using System.Net;
using System.Text;
using LehrerApp.Desktop.Services;
using Xunit;

namespace LehrerApp.Desktop.Tests;

public sealed class WebUntisIntegrationServiceTests
{
    [Fact]
    public async Task ConnectUndAbruf_GehenDirektAnWebUntisUndVerwendenDieselbeSession()
    {
        var handler = new QueueHandler(
            Json("{\"result\":{\"sessionId\":\"desktop-session\"}}"),
            Json("{\"result\":[{\"id\":1,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"),
            Json("{\"result\":[{\"id\":42,\"name\":\"KUE\",\"longName\":\"Kürbis\",\"active\":true}]}"),
            Json("{\"result\":{}}"));
        var settings = TestSupport.BuildWebUntisSettingsService();
        await using var service = new WebUntisIntegrationService(new HttpClient(handler), settings);

        await service.ConnectAsync(new WebUntisCredentials(
            "bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
        var teachers = await service.GetTeachersAsync();

        Assert.Equal("KUE", Assert.Single(teachers).Name);
        Assert.Equal(3, handler.Requests.Count);
        Assert.All(handler.Requests, request =>
            Assert.StartsWith("https://arche.webuntis.com/WebUntis/", request.Uri));
        Assert.DoesNotContain(handler.Requests, request => request.Uri.Contains("/api/webuntis"));
        Assert.Single(handler.Requests, request => request.Body.Contains("\"method\":\"authenticate\""));
    }

    [Fact]
    public async Task GetClassAbsencesAsync_LoestKlasseNamensbasiertAufUndAdressiertSieAlsKLPlusId()
    {
        var csv = Encoding.UTF8.GetBytes(
            "Schüler*innen\tExterne Id\tText\tKlasse\tDatum\tWochentag\tFehlstd.\tFehlmin.\tLehrkraft\tFach\t" +
            "Abwesenheitsgrund\tText\tENr\tErledigt\tAbwesenheit zählt\tEntschuldigungstext\tStundennr.\tStatus\tFehltage\r\n" +
            "Muster Max\t12345\t\t10c\t24.08.26\tMo.\t1\t45\tHED\tChe\tAbsent\tKrank gemeldet\t555\t24.08.26\ttrue\t\t3\tnicht entsch.\t1\r\n");
        var handler = new QueueHandler(
            Json("{\"result\":{\"sessionId\":\"desktop-session\"}}"), // authenticate (ConnectAsync)
            Json("{\"result\":[{\"id\":7,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"), // getSchoolyears (ConnectAsync-Validierung)
            Json("{\"result\":[{\"id\":7,\"name\":\"2026/27\",\"startDate\":20260801,\"endDate\":20270731}]}"), // getSchoolyears (ResolveClassIdAsync)
            Json("{\"result\":[{\"id\":874,\"name\":\"10c\"}]}"), // getKlassen
            Json("{\"data\":{\"finished\":true,\"error\":false," +
                 "\"reportParams\":\"get=rpt.tmp&name=AbsencePerStudent&format=csv\"}}"),
            new HttpResponseMessage(HttpStatusCode.OK) { Content = new ByteArrayContent(csv) },
            Json("{\"result\":{}}")); // logout (Dispose)
        var settings = TestSupport.BuildWebUntisSettingsService();
        await using var service = new WebUntisIntegrationService(new HttpClient(handler), settings);

        await service.ConnectAsync(new WebUntisCredentials(
            "bk-ostvest", "arche.webuntis.com", "lehrkraft", "geheim"));
        var entries = await service.GetClassAbsencesAsync("10c",
            new DateOnly(2026, 8, 24), new DateOnly(2026, 8, 28));

        var entry = Assert.Single(entries);
        Assert.Equal("Muster Max", entry.StudentName);
        Assert.Equal("nicht entsch.", entry.Status);
        // Zweimal getSchoolyears: einmal als ConnectAsync-Validierung, einmal in ResolveClassIdAsync.
        Assert.Equal(2, handler.Requests.Count(request => request.Body.Contains("\"method\":\"getSchoolyears\"")));
        Assert.Single(handler.Requests, request => request.Body.Contains("\"method\":\"getKlassen\""));
        Assert.Single(handler.Requests, request =>
            request.Uri.Contains("reports.do?name=AbsencePerStudent") &&
            request.Uri.Contains("klasseOrStudentgroupId=KL874"));
    }

    private static HttpResponseMessage Json(string json) => new(HttpStatusCode.OK)
    {
        Content = new StringContent(json, Encoding.UTF8, "application/json"),
    };

    private sealed class QueueHandler(params HttpResponseMessage[] responses) : HttpMessageHandler
    {
        private readonly Queue<HttpResponseMessage> _responses = new(responses);
        public List<CapturedRequest> Requests { get; } = [];

        protected override async Task<HttpResponseMessage> SendAsync(HttpRequestMessage request,
            CancellationToken cancellationToken)
        {
            Requests.Add(new(request.RequestUri?.ToString() ?? "",
                request.Content is null ? "" : await request.Content.ReadAsStringAsync(cancellationToken)));
            return _responses.Dequeue();
        }
    }

    private sealed record CapturedRequest(string Uri, string Body);
}