package com.trafficaudit.holiday.service;

import com.trafficaudit.holiday.service.HolidayStatService.DailyMetrics;
import org.junit.jupiter.api.Test;

import java.lang.reflect.Method;
import java.math.BigDecimal;
import java.util.function.Function;

import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertNull;
import static org.junit.jupiter.api.Assertions.assertSame;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

class HolidayBulletinServiceTest {

    @Test
    void formatsTableRatiosAsSignedPercentages() throws Exception {
        HolidayBulletinService service = new HolidayBulletinService(null);

        assertEquals("-4.7%", ratio(service, "95.3", "100"));
        assertEquals("1.0%", ratio(service, "101", "100"));
        assertEquals("0%", ratio(service, "100", "100"));
        assertEquals("0%", ratio(service, "10004", "10000"));
        assertEquals("—", ratio(service, "100", null));
        assertEquals("—", ratio(service, "100", "0"));
    }

    @Test
    void comparesCivilAviationOnlyThroughCoveredDay() throws Exception {
        HolidayStatService stat = mock(HolidayStatService.class);
        HolidayBulletinService service = new HolidayBulletinService(stat);

        DailyMetrics current = new DailyMetrics();
        current.setYear(2026);
        current.setHolidayType("NATIONAL_DAY");
        current.setDayIndex(2);

        DailyMetrics coveredDay = new DailyMetrics();
        coveredDay.setCivilAviation(new BigDecimal("6.7482"));
        DailyMetrics missingDay = new DailyMetrics();

        when(stat.dailyMetrics(2026, "NATIONAL_DAY", 2)).thenReturn(missingDay);
        when(stat.dailyMetrics(2026, "NATIONAL_DAY", 1)).thenReturn(coveredDay);

        DailyMetrics previousYear = new DailyMetrics();
        previousYear.setYear(2025);
        DailyMetrics previousYearThroughDay1 = new DailyMetrics();
        previousYearThroughDay1.setCivilAviation(new BigDecimal("7.5003"));
        when(stat.cumulativeMetrics(2025, "NATIONAL_DAY", 1)).thenReturn(previousYearThroughDay1);

        Object result = comparableCumulative(service, current, previousYear, DailyMetrics::getCivilAviation);

        assertSame(previousYearThroughDay1, result);
        verify(stat).cumulativeMetrics(2025, "NATIONAL_DAY", 1);
        verify(stat, never()).cumulativeMetrics(2025, "NATIONAL_DAY", 2);
    }

    @Test
    void comparableCumulativeIsNullWhenCurrentYearHasNoMetricData() throws Exception {
        HolidayStatService stat = mock(HolidayStatService.class);
        HolidayBulletinService service = new HolidayBulletinService(stat);

        DailyMetrics current = new DailyMetrics();
        current.setYear(2026);
        current.setHolidayType("NATIONAL_DAY");
        current.setDayIndex(2);
        when(stat.dailyMetrics(2026, "NATIONAL_DAY", 2)).thenReturn(new DailyMetrics());
        when(stat.dailyMetrics(2026, "NATIONAL_DAY", 1)).thenReturn(new DailyMetrics());

        Object result = comparableCumulative(service, current, new DailyMetrics(), DailyMetrics::getCivilAviation);

        assertNull(result);
        verify(stat, never()).cumulativeMetrics(0, "NATIONAL_DAY", 1);
    }

    @Test
    void cumulativeParagraphUsesWanUnitAndSingleRounding() throws Exception {
        HolidayBulletinService service = new HolidayBulletinService(null);

        DailyMetrics current = new DailyMetrics();
        current.setTotalPersonFlow(new BigDecimal("3088.62958"));
        DailyMetrics previousYear = new DailyMetrics();
        previousYear.setTotalPersonFlow(new BigDecimal("3232.42742"));
        DailyMetrics twoYearsAgo = new DailyMetrics();
        twoYearsAgo.setTotalPersonFlow(new BigDecimal("3137.80860"));

        Method method = HolidayBulletinService.class.getDeclaredMethod(
                "cumulativeParagraph", DailyMetrics.class, DailyMetrics.class, DailyMetrics.class);
        method.setAccessible(true);
        String text = (String) method.invoke(service, current, previousYear, twoYearsAgo);

        assertEquals(
                "假期以来，全省全社会跨区域人员流动量累计3088.63万人次，比2025年同期下降4.4%，比2024年同期下降1.6%。",
                text);
    }

    private Object comparableCumulative(HolidayBulletinService service, DailyMetrics current,
                                        DailyMetrics comparisonYear,
                                        Function<DailyMetrics, BigDecimal> selector) throws Exception {
        Method method = HolidayBulletinService.class.getDeclaredMethod(
                "comparableCumulative", DailyMetrics.class, DailyMetrics.class, Function.class);
        method.setAccessible(true);
        return method.invoke(service, current, comparisonYear, selector);
    }

    private String ratio(HolidayBulletinService service, String current, String base) throws Exception {
        Method method = HolidayBulletinService.class.getDeclaredMethod("ratio", BigDecimal.class, BigDecimal.class);
        method.setAccessible(true);
        BigDecimal currentValue = current == null ? null : new BigDecimal(current);
        BigDecimal baseValue = base == null ? null : new BigDecimal(base);
        return (String) method.invoke(service, currentValue, baseValue);
    }
}