using System.Net;
using BigRegister.Api.Data;
using BigRegister.Api.Zgw;
using BigRegister.Domain.Applications;
using BigRegister.Domain.Authorization;
using BigRegister.Tests.Builders;

namespace BigRegister.Tests;

/// <summary>
/// Exercises the OpenZaak read source against a stub HttpMessageHandler (no live server, no
/// mocking library) — the guarantee that it follows ZGW pagination, maps a zaak's zaaktype
/// back to the internal aanvraag-type key, and always sends a Bearer token.
/// </summary>
public class OpenZaakZaakSourceTests
{
  private const string ZrcBase = "https://oz.example/zaken/api/v1";
  private const string ZtBase = "https://oz.example/catalogi/api/v1";
  private const string ZaaktypeUrl = $"{ZtBase}/zaaktypen/zt-1";

  private static string Page1 => $$"""
    { "count": 2, "next": "{{ZrcBase}}/zaken?page=2", "results": [
      { "url": "{{ZrcBase}}/zaken/uuid-1", "identificatie": "ZAAK-1",
        "zaaktype": "{{ZaaktypeUrl}}", "startdatum": "2026-03-01",
        "einddatum": null, "registratiedatum": "2026-03-01" } ] }
    """;

  private static string Page2 => $$"""
    { "count": 2, "next": null, "results": [
      { "url": "{{ZrcBase}}/zaken/uuid-2", "identificatie": "ZAAK-2",
        "zaaktype": "{{ZaaktypeUrl}}", "startdatum": "2026-01-01",
        "einddatum": "2026-02-01", "registratiedatum": "2026-01-01" } ] }
    """;

  [Fact]
  public void Follows_pagination_maps_the_internal_aanvraag_type_and_sends_bearer_token()
  {
    // Regression for a real bug found via a live behandelportal walkthrough: this used to
    // return OpenZaak's human zaaktype label ("Herregistratie arts") as Type, which the FE's
    // AANVRAAG_TYPES trust boundary always rejects (it only accepts the internal key, the
    // same contract LocalZaakSource honors) — every werkvoorraad load failed to parse.
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url == $"{ZrcBase}/zaken" => Page1,
      _ when url == $"{ZrcBase}/zaken?page=2" => Page2,
      _ => throw new InvalidOperationException($"unexpected ZGW GET {url}"),
    });

    var options = new ZgwOptions
    {
      ZrcBaseUrl = ZrcBase,
      ZtcBaseUrl = ZtBase,
      ClientId = "c",
      Secret = "s",
      ZaaktypeUrls = new() { ["herregistratie"] = ZaaktypeUrl },
    };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);

    var cases = source.ListCases(DateTimeOffset.UtcNow);

    // Both pages accumulated.
    Assert.Equal(2, cases.Count);
    Assert.Equal(new[] { "uuid-1", "uuid-2" }, cases.Select(c => c.Id));
    Assert.All(cases, c => Assert.Equal("herregistratie", c.Type));
    Assert.Equal("InBehandeling", cases[0].Status.Tag);   // open
    Assert.Equal("Goedgekeurd", cases[1].Status.Tag);     // closed

    // No Catalogi round-trip needed — the type maps back via the local Zgw:ZaaktypeUrls config.
    Assert.DoesNotContain(handler.Requests, r => r.Contains("zaaktypen"));
    // Every outbound request carried a Bearer token.
    Assert.All(handler.AuthSchemes, s => Assert.Equal("Bearer", s));
  }

  [Fact]
  public void ListCases_throws_when_a_zaak_zaaktype_has_no_configured_aanvraag_type()
  {
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url == $"{ZrcBase}/zaken" => Page1,
      _ when url == $"{ZrcBase}/zaken?page=2" => Page2,
      _ => throw new InvalidOperationException($"unexpected ZGW GET {url}"),
    });
    var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);

    Assert.Throws<InvalidOperationException>(() => source.ListCases(DateTimeOffset.UtcNow));
  }

  [Fact]
  public void ListMyCases_filters_by_the_callers_bsn()
  {
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url.StartsWith($"{ZrcBase}/zaken") => """{ "count": 0, "next": null, "results": [] }""",
      _ => throw new InvalidOperationException($"unexpected ZGW GET {url}"),
    });

    var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var caller = new ZorgverlenerCaller("111222333", "Dr. Test", PrincipalRole.Drafter);

    source.ListMyCases(caller, DateTimeOffset.UtcNow);

