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

import cn.idev.excel.FastExcel;
import com.tcm.training.admin.trade.service.PaymentFlowAppService;
import com.tcm.training.admin.statistics.excel.RevenueStatisticsExcelRow;
import com.tcm.training.admin.statistics.mapper.RevenueStatisticsMapper;
import com.tcm.training.admin.statistics.row.RevenueStatisticsDailyRow;
import com.tcm.training.admin.statistics.vo.RevenueStatisticsOverviewVO;
import com.tcm.training.admin.statistics.vo.RevenueStatisticsTrendItemVO;
import com.tcm.training.admin.statistics.vo.RevenueStatisticsVO;
import org.springframework.stereotype.Service;

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.net.URLEncoder;
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 RevenueStatisticsAppService {

    private static final String FILTER_ALL = "ALL";
    private static final String FILTER_HEALTH = "HEALTH";
    private static final String FILTER_MEMBER = "MEMBER";
    private static final String BUSINESS_TYPE_HEALTH = "COURSE_PURCHASE";
    private static final String BUSINESS_TYPE_MEMBER = "MEMBER_PURCHASE";

    private final RevenueStatisticsMapper revenueStatisticsMapper;
    private final PaymentFlowAppService paymentFlowAppService;

    public RevenueStatisticsAppService(RevenueStatisticsMapper revenueStatisticsMapper,
                                       PaymentFlowAppService paymentFlowAppService) {
        this.revenueStatisticsMapper = revenueStatisticsMapper;
        this.paymentFlowAppService = paymentFlowAppService;
    }

    public RevenueStatisticsVO statistics(String type, LocalDate dateFrom, LocalDate dateTo) {
        DateRange range = normalizeRange(dateFrom, dateTo);
        String normalizedType = normalizeType(type);

        paymentFlowAppService.syncFlows();

        List<RevenueStatisticsDailyRow> rows = revenueStatisticsMapper.selectDailyStatistics(
                resolveBusinessType(normalizedType),
                range.getStart().atStartOfDay(),
                LocalDateTime.of(range.getEnd(), LocalTime.MAX)
        );
        List<RevenueStatisticsTrendItemVO> trend = buildTrend(rows, range);

        RevenueStatisticsVO result = new RevenueStatisticsVO();
        result.setOverview(buildOverview(trend));
        result.setTrend(trend);
        return result;
    }

    public void export(HttpServletResponse response, String type, LocalDate dateFrom, LocalDate dateTo) throws IOException {
        RevenueStatisticsVO statistics = statistics(type, dateFrom, dateTo);

        response.setContentType("application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        response.setCharacterEncoding("utf-8");
        String filename = URLEncoder.encode("营收数据统计", "UTF-8").replace("+", "%20");
        response.setHeader("Content-Disposition", "attachment;filename*=utf-8''" + filename + ".xlsx");

        List<RevenueStatisticsExcelRow> exports = new ArrayList<RevenueStatisticsExcelRow>();
        for (RevenueStatisticsTrendItemVO item : statistics.getTrend()) {
            RevenueStatisticsExcelRow export = new RevenueStatisticsExcelRow();
            export.setDate(item.getDate());
            export.setTotalIncome(formatAmount(item.getTotalIncome()));
            export.setHealthIncome(formatAmount(item.getHealthIncome()));
            export.setMemberIncome(formatAmount(item.getMemberIncome()));
            export.setRefundAmount(formatAmount(item.getRefundAmount()));
            export.setProfit(formatAmount(item.getProfit()));
            exports.add(export);
        }
        FastExcel.write(response.getOutputStream(), RevenueStatisticsExcelRow.class)
                .sheet("营收数据")
                .doWrite(exports);
    }

    private List<RevenueStatisticsTrendItemVO> buildTrend(List<RevenueStatisticsDailyRow> rows, DateRange range) {
        Map<LocalDate, RevenueStatisticsDailyRow> rowMap = new HashMap<LocalDate, RevenueStatisticsDailyRow>();
        for (RevenueStatisticsDailyRow row : rows) {
            rowMap.put(row.getStatDate(), row);
        }

