(() => {
    console.log('tasksError', tasksError);
    console.log('createError', createError);
    console.log('completeError', completeError);
    console.log('skipError', skipError);

    if (tasksError) {
      Alert.alert('错误', tasksError);
      dispatch(clearTaskErrors());
    }
    if (createError) {
      Alert.alert('创建失败', createError);
      dispatch(clearErrors());
    }
    if (completeError) {
      Alert.alert('完成失败', completeError);
      dispatch(clearTaskErrors());
    }
    if (skipError) {
      Alert.alert('跳过失败', skipError);
      dispatch(clearTaskErrors());
    }
  }, [tasksError, createError, completeError, skipError, dispatch]);

  // 创建目标处理函数
  const handleCreateGoal = async (goalData: CreateGoalRequest) => {
    try {
      await dispatch(createGoal(goalData)).unwrap();
      setShowCreateModal(false);
      Alert.alert('成功', '目标创建成功！');
      // 创建目标后重新加载任务列表
      loadTasks();
    } catch (error) {
      // 错误已在useEffect中处理
    }
  };

  // 任务点击处理
  const handleTaskPress = (task: TaskListItem) => {
    console.log('Task pressed:', task.title);
    // 这里可以导航到任务详情页面
  };

  // 完成任务处理
  const handleCompleteTask = async (task: TaskListItem) => {
    try {
      await dispatch(completeTask({
        taskId: task.id,
        completionData: {
          count: 1,
          notes: '通过任务卡片完成'
        }
      })).unwrap();
    } catch (error) {
      Alert.alert('错误', '完成任务失败');
    }
  };

  // 跳过任务处理
  const handleSkipTask = async (task: TaskListItem) => {
    try {
      await dispatch(skipTask({
        taskId: task.id,
        skipData: {
          reason: '用户主动跳过'
        }
      })).unwrap();
    } catch (error) {
      Alert.alert('错误', '跳过任务失败');
    }
  };

  // 导航到目标管理页面
  const handleNavigateToGoals = () => {
    router.push('/goals-detail');
  };

  // 计算各状态的任务数量
  const taskCounts = {
    all: tasks.length,
    pending: tasks.filter(task => task.status === 'pending').length,
    completed: tasks.filter(task => task.status === 'completed').length,
  };

  // 根据筛选条件过滤任务
  const filteredTasks = React.useMemo(() => {
    switch (selectedFilter) {
      case 'pending':
        return tasks.filter(task => task.status === 'pending');
      case 'completed':
        return tasks.filter(task => task.status === 'completed');
      default:
        return tasks;
    }
  }, [tasks, selectedFilter]);

  // 处理筛选变化
  const handleFilterChange = (filter: TaskFilterType) => {
    setSelectedFilter(filter);
  };

  // 渲染任务项
  const renderTaskItem = ({ item }: { item: TaskListItem }) => (
    <TaskCard
      task={item}
      onPress={handleTaskPress}
      onComplete={handleCompleteTask}
      onSkip={handleSkipTask}
    />
  );

  // 渲染空状态
  const renderEmptyState = () => {
    let title = '暂无任务';
    let subtitle = '创建目标后，系统会自动生成相应的任务';
    
    if (selectedFilter === 'pending') {
      title = '暂无待完成的任务';
      subtitle = '当前没有待完成的任务';
    } else if (selectedFilter === 'completed') {
      title = '暂无已完成的任务';
      subtitle = '完成一些任务后，它们会显示在这里';
    }
    
    return (
      <View style={styles.emptyState}>
        <Image
          source={require('@/assets/images/task/ImageEmpty.png')}
          style={styles.emptyStateImage}
          resizeMode="contain"
        />
        <Text style={[styles.emptyStateTitle, { color: colorTokens.text }]}>
          {title}
        </Text>
        <Text style={[styles.emptyStateSubtitle, { color: colorTokens.textSecondary }]}>
          {subtitle}
        </Text>
      </View>
    );
  };

  // 渲染加载更多
  const renderLoadMore = () => {
    if (!tasksPagination.hasMore) return null;
    return (
      <View style={styles.loadMoreContainer}>
        <Text style={[styles.loadMoreText, { color: colorTokens.textSecondary }]}>
          {tasksLoading ? '加载中...' : '上拉加载更多'}
        </Text>
      </View>
    );
  };

  return (
    <SafeAreaView style={styles.container}>
      <StatusBar
        backgroundColor="transparent"
        translucent
      />

      {/* 背景渐变 */}
      <LinearGradient
        colors={['#F0F9FF', '#E0F2FE']}
        style={styles.gradientBackground}
        start={{ x: 0, y: 0 }}
        end={{ x: 1, y: 1 }}
      />

      <View style={{
        position: 'absolute',
        top: 0,
        left: 0,
        right: 0,
        backgroundColor: '#7A5AF8',
        height: 233,
        borderBottomLeftRadius: 24,
        borderBottomRightRadius: 24,
      }}>
        {/* 右下角图片 */}
        <Image
          source={require('@/assets/images/task/imageTodo.png')}
          style={styles.bottomRightImage}
          resizeMode="contain"
        />
      </View>

      <View style={styles.content}>
        {/* 标题区域 */}
        <View style={styles.header}>
          <View>
          <Text style={[styles.pageTitle, { color: '#FFFFFF' }]}>
            等待完成
          </Text>
          <Text style={[styles.pageTitle2, { color: '#FFFFFF' }]}>
            让我们检查你的目标！
          </Text>
          </View>
        </View>

