namespace HSchool.People.Tests;

public class RosterGeneratorTests
{
    [Fact]
    public void SameSeedMapAndNameSet_YieldTheSameRoster()
    {
        var map = Fixtures.Classrooms(4);
        var a = Fixtures.Generate(map);
        var b = Fixtures.Generate(map);

        Assert.Equal(Snapshot(a), Snapshot(b));
    }

    /// <summary>
    /// Each family draws from its own seeded stream, so a bigger map does not reshuffle the
    /// families already planned: the first twelve keep their surname, their size and every given
    /// name. What a bigger map does move is which classroom a child sits in — seats are dealt
    /// across the whole school so siblings are not automatically classmates — and with the
    /// classroom comes the year, hence the birth year. That is the one thing not asserted here.
    /// </summary>
    [Fact]
    public void ThirteenthFamily_DoesNotChangeHowTheFirstTwelveAreDrawn()
    {
        var twelve = FamilyIdentities(Fixtures.Generate(Fixtures.Classrooms(4)), take: 12);
        var thirteen = FamilyIdentities(Fixtures.Generate(Fixtures.Classrooms(5)), take: 12);

        Assert.Equal(12, twelve.Count);
        Assert.Equal(twelve, thirteen);
    }

    [Fact]
    public void FamilyNames_ShareSurnameAndPatronymicFromTheFather()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var people = roster.People.ToDictionary(person => person.Id, StringComparer.Ordinal);

        foreach (var family in roster.Families)
        {
            if (family.ChildIds.Count == 0)
            {
                continue;
            }

            // One parent may be absent, so the father's name comes off the family, not off a person.
            var parents = family.ParentIds.Select(id => people[id]).ToArray();
            Assert.NotEmpty(parents);
            Assert.Equal(parents.Length, parents.DistinctBy(parent => parent.Female).Count());
            Assert.NotEmpty(family.FatherGiven);

            foreach (var parent in parents)
            {
                Assert.Equal(parent.Name.SurnameCases.Nom, parent.Name.Surname);
            }

            foreach (var childId in family.ChildIds)
            {
                var child = people[childId];
                Assert.Equal(
                    NameGrammar.Patronymic(family.FatherGiven, child.Female, NameGrammar.SlavicPatronymic),
                    child.Name.Patronymic);

                var sameSexParent = parents.FirstOrDefault(parent => parent.Female == child.Female);
                if (sameSexParent is not null)
                {
                    Assert.Equal(sameSexParent.Name.Surname, child.Name.Surname);
                }

                Assert.Equal(child.Name.SurnameCases.Nom, child.Name.Surname);
            }
        }
    }

    [Fact]
    public void ObesePupil_CannotHaveHighAgility()
    {
        var agility = Fixtures.Catalog().Skills["Agility"];
        var clamped = PersonSampler.ApplyBodyLimits(
            80,
            agility,
            new Dictionary<string, string> { [BodyBuilds.Attribute] = BodyBuilds.Obese });
        Assert.Equal(25, clamped);

        var roster = Fixtures.Generate(Fixtures.Classrooms(11));
        var obesePupils = roster.People.Where(person =>
            person.IsStudent
            && person.Choices.TryGetValue(BodyBuilds.Attribute, out var build)
            && build == BodyBuilds.Obese);

        Assert.All(
            obesePupils,
            person => Assert.True(
                person.Skills["Agility"] <= 25,
                $"{person.Name.Surname} {person.Name.Given} is obese with agility {person.Skills["Agility"]}."));
    }

    [Fact]
    public void OneClassroomAndEleven_BothFillSeatsAndJobs()
    {
        AssertFilled(Fixtures.Generate(Fixtures.Classrooms(1)), classrooms: 1);
        AssertFilled(Fixtures.Generate(Fixtures.Classrooms(11)), classrooms: 11);
    }

    [Fact]
    public void SomeStaffAreAlsoParents()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        Assert.Contains(roster.People, person => person.IsStaff && person.IsParent);
    }

