using Arch.Core;
using HSchool.Ai;
using HSchool.Content;
using HSchool.People;
using HSchool.Protocol;
using HSchool.Simulation;

namespace HSchool.Simulation.Tests;

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

    [Fact]
    public void WithoutClassTeacher_SameDaySeed_DoesNotStart()
    {
        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: false);
        using (school)
        {
            Assert.Null(schoolClass.ClassTeacherId);
            Assert.False(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
            Assert.Empty(school.ActiveParentMeetings);
            Assert.DoesNotContain(
                school.DrainWorldEvents(),
                row => row.Trigger.Equals(EventTriggers.ParentMeeting, StringComparison.Ordinal));
        }
    }

    [Fact]
    public void WithClassTeacher_ParentsAppearThenLeaveAfterMeeting()
    {
        var (school, schoolClass, teacherId) = ClassWithParentsAfterLastLesson(assignTeacher: true);
        using (school)
        {
            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
            var session = Assert.Single(school.ActiveParentMeetings);
            Assert.NotEmpty(session.AttendeeIds);

            PlaceAt(school, teacherId, schoolClass.RoomId);
            foreach (var parentId in session.AttendeeIds)
            {
                PlaceAt(school, parentId, schoolClass.RoomId);
                Assert.Equal(schoolClass.RoomId, NodeOf(school, parentId));
            }

            ParentMeetingSystem.Apply(school);
            Assert.True(ActivitySystem.IsParentMeeting(ActivityOf(school, teacherId)));

            ParentMeetingSystem.CompleteMeeting(school, teacherId);
            Assert.Empty(school.ActiveParentMeetings);

            foreach (var parentId in session.AttendeeIds)
            {
                var person = school.Roster!.People.First(row => row.Id == parentId);
                if (person.IsStaff)
                {
                    continue;
                }

                var node = NodeOf(school, parentId);
                var headingHome = IsHeadingHome(school, parentId);
                Assert.True(
                    node is null || headingHome,
                    $"Parent {parentId} should leave campus, node={node}, headingHome={headingHome}");
            }
        }
    }

    [Fact]
    public void MeetingDoesNotStartBeforeLastLessonOfClass()
    {
        var (school, schoolClass, teacherId) = ClassWithParents(assignTeacher: true, advancePastLastLesson: false);
        using (school)
        {
            PlaceAt(school, teacherId, schoolClass.RoomId);
            // Still during period 1 — last lesson has not ended.
            Assert.False(ParentMeetings.IsAfterLastLesson(
                school.Catalog!,
                school.Timetable,
                schoolClass,
                school.Clock.Time,
                school.SchoolWeekDays));
            Assert.False(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
            Assert.Empty(school.ActiveParentMeetings);
        }
    }

    [Fact]
    public void SameClassAndDaySeed_SameAttendees()
    {
        var first = AttendeesFromSeed(seed: 42);
        var second = AttendeesFromSeed(seed: 42);
        Assert.Equal(first, second);
        Assert.NotEmpty(first);
    }

    [Fact]
    public void PlayerCannotScheduleMeeting_NoProtocolOrPublicApi()
    {
        Assert.DoesNotContain(
            Enum.GetNames<MessageType>(),
            name => name.Contains("ParentMeeting", StringComparison.OrdinalIgnoreCase)
                || name.Contains("Meeting", StringComparison.OrdinalIgnoreCase)
                    && name.Contains("Parent", StringComparison.OrdinalIgnoreCase));
        Assert.DoesNotContain(
            typeof(School).GetMethods(System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public),
            method => method.Name.Contains("Meeting", StringComparison.OrdinalIgnoreCase)
                && (method.Name.StartsWith("Set", StringComparison.Ordinal)
                    || method.Name.StartsWith("Start", StringComparison.Ordinal)
                    || method.Name.StartsWith("Schedule", StringComparison.Ordinal)
                    || method.Name.StartsWith("Enqueue", StringComparison.Ordinal)));
    }

    [Fact]
    public void SkipEmpty_DoesNotLeaveParentsInHomeroom()
    {
        var (school, schoolClass, teacherId) = ClassWithParentsAfterLastLesson(assignTeacher: true);
        using (school)
        {
            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
            var session = Assert.Single(school.ActiveParentMeetings);
            PlaceAt(school, teacherId, schoolClass.RoomId);
            foreach (var parentId in session.AttendeeIds)
            {
                PlaceAt(school, parentId, schoolClass.RoomId);
            }

            // Jump past the work window so skip is allowed, with campus cleared of pupils/staff
            // except we force parents off via ClearAll path used by skip.
            ParentMeetingSystem.ClearAll(school);
            Assert.Empty(school.ActiveParentMeetings);
            foreach (var parentId in session.AttendeeIds)
            {
                var person = school.Roster!.People.First(row => row.Id == parentId);
                if (person.IsStaff || person.IsStudent)
                {
                    continue;
                }

