using Arch.Core;
using HSchool.Ai;
using HSchool.Content;
using HSchool.People;
using HSchool.Schedule;

namespace HSchool.Simulation.Tests;

public class SickStaffLessonTests
{
    private static readonly DateTime TuesdayMorning = new(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc);
    private static readonly DateTime LessonStart = new(2012, 4, 3, 8, 30, 0, DateTimeKind.Utc);

    [Fact]
    public void SickTeacherOffCampus_PupilsDoNotGainLikeWithTeacher()
    {
        var (sickSchool, room, pupilId, teacherId) = StaffedMath();
        using (sickSchool)
        {
            InfectHeavyFlu(sickSchool, teacherId);
            var stayDay = TuesdayWithStayHome(sickSchool, teacherId);
            RebuildDayAt(sickSchool, stayDay);
            AdvanceTo(sickSchool, stayDay.Date.Add(LessonStart.TimeOfDay));
            Assert.False(IsOnCampus(sickSchool, teacherId));
            SetPlace(sickSchool, pupilId, room);
            var before = SkillOf(sickSchool, pupilId, "Mathematics");

            LessonLearningSystem.Apply(sickSchool, 45);

            Assert.Equal(before, SkillOf(sickSchool, pupilId, "Mathematics"));
            Assert.Equal(2, MarkOf(sickSchool, pupilId)!.Value);
        }

        var (healthySchool, healthyRoom, healthyPupil, healthyTeacher) = StaffedMath();
        using (healthySchool)
        {
            AdvanceTo(healthySchool, LessonStart);
            SetPlace(healthySchool, healthyPupil, healthyRoom);
            SetPlace(healthySchool, healthyTeacher, healthyRoom);
            var before = SkillOf(healthySchool, healthyPupil, "Mathematics");

            LessonLearningSystem.Apply(healthySchool, 45);

            Assert.True(SkillOf(healthySchool, healthyPupil, "Mathematics") > before);
        }
    }

    [Fact]
    public void SickTeacher_NoticeAndLog_AtMostOncePerSlot()
    {
        var (school, room, pupilId, teacherId) = StaffedMath();
        using (school)
        {
            InfectHeavyFlu(school, teacherId);
            var stayDay = TuesdayWithStayHome(school, teacherId);
            RebuildDayAt(school, stayDay);
            // Jump — do not AdvanceTo through the lesson, or Tick raises the event and claims it.
            school.Clock.JumpTo(DateTime.SpecifyKind(stayDay.Date.Add(LessonStart.TimeOfDay), DateTimeKind.Utc));
            SetPlace(school, pupilId, room);
            SetPlace(school, teacherId, null);
            school.DrainWorldEvents();

            Assert.True(school.Plans.TryGetValue(teacherId, out var plan) && !plan.Comes);

            LessonLearningSystem.Apply(school, 5);
            LessonLearningSystem.Apply(school, 5);
            LessonLearningSystem.Apply(school, 5);

            var logs = school.DayLog
                .Where(row => row.PersonId == pupilId && row.Type == PersonLogTypes.LessonNoTeacher)
                .ToArray();
            Assert.Single(logs);

            var facts = school.DrainWorldEvents()
                .Where(row => row.Trigger.Equals(EventTriggers.LessonNoTeacher, StringComparison.Ordinal))
                .ToArray();
            Assert.Single(facts);
            Assert.Equal(teacherId, facts[0].PersonKey);
        }
    }

    [Fact]
    public void PupilsPresent_WhileTeacherSick_AreNotMarkedTruancy()
    {
        var (school, room, pupilId, teacherId) = StaffedMath();
        using (school)
        {
            InfectHeavyFlu(school, teacherId);
            var stayDay = TuesdayWithStayHome(school, teacherId);
            RebuildDayAt(school, stayDay);
            var lessonAt = stayDay.Date.Add(LessonStart.TimeOfDay);
            AdvanceTo(school, lessonAt.AddMinutes(-1));
            SetPlace(school, pupilId, room);
            SetPlace(school, teacherId, null);

            school.Clock.JumpTo(lessonAt);
            AttendanceSystem.Apply(school);
            school.Clock.JumpTo(lessonAt.AddMinutes(45));
            AttendanceSystem.Apply(school);

            var row = school.Roster!.People.First(p => p.Id == pupilId).Attendance?.LastOrDefault();
            Assert.NotNull(row);
            Assert.Equal(AttendanceStatuses.Present, row!.Status);
            Assert.Null(row.AbsenceReason);
            Assert.NotEqual(AbsenceReasons.Truancy, row.AbsenceReason);
        }
    }

