using System.Net;
using System.Net.Http.Json;
using ItWorx.KnowledgeHub.Contracts.Knowledge;
using ItWorx.KnowledgeHub.IntegrationTests.Infrastructure;

namespace ItWorx.KnowledgeHub.IntegrationTests.Knowledge;

/// <summary>Every published mutation creates a revision atomically (M3-A01), and a user
/// can compare/restore past revisions without losing the current version (M3-A02).</summary>
[Collection(PostgresTestGroup.Name)]
public sealed class RevisionsTests(PostgresContainerFixture postgres) : OwnerSetupTestBase(postgres)
{
    [Fact]
    public async Task Publishing_creates_a_new_revision_every_time()
    {
        using var client = Factory.CreateClient();
        await SetupHelper.LoginAsync(client, OwnerEmail, OwnerPassword);

        var createResponse = await SetupHelper.PostWithCsrfAsync(
            client, "/api/v1/pages", new CreatePageRequest(null, "Revisiepagina", "WikiPage", "Versie 1", null));
        var page = await createResponse.Content.ReadFromJsonAsync<PageDetail>();
        Assert.NotNull(page);

        await SetupHelper.PutWithCsrfAsync(
            client,
            $"/api/v1/pages/{page.Id}",
            new UpdatePageRequest("Revisiepagina", "Versie 2", "WikiPage", "Active", "Naar versie 2"),
            page.ETag);

        var revisions = await client.GetFromJsonAsync<List<PageRevisionSummary>>($"/api/v1/pages/{page.Id}/revisions");

        Assert.NotNull(revisions);
        Assert.Equal(2, revisions.Count);
        // Most recent first.
        Assert.Equal(2, revisions[0].RevisionNumber);
        Assert.Equal(1, revisions[1].RevisionNumber);
        Assert.Equal("Naar versie 2", revisions[0].ChangeSummary);
    }

    [Fact]
    public async Task Restoring_a_past_revision_creates_a_new_revision_without_losing_history()
    {
        using var client = Factory.CreateClient();
        await SetupHelper.LoginAsync(client, OwnerEmail, OwnerPassword);

        var createResponse = await SetupHelper.PostWithCsrfAsync(
            client, "/api/v1/pages", new CreatePageRequest(null, "Titel A", "WikiPage", "Inhoud A", null));
        var page = await createResponse.Content.ReadFromJsonAsync<PageDetail>();
        Assert.NotNull(page);

        var afterFirstEdit = await SetupHelper.PutWithCsrfAsync(
            client,
            $"/api/v1/pages/{page.Id}",
            new UpdatePageRequest("Titel B", "Inhoud B", "WikiPage", "Active", null),
            page.ETag);
        var pageAfterEdit = await afterFirstEdit.Content.ReadFromJsonAsync<PageDetail>();
        Assert.NotNull(pageAfterEdit);
        Assert.Equal("Titel B", pageAfterEdit.Title);

        // Fetch the original revision's content before restoring it.
        var originalRevision = await client.GetFromJsonAsync<PageRevisionDetailResponse>($"/api/v1/pages/{page.Id}/revisions/1");
        Assert.NotNull(originalRevision);
        Assert.Equal("Titel A", originalRevision.Title);
        Assert.Equal("Inhoud A", originalRevision.Markdown);

        var restoreResponse = await SetupHelper.PostWithCsrfAndIfMatchAsync(
            client, $"/api/v1/pages/{page.Id}/revisions/1/restore", (object?)null, pageAfterEdit.ETag);
        Assert.Equal(HttpStatusCode.OK, restoreResponse.StatusCode);

        var restored = await restoreResponse.Content.ReadFromJsonAsync<PageDetail>();
        Assert.NotNull(restored);
        Assert.Equal("Titel A", restored.Title);
        Assert.Equal("Inhoud A", restored.Markdown);
        Assert.Equal(3, restored.CurrentRevisionNumber);

        // History is never rewritten: all three revisions remain, including the
        // "Titel B" state that briefly existed as the current version.
        var revisions = await client.GetFromJsonAsync<List<PageRevisionSummary>>($"/api/v1/pages/{page.Id}/revisions");
        Assert.NotNull(revisions);
        Assert.Equal(3, revisions.Count);
        Assert.Contains(revisions, revision => revision.RevisionNumber == 2 && revision.Title == "Titel B");
    }

    [Fact]
    public async Task Restoring_against_a_stale_etag_is_rejected_as_a_conflict()
    {
        using var client = Factory.CreateClient();
        await SetupHelper.LoginAsync(client, OwnerEmail, OwnerPassword);

        var createResponse = await SetupHelper.PostWithCsrfAsync(
            client, "/api/v1/pages", new CreatePageRequest(null, "Titel A", "WikiPage", "Inhoud A", null));
        var page = await createResponse.Content.ReadFromJsonAsync<PageDetail>();
        Assert.NotNull(page);

        await SetupHelper.PutWithCsrfAsync(
            client,
            $"/api/v1/pages/{page.Id}",
            new UpdatePageRequest("Titel B", "Inhoud B", "WikiPage", "Active", null),
            page.ETag);

        // page.ETag is now stale (it was captured before the edit above).
        var restoreResponse = await SetupHelper.PostWithCsrfAndIfMatchAsync(
            client, $"/api/v1/pages/{page.Id}/revisions/1/restore", (object?)null, page.ETag);

        Assert.Equal(HttpStatusCode.PreconditionFailed, restoreResponse.StatusCode);
    }
}