                Assert.Null(NodeOf(school, parentId));
            }
        }
    }

    [Fact]
    public void StartingMeeting_RaisesParentMeetingWorldEvent()
    {
        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: true);
        using (school)
        {
            school.DrainWorldEvents();
            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 1f));
            var fact = Assert.Single(
                school.DrainWorldEvents(),
                row => row.Trigger.Equals(EventTriggers.ParentMeeting, StringComparison.Ordinal));
            Assert.Equal(schoolClass.ClassTeacherId, fact.PersonKey);
        }
    }

    private static IReadOnlyList<string> AttendeesFromSeed(int seed)
    {
        var (school, schoolClass, _) = ClassWithParentsAfterLastLesson(assignTeacher: true, seed: seed);
        using (school)
        {
            Assert.True(ParentMeetingSystem.TryStart(school, schoolClass.Id, chance: 1f, fraction: 0.5f));
            return Assert.Single(school.ActiveParentMeetings).AttendeeIds.ToArray();
        }
    }

    private static (School School, SchoolClass Class, string TeacherId) ClassWithParentsAfterLastLesson(
        bool assignTeacher,
        int seed = 42) =>
        ClassWithParents(assignTeacher, advancePastLastLesson: true, seed);

    private static (School School, SchoolClass Class, string TeacherId) ClassWithParents(
        bool assignTeacher,
        bool advancePastLastLesson,
        int seed = 42)
    {
        var (catalog, map) = Vanilla();
        var start = TuesdayMorning;
        var roster = RosterGenerator.Generate(catalog, map, seed, "Russia", start);
        var pool = ApplicantPool.Create(catalog, roster, seed, "Russia", start);
        var schoolClass = roster.Classes.First(row => row.RoomId == "classroom-101");
        var school = School.Create(seed, "ParentMeeting", start, catalog, map);
        school.InstallPeople(roster, seed, "Russia", pool);
        school.SetTimetable(new HSchool.Schedule.Timetable(
            [
                new HSchool.Schedule.LessonPlacement(
                    schoolClass.Id,
                    "Mathematics",
                    "t1",
                    schoolClass.RoomId,
                    Day: 1,
                    Period: 1),
            ],
            []));
        school.ConfigurePresence(weekDays: 5, maxDecisionsPerTick: 10_000);

        var teacherId = "";
        if (assignTeacher)
        {
            teacherId = HireTeacher(school);
            var assigned = ClassTeachers.Assign(school.Roster!, schoolClass.Id, teacherId);
            Assert.Equal(ClassTeacherError.None, assigned.Error);
            school.ApplyRosterData(assigned.Roster);
            schoolClass = school.Roster!.Classes.First(row => row.Id == schoolClass.Id);
            PlaceAt(school, teacherId, schoolClass.RoomId);
        }

        if (advancePastLastLesson)
        {
            var end = ParentMeetings.LastLessonEnd(catalog, school.Timetable, schoolClass, school.Clock.Time);
            Assert.NotNull(end);
            AdvanceTo(school, end.Value.AddMinutes(1));
            if (assignTeacher)
            {
                PlaceAt(school, teacherId, schoolClass.RoomId);
            }
        }
        else if (assignTeacher)
        {
            // Mid-lesson: period 1 is still running.
            var mid = SchoolDay.PeriodStart(catalog.DayFrame!, 1);
            var midTime = TuesdayMorning.Date + mid.ToTimeSpan() + TimeSpan.FromMinutes(10);
            AdvanceTo(school, DateTime.SpecifyKind(midTime, DateTimeKind.Utc));
            PlaceAt(school, teacherId, schoolClass.RoomId);
        }

        schoolClass = school.Roster!.Classes.First(row => row.Id == schoolClass.Id);
        return (school, schoolClass, teacherId);
    }

    private static string HireTeacher(School school)
    {
        const float cap = 100_000f;
        var pool = school.Applicants!;
        var hired = Staffing.Hire(
            school.Catalog!,
            school.Map!,
            school.Roster!,
            pool,
            pool.Applicants[0].Person.Id,
            Staffing.TeacherPosition,
            cap);
        Assert.Equal(StaffingError.None, hired.Error);
        school.ApplyStaffing(hired.Roster, hired.Pool);
        return school.Roster!.People.First(person =>
            person.IsStaff && Staffing.TeacherPosition.Equals(person.Position, StringComparison.Ordinal)).Id;
    }

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

    private static void PlaceAt(School school, string personId, string? nodeId)
    {
        TalkCircleSystem.Interrupt(school, personId);
        var query = new QueryDescription().WithAll<PersonIdentity, Presence, PersonActivity, Intent>();
        school.World.Query(in query, (ref PersonIdentity identity, ref Presence presence, ref PersonActivity activity, ref Intent intent) =>
        {
            if (identity.Id.Equals(personId, StringComparison.Ordinal))
            {
                presence = nodeId is null ? Presence.OffCampus : new Presence(nodeId, 0f, nodeId, false, []);
                activity = PersonActivity.Idle;
                intent = Intent.None;
            }
        });
    }

    private static string? NodeOf(School school, string personId)
    {
        string? found = null;
        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))
            {
                found = presence.NodeId;
            }
        });
        return found;
    }

    private static bool IsHeadingHome(School school, string personId)
    {
        var heading = 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))
            {
                heading = presence.HeadingHome;
            }
        });
        return heading;
    }

    private static string? ActivityOf(School school, string personId)
    {
        string? found = null;
        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.IsActive)
            {
                found = activity.ActionId;
            }
        });
        return found;
    }

    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;
            }

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

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