    [Fact]
    public void SameDiseaseSeed_SameStayHomeDecision()
    {
        var (school, _, _, teacherId) = StaffedMath();
        using (school)
        {
            InfectHeavyFlu(school, teacherId);
            var teacher = school.Roster!.People.First(row => row.Id == teacherId);
            var when = LessonStart.AddDays(2);
            var first = DiseaseEffects.ShouldStayHome(teacher, school.Catalog!, school.PeopleSeed, when);
            var second = DiseaseEffects.ShouldStayHome(teacher, school.Catalog!, school.PeopleSeed, when);
            Assert.Equal(first, second);
        }
    }

    private static void InfectHeavyFlu(School school, string teacherId)
    {
        var teacher = school.Roster!.People.First(row => row.Id == teacherId);
        HealthConditions.Add(
            teacher,
            new HealthCondition
            {
                DefName = "Influenza",
                Severity = 0.85f,
                Progress = 0.1f,
                Source = "cold",
                StartedAt = TuesdayMorning.AddDays(-3),
            });
        Assert.True(DiseaseEffects.StayHomeChance(teacher, school.Catalog!, LessonStart) >= 0.9f);
    }

    private static DateTime TuesdayWithStayHome(School school, string teacherId)
    {
        var teacher = school.Roster!.People.First(row => row.Id == teacherId);
        for (var i = 0; i < 60; i++)
        {
            var candidate = LessonStart.AddDays(i * 7);
            if (DiseaseEffects.ShouldStayHome(teacher, school.Catalog!, school.PeopleSeed, candidate))
            {
                return candidate;
            }
        }

        throw new InvalidOperationException("Heavy flu should stay home on some Tuesday.");
    }

    private static void RebuildDayAt(School school, DateTime lessonInstant)
    {
        school.PlanDay = null;
        school.Clock.JumpTo(DateTime.SpecifyKind(lessonInstant.Date.AddHours(6), DateTimeKind.Utc));
        school.Tick(0.2d, 5d);
    }

    private static bool IsOnCampus(School school, string personId)
    {
        var on = false;
        var query = new QueryDescription().WithAll<PersonIdentity, Presence>();
        school.World.Query(
            in query,
            (ref PersonIdentity identity, ref Presence presence) =>
            {
                if (identity.Id.Equals(personId, StringComparison.Ordinal))
                {
                    on = presence.IsOnCampus;
                }
            });
        return on;
    }

    private static LessonMarkRecord? MarkOf(School school, string pupilId) =>
        school.Roster!.People.First(row => row.Id == pupilId).LessonMarks?.LastOrDefault();

    private static void AdvanceTo(School school, DateTime until)
    {
        while (school.Clock.Time < until)
        {
            school.Tick(0.2d, 5d);
        }
    }

    private static void SetPlace(School school, string personId, string? nodeId)
    {
        var query = new QueryDescription().WithAll<PersonIdentity, Presence>();
        school.World.Query(
            in query,
            (ref PersonIdentity identity, ref Presence presence) =>
            {
                if (!identity.Id.Equals(personId, StringComparison.Ordinal))
                {
                    return;
                }

                presence = nodeId is null
                    ? Presence.OffCampus
                    : new Presence(nodeId, 0f, nodeId, false, []);
            });
    }

    private static float SkillOf(School school, string personId, string skill)
    {
        var value = float.NaN;
        var query = new QueryDescription().WithAll<PersonIdentity, PersonSkills>();
        school.World.Query(
            in query,
            (ref PersonIdentity identity, ref PersonSkills skills) =>
            {
                if (identity.Id.Equals(personId, StringComparison.Ordinal))
                {
                    value = skills.Values.GetValueOrDefault(skill);
                }
            });
        return value;
    }

    private static (School School, string Homeroom, string PupilId, string TeacherId) StaffedMath()
    {
        var (catalog, map) = Vanilla();
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 1, "Russia", TuesdayMorning);
        var pool = ApplicantPool.Create(catalog, roster, schoolSeed: 1, "Russia", TuesdayMorning);
        var hired = Staffing.Hire(catalog, map, roster, pool, pool.Applicants[0].Person.Id, Staffing.TeacherPosition, 1_000_000f);
        Assert.Equal(StaffingError.None, hired.Error);
        roster = hired.Roster;
        pool = hired.Pool;
        var hiredId = roster.People.First(person => person.IsStaff).Id;
        var schoolClass = roster.Classes.First(row =>
            row.RoomId is "classroom-101" or "classroom-102" or "classroom-103" or "classroom-104");
        var school = School.Create(1, "Больной учитель", TuesdayMorning, catalog, map);
        school.InstallPeople(roster, seed: 1, "Russia", pool);
        school.SetTimetable(new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", hiredId, schoolClass.RoomId, Day: 1, Period: 1)],
            []));
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
        var pupil = schoolClass.PupilIds
            .Select(id => school.Roster!.People.First(person => person.Id == id))
            .First(person => !person.Traits.Contains("Lazy"));
        return (school, schoolClass.RoomId, pupil.Id, hiredId);
    }

    private static (DefCatalog Catalog, MapLayout Map) Vanilla()
    {
        var root = Path.Combine(AppContext.BaseDirectory, "vanilla");
        var documents = new List<ContentDocument>();
        foreach (var path in Directory.EnumerateFiles(root, "*.*", SearchOption.AllDirectories))
        {
            if (!path.EndsWith(".jsonc", StringComparison.OrdinalIgnoreCase)
                && !path.EndsWith(".json", StringComparison.OrdinalIgnoreCase))
            {
                continue;
            }

            var relative = Path.GetRelativePath(root, path).Replace('\\', '/');
            documents.Add(new ContentDocument(CatalogLoader.CorePackId, relative, File.ReadAllText(path)));
        }

        var catalog = new CatalogLoader().Load([CatalogLoader.CorePackId], documents);
        var map = CatalogLoader.LastDefaultMap([CatalogLoader.CorePackId], documents);
        Assert.NotNull(map);
        return (catalog, map);
    }
}