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

namespace HSchool.Ai.Tests;

public class WalkingTests
{
    private static readonly DateTime TuesdayLesson = new(2012, 4, 3, 8, 45, 0, DateTimeKind.Utc);
    private static readonly DateTime Sunday = new(2012, 4, 8, 10, 0, 0, DateTimeKind.Utc);
    private static readonly DateTime SpringBreak = new(2012, 3, 31, 10, 0, 0, DateTimeKind.Utc);

    [Fact]
    public void PathFrom201ToFirstFloorRestroom_GoesThroughStairsAndCorridors()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var walks = WalkGraph.Build(catalog, map);

        var hops = walks.Path("classroom-201", "restroom-1");

        Assert.Equal(["corridor-2", "stairs-2", "stairs-1", "corridor-1", "restroom-1"], hops);
        Assert.DoesNotContain("yard", hops);
        Assert.Equal(6.5f, walks.Minutes("classroom-201", "restroom-1"));
    }

    [Fact]
    public void PresenceStepper_TakesTheSameMinutesAsTheGraph()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var walks = WalkGraph.Build(catalog, map);
        var hops = walks.Path("classroom-201", "restroom-1");
        var cost = walks.Minutes("classroom-201", "restroom-1");
        var presence = new Presence("classroom-201", 0f, "restroom-1", HeadingHome: false, [.. hops]);

        var walked = PresenceStepper.Advance(presence, walks, cost);

        Assert.Equal("restroom-1", walked.NodeId);
        Assert.Empty(walked.Path);
        Assert.Equal(0f, walked.RemainingMinutes);

        var stepwise = presence;
        var elapsed = 0f;
        const float step = 0.25f;
        while (stepwise.NodeId != "restroom-1" || stepwise.Path.Length > 0 || stepwise.RemainingMinutes > 0)
        {
            stepwise = PresenceStepper.Advance(stepwise, walks, step);
            elapsed += step;
            Assert.True(elapsed <= cost + step);
        }

        Assert.Equal(cost, elapsed);
    }

    [Fact]
    public void GymAfterClassroom101_CostsSixMinutesAgainstATenMinuteBreak()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var walks = WalkGraph.Build(catalog, map);
        var hops = walks.Path("classroom-101", "gym-hall");

        Assert.Equal(["corridor-1", "porch", "yard", "gym-hall"], hops);
        Assert.Equal(6f, walks.Minutes("classroom-101", "gym-hall"));
        Assert.Equal(10, catalog.DayFrame!.BreakMinutes);
        Assert.True(walks.Minutes("classroom-101", "gym-hall") < catalog.DayFrame.BreakMinutes);
    }

    [Fact]
    public void ComesToday_IsFalseOnSundayAndHolidays()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 1, "Russia", TuesdayLesson);
        var pupil = roster.People.First(person => person.IsStudent);
        var schoolClass = roster.Classes.First(row => row.Id == pupil.ClassId);
        var table = new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1)],
            []);

        Assert.True(Duty.ComesToday(pupil, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.False(Duty.ComesToday(pupil, table, catalog, Sunday, weekDays: 5));
        Assert.False(Duty.ComesToday(pupil, table, catalog, SpringBreak, weekDays: 5));
        Assert.False(Duty.ComesToday(
            roster.People.First(person => person.IsParent && !person.IsStaff && !person.IsStudent),
            table,
            catalog,
            TuesdayLesson,
            weekDays: 5));
    }

    [Fact]
    public void ClassWithoutLessons_StaysAway_TeacherWithAnotherClassComes()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 1, "Russia", TuesdayLesson);
        var idle = roster.Classes[0];
        var busy = roster.Classes[1];
        var idlePupil = roster.People.First(person => person.Id == idle.PupilIds[0]);
        var busyPupil = roster.People.First(person => person.Id == busy.PupilIds[0]);
        var teacher = roster.People.First(person => person.IsParent && !person.IsStudent && !person.IsStaff) with
        {
            IsStaff = true,
            Position = Staffing.TeacherPosition,
        };
        var table = new Timetable(
            [new LessonPlacement(busy.Id, "Mathematics", teacher.Id, busy.RoomId, Day: 1, Period: 1)],
            []);

        Assert.False(Duty.ComesToday(idlePupil, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.True(Duty.ComesToday(busyPupil, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.True(Duty.ComesToday(teacher, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.Null(Duty.RoomAt(idlePupil, idle, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.Equal(busy.RoomId, Duty.RoomAt(busyPupil, busy, table, catalog, TuesdayLesson, weekDays: 5));
        Assert.Equal(busy.RoomId, Duty.RoomAt(teacher, null, table, catalog, TuesdayLesson, weekDays: 5));
    }

