using System.Net;
using System.Net.Http.Json;
using BigRegister.Api.Contracts;
using BigRegister.Api.Data;
using Microsoft.AspNetCore.Mvc.Testing;

namespace BigRegister.Tests;

/// <summary>
/// The brief is a single process-global demo entity, so each test resets it first
/// (tests within a class run sequentially in xUnit). Role is the dev-only X-Role
/// header: absent = drafter, "approver" = a different identity.
/// </summary>
public class BriefEndpointTests(TestWebApplicationFactory factory) : IClassFixture<TestWebApplicationFactory>
{
  private readonly HttpClient _client = factory.CreateClient();

  private static LetterBlockDto FreeText(string id) =>
      new("freeText", id, new RichTextBlockDto(new[] { new ParagraphDto(new[] { new RichTextNodeDto("text", Text: "inhoud") }) }));

  // Fill every REQUIRED section with a block so submit is allowed.
  private static SaveBriefRequest FilledFrom(BriefDto brief)
  {
    var i = 0;
    var sections = brief.Sections
        .Select(s => new LetterSectionDto(s.SectionKey, s.Title, s.Required, s.Required ? new[] { FreeText($"local-{++i}") } : s.Blocks))
        .ToList();
    return new SaveBriefRequest(sections);
  }

  private async Task<BriefDto> Get()
  {
    BriefStore.Reset();
    var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
    return view!.Brief;
  }

  private HttpRequestMessage Post(string path, string? role = null, object? body = null)
  {
    var req = new HttpRequestMessage(HttpMethod.Post, path);
    if (role is not null) req.Headers.Add("X-Role", role);
    if (body is not null) req.Content = JsonContent.Create(body);
    return req;
  }

  [Fact]
  public async Task Get_creates_a_draft_from_the_template_with_scoped_passages()
  {
    var brief = await Get();
    Assert.Equal("draft", brief.Status.Tag);
    Assert.Equal(new[] { "aanhef", "kern", "slot" }, brief.Sections.Select(s => s.SectionKey));
    // aanhef + slot are locked, predefined and prefilled; only kern is editable + empty.
    var aanhef = brief.Sections.Single(s => s.SectionKey == "aanhef");
    Assert.True(aanhef.Locked);
    Assert.NotEmpty(aanhef.Blocks);
    Assert.True(brief.Sections.Single(s => s.SectionKey == "slot").Locked);
    var kern = brief.Sections.Single(s => s.SectionKey == "kern");
    Assert.False(kern.Locked);
    Assert.Empty(kern.Blocks);

    var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
    // global passages + the arts-scoped one; no other-beroep passages leak in.
    Assert.Contains(view!.AvailablePassages, p => p.PassageId == "p-kern-arts");
    Assert.All(view.AvailablePassages, p => Assert.True(p.Scope == "global" || p.Beroep == "arts"));
  }

  [Fact]
  public async Task Save_is_drafter_only()
  {
    var brief = await Get();
    var save = FilledFrom(brief);

    var approver = Post("/api/v1/brief", role: "approver");
    approver.Method = HttpMethod.Put;
    approver.Content = JsonContent.Create(save);
    Assert.Equal(HttpStatusCode.Forbidden, (await _client.SendAsync(approver)).StatusCode);

    Assert.Equal(HttpStatusCode.OK, (await _client.PutAsJsonAsync("/api/v1/brief", save)).StatusCode);
  }

  [Fact]
  public async Task Submit_blocks_on_empty_required_section_then_succeeds_when_filled()
  {
    await Get();
    // Nothing filled yet → required sections empty → 409.
    Assert.Equal(HttpStatusCode.Conflict, (await _client.SendAsync(Post("/api/v1/brief/submit"))).StatusCode);

    var brief = (await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief"))!.Brief;
    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));

    var res = await _client.SendAsync(Post("/api/v1/brief/submit"));
    res.EnsureSuccessStatusCode();
    var submitted = await res.Content.ReadFromJsonAsync<BriefViewDto>();
    Assert.Equal("submitted", submitted!.Brief.Status.Tag);
  }

  [Fact]
  public async Task Drafter_cannot_approve_own_letter_but_a_different_reviewer_can()
  {
    var brief = await Get();
    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
    await _client.SendAsync(Post("/api/v1/brief/submit"));

