package com.tcm.training.admin.statistics.service;

import com.tcm.training.admin.statistics.mapper.ContentStatisticsMapper;
import com.tcm.training.admin.statistics.row.ContentStatisticsDailyRow;
import com.tcm.training.admin.statistics.vo.ContentStatisticsOverviewVO;
import com.tcm.training.admin.statistics.vo.ContentStatisticsTrendItemVO;
import com.tcm.training.admin.statistics.vo.ContentStatisticsVO;
import org.springframework.stereotype.Service;

import java.time.LocalDate;
import java.time.LocalDateTime;
import java.time.LocalTime;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Service
public class ContentStatisticsAppService {

    private final ContentStatisticsMapper contentStatisticsMapper;

    public ContentStatisticsAppService(ContentStatisticsMapper contentStatisticsMapper) {
        this.contentStatisticsMapper = contentStatisticsMapper;
    }

    public ContentStatisticsVO statistics(LocalDate dateFrom, LocalDate dateTo) {
        DateRange range = normalizeRange(dateFrom, dateTo);
        List<ContentStatisticsDailyRow> rows = contentStatisticsMapper.selectDailyStatistics(
                range.getStart().atStartOfDay(),
                LocalDateTime.of(range.getEnd(), LocalTime.MAX)
        );

        Map<LocalDate, ContentStatisticsDailyRow> rowMap = new HashMap<LocalDate, ContentStatisticsDailyRow>();
        for (ContentStatisticsDailyRow row : rows) {
            rowMap.put(row.getStatDate(), row);
        }

        ContentStatisticsOverviewVO overview = new ContentStatisticsOverviewVO();
        overview.setVideoPlayCount(0L);
        overview.setCourseFavoriteCount(0L);
        overview.setPointsEarnedCount(0L);
        overview.setConsultClickCount(0L);

        List<ContentStatisticsTrendItemVO> contentTrend = new ArrayList<ContentStatisticsTrendItemVO>();
        List<ContentStatisticsTrendItemVO> pointsTrend = new ArrayList<ContentStatisticsTrendItemVO>();

        LocalDate cursor = range.getStart();
        while (!cursor.isAfter(range.getEnd())) {
            ContentStatisticsDailyRow row = rowMap.get(cursor);
            Long videoPlayCount = nvl(row == null ? null : row.getVideoPlayCount());
            Long courseFavoriteCount = nvl(row == null ? null : row.getCourseFavoriteCount());
            Long consultClickCount = nvl(row == null ? null : row.getConsultClickCount());
            Long pointsEarnedCount = nvl(row == null ? null : row.getPointsEarnedCount());

            ContentStatisticsTrendItemVO contentTrendItem = new ContentStatisticsTrendItemVO();
            contentTrendItem.setDate(cursor.toString());
            contentTrendItem.setVideoPlayCount(videoPlayCount);
            contentTrendItem.setCourseFavoriteCount(courseFavoriteCount);
            contentTrendItem.setConsultClickCount(consultClickCount);
            contentTrend.add(contentTrendItem);

            ContentStatisticsTrendItemVO pointsTrendItem = new ContentStatisticsTrendItemVO();
            pointsTrendItem.setDate(cursor.toString());
            pointsTrendItem.setPointsEarnedCount(pointsEarnedCount);
            pointsTrend.add(pointsTrendItem);

            overview.setVideoPlayCount(overview.getVideoPlayCount() + videoPlayCount);
            overview.setCourseFavoriteCount(overview.getCourseFavoriteCount() + courseFavoriteCount);
            overview.setConsultClickCount(overview.getConsultClickCount() + consultClickCount);
            overview.setPointsEarnedCount(overview.getPointsEarnedCount() + pointsEarnedCount);
            cursor = cursor.plusDays(1);
        }

        ContentStatisticsVO result = new ContentStatisticsVO();
        result.setOverview(overview);
        result.setContentTrend(contentTrend);
        result.setPointsTrend(pointsTrend);
        return result;
    }

    private DateRange normalizeRange(LocalDate dateFrom, LocalDate dateTo) {
        LocalDate start = dateFrom;
        LocalDate end = dateTo;
        if (start == null && end == null) {
            start = LocalDate.now();
            end = start;
        } else if (start == null) {
            start = end;
        } else if (end == null) {
            end = start;
        }
        if (start.isAfter(end)) {
            throw new IllegalArgumentException("开始日期不能晚于结束日期");
        }
        return new DateRange(start, end);
    }

    private Long nvl(Long value) {
        return value == null ? 0L : value;
    }

    private static class DateRange {
        private final LocalDate start;
        private final LocalDate end;

        private DateRange(LocalDate start, LocalDate end) {
            this.start = start;
            this.end = end;
        }

        private LocalDate getStart() {
            return start;
        }

        private LocalDate getEnd() {
            return end;
        }
    }
}