    [Fact]
    public void SameSeedAndMap_YieldTheSameDayPlan()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var walks = WalkGraph.Build(catalog, map);
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 9, "Russia", TuesdayLesson);
        var pupil = roster.People.First(person => person.IsStudent);
        var schoolClass = roster.Classes.First(row => row.Id == pupil.ClassId);
        var table = new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1)],
            []);

        var first = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);
        var second = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);

        Assert.Equal(first, second);
        Assert.True(first.Comes);
        Assert.Equal(schoolClass.RoomId, first.FirstRoom);
        Assert.True(first.AppearAt < DateTime.SpecifyKind(TuesdayLesson.Date.Add(new TimeSpan(8, 30, 0)), DateTimeKind.Utc));
    }

    [Fact]
    public void SnowMinutes_AppearEarlierThanClear()
    {
        var (clear, snow, extra) = PlansWithExtra(catalog => catalog.BehaviorRules!.CommuteSnowMinutes);
        Assert.Equal(6, extra);
        Assert.Equal(clear.AppearAt!.Value.AddMinutes(-extra), snow.AppearAt);
    }

    [Fact]
    public void RainMinutes_AppearEarlierThanClear()
    {
        var (clear, rain, extra) = PlansWithExtra(catalog => catalog.BehaviorRules!.CommuteRainMinutes);
        Assert.Equal(3, extra);
        Assert.Equal(clear.AppearAt!.Value.AddMinutes(-extra), rain.AppearAt);
    }

    [Fact]
    public void Clear_MatchesOmittedExtraArgument()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
        var implied = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);
        var explicitZero = DayPlans.Build(
            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extraCommuteMinutes: 0);

        Assert.Equal(implied, explicitZero);
        Assert.True(implied.Comes);
    }

    [Fact]
    public void Lazy_AppearsCloserToTheBell_OnSnow()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var walks = WalkGraph.Build(catalog, map);
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 9, "Russia", TuesdayLesson);
        var lazy = roster.People.First(person => person.IsStudent && person.Traits.Contains("Lazy"));
        var schoolClass = roster.Classes.First(row => row.Id == lazy.ClassId);
        var keen = roster.People.First(person =>
            person.IsStudent && person.ClassId == lazy.ClassId && !person.Traits.Contains("Lazy"));
        var table = new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1)],
            []);
        var extra = catalog.BehaviorRules!.CommuteSnowMinutes;
        var lazyPlan = DayPlans.Build(
            catalog, walks, lazy, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
        var keenPlan = DayPlans.Build(
            catalog, walks, keen, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);

        Assert.True(lazyPlan.Comes);
        Assert.True(keenPlan.Comes);
        Assert.True(lazyPlan.AppearAt > keenPlan.AppearAt);
    }

    [Fact]
    public void SameSeedAndSnowMinutes_YieldTheSameAppearAt()
    {
        var (catalog, map) = Fixtures.Vanilla();
        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
        var extra = catalog.BehaviorRules!.CommuteSnowMinutes;
        var first = DayPlans.Build(
            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
        var second = DayPlans.Build(
            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);

        Assert.Equal(first.AppearAt, second.AppearAt);
        Assert.True(first.Comes);
    }

    [Fact]
    public void Sources_DoNotMentionPrecipitation()
    {
        var root = Path.Combine(Fixtures.RepoRoot(), "src", "HSchool.Ai");
        foreach (var path in Directory.EnumerateFiles(root, "*.cs"))
        {
            var text = File.ReadAllText(path);
            Assert.DoesNotContain("Precipitation", text, StringComparison.Ordinal);
        }
    }

    private static (DayPlan Clear, DayPlan Weather, int Extra) PlansWithExtra(Func<DefCatalog, int> extraOf)
    {
        var (catalog, map) = Fixtures.Vanilla();
        var (walks, pupil, schoolClass, table) = ComingPupil(catalog, map);
        var extra = extraOf(catalog);
        var clear = DayPlans.Build(catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9);
        var weather = DayPlans.Build(
            catalog, walks, pupil, schoolClass, table, TuesdayLesson, weekDays: 5, schoolSeed: 9, extra);
        return (clear, weather, extra);
    }

    private static (WalkGraph Walks, Person Pupil, SchoolClass SchoolClass, Timetable Table) ComingPupil(
        DefCatalog catalog,
        MapLayout map)
    {
        var walks = WalkGraph.Build(catalog, map);
        var roster = RosterGenerator.Generate(catalog, map, schoolSeed: 9, "Russia", TuesdayLesson);
        var pupil = roster.People.First(person => person.IsStudent);
        var schoolClass = roster.Classes.First(row => row.Id == pupil.ClassId);
        var table = new Timetable(
            [new LessonPlacement(schoolClass.Id, "Mathematics", "t1", schoolClass.RoomId, Day: 1, Period: 1)],
            []);
        return (walks, pupil, schoolClass, table);
    }
}