using Microsoft.Extensions.Logging.Abstractions;
using Wiki.Application.Encyclopedia;
using Wiki.Core.Model;

namespace Wiki.Application.Tests;

public class AssignNotesUseCaseTests
{
    private static readonly EncyclopediaSettings Settings = new(16000, 10, 300_000, [], null);

    private static AssignNotesUseCase UseCase(FakeTextModel model) =>
        new(model, Settings, NullLogger<AssignNotesUseCase>.Instance);

    private static PlannedArticle Article(string slug, params string[] sources) =>
        new(slug, "Titel " + slug, "Title " + slug, ArticleCategory.System, "Scope " + slug, sources);

    private static ArticlePlan PlanWith(params PlannedArticle[] articles)
    {
        var plan = ArticlePlan.Empty();
        foreach (var a in articles) plan.AddArticle(a);
        return plan;
    }

    private static Document[] Batch(params string[] slugs) =>
        slugs.Select(s => TestNotes.Note(s)).ToArray();

    [Fact]
    public void Prompt_RoomNotesAlsoFeedTheRoomArticle()
    {
        Assert.Contains("additionally feeds that room's article (category room)", Prompts.Assign);
        Assert.Contains("\"EG Schlafzimmer\"", Prompts.Assign);
    }

    [Fact]
    public async Task Assign_ExistingAndNew()
    {
        var heating = Article("heating", "old");
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"garden","titleDe":"Garten","titleEn":"Garden","category":"room","scope":"Der Garten."}],
             "notes":[{"note":"a","articles":["heating","garden"]},{"note":"b","articles":["garden"]},{"note":"c","skip":true}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a", "b", "c"), [heating], PlanWith(heating), CancellationToken.None);

        Assert.False(outcome.Unusable);
        var garden = Assert.Single(outcome.New);
        Assert.Equal("garden", garden.Slug);
        Assert.Equal(ArticleCategory.Room, garden.Category);
        Assert.Equal(["a", "b"], garden.Sources);
        Assert.Equal(["heating", "garden"], outcome.Assignments["a"]);
        Assert.Empty(outcome.Assignments["c"]);
    }

    [Fact]
    public async Task Assign_NoteOutsideBatch_Dropped()
    {
        var heating = Article("heating");
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[{"note":"a","articles":["heating"]},{"note":"zzz","articles":["heating"]}]}""");

        var outcome = await UseCase(model).AssignAsync(Batch("a"), [heating], PlanWith(heating), CancellationToken.None);

        Assert.Equal(["a"], outcome.Assignments.Keys);
    }

    [Fact]
    public async Task Assign_ArticleOutsideCandidates_Dropped()
    {
        var heating = Article("heating");
        var other = Article("other");
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[{"note":"a","articles":["heating","other"]},{"note":"b","articles":["other"]}]}""");

        var outcome = await UseCase(model).AssignAsync(Batch("a", "b"), [heating], PlanWith(heating, other), CancellationToken.None);

        Assert.Equal(["heating"], outcome.Assignments["a"]);
        Assert.False(outcome.Assignments.ContainsKey("b"));
    }

    [Fact]
    public async Task Assign_NewWithExistingNonCandidateSlug_MergedIntoExistingArticle()
    {
        var heating = Article("heating");
        var plan = PlanWith(heating, Article("garden"));
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"garden","titleDe":"G","titleEn":"G","category":"room","scope":"s"}],
             "notes":[{"note":"a","articles":["garden"]},{"note":"b","articles":["heating"]}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a", "b"), [heating], plan, CancellationToken.None);

        Assert.False(outcome.Unusable);
        Assert.Empty(outcome.New);
        Assert.Equal(["garden"], outcome.Assignments["a"]);
        Assert.Equal(["heating"], outcome.Assignments["b"]);
    }

    [Fact]
    public async Task Assign_NewWithRedirectedSlug_DroppedAndItsNotesUnassigned()
    {
        var heating = Article("heating");
        var plan = PlanWith(heating, Article("garden"), Article("yard"));
        plan.Fold("yard", "garden", isPublic: false);
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"yard","titleDe":"G","titleEn":"G","category":"room","scope":"s"}],
             "notes":[{"note":"a","articles":["yard"]},{"note":"b","articles":["heating"]}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a", "b"), [heating], plan, CancellationToken.None);

