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

namespace HSchool.Simulation.Tests;

public class PresenceTests
{
    private static readonly DateTime TuesdayMorning = new(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc);
    private static readonly float Cap = 100_000f;

    [Fact]
    public void SundayAndHoliday_LeaveTheCampusEmpty()
    {
        var (catalog, map) = Vanilla();
        var sunday = new DateTime(2012, 4, 8, 10, 0, 0, DateTimeKind.Utc);
        using var onSunday = Open(catalog, map, sunday, seed: 1);
        onSunday.Tick(0.2d, 5d);
        Assert.True(onSunday.IsCampusEmpty());
        Assert.All(onSunday.CapturePresence(), row => Assert.Null(row.NodeId));

        var holiday = new DateTime(2012, 6, 1, 10, 0, 0, DateTimeKind.Utc);
        using var onHoliday = Open(catalog, map, holiday, seed: 1);
        onHoliday.Tick(0.2d, 5d);
        Assert.True(onHoliday.IsCampusEmpty());
    }

    [Fact]
    public void ClassWithoutLessons_StaysAway_TeacherWithAnotherClassComes()
    {
        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 idle = roster.Classes[0];
        var busy = roster.Classes[1];
        var hired = Staffing.Hire(catalog, map, roster, pool, pool.Applicants[0].Person.Id, Staffing.TeacherPosition, Cap);
        Assert.Equal(StaffingError.None, hired.Error);

        using var school = School.Create(1, "Два класса", TuesdayMorning, catalog, map);
        school.InstallPeople(hired.Roster, seed: 1, "Russia", hired.Pool);
        school.SetTimetable(new Timetable(
            [new LessonPlacement(busy.Id, "Mathematics", hired.Roster.People.First(person => person.IsStaff).Id, busy.RoomId, Day: 1, Period: 1)],
            []));
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);

        AdvanceTo(school, new DateTime(2012, 4, 3, 8, 30, 0, DateTimeKind.Utc));

        var teacherId = school.Roster!.People.First(person => person.IsStaff).Id;
        var idlePupil = idle.PupilIds[0];
        var byId = school.CapturePresence().ToDictionary(row => row.PersonId, StringComparer.Ordinal);
        Assert.Null(byId[idlePupil].NodeId);
        Assert.NotNull(byId[teacherId].NodeId);
    }

    [Fact]
    public void FirstLesson_PutsThePupilInTheirHomeroom()
    {
        var (school, homeroom, pupilId) = StaffedFirstFloorClass();
        using (school)
        {
            AdvanceTo(school, new DateTime(2012, 4, 3, 8, 30, 0, DateTimeKind.Utc));

            var row = school.CapturePresence().Single(item => item.PersonId == pupilId);
            Assert.Equal(homeroom, row.NodeId);
            Assert.Empty(row.Path);
        }
    }

    [Fact]
    public void PhysicalEducationAfterAClassroomLesson_ReachesTheGymOnTheBreak()
    {
        var (catalog, map) = Vanilla();
        var walks = WalkGraph.Build(catalog, map);
        Assert.Equal(6f, walks.Minutes("classroom-101", "gym-hall"));
        Assert.True(walks.Minutes("classroom-101", "gym-hall") < catalog.DayFrame!.BreakMinutes);

        var (school, _, pupilId) = StaffedFirstFloorClass();
        using (school)
        {
            AdvanceTo(school, new DateTime(2012, 4, 3, 9, 25, 0, DateTimeKind.Utc));
            var row = school.CapturePresence().Single(item => item.PersonId == pupilId);
            Assert.Equal("gym-hall", row.NodeId);
            Assert.Empty(row.Path);
        }
    }

    [Fact]
    public void SameSeedAndMap_YieldTheSamePlaces()
    {
        var (catalog, map) = Vanilla();
        using var a = OpenStaffed(catalog, map, seed: 9);
        using var b = OpenStaffed(catalog, map, seed: 9);
        var until = new DateTime(2012, 4, 3, 9, 20, 0, DateTimeKind.Utc);
        AdvanceTo(a, until);
        AdvanceTo(b, until);

        Assert.Equal(Fingerprint(a.CapturePresence()), Fingerprint(b.CapturePresence()));
    }

    [Fact]
    public void SaveAndLoadMidBreak_DoesNotTeleport()
    {
        var (catalog, map) = Vanilla();
        using var live = OpenStaffed(catalog, map, seed: 4);
        AdvanceTo(live, new DateTime(2012, 4, 3, 9, 18, 0, DateTimeKind.Utc));
        var snapshot = live.CapturePresence();
        Assert.Contains(snapshot, row => row.NodeId is not null && (row.Path.Count > 0 || row.RemainingMinutes > 0));

        using var loaded = School.Load(2, "Сейв", live.Clock.Time, running: true, speedIndex: 0, catalog, map);
        loaded.InstallPeople(live.Roster!, seed: 4, "Russia", live.Applicants);
        loaded.SetTimetable(live.Timetable!);
        loaded.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
        loaded.RestorePresence(snapshot);

