using AIStudio.Assistants.BeyondFactsLab;
using AIStudio.Settings.DataModel;

namespace AIStudio.Tests.BeyondFactsLab;

/// <summary>
/// Checks that AI Studio comes with every prompt of the BeyondFacts Lab, and that they stay small enough.
/// </summary>
/// <remarks>
/// The tests run a development build, which reads the prompts from its output folder: the project file copies every
/// embedded file there as well.
/// </remarks>
[TestFixture]
public sealed class BflPromptLibraryTests
{
    /// <summary>
    /// How many characters the fixed part of the longest system prompt may have: the core, the guide, the longest step,
    /// and the form of address.
    /// </summary>
    /// <remarks>
    /// German takes about four characters per token, so this is about 22,000 tokens. The lab accepts models with a
    /// context of 32,000 tokens; the rest is left for the details of the person and the conversation. Raising this
    /// limit means raising that minimum, too.
    /// </remarks>
    private const int MAX_FIXED_PROMPT_CHARACTERS = 90_000;

    [Test]
    public async Task EveryPromptComesWithTheApp()
    {
        foreach (var path in BflPromptLibrary.AllPaths)
            Assert.That(await BflPromptLibrary.ReadAsync(path), Is.Not.Empty, path);
    }

    [Test]
    public void EveryStepHasAPromptOfItsOwn()
    {
        var paths = BflStep.All.Select(BflPromptLibrary.StepPath).ToList();

        Assert.That(paths, Is.Unique);
    }

    [Test]
    public void BothFormsOfAddressHaveAnInstructionOfTheirOwn()
    {
        Assert.That(BflPromptLibrary.AddressPath(AddressForm.INFORMAL), Is.Not.EqualTo(BflPromptLibrary.AddressPath(AddressForm.FORMAL)));
    }

    [Test]
    public async Task AMissingPromptIsAnError()
    {
        await Assert.ThrowsAsync<FileNotFoundException>(async () => await BflPromptLibrary.ReadAsync("Assistants/BeyondFactsLab/Prompts/does-not-exist.md"));
    }

    [Test]
    public async Task TheFixedPartOfTheLongestPromptLeavesRoomForTheConversation()
    {
        var core = await BflPromptLibrary.ReadAsync(BflPromptLibrary.CORE_PATH);
        var knowledge = await BflPromptLibrary.ReadAsync(BflPromptLibrary.KNOWLEDGE_PATH);
        var longestStep = 0;
        foreach (var step in BflStep.All)
            longestStep = Math.Max(longestStep, (await BflPromptLibrary.ReadAsync(BflPromptLibrary.StepPath(step))).Length);

        var longestAddress = 0;
        foreach (var addressForm in Enum.GetValues<AddressForm>())
            longestAddress = Math.Max(longestAddress, (await BflPromptLibrary.ReadAsync(BflPromptLibrary.AddressPath(addressForm))).Length);

        Assert.That(core.Length + knowledge.Length + longestStep + longestAddress, Is.LessThanOrEqualTo(MAX_FIXED_PROMPT_CHARACTERS));
    }
}