using Core.Entities;
using Core.Models;
using Core.YearTransition;
using NUnit.Framework;
using Tests.Builders;

namespace Tests.YearTransition;

[TestFixture]
public class GraduatingGradeResolver_Tests
{
    [Test]
    public void FromSchoolLevel_MiddleSchool_Returns8()
    {
        Assert.That(GraduatingGradeResolver.FromSchoolLevel(SchoolLevel.MiddleSchool), Is.EqualTo(8));
    }

    [Test]
    public void FromSchoolLevel_HighSchool_Returns12()
    {
        Assert.That(GraduatingGradeResolver.FromSchoolLevel(SchoolLevel.HighSchool), Is.EqualTo(12));
    }

    [Test]
    public void FromSchoolLevel_Null_ReturnsNull()
    {
        Assert.That(GraduatingGradeResolver.FromSchoolLevel(null), Is.Null);
    }
}

[TestFixture]
public class YearTransitionPlanner_Tests
{
    [SetUp]
    public void SetUp()
    {
        StudentBuilder.ResetIdCounter();
    }

    [Test]
    public void SuggestReturning_BelowGraduatingGrade_IsTrue()
    {
        var student = StudentBuilder.Create("Ann", "Lee").WithGrade(7).Build();
        Assert.That(YearTransitionPlanner.SuggestReturning(student, graduatingGrade: 8), Is.True);
    }

    [Test]
    public void SuggestReturning_AtGraduatingGrade_IsFalse()
    {
        var student = StudentBuilder.Create("Ann", "Lee").WithGrade(8).Build();
        Assert.That(YearTransitionPlanner.SuggestReturning(student, graduatingGrade: 8), Is.False);
    }

    [Test]
    public void Build_PromotesReturningStudents_MiddleSchool()
    {
        var returning = StudentBuilder.Create("Ann", "Lee").WithGrade(6).WithTsaYear(1).Build();
        var graduating = StudentBuilder.Create("Bob", "Smith").WithGrade(8).WithTsaYear(3).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [returning, graduating],
            ReturningStudentIds = new HashSet<int> { returning.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027"
        });

        Assert.That(plan.ReturningCount, Is.EqualTo(1));
        Assert.That(plan.RemovalCount, Is.EqualTo(1));
        Assert.That(plan.Promotions[0].NewGrade, Is.EqualTo(7));
        Assert.That(plan.Promotions[0].NewTsaYear, Is.EqualTo(2));
        Assert.That(plan.StudentsToRemove[0].Id, Is.EqualTo(graduating.Id));
    }

    [Test]
    public void Build_CapsGradeAtGraduatingGrade_HighSchool()
    {
        var senior = StudentBuilder.Create("Chris", "Young").WithGrade(12).WithTsaYear(4).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [senior],
            ReturningStudentIds = new HashSet<int> { senior.Id },
            GraduatingGrade = 12,
            TargetCompetitionYear = "2027"
        });

        Assert.That(plan.Promotions[0].NewGrade, Is.EqualTo(12));
        Assert.That(plan.Promotions[0].NewTsaYear, Is.EqualTo(5));
        Assert.That(plan.Warnings, Has.Some.Contain("graduating grade"));
    }

    [Test]
    public void Build_CapsGradeAtEight_WhenMiddleSchoolReturnerAtGraduatingGrade()
    {
        var eighth = StudentBuilder.Create("Dana", "Nguyen").WithGrade(8).WithTsaYear(2).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [eighth],
            ReturningStudentIds = new HashSet<int> { eighth.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027"
        });

        Assert.That(plan.Promotions[0].NewGrade, Is.EqualTo(8));
        Assert.That(plan.Warnings, Has.Some.Contain("graduating grade"));
    }

    [Test]
    public void Build_AssignsOfficersAndClearsOthers()
    {
        var president = StudentBuilder.Create("Eve", "Adams").WithGrade(7).AsPresident().Build();
        var vp = StudentBuilder.Create("Frank", "Baker").WithGrade(6).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [president, vp],
            ReturningStudentIds = new HashSet<int> { president.Id, vp.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027",
            OfficerAssignments = new Dictionary<OfficerRole, int?>
            {
                [OfficerRole.President] = vp.Id,
                [OfficerRole.VicePresident] = president.Id
            }
        });

        var eve = plan.Promotions.Single(p => p.Student.Id == president.Id);
        var frank = plan.Promotions.Single(p => p.Student.Id == vp.Id);

