using System.IO.Compression;
using System.Xml.Linq;
using LehrerApp.Core.Services;
using Xunit;

namespace LehrerApp.Tests;

public sealed class LetterTemplateServiceTests : IDisposable
{
    private static readonly XNamespace W = "http://schemas.openxmlformats.org/wordprocessingml/2006/main";
    private readonly string _directory = Path.Combine(Path.GetTempPath(), $"lehrerapp-letter-tests-{Guid.NewGuid():N}");

    public LetterTemplateServiceTests() => Directory.CreateDirectory(_directory);

    [Fact]
    public void Validate_OhneInhaltssteuerelement_Warnt()
    {
        var path = CreateDocx("<w:p><w:r><w:t>Brief</w:t></w:r></w:p>");

        var result = new LetterTemplateService(_directory).Validate(path);

        Assert.Contains(result.Issues, i => i.Severity == TemplateIssueSeverity.Warning
                                            && i.Message.Contains("keine Inhaltssteuerelemente"));
    }

    [Fact]
    public void Validate_UnbekannterTag_Warnt()
    {
        var path = CreateDocx(Control("Something.EntirelyUnknown"));

        var result = new LetterTemplateService(_directory).Validate(path);

        Assert.Contains(result.Issues, i => i.Tag == "Something.EntirelyUnknown"
                                            && i.Severity == TemplateIssueSeverity.Warning);
    }

    [Fact]
    public void Validate_WahrscheinlicherTippfehler_WarntDeutlichMitVorschlag()
    {
        var path = CreateDocx(Control("Contact.Adress"));

        var result = new LetterTemplateService(_directory).Validate(path);

        var issue = Assert.Single(result.Issues);
        Assert.Equal(TemplateIssueSeverity.StrongWarning, issue.Severity);
        Assert.Equal("Contact.Address", issue.SuggestedTag);
        Assert.Contains("Meinten Sie", issue.Message);
    }

    [Fact]
    public void Validate_FindetTagsInKopfzeile()
    {
        var path = CreateDocx(Control("Student.FirstName"), Control("CurrentDate"));

        var result = new LetterTemplateService(_directory).Validate(path);

        Assert.Contains("Student.FirstName", result.Tags);
        Assert.Contains("CurrentDate", result.Tags);
        Assert.Empty(result.Issues);
    }

    [Fact]
    public void Generate_BefuelltTextUndMehrzeiligeAdresse_OhneVorlageZuVeraendern()
    {
        var path = CreateDocx(Control("Student.FirstName") + Control("Contact.Address"));
        var original = File.ReadAllBytes(path);
        var output = Path.Combine(_directory, "filled.docx");
        var service = new LetterTemplateService(_directory);

        service.Generate(path, output, new Dictionary<string, string?>
        {
            ["Student.FirstName"] = "Mara",
            ["Contact.Address"] = "Hauptstraße 1\n12345 Musterstadt",
        });

        Assert.Equal(original, File.ReadAllBytes(path));
        using var archive = ZipFile.OpenRead(output);
        var entry = archive.GetEntry("word/document.xml")!;
        using var reader = new StreamReader(entry.Open());
        var xml = XDocument.Parse(reader.ReadToEnd());
        Assert.Contains("Mara", xml.Descendants(W + "t").Select(t => t.Value));
        Assert.Single(xml.Descendants(W + "br"));
        Assert.Contains("12345 Musterstadt", xml.Descendants(W + "t").Select(t => t.Value));
    }

    [Fact]
    public void Import_KopiertVorlageUndLoeschenEntferntSie()
    {
        var path = CreateDocx(Control("CurrentDate"));
        var service = new LetterTemplateService(Path.Combine(_directory, "appdata"));

        var imported = service.Import(path, "Elternbrief");

        Assert.Equal("Elternbrief", Assert.Single(service.GetTemplates()).Name);
        Assert.True(File.Exists(service.GetTemplatePath(imported)));
        service.Delete(imported.Id);
        Assert.Empty(service.GetTemplates());
        Assert.False(File.Exists(service.GetTemplatePath(imported)));
    }

    private string CreateDocx(string body, string? header = null)
    {
        var path = Path.Combine(_directory, $"{Guid.NewGuid():N}.docx");
        using var archive = ZipFile.Open(path, ZipArchiveMode.Create);
        AddXml(archive, "word/document.xml", body);
        if (header is not null) AddXml(archive, "word/header1.xml", header);
        return path;
    }

    private static void AddXml(ZipArchive archive, string name, string content)
    {
        var entry = archive.CreateEntry(name);
        using var writer = new StreamWriter(entry.Open());
        writer.Write($"<w:document xmlns:w=\"{W}\"><w:body>{content}</w:body></w:document>");
    }

    private static string Control(string tag) =>
        $"<w:sdt><w:sdtPr><w:tag w:val=\"{tag}\"/></w:sdtPr><w:sdtContent>" +
        "<w:p><w:r><w:rPr><w:b/></w:rPr><w:t>Platzhalter</w:t></w:r></w:p>" +
        "</w:sdtContent></w:sdt>";

    public void Dispose()
    {
        if (Directory.Exists(_directory)) Directory.Delete(_directory, recursive: true);
    }
}