    Assert.Single(handler.Requests, r =>
        r.StartsWith($"{ZrcBase}/zaken?") &&
        r.Contains("rol__betrokkeneIdentificatie__natuurlijkPersoon__inpBsn=111222333"));
  }

  [Fact]
  public void CreateZaak_posts_zaak_status_and_rol_and_maps_the_result_back()
  {
    const string zaaktypeUrl = $"{ZtBase}/zaaktypen/zt-registratie";
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url == $"{ZrcBase}/zaken" => $$"""
        { "url": "{{ZrcBase}}/zaken/uuid-new", "identificatie": "BIG-2026-000123",
          "zaaktype": "{{zaaktypeUrl}}", "startdatum": "2026-07-28",
          "einddatum": null, "registratiedatum": "2026-07-28" }
        """,
      _ when url.StartsWith($"{ZtBase}/statustypen") => """
        { "count": 1, "next": null,
          "results": [ { "url": "https://oz.example/catalogi/api/v1/statustypen/st-1", "volgnummer": 1 } ] }
        """,
      _ when url.StartsWith($"{ZtBase}/roltypen") => """
        { "count": 1, "next": null,
          "results": [ { "url": "https://oz.example/catalogi/api/v1/roltypen/rt-initiator" } ] }
        """,
      _ when url == $"{ZrcBase}/statussen" => "{}",
      _ when url == $"{ZrcBase}/rollen" => "{}",
      _ => throw new InvalidOperationException($"unexpected ZGW call {url}"),
    });

    var options = new ZgwOptions
    {
      ZrcBaseUrl = ZrcBase,
      ZtcBaseUrl = ZtBase,
      ClientId = "c",
      Secret = "s",
      Bronorganisatie = "123443210",
      VerantwoordelijkeOrganisatie = "123443210",
      ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
    };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var aanvraag = Given.Concept(type: "registratie", owner: "111222333").Submitted().Build();

    var caller = new ZorgverlenerCaller(aanvraag.Owner, "Dr. Test", PrincipalRole.Drafter);
    var (referentie, status, zaakUrl) = source.CreateZaak(aanvraag, new DateTimeOffset(2026, 7, 28, 12, 0, 0, TimeSpan.Zero), caller);

    // The stub echoes back its own (hardcoded) identificatie, same as a real OpenZaak response.
    Assert.Equal("BIG-2026-000123", referentie);
    Assert.Equal("InBehandeling", status.Tag);
    Assert.Equal("BIG-2026-000123", status.Referentie);
    Assert.Equal($"{ZrcBase}/zaken/uuid-new", zaakUrl);

    // Zaak: mapped zaaktype + configured RSINs + the local reference as identificatie.
    var zaakBody = handler.BodyOf($"{ZrcBase}/zaken");
    Assert.Contains(zaaktypeUrl, zaakBody);
    Assert.Contains("123443210", zaakBody);
    Assert.Contains(aanvraag.Referentie, zaakBody);

    // Status: points at the created zaak's URL and the resolved statustype.
    var statusBody = handler.BodyOf($"{ZrcBase}/statussen");
    Assert.Contains($"{ZrcBase}/zaken/uuid-new", statusBody);
    Assert.Contains("statustypen/st-1", statusBody);

    // Rol: points at the created zaak, the resolved initiator roltype, and the BSN.
    var rolBody = handler.BodyOf($"{ZrcBase}/rollen");
    Assert.Contains($"{ZrcBase}/zaken/uuid-new", rolBody);
    Assert.Contains("roltypen/rt-initiator", rolBody);
    Assert.Contains("111222333", rolBody);
  }

  [Fact]
  public void CreateZaak_throws_when_the_aanvraag_type_has_no_configured_zaaktype()
  {
    var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
    var handler = new ZgwStubHandler(url => throw new InvalidOperationException($"no HTTP call expected, got {url}"));
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var aanvraag = Given.Concept(type: "unknown-type", owner: "111222333").Submitted().Build();
    var caller = new ZorgverlenerCaller(aanvraag.Owner, "Dr. Test", PrincipalRole.Drafter);

    Assert.Throws<InvalidOperationException>(() => source.CreateZaak(aanvraag, DateTimeOffset.UtcNow, caller));
  }

  // --- WP-66: besluit write (a status transition on an existing zaak) --------------------

