package com.trafficaudit.holiday.service;

import com.baomidou.mybatisplus.core.conditions.query.LambdaQueryWrapper;
import com.trafficaudit.dataimport.entity.ImportBatch;
import com.trafficaudit.dataimport.mapper.ImportBatchMapper;
import com.trafficaudit.holiday.HolidayConstants;
import com.trafficaudit.holiday.HolidayNumberUtils;
import com.trafficaudit.holiday.entity.HolidayCalendar;
import com.trafficaudit.holiday.entity.HolidayPassengerFlow;
import com.trafficaudit.holiday.entity.HolidayVehicleFlow;
import com.trafficaudit.holiday.mapper.HolidayPassengerFlowMapper;
import com.trafficaudit.holiday.mapper.HolidayVehicleFlowMapper;
import lombok.Data;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.web.multipart.MultipartFile;

import javax.annotation.Resource;
import java.math.BigDecimal;
import java.time.LocalDate;
import java.time.LocalDateTime;
import java.util.ArrayList;
import java.util.Collections;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;

@Service
public class HolidayStatService {

    @Resource
    private HolidayConfigService configService;
    @Resource
    private HolidayWorkbookService workbookService;
    @Resource
    private HolidayPassengerFlowMapper passengerFlowMapper;
    @Resource
    private HolidayVehicleFlowMapper vehicleFlowMapper;
    @Resource
    private ImportBatchMapper importBatchMapper;

    public Map<String, Object> overview(int year, String holidayType) {
        List<HolidayCalendar> calendar = configService.findHolidayDays(year, holidayType);
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("year", year);
        result.put("holidayType", holidayType);
        result.put("holidayTypeLabel", HolidayConstants.HOLIDAY_TYPE_LABELS.get(holidayType));
        result.put("days", calendar);
        result.put("rows", buildOverviewRows(year, holidayType, calendar));
        result.put("templateFileName", workbookService.referenceFileName());
        return result;
    }

    @Transactional
    public Map<String, Object> importWorkbook(MultipartFile file, int year, String holidayType, boolean allowHistoricalOverwrite) {
        HolidayWorkbookService.ImportSummary summary = workbookService.importWorkbook(file, year, holidayType, allowHistoricalOverwrite);
        if (summary.isConfirmationRequired()) {
            return importResult(summary);
        }
        ImportBatch batch = new ImportBatch();
        batch.setFileName(file == null ? null : file.getOriginalFilename());
        batch.setImportType("HOLIDAY_FLOW");
        batch.setReportPeriod(year + "-" + holidayType);
        batch.setTotalRows(summary.getSuccessRows() + summary.getFailRows());
        batch.setSuccessRows(summary.getSuccessRows());
        batch.setFailRows(summary.getFailRows());
        batch.setErrorDetail(joinErrors(summary.getErrors()));
        batch.setCreatedAt(LocalDateTime.now());
        importBatchMapper.insert(batch);

        return importResult(summary);
    }

    private Map<String, Object> importResult(HolidayWorkbookService.ImportSummary summary) {
        Map<String, Object> result = new LinkedHashMap<>();
        result.put("passengerRows", summary.getPassengerRows());
        result.put("vehicleRows", summary.getVehicleRows());
        result.put("skippedRows", summary.getSkippedRows());
        result.put("successRows", summary.getSuccessRows());
        result.put("failRows", summary.getFailRows());
        result.put("errors", summary.getErrors());
        result.put("confirmationRequired", summary.isConfirmationRequired());
        result.put("historicalChanges", summary.getHistoricalChanges());
        return result;
    }

    public byte[] exportWorkbook(int year, String holidayType) {
        return workbookService.exportWorkbook(year, holidayType);
    }