        List<RevenueStatisticsTrendItemVO> result = new ArrayList<RevenueStatisticsTrendItemVO>();
        LocalDate cursor = range.getStart();
        while (!cursor.isAfter(range.getEnd())) {
            RevenueStatisticsDailyRow row = rowMap.get(cursor);
            BigDecimal healthIncome = nvl(row == null ? null : row.getHealthIncome());
            BigDecimal memberIncome = nvl(row == null ? null : row.getMemberIncome());
            BigDecimal healthRefundAmount = nvl(row == null ? null : row.getHealthRefundAmount());
            BigDecimal memberRefundAmount = nvl(row == null ? null : row.getMemberRefundAmount());
            BigDecimal refundAmount = healthRefundAmount.add(memberRefundAmount);
            BigDecimal totalIncome = healthIncome.add(memberIncome);

            RevenueStatisticsTrendItemVO item = new RevenueStatisticsTrendItemVO();
            item.setDate(cursor.toString());
            item.setHealthIncome(healthIncome);
            item.setMemberIncome(memberIncome);
            item.setHealthRefundAmount(healthRefundAmount);
            item.setMemberRefundAmount(memberRefundAmount);
            item.setTotalIncome(totalIncome);
            item.setRefundAmount(refundAmount);
            item.setProfit(totalIncome.subtract(refundAmount));
            result.add(item);
            cursor = cursor.plusDays(1);
        }
        return result;
    }

    private RevenueStatisticsOverviewVO buildOverview(List<RevenueStatisticsTrendItemVO> trend) {
        RevenueStatisticsOverviewVO overview = new RevenueStatisticsOverviewVO();
        BigDecimal totalIncome = BigDecimal.ZERO;
        BigDecimal healthIncome = BigDecimal.ZERO;
        BigDecimal memberIncome = BigDecimal.ZERO;
        BigDecimal refundAmount = BigDecimal.ZERO;
        BigDecimal profit = BigDecimal.ZERO;

        for (RevenueStatisticsTrendItemVO item : trend) {
            totalIncome = totalIncome.add(nvl(item.getTotalIncome()));
            healthIncome = healthIncome.add(nvl(item.getHealthIncome()));
            memberIncome = memberIncome.add(nvl(item.getMemberIncome()));
            refundAmount = refundAmount.add(nvl(item.getRefundAmount()));
            profit = profit.add(nvl(item.getProfit()));
        }

        overview.setTotalIncome(totalIncome);
        overview.setHealthIncome(healthIncome);
        overview.setMemberIncome(memberIncome);
        overview.setRefundAmount(refundAmount);
        overview.setProfit(profit);
        return overview;
    }

    private String normalizeType(String type) {
        String normalized = trimToNull(type);
        if (normalized == null) {
            return FILTER_ALL;
        }
        if (FILTER_ALL.equals(normalized) || FILTER_HEALTH.equals(normalized) || FILTER_MEMBER.equals(normalized)) {
            return normalized;
        }
        throw new IllegalArgumentException("统计类型不合法");
    }

    private String resolveBusinessType(String normalizedType) {
        if (FILTER_HEALTH.equals(normalizedType)) {
            return BUSINESS_TYPE_HEALTH;
        }
        if (FILTER_MEMBER.equals(normalizedType)) {
            return BUSINESS_TYPE_MEMBER;
        }
        return null;
    }

    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 String formatAmount(BigDecimal value) {
        return nvl(value).setScale(2, RoundingMode.HALF_UP).toPlainString();
    }

    private BigDecimal nvl(BigDecimal value) {
        return value == null ? BigDecimal.ZERO : value;
    }

    private String trimToNull(String value) {
        if (value == null) {
            return null;
        }
        String trimmed = value.trim();
        return trimmed.isEmpty() ? null : trimmed;
    }

    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;
        }
    }
}