using LehrerApp.Core.Models;
using LehrerApp.Desktop.Services.Mcp.Tools;
using LehrerApp.Templating;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class LetterTemplateToolsTests : IDisposable
{
    private readonly string _directory = Path.Combine(Path.GetTempPath(), $"lehrerapp-lettertools-tests-{Guid.NewGuid():N}");
    public LetterTemplateToolsTests() => Directory.CreateDirectory(_directory);
    public void Dispose() { if (Directory.Exists(_directory)) Directory.Delete(_directory, true); }

    private LetterTemplateTools BuildTool(TemplateStore store, FakeStudents? students = null, FakeGroups? groups = null) =>
        new(store, new TemplateLoader(), new QuestTemplateRenderer(), students ?? new FakeStudents([]), groups ?? new FakeGroups([]));

    private TemplateStore StoreWithTemplate(string name, params PlaceholderDefinition[] definitions)
    {
        var source = Path.Combine(_directory, $"{Guid.NewGuid():N}.lavorlage");
        var manifest = new TemplateManifest { Id = $"brief-{Guid.NewGuid():N}", Name = name, Placeholders = [.. definitions] };
        var lines = new List<string> { "PAGE 210 297 mm" };
        var y = 20;
        foreach (var definition in definitions)
        {
            var element = definition.Type == PlaceholderType.Multiline ? "TEXTBOX" : "TEXT";
            lines.Add(element == "TEXTBOX" ? $"TEXTBOX 20 {y} 170 80 ${definition.Name}" : $"TEXT 20 {y} ${definition.Name}");
            y += 20;
        }
        TemplatePackage.Create(source, manifest, string.Join('\n', lines), new Dictionary<string, byte[]>());
        var store = new TemplateStore(Path.Combine(_directory, $"store-{Guid.NewGuid():N}"));
        store.Import(source);
        return store;
    }

    private static Student StudentWithContact(string? salutation = "Sehr geehrte Frau Muster,") => new()
    {
        FirstName = "Lena", LastName = "Beispiel",
        Contacts = [new Contact
        {
            Name = "Frau Muster", Relation = "Mutter", LetterSalutation = salutation,
            Street = "Hauptstraße 1", PostalCode = "12345", City = "Musterstadt",
        }],
    };

    [Fact]
    public void ListLetterTemplates_ListetVorlageMitPlatzhaltern()
    {
        var store = StoreWithTemplate("Elternbrief", new PlaceholderDefinition("Anrede", PlaceholderType.Text, true));
        var tool = BuildTool(store);

        var result = Assert.Single(tool.ListLetterTemplates());

        Assert.Equal("Elternbrief", result.Name);
        Assert.Contains(result.Placeholders, p => p.Name == "Anrede" && p.Required);
    }

    [Fact]
    public void RenderLetter_UnbekannteVorlage_LiefertFehler()
    {
        var student = StudentWithContact();
        var tool = BuildTool(new TemplateStore(_directory), new FakeStudents([student]));

        var result = tool.RenderLetter("nicht-vorhanden", student.Id, "Text", "Frau Lehrer");

        Assert.False(result.Success);
        Assert.Null(result.Base64Pdf);
    }

    [Fact]
    public void RenderLetter_UnbekannterSchueler_LiefertFehler()
    {
        var store = StoreWithTemplate("Elternbrief", new PlaceholderDefinition("Anrede", PlaceholderType.Text, true));
        var installed = Assert.Single(store.GetTemplates());
        var tool = BuildTool(store);

        var result = tool.RenderLetter(installed.Id, Guid.NewGuid(), "Text", "Frau Lehrer");

        Assert.False(result.Success);
    }

    [Fact]
    public void RenderLetter_PflichtplatzhalterFehlt_LiefertFehlerOhnePdf()
    {
        var store = StoreWithTemplate("Elternbrief", new PlaceholderDefinition("Anrede", PlaceholderType.Text, true));
        var installed = Assert.Single(store.GetTemplates());
        var student = StudentWithContact(salutation: null); // keine Anrede hinterlegt
        var tool = BuildTool(store, new FakeStudents([student]));

        var result = tool.RenderLetter(installed.Id, student.Id, "Text", "Frau Lehrer");

        Assert.False(result.Success);
        Assert.Contains("Anrede", result.Message);
        Assert.Null(result.Base64Pdf);
    }

    [Fact]
    public void RenderLetter_VollstaendigeDaten_LiefertBase64Pdf()
    {
        var store = StoreWithTemplate("Elternbrief",
            new PlaceholderDefinition("Anrede", PlaceholderType.Text, true),
            new PlaceholderDefinition("Datum", PlaceholderType.Date, true),
            new PlaceholderDefinition("Brieftext", PlaceholderType.Multiline, true));
        var installed = Assert.Single(store.GetTemplates());
        var student = StudentWithContact();
        var tool = BuildTool(store, new FakeStudents([student]));

        var result = tool.RenderLetter(installed.Id, student.Id, "Dies ist der Inhalt.", "Frau Lehrer");

        Assert.True(result.Success);
        Assert.NotNull(result.Base64Pdf);
        var bytes = Convert.FromBase64String(result.Base64Pdf!);
        Assert.Equal("%PDF", System.Text.Encoding.ASCII.GetString(bytes, 0, 4));
        Assert.Equal("Elternbrief_Beispiel_Lena.pdf", result.SuggestedFileName);
    }

    [Fact]
    public void RenderLetter_ExtraValues_FuelltZusaetzlichenPlatzhalter()
    {
        var store = StoreWithTemplate("Elternbrief",
            new PlaceholderDefinition("Anrede", PlaceholderType.Text, true),
            new PlaceholderDefinition("Betreff", PlaceholderType.Text, true));
        var installed = Assert.Single(store.GetTemplates());
        var student = StudentWithContact();
        var tool = BuildTool(store, new FakeStudents([student]));

        var result = tool.RenderLetter(installed.Id, student.Id, "Text", "Frau Lehrer",
            extraValues: new Dictionary<string, string> { ["Betreff"] = "Elternabend" });

        Assert.True(result.Success);
        Assert.NotNull(result.Base64Pdf);
    }
}