using LehrerApp.Core.Models;
using LehrerApp.Core.Services;
using LehrerApp.Desktop.ViewModels.Groups;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class GroupRolloverDialogViewModelTests
{
    [Fact]
    public void Vorauswahl_NimmtNurAktiveSchuelerAmSchuljahresende()
    {
        var group = new LearningGroup { Name = "8a", SchoolYear = "2025/26", GradeLevel = 8 };
        var fullYearStudent = Student("Ganzjahr");
        var h1Student = Student("Halbjahr");
        var withdrawnStudent = Student("Ausgetreten");
        var inactiveStudent = Student("Inaktiv", active: false);
        var membershipList = new List<GroupMembership>
        {
            Membership(group, fullYearStudent, MembershipPeriod.FullYear),
            Membership(group, h1Student, MembershipPeriod.H1Only),
            Membership(group, withdrawnStudent, MembershipPeriod.FullYear, new DateOnly(2026, 5, 1)),
            Membership(group, inactiveStudent, MembershipPeriod.FullYear),
        };
        var groups = new FakeGroups([group]);
        var memberships = new FakeMemberships(membershipList);
        var schemes = new FakeSchemes();
        var schoolYears = new SchoolYearService();
        var vm = new GroupRolloverDialogViewModel(group,
            new FakeStudents([fullYearStudent, h1Student, withdrawnStudent, inactiveStudent]),
            memberships, schemes, schoolYears,
            new GroupRolloverService(groups, memberships, schemes, schoolYears));

        Assert.True(vm.Students.Single(s => s.FullName.Contains("Ganzjahr")).IsSelected);
        Assert.False(vm.Students.Single(s => s.FullName.Contains("Halbjahr")).IsSelected);
        Assert.False(vm.Students.Single(s => s.FullName.Contains("Ausgetreten")).IsSelected);
        var inactive = vm.Students.Single(s => s.FullName.Contains("Inaktiv"));
        Assert.False(inactive.IsSelected);
        Assert.False(inactive.CanSelect);
        Assert.Equal(1, vm.SelectedCount);
    }

    [Fact]
    public void Dialog_SchlaegtNaechstesSchuljahrUndNaechsteStufeVor()
    {
        var group = new LearningGroup { Name = "8a", SchoolYear = "2025/26", GradeLevel = 8 };
        var student = Student("Ganzjahr");
        var membershipList = new List<GroupMembership> { Membership(group, student, MembershipPeriod.FullYear) };
        var groups = new FakeGroups([group]);
        var memberships = new FakeMemberships(membershipList);
        var schemes = new FakeSchemes();
        var schoolYears = new SchoolYearService();

        var vm = new GroupRolloverDialogViewModel(group, new FakeStudents([student]), memberships,
            schemes, schoolYears, new GroupRolloverService(groups, memberships, schemes, schoolYears));

        Assert.Equal("2026/27", vm.TargetSchoolYear);
        Assert.Equal(9, vm.GradeLevel);
        Assert.True(vm.ArchiveSource);
    }

    private static Student Student(string lastName, bool active = true) =>
        new() { FirstName = "Test", LastName = lastName, IsActive = active };

    private static GroupMembership Membership(LearningGroup group, Student student,
        MembershipPeriod period, DateOnly? leftAt = null) => new()
    {
        GroupId = group.Id,
        StudentId = student.Id,
        Period = period,
        JoinedAt = new DateOnly(2025, 8, 1),
        LeftAt = leftAt,
    };
}