        Assert.Empty(outcome.New);
        Assert.False(outcome.Assignments.ContainsKey("a"));
        Assert.Equal(["heating"], outcome.Assignments["b"]);
    }

    [Fact]
    public async Task Assign_NewWithRetiredSlug_DroppedAndItsNotesUnassigned()
    {
        var heating = Article("heating");
        var plan = PlanWith(heating, Article("garden", "gone"));
        plan.RemoveNote("gone");
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"garden","titleDe":"G","titleEn":"G","category":"room","scope":"s"}],
             "notes":[{"note":"a","articles":["garden"]},{"note":"b","articles":["heating"]}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a", "b"), [heating], plan, CancellationToken.None);

        Assert.Empty(outcome.New);
        Assert.False(outcome.Assignments.ContainsKey("a"));
        Assert.Equal(["heating"], outcome.Assignments["b"]);
    }

    [Fact]
    public async Task Assign_UnreferencedNew_Dropped()
    {
        var heating = Article("heating");
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"garden","titleDe":"G","titleEn":"G","category":"room","scope":"s"}],
             "notes":[{"note":"a","articles":["heating"]}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a"), [heating], PlanWith(heating), CancellationToken.None);

        Assert.False(outcome.Unusable);
        Assert.Empty(outcome.New);
    }

    [Fact]
    public async Task Assign_Truncated_IsUnusable()
    {
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[{"note":"a","skip":true}]}""", truncated: true);

        var outcome = await UseCase(model).AssignAsync(Batch("a"), [], ArticlePlan.Empty(), CancellationToken.None);

        Assert.True(outcome.Unusable);
        Assert.Empty(outcome.Assignments);
    }

    [Fact]
    public async Task Assign_PromptIsBounded()
    {
        var articles = Enumerable.Range(0, 500).Select(i => Article($"article-{i}", "n")).ToArray();
        var plan = PlanWith(articles);
        var batch = Batch(Enumerable.Range(0, 20).Select(i => $"note-{i:00}").ToArray());
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");

        await UseCase(model).AssignAsync(batch, articles.Take(100).ToArray(), plan, CancellationToken.None);

        var user = model.Calls[0].User;
        Assert.Equal(20, user.Split('\n').Count(l => l.StartsWith("note-")));
        Assert.Equal(20, user.Split('\n').Count(l => l.StartsWith("article-")));
        Assert.DoesNotContain("article-20 ", user);
    }

    [Fact]
    public async Task Assign_FirstParagraph_SkipsHeadingsAndBlankLines()
    {
        var note = TestNotes.Note("a") with { Body = "# T\n\n  \nfirst line\ncontinued\n\nsecond para" };
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");

        await UseCase(model).AssignAsync([note], [], ArticlePlan.Empty(), CancellationToken.None);

        var line = model.Calls[0].User.Split('\n').Single(l => l.StartsWith("a | "));
        Assert.EndsWith(" | first line continued", line);
    }

    [Fact]
    public async Task Assign_FirstParagraph_CutTo300()
    {
        var note = TestNotes.Note("a") with { Body = new string('y', 500) };
        var model = new FakeTextModel().Reply("""{"new":[],"notes":[]}""");

        await UseCase(model).AssignAsync([note], [], ArticlePlan.Empty(), CancellationToken.None);

        var line = model.Calls[0].User.Split('\n').Single(l => l.StartsWith("a | "));
        Assert.EndsWith(" | " + new string('y', 300), line);
    }

    [Fact]
    public async Task Assign_NewWithoutTitle_Dropped()
    {
        var heating = Article("heating");
        var model = new FakeTextModel().Reply("""
            {"new":[{"slug":"garden","titleDe":"G","category":"room","scope":"s"}],
             "notes":[{"note":"a","articles":["garden","heating"]}]}
            """);

        var outcome = await UseCase(model).AssignAsync(Batch("a"), [heating], PlanWith(heating), CancellationToken.None);

        Assert.Empty(outcome.New);
        Assert.Equal(["heating"], outcome.Assignments["a"]);
    }

    [Fact]
    public async Task Assign_ModelUnavailable_Propagates()
    {
        var model = new FakeTextModel().Throw(new ModelUnavailableException("down"));

        await Assert.ThrowsAsync<ModelUnavailableException>(() =>
            UseCase(model).AssignAsync(Batch("a"), [], ArticlePlan.Empty(), CancellationToken.None));
    }
}