    public List<Map<String, Object>> buildOverviewRows(int year, String holidayType, List<HolidayCalendar> calendar) {
        Map<LocalDate, Map<String, BigDecimal>> passengerByDate = loadPassengerByDate(year);
        Map<LocalDate, Map<String, BigDecimal>> vehicleByDate = loadVehicleByDate(year);
        Map<LocalDate, BigDecimal> comparisonBaseByDate = loadComparisonBaseByDate(year);
        BigDecimal coefficient = configService.coefficientOf(year, HolidayConstants.CATEGORY_HOLIDAY);
        List<Map<String, Object>> rows = new ArrayList<>();
        BigDecimal previousNationalProvincial = null;
        for (HolidayCalendar day : calendar) {
            Map<String, BigDecimal> passenger = passengerByDate.getOrDefault(day.getHolidayDate(), Collections.emptyMap());
            Map<String, BigDecimal> vehicle = vehicleByDate.getOrDefault(day.getHolidayDate(), Collections.emptyMap());
            BigDecimal expressway = vehicle.get(HolidayConstants.ROAD_EXPRESSWAY);
            BigDecimal nationalProvincial = vehicle.get(HolidayConstants.ROAD_NATIONAL_PROVINCIAL);
            BigDecimal comparisonBase = comparisonBaseByDate.get(day.getHolidayDate());
            BigDecimal nationalProvincialRingRatio = nationalProvincialRingRatio(
                    year, nationalProvincial, previousNationalProvincial, comparisonBase);
            BigDecimal nonBusinessPersonFlow = null;
            if (coefficient != null && (expressway != null || nationalProvincial != null)) {
                nonBusinessPersonFlow = HolidayNumberUtils.multiply(
                        HolidayNumberUtils.sumNullable(expressway, nationalProvincial), coefficient);
            }
            Map<String, Object> row = new LinkedHashMap<>();
            row.put("dayIndex", day.getDayIndex());
            row.put("date", day.getHolidayDate());
            row.put("rail", passenger.get(HolidayConstants.MODE_RAIL));
            row.put("civilAviation", passenger.get(HolidayConstants.MODE_CIVIL_AVIATION));
            row.put("road", passenger.get(HolidayConstants.MODE_ROAD));
            row.put("water", passenger.get(HolidayConstants.MODE_WATER));
            row.put("expressway", expressway);
            row.put("nationalProvincial", nationalProvincial);
            row.put("comparisonBase", comparisonBase);
            row.put("nationalProvincialRingRatio", nationalProvincialRingRatio);
            row.put("coefficient", coefficient);
            row.put("nonBusinessPersonFlow", nonBusinessPersonFlow);
            row.put("totalPersonFlow", totalPersonFlow(passenger, nonBusinessPersonFlow));
            rows.add(row);
            previousNationalProvincial = nationalProvincial;
        }
        return rows;
    }

    public DailyMetrics dailyMetrics(int year, String holidayType, int dayIndex) {
        List<HolidayCalendar> calendar = configService.findHolidayDays(year, holidayType);
        HolidayCalendar target = null;
        for (HolidayCalendar day : calendar) {
            if (day.getDayIndex() != null && day.getDayIndex() == dayIndex) {
                target = day;
                break;
            }
        }
        if (target == null) return null;

        Map<LocalDate, Map<String, BigDecimal>> passengerByDate = loadPassengerByDate(year);
        Map<LocalDate, Map<String, BigDecimal>> vehicleByDate = loadVehicleByDate(year);
        Map<LocalDate, BigDecimal> comparisonBaseByDate = loadComparisonBaseByDate(year);
        Map<String, BigDecimal> passenger = passengerByDate.getOrDefault(target.getHolidayDate(), Collections.emptyMap());
        Map<String, BigDecimal> vehicle = vehicleByDate.getOrDefault(target.getHolidayDate(), Collections.emptyMap());
        BigDecimal coefficient = configService.coefficientOf(year, HolidayConstants.CATEGORY_HOLIDAY);
        BigDecimal expressway = vehicle.get(HolidayConstants.ROAD_EXPRESSWAY);
        BigDecimal nationalProvincial = vehicle.get(HolidayConstants.ROAD_NATIONAL_PROVINCIAL);
        BigDecimal comparisonBase = comparisonBaseByDate.get(target.getHolidayDate());
        BigDecimal nonBusiness = null;
        if (coefficient != null && (expressway != null || nationalProvincial != null)) {
            nonBusiness = HolidayNumberUtils.multiply(
                    HolidayNumberUtils.sumNullable(expressway, nationalProvincial), coefficient);
        }