    [Fact]
    public void VanillaMap_HasElevenHomeroomsNotTheComputerLab()
    {
        var catalog = Fixtures.Catalog();
        var root = Path.Combine(AppContext.BaseDirectory, "vanilla");
        var map = CatalogLoader.LastDefaultMap(
            [CatalogLoader.CorePackId],
            PackDocuments.FromDirectory(CatalogLoader.CorePackId, root));
        Assert.NotNull(map);

        var demand = SchoolDemand.From(catalog, map);
        Assert.Equal(11, demand.Classes.Count);
        Assert.Equal(11 * 16, demand.Seats.Count);
        Assert.DoesNotContain(demand.Classes, schoolClass => schoolClass.RoomId == "computer-lab");
        Assert.Contains(demand.Staff, opening => opening.RoomId == "computer-lab" && opening.Position == "Teacher");
    }

    [Fact]
    public void RosterJson_RoundTripsAGeneratedRoster()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(1));
        var json = RosterJson.Serialize(RosterDocument.From(7, roster));
        var loaded = RosterJson.Parse(json).ToRoster();

        Assert.Equal(roster.People.Count, loaded.People.Count);
        Assert.Equal(roster.People[0].Name.Given, loaded.People[0].Name.Given);
        Assert.Equal(roster.People[0].Name.SurnameCases.Gen, loaded.People[0].Name.SurnameCases.Gen);
        Assert.True(RosterFit.Matches(loaded, SchoolDemand.From(Fixtures.Catalog(), Fixtures.Classrooms(1))));
        Assert.False(RosterFit.Matches(loaded, SchoolDemand.From(Fixtures.Catalog(), Fixtures.Classrooms(2))));
    }

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

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

    private static void AssertFilled(Roster roster, int classrooms)
    {
        Assert.Equal(classrooms, roster.Classes.Count);
        Assert.Equal(classrooms * 16, roster.People.Count(person => person.IsStudent));
        Assert.All(roster.Classes, schoolClass =>
        {
            Assert.Equal(schoolClass.Capacity, schoolClass.PupilIds.Count);
            Assert.InRange(schoolClass.Year, 1, 11);
        });

        var demand = SchoolDemand.From(Fixtures.Catalog(), Fixtures.Classrooms(classrooms));
        Assert.Equal(demand.Staff.Count, roster.People.Count(person => person.IsStaff));
        Assert.All(demand.Staff, opening =>
            Assert.Contains(
                roster.People,
                person => person.IsStaff && person.Position == opening.Position && person.WorkplaceRoomId == opening.RoomId));
    }

    private static string Snapshot(Roster roster) =>
        string.Join('\n', roster.People.Select(person =>
            $"{person.Id}|{person.FamilyId}|{person.Female}|{person.BirthDate:O}|{person.Name.Given}|{person.Name.Surname}|{person.Name.Patronymic}|{person.IsStudent}|{person.IsStaff}|{person.IsParent}|{person.ClassId}|{person.Position}|{person.Choices[BodyBuilds.Attribute]}|{Skills(person)}|{string.Join(',', person.Traits)}"));

    private static string Skills(Person person) =>
        string.Join(',', person.Skills.OrderBy(pair => pair.Key, StringComparer.Ordinal).Select(pair => $"{pair.Key}={pair.Value}"));

    /// <summary>Who a family is, without where its children ended up sitting.</summary>
    private static List<string> FamilyIdentities(Roster roster, int take)
    {
        var people = roster.People.ToDictionary(person => person.Id, StringComparer.Ordinal);
        return roster.Families
            .OrderBy(family => family.Id, StringComparer.Ordinal)
            .Take(take)
            .Select(family =>
            {
                var members = family.ParentIds.Concat(family.ChildIds).Select(id => people[id]);
                return string.Join(';', members.Select(person =>
                    $"{person.Id}:{person.Name.Surname} {person.Name.Given} {person.Name.Patronymic}:{person.Female}"));
            })
            .ToList();
    }

    private static List<string> FamilySnapshots(Roster roster, int take)
    {
        var people = roster.People.ToDictionary(person => person.Id, StringComparer.Ordinal);
        return roster.Families
            .OrderBy(family => family.Id, StringComparer.Ordinal)
            .Take(take)
            .Select(family =>
            {
                var members = family.ParentIds.Concat(family.ChildIds).Select(id => people[id]);
                return string.Join(';', members.Select(person =>
                    $"{person.Id}:{person.Name.Surname} {person.Name.Given} {person.Name.Patronymic}:{person.BirthDate:O}:{person.Female}:{Skills(person)}"));
            })
            .ToList();
    }
}