using SantaClausInc.Core;

namespace SantaClausInc.Test;

public sealed class SleighTests
{
    [Fact]
    public void Construction()
    {
        const string City = "Salzburg";
        var sleigh = new Sleigh(5, City);

        sleigh.TargetCity.Should().Be(City);
    }

    [Fact]
    public void Load_Single()
    {
        var sleigh = new Sleigh(5, "Graz");

        sleigh.Load(CreateParcelPile(true))
              .Should().BeTrue("enough capacity, can load this pile");
    }

    [Fact]
    public void Load_Multiple()
    {
        var sleigh = new Sleigh(4, "Graz");

        for (var i = 0; i < 4; i++)
        {
            sleigh.Load(CreateParcelPile(i % 2 == 0))
                  .Should().BeTrue("still enough capacity");
        }

        sleigh.Load(CreateParcelPile(true))
              .Should().BeFalse("capacity exceeded");
    }

    [Fact]
    public void ExecuteTour()
    {
        var sleigh = new Sleigh(5, "Bregenz");

        sleigh.Load(CreateParcelPile(true));
        sleigh.Load(CreateParcelPile(false));

        var tourPlan = sleigh.ExecuteTour();

        tourPlan.Should().NotBeNull();
        tourPlan.Count.Should().Be(10);
        for (var i = 0; i < tourPlan.Count; i++)
        {
            var (expected, reason) = i switch
                                     {
                                         0 => ("#01: Travelling to city Bregenz",
                                               "first sleigh has to travel to destination city"),
                                         1 => (" #02: Moving to house with ID 10",
                                               "unloading starts at back of the sleight, last in, first out"),
                                         2 => ("  #03: Putting into chimney: Doll for Martin (age 11)",
                                               "topmost parcel goes in first"),
                                         3 => ("  #04: Putting into chimney: Lego for Martin (age 11)",
                                               "then the next parcel - mind the indents"),
                                         4 => (" #05: Moving to house with ID 5",
                                               "done with this house, moving to the next"),
                                         5 => ("  #06: Putting into chimney: Raspberry for Maria (age 16)",
                                               "starting to process last pile on sleigh"),
                                         6 => ("  #07: Putting into chimney: Doll for Maria (age 16)",
                                               "processing next parcel"),
                                         7 => ("  #08: Putting into chimney: Board Game for Maria (age 16)",
                                               "processing next parcel"),
                                         8 => ("  #09: Putting into chimney: Car for Maria (age 16)",
                                               "last parcel in pile and the last pile"),
                                         9 => ("#10: Tour done, returning to Northpole HQ", "completed"),
                                         _ => (null, "shouldn't exist")
                                     };
            tourPlan[i].Should().Be(expected, reason);
        }
    }

    private static Stack<Parcel> CreateParcelPile(bool setOne)
    {
        var children = SampleData.CreateSampleChildren();
        var pile = new Stack<Parcel>();

        var childId = setOne ? 4 : 9;
        var child = children[childId];
        if (child is null)
        {
            Assert.Fail($"Child with id {childId} not found");
        }

        if (setOne)
        {
            pile.Push(new Parcel(child, "Car"));
            pile.Push(new Parcel(child, "Board Game"));
            pile.Push(new Parcel(child, "Doll"));
            pile.Push(new Parcel(child, "Raspberry"));
        }
        else
        {
            pile.Push(new Parcel(child, "Lego"));
            pile.Push(new Parcel(child, "Doll"));
        }

        return pile;
    }
}