package com.guo.learningprogresstracker.service.impl;

import com.baomidou.mybatisplus.core.toolkit.Wrappers;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.guo.learningprogresstracker.dto.StudySessionsDto;
import com.guo.learningprogresstracker.dto.response.StudySessionResponse;
import com.guo.learningprogresstracker.entity.StudyReportFragmentsEntity;
import com.guo.learningprogresstracker.entity.StudyReportsEntity;
import com.guo.learningprogresstracker.entity.StudySessionsEntity;
import com.guo.learningprogresstracker.entity.TaskEntity;
import com.guo.learningprogresstracker.enums.StudySessionStateEnum;
import com.guo.learningprogresstracker.exception.ErrorParameterException;
import com.guo.learningprogresstracker.exception.NotFindEntitiesException;
import com.guo.learningprogresstracker.mapStruct.StudySessionConvert;
import com.guo.learningprogresstracker.mapper.StudyReportFragmentsMapper;
import com.guo.learningprogresstracker.mapper.StudyReportsMapper;
import com.guo.learningprogresstracker.mapper.StudySessionsMapper;
import com.guo.learningprogresstracker.service.StudySessionsService;
import lombok.RequiredArgsConstructor;
import org.springframework.stereotype.Service;

import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Optional;
import java.util.stream.Collectors;

/**
 * @author guo
 * @description 针对表【study_sessions(记录每次学习会话的具体数据)】的数据库操作Service实现
 * @createDate 2024-06-09 15:28:48
 */
@Service
@RequiredArgsConstructor
public class StudySessionsServiceImpl extends ServiceImpl<StudySessionsMapper, StudySessionsEntity>
        implements StudySessionsService {

    private final TasksServiceImpl tasksServiceImpl;
    private final StudyReportFragmentsServiceImpl studyReportFragmentsServiceImpl;
    private final StudyReportFragmentsMapper studyReportFragmentsMapper;
    private final StudyReportsMapper studyReportsMapper;

    public StudySessionResponse startOrContinueStudySession(String taskNum) throws NotFindEntitiesException {
        // taskNum是否存在
        TaskEntity taskEntity = tasksServiceImpl.getOneOpt(Wrappers.lambdaQuery(TaskEntity.class).eq(TaskEntity::getTaskNum, taskNum))
                .orElseThrow(() -> new NotFindEntitiesException(String.format("[%s]不存在", taskNum)));
        // 任务taskNum下是否存在非"已结束"的学习会话
        Optional<StudySessionsEntity> oneOpt = this.getOneOpt(Wrappers.<StudySessionsEntity>lambdaQuery()
                .eq(StudySessionsEntity::getTaskNum, taskNum)
                .ne(StudySessionsEntity::getSessionState, StudySessionStateEnum.ENDED.name()));
        StudySessionsEntity studySessionsEntity;
        // 有则返回该未完成会话，否则创建新的会话
        if (oneOpt.isEmpty()) {
            // 返回一个新的会话
            studySessionsEntity = StudySessionsEntity.initNewSession();
            studySessionsEntity.setTaskNum(taskNum);
            studySessionsEntity.setLastStartTime(LocalDateTime.now());
            this.save(studySessionsEntity);
        } else {
            // 返回已经存在的会话
            studySessionsEntity = oneOpt.get();
            studySessionsEntity.continueStudySession();
            this.updateById(studySessionsEntity);
        }
        StudySessionResponse response = StudySessionConvert.MAPPER.toStudySessionResponse(studySessionsEntity);
        response.setTaskName(taskEntity.getTaskName());
        return response;
    }

    @Override
    public void pauseStudySession(String sessionNum) throws ErrorParameterException {
        StudySessionsEntity studySessionsEntity = this.getOneOpt(Wrappers.lambdaQuery(StudySessionsEntity.class)
                        .eq(StudySessionsEntity::getSessionNum, sessionNum))
                .orElseThrow(() -> new ErrorParameterException("会话[" + sessionNum + "]不存在"));
        studySessionsEntity.pausedStudySession();
        this.updateById(studySessionsEntity);
    }


    @Override
    public void endedStudySession(String sessionNum, String content) throws ErrorParameterException {
        StudySessionsEntity studySessionsEntity = this.getOneOpt(Wrappers.lambdaQuery(StudySessionsEntity.class)
                        .eq(StudySessionsEntity::getSessionNum, sessionNum))
                .orElseThrow(() -> new ErrorParameterException("会话[" + sessionNum + "]不存在"));
        studySessionsEntity.endedStudySession();
        this.updateById(studySessionsEntity);
        // 创建学习报告
        StudyReportsEntity studyReportsEntity = new StudyReportsEntity();
        studyReportsEntity.setSessionNum(sessionNum);
        studyReportsEntity.setContent(content);
        studyReportsMapper.insert(studyReportsEntity);
    }

    @Override
    public StudySessionResponse getNotEndedStudySessionByTaskNum(String taskNum) throws ErrorParameterException {
        StudySessionsDto dto = Optional.ofNullable(studyReportsMapper.getNotEndedStudySessionDtoByTaskNum(taskNum))
                .orElseThrow(() -> new ErrorParameterException("任务[" + taskNum + "]不存在进行中或暂停中的会话"));
        return StudySessionConvert.MAPPER.toStudySessionResponse(dto);
    }

    @Override
    public ArrayList<String> getAllFragments(String sessionNum) throws ErrorParameterException {
        if (this.exists(Wrappers.lambdaQuery(StudySessionsEntity.class)
                .eq(StudySessionsEntity::getSessionNum, sessionNum))) {
            // todo guo 后续可在此补充更高级的整理方式
            return studyReportFragmentsMapper.selectList(Wrappers.lambdaQuery(StudyReportFragmentsEntity.class)
                            .eq(StudyReportFragmentsEntity::getSessionNum, sessionNum))
                    .stream().map(StudyReportFragmentsEntity::getContent).collect(Collectors.toCollection(ArrayList::new));
        } else {
            throw new ErrorParameterException("会话[" + sessionNum + "]不存在");
        }
    }

}