using QuestionsApi.Models;
using QuestionsApi.Services;
using Xunit;

namespace QuestionsApi.Tests;

public sealed class ProgressionPolicyTests
{
    [Fact]
    public void New_learner_starts_as_case_scout_three()
    {
        Assert.Equal(0, ProgressionPolicy.Qualified([], 0));
        Assert.Equal("Case Scout", ProgressionPolicy.Name(0));
        Assert.Equal("III", ProgressionPolicy.Division(0));
    }

    [Fact]
    public void Pattern_hunter_requires_every_visible_gate()
    {
        var systems = Systems(learning: 6, practicing: 2, strong: 0, mastered: 0, hard: 6);
        Assert.Equal(1, ProgressionPolicy.Qualified(systems, 0));
        Assert.Equal(3, ProgressionPolicy.Qualified(systems, 1));
        Assert.Equal("Pattern Hunter", ProgressionPolicy.Name(3));
        Assert.Equal("III", ProgressionPolicy.Division(3));
    }

    [Fact]
    public void Highest_division_requires_breadth_challenge_and_retention()
    {
        var systems = Systems(learning: 14, practicing: 14, strong: 14, mastered: 12, hard: 105);
        Assert.Equal(13, ProgressionPolicy.Qualified(systems, 20));
        Assert.Equal(14, ProgressionPolicy.Qualified(systems, 21));
        Assert.Equal("Clinical Vanguard", ProgressionPolicy.Name(14));
        Assert.Equal("I", ProgressionPolicy.Division(14));
    }

    [Theory]
    [InlineData("unseen", 0)] [InlineData("learning", 1)] [InlineData("practicing", 2)]
    [InlineData("strong", 3)] [InlineData("mastered", 4)]
    public void Mastery_states_have_stable_order(string state, int expected) =>
        Assert.Equal(expected, ProgressionPolicy.State(state));

    private static List<DashboardSystemPerformance> Systems(int learning, int practicing, int strong, int mastered, int hard)
    {
        var result = new List<DashboardSystemPerformance>();
        for (var i = 0; i < 14; i++)
        {
            var state = i < mastered ? MasteryStates.Mastered
                : i < strong ? MasteryStates.Strong
                : i < practicing ? MasteryStates.Practicing
                : i < learning ? MasteryStates.Learning : MasteryStates.Unseen;
            result.Add(new DashboardSystemPerformance { System = $"s{i}", MasteryState = state });
        }
        for (var i = 0; i < hard; i++) result[i % result.Count].Difficulty4PlusSuccessful++;
        return result;
    }
}