        Assert.Equal(Fingerprint(snapshot), Fingerprint(loaded.CapturePresence()));
    }

    [Fact]
    public void SkipEmpty_FromSaturdayLandsOnMondaySix()
    {
        using var school = OpenEmpty(new DateTime(2012, 4, 7, 10, 0, 0, DateTimeKind.Utc));
        var result = school.TrySkipEmpty();

        Assert.True(result.Succeeded);
        Assert.Equal(new DateTime(2012, 4, 9, 6, 0, 0, DateTimeKind.Utc), school.Clock.Time);
    }

    [Fact]
    public void SkipEmpty_FromTuesdayNightLandsOnThatMorning()
    {
        using var school = OpenEmpty(new DateTime(2012, 4, 3, 3, 0, 0, DateTimeKind.Utc));
        var result = school.TrySkipEmpty();

        Assert.True(result.Succeeded);
        Assert.Equal(new DateTime(2012, 4, 3, 6, 0, 0, DateTimeKind.Utc), school.Clock.Time);
    }

    [Fact]
    public void SkipEmpty_FromTuesdayEveningLandsOnWednesday()
    {
        using var school = OpenEmpty(new DateTime(2012, 4, 3, 22, 0, 0, DateTimeKind.Utc));
        var result = school.TrySkipEmpty();

        Assert.True(result.Succeeded);
        Assert.Equal(new DateTime(2012, 4, 4, 6, 0, 0, DateTimeKind.Utc), school.Clock.Time);
    }

    [Fact]
    public void SkipEmpty_InTheWorkWindow_IsRejectedEvenWhenEmpty()
    {
        using var school = OpenEmpty(new DateTime(2012, 4, 3, 7, 0, 0, DateTimeKind.Utc));
        Assert.True(school.IsCampusEmpty());

        var result = school.TrySkipEmpty();

        Assert.False(result.Succeeded);
        Assert.Equal(SkipEmptyError.InWorkWindow, result.Error);
        Assert.Equal(new DateTime(2012, 4, 3, 7, 0, 0, DateTimeKind.Utc), school.Clock.Time);
    }

    [Fact]
    public void SkipEmpty_SchoolWithoutTeachers_StillHasAWorkDay()
    {
        using var school = OpenEmpty(new DateTime(2012, 4, 3, 10, 0, 0, DateTimeKind.Utc));
        Assert.Equal(0, school.Roster!.People.Count(person => person.IsStaff));

        var result = school.TrySkipEmpty();

        Assert.False(result.Succeeded);
        Assert.Equal(SkipEmptyError.InWorkWindow, result.Error);
    }

    [Fact]
    public void SkipEmpty_OverSummer_RunsFirstSeptemberIntake()
    {
        var start = new DateTime(2012, 6, 1, 22, 0, 0, DateTimeKind.Utc);
        using var school = OpenEmpty(start);
        var before = school.Roster!;
        var oldest = before.Classes.Max(row => row.Year);
        var graduated = before.Classes
            .Where(row => row.Year == oldest)
            .SelectMany(row => row.PupilIds)
            .ToHashSet(StringComparer.Ordinal);

        var result = school.TrySkipEmpty();

        Assert.True(result.Succeeded);
        Assert.True(result.PeopleChanged);
        Assert.Equal(new DateTime(2012, 9, 3, 6, 0, 0, DateTimeKind.Utc), school.Clock.Time);
        Assert.Contains(school.Roster!.Classes, row => row.Year == 1);
        Assert.DoesNotContain(school.Roster.People, person => graduated.Contains(person.Id));
        Assert.Equal(before.People.Count(person => person.IsStudent), school.Roster.People.Count(person => person.IsStudent));
    }

    [Fact]
    public void SkipEmpty_Week_MatchesALivedWeek()
    {
        var start = new DateTime(2012, 4, 6, 22, 0, 0, DateTimeKind.Utc);
        var until = new DateTime(2012, 4, 9, 6, 0, 0, DateTimeKind.Utc);
        using var skipped = OpenEmpty(start);
        using var lived = OpenEmpty(start);

        Assert.True(skipped.TrySkipEmpty().Succeeded);
        while (lived.Clock.Time < until)
        {
            lived.Tick(0.2d, 5d);
        }

        Assert.Equal(until, skipped.Clock.Time);
        Assert.Equal(until, lived.Clock.Time);
        Assert.Equal(skipped.Applicants!.Week, lived.Applicants!.Week);
        Assert.Equal(
            skipped.Applicants.Applicants.Select(row => row.Person.Id),
            lived.Applicants.Applicants.Select(row => row.Person.Id));
        Assert.Equal(
            skipped.Roster!.People.Select(person => person.Id).Order(StringComparer.Ordinal),
            lived.Roster!.People.Select(person => person.Id).Order(StringComparer.Ordinal));
        Assert.True(skipped.IsCampusEmpty());
        Assert.True(lived.IsCampusEmpty());
        Assert.Equal(Fingerprint(skipped.CapturePresence()), Fingerprint(lived.CapturePresence()));
    }