    // drafter role approving own letter → 403
    Assert.Equal(HttpStatusCode.Forbidden, (await _client.SendAsync(Post("/api/v1/brief/approve"))).StatusCode);

    var res = await _client.SendAsync(Post("/api/v1/brief/approve", role: "approver"));
    res.EnsureSuccessStatusCode();
    Assert.Equal("approved", (await res.Content.ReadFromJsonAsync<BriefViewDto>())!.Brief.Status.Tag);
  }

  [Fact]
  public async Task Reject_returns_comments_and_editing_reopens_to_draft()
  {
    var brief = await Get();
    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
    await _client.SendAsync(Post("/api/v1/brief/submit"));

    var rejected = await (await _client.SendAsync(
        Post("/api/v1/brief/reject", role: "approver", body: new RejectBriefRequest("Graag aanvullen.")))).Content.ReadFromJsonAsync<BriefViewDto>();
    Assert.Equal("rejected", rejected!.Brief.Status.Tag);
    Assert.Equal("Graag aanvullen.", rejected.Brief.Status.Comments);

    // A drafter save on a rejected letter reopens it to draft.
    var reopened = await (await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief))).Content.ReadFromJsonAsync<BriefViewDto>();
    Assert.Equal("draft", reopened!.Brief.Status.Tag);
  }

  [Fact]
  public async Task Send_only_from_approved()
  {
    var brief = await Get();
    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
    await _client.SendAsync(Post("/api/v1/brief/submit"));

    // submitted (not approved) → send 409
    Assert.Equal(HttpStatusCode.Conflict, (await _client.SendAsync(Post("/api/v1/brief/send"))).StatusCode);

    await _client.SendAsync(Post("/api/v1/brief/approve", role: "approver"));
    var res = await _client.SendAsync(Post("/api/v1/brief/send"));
    res.EnsureSuccessStatusCode();
    Assert.Equal("sent", (await res.Content.ReadFromJsonAsync<BriefViewDto>())!.Brief.Status.Tag);
  }

  [Fact]
  public async Task Decisions_on_the_view_mirror_the_acting_principal_and_live_status()
  {
    var brief = await Get();
    var view = await _client.GetFromJsonAsync<BriefViewDto>("/api/v1/brief");
    Assert.True(view!.Decisions.CanEdit); // default (no X-Role) = drafter, draft status
    Assert.False(view.Decisions.CanApprove);

    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
    await _client.SendAsync(Post("/api/v1/brief/submit"));

    var asApprover = await _client.SendAsync(
        new HttpRequestMessage(HttpMethod.Get, "/api/v1/brief") { Headers = { { "X-Role", "approver" } } });
    var approverView = await asApprover.Content.ReadFromJsonAsync<BriefViewDto>();
    Assert.True(approverView!.Decisions.CanApprove);
    Assert.False(approverView.Decisions.CanEdit); // approver never edits
  }

  [Fact]
  public async Task Me_returns_no_capabilities_for_drafter_and_the_brief_set_for_approver()
  {
    var asDrafter = await _client.GetFromJsonAsync<MeDto>("/api/v1/me");
    Assert.Empty(asDrafter!.Capabilities);

    var res = await _client.SendAsync(new HttpRequestMessage(HttpMethod.Get, "/api/v1/me") { Headers = { { "X-Role", "approver" } } });
    var asApprover = await res.Content.ReadFromJsonAsync<MeDto>();
    Assert.Equal(new[] { "brief:approve", "brief:reject", "brief:send" }, asApprover!.Capabilities);
  }

  [Fact]
  public async Task Reset_recreates_a_fresh_draft_with_locked_prefilled_sections()
  {
    var brief = await Get();
    // Advance out of draft so the reset back to draft is observable.
    await _client.PutAsJsonAsync("/api/v1/brief", FilledFrom(brief));
    await _client.SendAsync(Post("/api/v1/brief/submit"));

    var res = await _client.SendAsync(Post("/api/v1/brief/reset"));
    res.EnsureSuccessStatusCode();
    var view = await res.Content.ReadFromJsonAsync<BriefViewDto>();
    Assert.Equal("draft", view!.Brief.Status.Tag);
    var aanhef = view.Brief.Sections.Single(s => s.SectionKey == "aanhef");
    Assert.True(aanhef.Locked);
    Assert.NotEmpty(aanhef.Blocks);
    Assert.Empty(view.Brief.Sections.Single(s => s.SectionKey == "kern").Blocks);
  }
}