        DailyMetrics metrics = new DailyMetrics();
        metrics.setYear(year);
        metrics.setHolidayType(holidayType);
        metrics.setDayIndex(dayIndex);
        metrics.setDate(target.getHolidayDate());
        metrics.setRail(passenger.get(HolidayConstants.MODE_RAIL));
        metrics.setCivilAviation(passenger.get(HolidayConstants.MODE_CIVIL_AVIATION));
        metrics.setRoad(passenger.get(HolidayConstants.MODE_ROAD));
        metrics.setWater(passenger.get(HolidayConstants.MODE_WATER));
        metrics.setExpressway(expressway);
        metrics.setNationalProvincial(nationalProvincial);
        metrics.setComparisonBase(comparisonBase);
        metrics.setCoefficient(coefficient);
        metrics.setNonBusinessPersonFlow(nonBusiness);
        metrics.setRoadPersonFlow(sumNullable(metrics.getRoad(), nonBusiness));
        metrics.setTotalPersonFlow(totalPersonFlow(passenger, nonBusiness));
        return metrics;
    }

    public DailyMetrics cumulativeMetrics(int year, String holidayType, int dayIndex) {
        DailyMetrics cumulative = new DailyMetrics();
        cumulative.setYear(year);
        cumulative.setHolidayType(holidayType);
        cumulative.setDayIndex(dayIndex);
        for (int day = 1; day <= dayIndex; day++) {
            DailyMetrics item = dailyMetrics(year, holidayType, day);
            if (item == null) continue;
            cumulative.setRail(sumNullable(cumulative.getRail(), item.getRail()));
            cumulative.setCivilAviation(sumNullable(cumulative.getCivilAviation(), item.getCivilAviation()));
            cumulative.setRoad(sumNullable(cumulative.getRoad(), item.getRoad()));
            cumulative.setWater(sumNullable(cumulative.getWater(), item.getWater()));
            cumulative.setExpressway(sumNullable(cumulative.getExpressway(), item.getExpressway()));
            cumulative.setNationalProvincial(sumNullable(cumulative.getNationalProvincial(), item.getNationalProvincial()));
            cumulative.setNonBusinessPersonFlow(sumNullable(cumulative.getNonBusinessPersonFlow(), item.getNonBusinessPersonFlow()));
            cumulative.setRoadPersonFlow(sumNullable(cumulative.getRoadPersonFlow(), item.getRoadPersonFlow()));
            cumulative.setTotalPersonFlow(sumNullable(cumulative.getTotalPersonFlow(), item.getTotalPersonFlow()));
        }
        return cumulative;
    }


    public DailyMetrics findMetricsByDate(LocalDate date) {
        HolidayCalendar calendar = configService.findHolidayByDate(date);
        if (calendar == null) return null;
        return dailyMetrics(calendar.getYear(), calendar.getHolidayType(), calendar.getDayIndex());
    }

    private Map<LocalDate, Map<String, BigDecimal>> loadPassengerByDate(int year) {
        Map<LocalDate, Map<String, BigDecimal>> result = new LinkedHashMap<>();
        List<HolidayPassengerFlow> rows = passengerFlowMapper.selectList(
                new LambdaQueryWrapper<HolidayPassengerFlow>().eq(HolidayPassengerFlow::getYear, year));
        for (HolidayPassengerFlow row : rows) {
            result.computeIfAbsent(row.getFlowDate(), key -> new LinkedHashMap<>())
                    .put(row.getTransportMode(), row.getPassengerCount());
        }
        return result;
    }

