package com.guwan.backend.service.impl;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.baomidou.mybatisplus.core.metadata.IPage;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.guwan.backend.pojo.dto.ReadingStatistics;
import com.guwan.backend.pojo.entity.ReadingProgress;
import com.guwan.backend.mapper.ReadingProgressMapper;
import com.guwan.backend.service.ReadingProgressService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

import java.time.LocalDateTime;

@Slf4j
@Service
@RequiredArgsConstructor
public class ReadingProgressServiceImpl implements ReadingProgressService {

    private final ReadingProgressMapper progressMapper;

    @Override
    @Transactional
    public ReadingProgress updateProgress(ReadingProgress progress) {
        progress.setLastReadTime(LocalDateTime.now());
        
        // 检查是否存在记录
        ReadingProgress existing = getProgress(progress.getUserId(), progress.getBookId());
        if (existing != null) {
            progress.setId(existing.getId());
            progressMapper.updateById(progress);
        } else {
            progressMapper.insert(progress);
        }
        return progress;
    }

    @Override
    public ReadingProgress getProgress(Long userId, Long bookId) {
        return progressMapper.selectOne(
            new LambdaQueryWrapper<ReadingProgress>()
                .eq(ReadingProgress::getUserId, userId)
                .eq(ReadingProgress::getBookId, bookId)
        );
    }

    @Override
    public IPage<ReadingProgress> getUserProgress(Long userId, Integer pageNum, Integer pageSize) {
        return progressMapper.selectPage(
            new Page<>(pageNum, pageSize),
            new LambdaQueryWrapper<ReadingProgress>()
                .eq(ReadingProgress::getUserId, userId)
                .orderByDesc(ReadingProgress::getLastReadTime)
        );
    }

    @Override
    public IPage<ReadingProgress> getProgressByStatus(Long userId, String status, Integer pageNum, Integer pageSize) {
        return progressMapper.selectPage(
            new Page<>(pageNum, pageSize),
            new LambdaQueryWrapper<ReadingProgress>()
                .eq(ReadingProgress::getUserId, userId)
                .eq(ReadingProgress::getStatus, status)
                .orderByDesc(ReadingProgress::getLastReadTime)
        );
    }

    @Override
    @Transactional
    public void updateReadingTime(Long userId, Long bookId, Integer minutes) {
        ReadingProgress progress = getProgress(userId, bookId);
        if (progress != null) {
            progress.setReadingTime(progress.getReadingTime() + minutes);
            progress.setLastReadTime(LocalDateTime.now());
            progressMapper.updateById(progress);
        }
    }

    @Override
    public ReadingStatistics getReadingStatistics(Long userId) {
        // TODO: 实现阅读统计逻辑
        return new ReadingStatistics();
    }
}