        Assert.That(eve.PreviousOfficerRole, Is.EqualTo(OfficerRole.President));
        Assert.That(eve.NewOfficerRole, Is.EqualTo(OfficerRole.VicePresident));
        Assert.That(frank.NewOfficerRole, Is.EqualTo(OfficerRole.President));

        var presidentChange = plan.OfficerChanges.Single(c => c.Role == OfficerRole.President);
        Assert.That(presidentChange.PreviousOfficer!.Id, Is.EqualTo(president.Id));
        Assert.That(presidentChange.NewOfficer!.Id, Is.EqualTo(vp.Id));
    }

    [Test]
    public void Build_WarnsWhenOfficerAssignedToNonReturningStudent()
    {
        var returning = StudentBuilder.Create("Gina", "Cole").WithGrade(6).Build();
        var leaving = StudentBuilder.Create("Hank", "Diaz").WithGrade(8).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [returning, leaving],
            ReturningStudentIds = new HashSet<int> { returning.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027",
            OfficerAssignments = new Dictionary<OfficerRole, int?>
            {
                [OfficerRole.President] = leaving.Id
            }
        });

        Assert.That(plan.Warnings, Has.Some.Contain("not marked returning"));
        Assert.That(plan.Promotions[0].NewOfficerRole, Is.Null);
    }

    [Test]
    public void Build_WarnsWhenSameStudentHasTwoOffices()
    {
        var student = StudentBuilder.Create("Ivy", "Evans").WithGrade(7).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [student],
            ReturningStudentIds = new HashSet<int> { student.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027",
            OfficerAssignments = new Dictionary<OfficerRole, int?>
            {
                [OfficerRole.President] = student.Id,
                [OfficerRole.Treasurer] = student.Id
            }
        });

        Assert.That(plan.Warnings, Has.Some.Contain("more than one officer role"));
        Assert.That(plan.Promotions[0].NewOfficerRole, Is.Null);
    }

    [Test]
    public void MatchPastedNames_MatchesLastCommaFirstAndFirstLast()
    {
        var a = StudentBuilder.Create("Ann", "Lee").WithGrade(6).Build();
        var b = StudentBuilder.Create("Bob", "Smith").WithGrade(7).Build();

        var result = YearTransitionPlanner.MatchPastedNames(
            [a, b],
            ["Lee, Ann", "Bob Smith", "Nobody Here"]);

        Assert.That(result.MatchedStudentIds, Is.EquivalentTo(new[] { a.Id, b.Id }));
        Assert.That(result.UnmatchedNames, Is.EquivalentTo(new[] { "Nobody Here" }));
    }

    [Test]
    public void MatchPastedNames_AmbiguousWhenDuplicateNames()
    {
        var a = StudentBuilder.Create("Ann", "Lee").WithGrade(6).Build();
        var b = StudentBuilder.Create("Ann", "Lee").WithGrade(7).Build();

        var result = YearTransitionPlanner.MatchPastedNames([a, b], ["Ann Lee"]);

        Assert.That(result.AmbiguousNames, Is.EquivalentTo(new[] { "Ann Lee" }));
        Assert.That(result.MatchedStudentIds, Is.EquivalentTo(new[] { a.Id, b.Id }));
    }

    [Test]
    public void Build_IncludesUnmatchedAndAmbiguousFromPaste()
    {
        var a = StudentBuilder.Create("Ann", "Lee").WithGrade(6).Build();
        var b = StudentBuilder.Create("Ann", "Lee").WithGrade(7).Build();

        var plan = YearTransitionPlanner.Build(new YearTransitionRequest
        {
            Students = [a, b],
            ReturningStudentIds = new HashSet<int> { a.Id },
            GraduatingGrade = 8,
            TargetCompetitionYear = "2027",
            PastedNames = ["Ann Lee", "Zed Zulu"]
        });

        Assert.That(plan.AmbiguousPastedNames, Has.Member("Ann Lee"));
        Assert.That(plan.UnmatchedPastedNames, Has.Member("Zed Zulu"));
        Assert.That(plan.Warnings, Has.Some.Contain("matched more than one"));
    }
}