namespace HSchool.People.Tests;

public class RosterBrowserTests
{
    [Fact]
    public void FilterByRoleAndYear_KeepsOnlyThosePupils()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(role: PersonRoles.Student, year: 1, pageSize: RosterBrowser.MaxPageSize));

        Assert.NotEmpty(page.People);
        Assert.Equal(page.People.Count, page.Total);
        Assert.All(page.People, person =>
        {
            Assert.True(person.IsStudent);
            var schoolClass = roster.Classes.Single(candidate => candidate.Id == person.ClassId);
            Assert.Equal(1, schoolClass.Year);
        });
    }

    /// <summary>
    /// Alphabetical, with Ё counted as Е — see <c>RosterBrowser.NameOrder</c>. Ordinal order would
    /// agree on this sample (no vanilla surname starts with Ё), which is exactly why the rule is
    /// pinned down separately in <c>ReviewFixTests</c>.
    /// </summary>
    [Fact]
    public void SortBySurname_IsAlphabetical()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var page = RosterBrowser.Apply(roster, Fixtures.AsOf, Query(pageSize: 20));

        var surnames = page.People.Select(person => person.Name.Surname).ToArray();
        var expected = surnames
            .OrderBy(name => name.Replace('Ё', 'Е').Replace('ё', 'е'), StringComparer.Ordinal)
            .ToArray();
        Assert.Equal(expected, surnames);
    }

    [Fact]
    public void PagePastTheEnd_IsEmptyButKeepsTheTotal()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(2));
        var first = RosterBrowser.Apply(roster, Fixtures.AsOf, Query(page: 1, pageSize: 10));
        var past = RosterBrowser.Apply(roster, Fixtures.AsOf, Query(page: 999, pageSize: 10));

        Assert.True(first.Total > 10);
        Assert.Equal(10, first.People.Count);
        Assert.Equal(first.Total, past.Total);
        Assert.Empty(past.People);
    }

    [Fact]
    public void ParentFilter_ReturnsOnlyParents()
    {
        var roster = Fixtures.Generate(Fixtures.VanillaMap());
        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(role: PersonRoles.Parent, pageSize: RosterBrowser.MaxPageSize));

        Assert.NotEmpty(page.People);
        Assert.All(page.People, person => Assert.True(person.IsParent));
    }

    [Fact]
    public void FilterBySex_KeepsOnlyThatSex()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(female: true, pageSize: RosterBrowser.MaxPageSize));

        Assert.NotEmpty(page.People);
        Assert.True(page.Total < roster.People.Count);
        Assert.All(page.People, person => Assert.True(person.Female));
    }

    [Fact]
    public void FilterByLetter_KeepsOnlyThatClassLetter()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var letter = roster.Classes[0].Letter;
        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(letter: letter, pageSize: RosterBrowser.MaxPageSize));
        var classes = roster.Classes.ToDictionary(schoolClass => schoolClass.Id, StringComparer.Ordinal);

        Assert.NotEmpty(page.People);
        Assert.All(page.People, person =>
            Assert.Equal(letter, person.ClassId is { } classId ? classes[classId].Letter : null));
    }

    [Fact]
    public void FilterByAgeRange_KeepsAgesInside()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var pupil = roster.People.First(person => person.IsStudent);
        var age = pupil.AgeOn(Fixtures.AsOf);
        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(ageMin: age, ageMax: age, pageSize: RosterBrowser.MaxPageSize));

        Assert.Contains(page.People, person => person.Id == pupil.Id);
        Assert.All(page.People, person => Assert.Equal(age, person.AgeOn(Fixtures.AsOf)));
    }

    [Fact]
    public void FilterByPosition_KeepsThatJob()
    {
        var roster = Fixtures.Generate(Fixtures.Classrooms(4));
        var parent = roster.People.First(person => person.IsParent);
        roster = roster with
        {
            People = roster.People
                .Select(person => person.Id.Equals(parent.Id, StringComparison.Ordinal)
                    ? person with { IsStaff = true, Position = "Librarian" }
                    : person)
                .ToArray(),
        };

        var page = RosterBrowser.Apply(
            roster,
            Fixtures.AsOf,
            Query(position: "Librarian", pageSize: RosterBrowser.MaxPageSize));

        Assert.Equal(parent.Id, Assert.Single(page.People).Id);
    }

    private static RosterQuery Query(
        string? role = null,
        int? year = null,
        string? letter = null,
        string? position = null,
        bool? female = null,
        int? ageMin = null,
        int? ageMax = null,
        int page = 1,
        int pageSize = RosterBrowser.DefaultPageSize) =>
        new(role, year, letter, position, female, ageMin, ageMax, PersonSort.Surname, Descending: false, page, pageSize);
}