import {
  createMoodCheckin,
  CreateMoodCheckinDto,
  deleteMoodCheckin,
  DeleteMoodCheckinDto,
  getDailyMoodCheckins,
  getMoodCheckinsHistory,
  getMoodStatistics,
  MoodCheckin,
  MoodType,
  updateMoodCheckin,
  UpdateMoodCheckinDto
} from '@/services/moodCheckins';
import { createAsyncThunk, createSlice, PayloadAction } from '@reduxjs/toolkit';
import dayjs from 'dayjs';

// 状态接口
interface MoodState {
  // 按日期存储的心情记录
  moodRecords: Record<string, MoodCheckin[]>;
  // 当前选中的日期
  selectedDate: string;
  // 当前选中的心情记录
  selectedMoodRecord: MoodCheckin | null;
  // 加载状态
  loading: {
    daily: boolean;
    history: boolean;
    statistics: boolean;
    create: boolean;
    update: boolean;
    delete: boolean;
  };
  // 错误信息
  error: string | null;
  // 统计数据
  statistics: {
    totalCheckins: number;
    averageIntensity: number;
    moodDistribution: Record<MoodType, number>;
    mostFrequentMood: MoodType | null;
  } | null;
}

// 初始状态
const initialState: MoodState = {
  moodRecords: {},
  selectedDate: dayjs().format('YYYY-MM-DD'),
  selectedMoodRecord: null,
  loading: {
    daily: false,
    history: false,
    statistics: false,
    create: false,
    update: false,
    delete: false,
  },
  error: null,
  statistics: null,
};

// 异步 actions
export const fetchDailyMoodCheckins = createAsyncThunk(
  'mood/fetchDailyMoodCheckins',
  async (date: string) => {
    const checkins = await getDailyMoodCheckins(date);
    return { date, checkins };
  }
);

export const fetchMoodHistory = createAsyncThunk(
  'mood/fetchMoodHistory',
  async (params: { startDate: string; endDate: string; moodType?: MoodType }) => {
    const checkins = await getMoodCheckinsHistory(params);
    return { params, checkins };
  }
);

export const fetchMoodStatistics = createAsyncThunk(
  'mood/fetchMoodStatistics',
  async (params: { startDate: string; endDate: string }) => {
    const statistics = await getMoodStatistics(params);
    return statistics;
  }
);

export const createMoodRecord = createAsyncThunk(
  'mood/createMoodRecord',
  async (dto: CreateMoodCheckinDto) => {
    const newRecord = await createMoodCheckin(dto);
    return newRecord;
  }
);

export const updateMoodRecord = createAsyncThunk(
  'mood/updateMoodRecord',
  async (dto: UpdateMoodCheckinDto) => {
    const updatedRecord = await updateMoodCheckin(dto);
    return updatedRecord;
  }
);

export const deleteMoodRecord = createAsyncThunk(
  'mood/deleteMoodRecord',
  async (dto: DeleteMoodCheckinDto) => {
    await deleteMoodCheckin(dto);
    return dto.id;
  }
);

// 创建 slice
const moodSlice = createSlice({
  name: 'mood',
  initialState,
  reducers: {
    // 设置选中的日期
    setSelectedDate: (state, action: PayloadAction<string>) => {
      state.selectedDate = action.payload;
      // 如果该日期没有记录，设置为 null
      const records = state.moodRecords[action.payload];
      state.selectedMoodRecord = records && records.length > 0 ? records[0] : null;
    },
    // 设置选中的心情记录
    setSelectedMoodRecord: (state, action: PayloadAction<MoodCheckin | null>) => {
      state.selectedMoodRecord = action.payload;
    },
    // 清除错误
    clearError: (state) => {
      state.error = null;
    },
    // 清除统计数据
    clearStatistics: (state) => {
      state.statistics = null;
    },
    // 清除所有数据
    clearMoodData: (state) => {
      state.moodRecords = {};
      state.selectedMoodRecord = null;
      state.statistics = null;
      state.error = null;
    },
  },
  extraReducers: (builder) => {
    // fetchDailyMoodCheckins
    builder
      .addCase(fetchDailyMoodCheckins.pending, (state) => {
        state.loading.daily = true;
        state.error = null;
      })
      .addCase(fetchDailyMoodCheckins.fulfilled, (state, action) => {
        state.loading.daily = false;
        const { date, checkins } = action.payload;
        state.moodRecords[date] = checkins;

        // 如果是当前选中的日期，更新选中的记录
        if (date === state.selectedDate) {
          state.selectedMoodRecord = checkins.length > 0 ? checkins[0] : null;
        }
      })
      .addCase(fetchDailyMoodCheckins.rejected, (state, action) => {
        state.loading.daily = false;
        state.error = action.error.message || '获取心情记录失败';
      });

    // fetchMoodHistory
    builder
      .addCase(fetchMoodHistory.pending, (state) => {
        state.loading.history = true;
        state.error = null;
      })
      .addCase(fetchMoodHistory.fulfilled, (state, action) => {
        state.loading.history = false;
        const { checkins } = action.payload;