    [Fact]
    public void HireAndAssignMath_DuringLessonThree_PutsSomeoneOnCampus()
    {
        var start = new DateTime(2012, 4, 3, 10, 20, 0, DateTimeKind.Utc);
        using var school = OpenEmpty(start);
        school.Tick(0.2d, 5d);
        Assert.True(school.IsCampusEmpty());

        var catalog = school.Catalog!;
        var map = school.Map!;
        var hired = Staffing.Hire(
            catalog,
            map,
            school.Roster!,
            school.Applicants!,
            school.Applicants!.Applicants[0].Person.Id,
            Staffing.TeacherPosition,
            Cap);
        Assert.Equal(StaffingError.None, hired.Error);
        school.ApplyStaffing(hired.Roster, hired.Pool);

        var assigned = Staffing.AssignSubject(catalog, hired.Roster, hired.Pool, hired.Roster.People.Single(person => person.IsStaff).Id, "Mathematics", Cap);
        Assert.Equal(StaffingError.None, assigned.Error);
        school.ApplyStaffing(assigned.Roster, assigned.Pool);
        school.SetTimetable(SchoolTimetables.Build(catalog, map, assigned.Roster, null, weekDays: 5));

        for (var i = 0; i < 20; i++)
        {
            school.Tick(0.2d, 5d);
        }

        Assert.Contains(school.CapturePresence(), row => row.NodeId is not null);
    }

    [Fact]
    public void Simulation_DoesNotReferenceSockets()
    {
        var names = typeof(School).Assembly.GetReferencedAssemblies().Select(assembly => assembly.Name!);
        Assert.DoesNotContain(names, name => name.Contains("Sockets", StringComparison.OrdinalIgnoreCase));
        Assert.DoesNotContain(names, name => name.Contains("AspNet", StringComparison.OrdinalIgnoreCase));
    }

    private static (School School, string Homeroom, string PupilId) StaffedFirstFloorClass()
    {
        var (catalog, map) = Vanilla();
        var school = OpenStaffed(catalog, map, seed: 1);
        var homeroomClass = school.Roster!.Classes.First(row =>
            row.RoomId is "classroom-101" or "classroom-102" or "classroom-103" or "classroom-104");
        var pupil = homeroomClass.PupilIds
            .Select(id => school.Roster.People.First(person => person.Id == id))
            .First(person => !person.Traits.Contains("Lazy"));
        return (school, homeroomClass.RoomId, pupil.Id);
    }

    private static School OpenStaffed(DefCatalog catalog, MapLayout map, int seed)
    {
        var roster = RosterGenerator.Generate(catalog, map, seed, "Russia", TuesdayMorning);
        var pool = ApplicantPool.Create(catalog, roster, seed, "Russia", TuesdayMorning);
        var schoolClass = roster.Classes.First(row =>
            row.RoomId is "classroom-101" or "classroom-102" or "classroom-103" or "classroom-104");
        var school = School.Create(seed, "Присутствие", TuesdayMorning, catalog, map);
        school.InstallPeople(roster, seed, "Russia", pool);
        school.SetTimetable(new Timetable(
            [
                new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1),
                new LessonPlacement(schoolClass.Id, "PhysicalEducation", "t2", "gym-hall", Day: 1, Period: 2),
            ],
            []));
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
        return school;
    }

    private static School Open(DefCatalog catalog, MapLayout map, DateTime start, int seed)
    {
        var roster = RosterGenerator.Generate(catalog, map, seed, "Russia", start);
        var pool = ApplicantPool.Create(catalog, roster, seed, "Russia", start);
        var schoolClass = roster.Classes[0];
        var school = School.Create(seed, "Присутствие", start, catalog, map);
        school.InstallPeople(roster, seed, "Russia", pool);
        school.SetTimetable(new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 0, Period: 1)],
            []));
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
        return school;
    }

    private static School OpenEmpty(DateTime start)
    {
        var (catalog, map) = Vanilla();
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 1, "Russia", start);
        var pool = ApplicantPool.Create(catalog, roster, schoolSeed: 1, "Russia", start);
        var school = School.Create(1, "Пустая", start, catalog, map);
        school.InstallPeople(roster, seed: 1, "Russia", pool);
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);
        return school;
    }

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

    private static string Fingerprint(IReadOnlyList<PresenceSnapshot> rows) =>
        string.Join(
            "|",
            rows.OrderBy(row => row.PersonId, StringComparer.Ordinal)
                .Select(row =>
                    $"{row.PersonId}:{row.NodeId ?? "-"}:{row.RemainingMinutes:0.###}:{row.DestinationId ?? "-"}:{(row.HeadingHome ? "1" : "0")}:{string.Join(",", row.Path)}"));

    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);
    }
}