        {/* 任务进度卡片 */}
        <View >
          <TaskProgressCard 
            tasks={tasks} 
            headerButtons={
              <View style={styles.cardHeaderButtons}>
                <TouchableOpacity
                  style={[styles.cardGoalsButton, { borderColor: colorTokens.primary }]}
                  onPress={handleNavigateToGoals}
                >
                  <MaterialIcons name="flag" size={16} color={colorTokens.primary} />
                </TouchableOpacity>
                <TouchableOpacity
                  style={[styles.cardAddButton, { backgroundColor: colorTokens.primary }]}
                  onPress={() => setShowCreateModal(true)}
                >
                  <Text style={styles.cardAddButtonText}>+</Text>
                </TouchableOpacity>
              </View>
            }
          />
        </View>

        {/* 任务筛选标签 */}
        <TaskFilterTabs
          selectedFilter={selectedFilter}
          onFilterChange={handleFilterChange}
          taskCounts={taskCounts}
        />

        {/* 任务列表 */}
        <View style={styles.taskListContainer}>
          <FlatList
            data={filteredTasks}
            renderItem={renderTaskItem}
            keyExtractor={(item) => item.id}
            contentContainerStyle={styles.taskList}
            showsVerticalScrollIndicator={false}
            refreshControl={
              <RefreshControl
                refreshing={refreshing}
                onRefresh={onRefresh}
                colors={['#0EA5E9']}
                tintColor="#0EA5E9"
              />
            }
            onEndReached={handleLoadMoreTasks}
            onEndReachedThreshold={0.1}
            ListEmptyComponent={renderEmptyState}
            ListFooterComponent={renderLoadMore}
          />
        </View>

        {/* 创建目标弹窗 */}
        <CreateGoalModal
          visible={showCreateModal}
          onClose={() => setShowCreateModal(false)}
          onSubmit={handleCreateGoal}
          loading={createLoading}
        />
      </View>
    </SafeAreaView>
  );
}

const styles = StyleSheet.create({
  container: {
    flex: 1,
  },
  gradientBackground: {
    position: 'absolute',
    left: 0,
    right: 0,
    top: 0,
    bottom: 0,
    opacity: 0.6,
  },
  decorativeCircle1: {
    position: 'absolute',
    top: -20,
    right: -20,
    width: 60,
    height: 60,
    borderRadius: 30,
    backgroundColor: '#0EA5E9',
    opacity: 0.1,
  },
  decorativeCircle2: {
    position: 'absolute',
    bottom: -15,
    left: -15,
    width: 40,
    height: 40,
    borderRadius: 20,
    backgroundColor: '#0EA5E9',
    opacity: 0.05,
  },
  content: {
    flex: 1,
  },
  header: {
    flexDirection: 'row',
    alignItems: 'center',
    justifyContent: 'space-between',
    paddingHorizontal: 20,
    paddingTop: 20,
    paddingBottom: 16,
  },
  headerButtons: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 12,
  },
  goalsButton: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 4,
    paddingHorizontal: 12,
    paddingVertical: 8,
    borderRadius: 20,
    backgroundColor: 'rgba(255, 255, 255, 0.8)',
    shadowColor: '#000',
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.1,
    shadowRadius: 4,
    elevation: 3,
  },
  pageTitle: {
    fontSize: 28,
    fontWeight: '800',
    marginBottom: 4,
  },
  pageTitle2: {
    fontSize: 16,
    fontWeight: '400',
    color: '#FFFFFF',
    lineHeight: 24,
  },
  addButton: {
    width: 30,
    height: 30,
    borderRadius: 20,
    backgroundColor: '#0EA5E9',
    alignItems: 'center',
    justifyContent: 'center',
    shadowColor: '#000',
    shadowOffset: { width: 0, height: 2 },
    shadowOpacity: 0.1,
    shadowRadius: 4,
    elevation: 3,
  },
  addButtonText: {
    color: '#FFFFFF',
    fontSize: 22,
    fontWeight: '600',
    lineHeight: 22,
  },

  taskListContainer: {
    flex: 1,
    borderTopLeftRadius: 24,
    borderTopRightRadius: 24,
    overflow: 'hidden',
  },
  taskList: {
    paddingHorizontal: 20,
    paddingTop: 20,
    paddingBottom: 20,
  },
  emptyState: {
    alignItems: 'center',
    justifyContent: 'center',
    paddingVertical: 60,
  },
  emptyStateImage: {
    width: 223,
    height: 59,
    marginBottom: 20,
  },
  emptyStateTitle: {
    fontSize: 18,
    fontWeight: '600',
    marginBottom: 8,
  },
  emptyStateSubtitle: {
    fontSize: 14,
    textAlign: 'center',
    lineHeight: 20,
  },
  loadMoreContainer: {
    alignItems: 'center',
    paddingVertical: 20,
  },
  loadMoreText: {
    fontSize: 14,
    fontWeight: '500',
  },
  bottomRightImage: {
    position: 'absolute',
    top: 56,
    right: 36,
    width: 80,
    height: 80,
  },
  // 任务进度卡片中的按钮样式
  cardHeaderButtons: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 8,
  },
  cardGoalsButton: {
    flexDirection: 'row',
    alignItems: 'center',
    gap: 4,
    paddingHorizontal: 10,
    paddingVertical: 6,
    borderRadius: 16,
    backgroundColor: '#F3F4F6',
    borderWidth: 1,
  },
  cardAddButton: {
    width: 28,
    height: 28,
    borderRadius: 14,
    alignItems: 'center',
    justifyContent: 'center',
  },
  cardAddButtonText: {
    color: '#FFFFFF',
    fontSize: 18,
    fontWeight: '600',
    lineHeight: 18,
  },
});