        // 将历史记录按日期分组存储
        checkins.forEach(checkin => {
          const date = checkin.checkinDate;
          if (!state.moodRecords[date]) {
            state.moodRecords[date] = [];
          }

          // 检查是否已存在相同 ID 的记录
          const existingIndex = state.moodRecords[date].findIndex(r => r.id === checkin.id);
          if (existingIndex >= 0) {
            state.moodRecords[date][existingIndex] = checkin;
          } else {
            state.moodRecords[date].push(checkin);
          }
        });
      })
      .addCase(fetchMoodHistory.rejected, (state, action) => {
        state.loading.history = false;
        state.error = action.error.message || '获取心情历史失败';
      });

    // fetchMoodStatistics
    builder
      .addCase(fetchMoodStatistics.pending, (state) => {
        state.loading.statistics = true;
        state.error = null;
      })
      .addCase(fetchMoodStatistics.fulfilled, (state, action) => {
        state.loading.statistics = false;
        state.statistics = action.payload;
      })
      .addCase(fetchMoodStatistics.rejected, (state, action) => {
        state.loading.statistics = false;
        state.error = action.error.message || '获取心情统计失败';
      });

    // createMoodRecord
    builder
      .addCase(createMoodRecord.pending, (state) => {
        state.loading.create = true;
        state.error = null;
      })
      .addCase(createMoodRecord.fulfilled, (state, action) => {
        state.loading.create = false;
        const newRecord = action.payload;
        const date = newRecord.checkinDate;

        // 添加到对应日期的记录中
        if (!state.moodRecords[date]) {
          state.moodRecords[date] = [];
        }
        state.moodRecords[date].unshift(newRecord); // 添加到开头

        // 如果是当前选中的日期，更新选中的记录
        if (date === state.selectedDate) {
          state.selectedMoodRecord = newRecord;
        }
      })
      .addCase(createMoodRecord.rejected, (state, action) => {
        state.loading.create = false;
        state.error = action.error.message || '创建心情记录失败';
      });

    // updateMoodRecord
    builder
      .addCase(updateMoodRecord.pending, (state) => {
        state.loading.update = true;
        state.error = null;
      })
      .addCase(updateMoodRecord.fulfilled, (state, action) => {
        state.loading.update = false;
        const updatedRecord = action.payload;
        const date = updatedRecord.checkinDate;

        // 更新对应日期的记录
        if (state.moodRecords[date]) {
          const index = state.moodRecords[date].findIndex(r => r.id === updatedRecord.id);
          if (index >= 0) {
            state.moodRecords[date][index] = updatedRecord;
          }
        }

        // 如果是当前选中的记录，更新选中的记录
        if (state.selectedMoodRecord?.id === updatedRecord.id) {
          state.selectedMoodRecord = updatedRecord;
        }
      })
      .addCase(updateMoodRecord.rejected, (state, action) => {
        state.loading.update = false;
        state.error = action.error.message || '更新心情记录失败';
      });

    // deleteMoodRecord
    builder
      .addCase(deleteMoodRecord.pending, (state) => {
        state.loading.delete = true;
        state.error = null;
      })
      .addCase(deleteMoodRecord.fulfilled, (state, action) => {
        state.loading.delete = false;
        const deletedId = action.payload;

        // 从所有日期的记录中删除
        Object.keys(state.moodRecords).forEach(date => {
          state.moodRecords[date] = state.moodRecords[date].filter(r => r.id !== deletedId);
        });

        // 如果是当前选中的记录被删除，清空选中的记录
        if (state.selectedMoodRecord?.id === deletedId) {
          state.selectedMoodRecord = null;
        }
      })
      .addCase(deleteMoodRecord.rejected, (state, action) => {
        state.loading.delete = false;
        state.error = action.error.message || '删除心情记录失败';
      });
  },
});

// 导出 actions
export const {
  setSelectedDate,
  setSelectedMoodRecord,
  clearError,
  clearStatistics,
  clearMoodData,
} = moodSlice.actions;

// 导出 reducer
export default moodSlice.reducer;

// 导出选择器
export const selectMoodState = (state: { mood: MoodState }) => state.mood;
export const selectMoodRecords = (state: { mood: MoodState }) => state.mood.moodRecords;
export const selectSelectedDate = (state: { mood: MoodState }) => state.mood.selectedDate;
export const selectSelectedMoodRecord = (state: { mood: MoodState }) => state.mood.selectedMoodRecord;
export const selectMoodLoading = (state: { mood: MoodState }) => state.mood.loading;
export const selectMoodError = (state: { mood: MoodState }) => state.mood.error;
export const selectMoodStatistics = (state: { mood: MoodState }) => state.mood.statistics;

// 获取指定日期的心情记录
export const selectMoodRecordsByDate = (date: string) => (state: { mood: MoodState }) => {
  return state.mood.moodRecords[date] || [];
};

// 获取指定日期的最新心情记录
export const selectLatestMoodRecordByDate = (date: string) => (state: { mood: MoodState }) => {
  const records = state.mood.moodRecords[date] || [];
  return records.length > 0 ? records[0] : null;
};