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

namespace HSchool.Simulation.Tests;

public class AttendanceSimulationTests
{
    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 InRoomAtStart_IsPresent()
    {
        var (school, room, pupilId, _) = StaffedMath();
        using (school)
        {
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            SetPlace(school, pupilId, room);
            school.Clock.JumpTo(LessonStart);
            AttendanceSystem.Apply(school);

            var row = RowOf(school, pupilId);
            Assert.NotNull(row);
            Assert.Equal(AttendanceStatuses.Present, row!.Status);
            Assert.Equal("Mathematics", row.Subject);
            Assert.Equal(1, row.Period);
            Assert.Null(row.AbsenceReason);
        }
    }

    [Fact]
    public void ArrivesAfterThreshold_IsLate()
    {
        var (school, room, pupilId, _) = StaffedMath();
        using (school)
        {
            Assert.Equal(5f, school.Catalog!.BehaviorRules!.LessonLateMinutes);
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            SetPlace(school, pupilId, null);
            school.Clock.JumpTo(LessonStart);
            AttendanceSystem.Apply(school);
            Assert.Null(RowOf(school, pupilId));

            school.Clock.JumpTo(LessonStart.AddMinutes(6));
            SetPlace(school, pupilId, room);
            AttendanceSystem.Apply(school);

            var row = RowOf(school, pupilId);
            Assert.NotNull(row);
            Assert.Equal(AttendanceStatuses.Late, row!.Status);
            Assert.Null(row.AbsenceReason);
        }
    }

    [Fact]
    public void OffCampusWholeSlot_IsAbsentTruancy()
    {
        var (school, _, pupilId, _) = StaffedMath();
        using (school)
        {
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            SetPlace(school, pupilId, null);
            school.Clock.JumpTo(LessonStart);
            AttendanceSystem.Apply(school);
            Assert.Null(RowOf(school, pupilId));

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

            var row = RowOf(school, pupilId);
            Assert.NotNull(row);
            Assert.Equal(AttendanceStatuses.Absent, row!.Status);
            Assert.Equal(AbsenceReasons.Truancy, row.AbsenceReason);
        }
    }

    [Fact]
    public void OtherNodeWholeSlot_IsAbsent()
    {
        var (school, room, pupilId, _) = StaffedMath();
        using (school)
        {
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            var other = room.Equals("classroom-101", StringComparison.Ordinal) ? "classroom-102" : "classroom-101";
            SetPlace(school, pupilId, other);
            school.Clock.JumpTo(LessonStart);
            AttendanceSystem.Apply(school);
            school.Clock.JumpTo(LessonStart.AddMinutes(45));
            AttendanceSystem.Apply(school);

            var row = RowOf(school, pupilId);
            Assert.NotNull(row);
            Assert.Equal(AttendanceStatuses.Absent, row!.Status);
        }
    }

    [Fact]
    public void SameDayAndSeed_SameAttendance()
    {
        var first = CapturePresent();
        var second = CapturePresent();
        Assert.Equal(first.Status, second.Status);
        Assert.Equal(first.Subject, second.Subject);
        Assert.Equal(first.Period, second.Period);
    }

    [Fact]
    public void Late_DoesNotCancelMarkWhenConfigured()
    {
        var (school, room, pupilId, teacherId) = StaffedMath();
        using (school)
        {
            Assert.True(school.Catalog!.BehaviorRules!.LessonMarkWhenLate);
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            SetIdle(school, pupilId);
            SetIdle(school, teacherId);
            school.Clock.JumpTo(LessonStart.AddMinutes(6));
            SetPlace(school, pupilId, room);
            SetPlace(school, teacherId, room);
            PlaceTextbook(school, pupilId, "Mathematics");
            LessonLearningSystem.Apply(school, 5);
            AttendanceSystem.Apply(school);

            Assert.Equal(AttendanceStatuses.Late, RowOf(school, pupilId)!.Status);
            var marks = school.Roster!.People.First(row => row.Id == pupilId).LessonMarks;
            Assert.NotNull(marks);
            Assert.Single(marks!);
        }
    }

    private static AttendanceRecord CapturePresent()
    {
        var (school, room, pupilId, _) = StaffedMath();
        using (school)
        {
            AdvanceTo(school, LessonStart.AddMinutes(-1));
            SetPlace(school, pupilId, room);
            school.Clock.JumpTo(LessonStart);
            AttendanceSystem.Apply(school);
            var row = RowOf(school, pupilId);
            Assert.NotNull(row);
            return row!;
        }
    }

    private static AttendanceRecord? RowOf(School school, string pupilId) =>
        school.Roster!.People.First(row => row.Id == pupilId).Attendance?.LastOrDefault();

    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, "Явка", 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 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? node, string[]? path = null, float remaining = 0f)
    {
        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 = node is null
                    ? Presence.OffCampus
                    : new Presence(node, remaining, node, HeadingHome: false, path ?? []);
            });
    }

    private static void SetIdle(School school, string personId)
    {
        var query = new QueryDescription().WithAll<PersonIdentity, PersonActivity>();
        school.World.Query(
            in query,
            (ref PersonIdentity identity, ref PersonActivity activity) =>
            {
                if (identity.Id.Equals(personId, StringComparison.Ordinal))
                {
                    activity = PersonActivity.Idle;
                }
            });
    }

    private static void PlaceTextbook(School school, string personId, string subject)
    {
        var person = school.Roster!.People.First(row => row.Id.Equals(personId, StringComparison.Ordinal));
        if (person.Items is not IList<InventoryItem> items || items.IsReadOnly)
        {
            throw new InvalidOperationException($"Cannot mutate items for {personId}.");
        }

        for (var i = items.Count - 1; i >= 0; i--)
        {
            if (items[i].Subject is not null)
            {
                items.RemoveAt(i);
            }
        }

        items.Add(new InventoryItem("Textbook", Color: null, Condition: 1f, ItemLocations.Bag, subject));
    }

    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);
    }
}