    private Map<LocalDate, Map<String, BigDecimal>> loadVehicleByDate(int year) {
        Map<LocalDate, Map<String, BigDecimal>> result = new LinkedHashMap<>();
        List<HolidayVehicleFlow> rows = vehicleFlowMapper.selectList(
                new LambdaQueryWrapper<HolidayVehicleFlow>().eq(HolidayVehicleFlow::getYear, year));
        for (HolidayVehicleFlow row : rows) {
            result.computeIfAbsent(row.getFlowDate(), key -> new LinkedHashMap<>())
                    .put(row.getRoadCategory(), row.getVehicleCount());
        }
        return result;
    }

    private Map<LocalDate, BigDecimal> loadComparisonBaseByDate(int year) {
        Map<LocalDate, BigDecimal> result = new LinkedHashMap<>();
        List<HolidayVehicleFlow> rows = vehicleFlowMapper.selectList(
                new LambdaQueryWrapper<HolidayVehicleFlow>()
                        .eq(HolidayVehicleFlow::getYear, year)
                        .eq(HolidayVehicleFlow::getRoadCategory, HolidayConstants.ROAD_NATIONAL_PROVINCIAL));
        for (HolidayVehicleFlow row : rows) {
            if (row.getComparisonBase() != null) result.put(row.getFlowDate(), row.getComparisonBase());
        }
        return result;
    }

    private BigDecimal totalPersonFlow(Map<String, BigDecimal> passenger, BigDecimal nonBusinessPersonFlow) {
        BigDecimal total = nonBusinessPersonFlow;
        total = sumNullable(total, passenger.get(HolidayConstants.MODE_ROAD));
        total = sumNullable(total, passenger.get(HolidayConstants.MODE_RAIL));
        total = sumNullable(total, passenger.get(HolidayConstants.MODE_CIVIL_AVIATION));
        total = sumNullable(total, passenger.get(HolidayConstants.MODE_WATER));
        return total;
    }

    private BigDecimal nationalProvincialRingRatio(int year, BigDecimal current,
                                                   BigDecimal previous, BigDecimal comparisonBase) {
        if (current == null) return null;
        if (HolidayConstants.supportsComparisonBase(year) && comparisonBase != null) {
            return ratio(current, comparisonBase);
        }
        return previous == null ? null : ratio(current, previous);
    }

    private BigDecimal ratio(BigDecimal current, BigDecimal base) {
        BigDecimal quotient = HolidayNumberUtils.divide(current, base);
        return quotient == null ? null : HolidayNumberUtils.normalize(quotient.subtract(BigDecimal.ONE));
    }

    private BigDecimal sumNullable(BigDecimal left, BigDecimal right) {
        return HolidayNumberUtils.sumNullable(left, right);
    }

    private String joinErrors(List<String> errors) {
        if (errors == null || errors.isEmpty()) return null;
        StringBuilder builder = new StringBuilder();
        int limit = Math.min(errors.size(), 200);
        for (int i = 0; i < limit; i++) {
            if (i > 0) builder.append('\n');
            builder.append(errors.get(i));
        }
        if (errors.size() > limit) {
            builder.append("\n... ").append(errors.size() - limit).append(" more");
        }
        return builder.toString();
    }

    @Data
    public static class DailyMetrics {
        private int year;
        private String holidayType;
        private int dayIndex;
        private LocalDate date;
        private BigDecimal rail;
        private BigDecimal civilAviation;
        private BigDecimal road;
        private BigDecimal water;
        private BigDecimal expressway;
        private BigDecimal nationalProvincial;
        private BigDecimal comparisonBase;
        private BigDecimal coefficient;
        private BigDecimal nonBusinessPersonFlow;
        private BigDecimal roadPersonFlow;
        private BigDecimal totalPersonFlow;
    }
}