  [Fact]
  public void RecordBesluit_posts_the_last_statustype_with_besluit_and_toelichting()
  {
    const string zaaktypeUrl = $"{ZtBase}/zaaktypen/zt-registratie";
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url.StartsWith($"{ZtBase}/statustypen") => """
        { "count": 2, "next": null, "results": [
          { "url": "https://oz.example/catalogi/api/v1/statustypen/st-1", "volgnummer": 1 },
          { "url": "https://oz.example/catalogi/api/v1/statustypen/st-2", "volgnummer": 2 } ] }
        """,
      _ when url.StartsWith($"{ZtBase}/resultaattypen") => """
        { "count": 1, "next": null,
          "results": [ { "url": "https://oz.example/catalogi/api/v1/resultaattypen/rst-1" } ] }
        """,
      _ when url == $"{ZrcBase}/resultaten" => "{}",
      _ when url == $"{ZrcBase}/statussen" => "{}",
      _ => throw new InvalidOperationException($"unexpected ZGW call {url}"),
    });

    var options = new ZgwOptions
    {
      ZrcBaseUrl = ZrcBase,
      ZtcBaseUrl = ZtBase,
      ClientId = "c",
      Secret = "s",
      ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
    };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var aanvraag = Given.Concept(type: "registratie", owner: "111222333")
        .Submitted()
        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
        .Build();
    var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);

    source.RecordBesluit(aanvraag, Besluit.Afwijzen, "onvolledig", DateTimeOffset.UtcNow, caller);

    // Picked the HIGHEST volgnummer (the eind statustype), not the first/lowest.
    var statusBody = handler.BodyOf($"{ZrcBase}/statussen");
    Assert.Contains($"{ZrcBase}/zaken/uuid-existing", statusBody);
    Assert.Contains("statustypen/st-2", statusBody);
    Assert.Contains("Afwijzen", statusBody);
    Assert.Contains("onvolledig", statusBody);
  }

  [Fact]
  public void RecordBesluit_creates_a_resultaat_before_posting_the_eindstatus()
  {
    // Regression for a real bug found against a live OpenZaak: posting straight to the eind
    // statustype without a Resultaat first gets rejected with 400 "Zaak has no resultaat" —
    // ZGW requires the Resultaat to exist before a zaak can reach its eindstatus.
    const string zaaktypeUrl = $"{ZtBase}/zaaktypen/zt-registratie";
    var handler = new ZgwStubHandler(url => url switch
    {
      _ when url.StartsWith($"{ZtBase}/statustypen") => """
        { "count": 1, "next": null,
          "results": [ { "url": "https://oz.example/catalogi/api/v1/statustypen/st-1", "volgnummer": 1 } ] }
        """,
      _ when url.StartsWith($"{ZtBase}/resultaattypen") => """
        { "count": 1, "next": null,
          "results": [ { "url": "https://oz.example/catalogi/api/v1/resultaattypen/rst-1" } ] }
        """,
      _ when url == $"{ZrcBase}/resultaten" => "{}",
      _ when url == $"{ZrcBase}/statussen" => "{}",
      _ => throw new InvalidOperationException($"unexpected ZGW call {url}"),
    });

    var options = new ZgwOptions
    {
      ZrcBaseUrl = ZrcBase,
      ZtcBaseUrl = ZtBase,
      ClientId = "c",
      Secret = "s",
      ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
    };
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var aanvraag = Given.Concept(type: "registratie", owner: "111222333")
        .Submitted()
        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
        .Build();
    var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);

    source.RecordBesluit(aanvraag, Besluit.Goedkeuren, null, DateTimeOffset.UtcNow, caller);

    var resultaatBody = handler.BodyOf($"{ZrcBase}/resultaten");
    Assert.Contains($"{ZrcBase}/zaken/uuid-existing", resultaatBody);
    Assert.Contains("resultaattypen/rst-1", resultaatBody);

    // The Resultaat must exist BEFORE the eindstatus is posted, not after.
    Assert.True(
        handler.Requests.IndexOf($"{ZrcBase}/resultaten") < handler.Requests.IndexOf($"{ZrcBase}/statussen"),
        "expected /resultaten to be posted before /statussen");
  }

  [Fact]
  public void RecordBesluit_does_nothing_when_the_aanvraag_has_no_zaak()
  {
    var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
    var handler = new ZgwStubHandler(url => throw new InvalidOperationException($"no HTTP call expected, got {url}"));
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    // ZaakUrl deliberately left unset — no builder call touches it, so it stays null.
    var aanvraag = Given.Concept(type: "registratie", owner: "111222333").Submitted().Build();
    var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);

    source.RecordBesluit(aanvraag, Besluit.Goedkeuren, null, DateTimeOffset.UtcNow, caller);

    Assert.Empty(handler.Requests);
  }

  [Fact]
  public void RecordBesluit_throws_when_the_aanvraag_type_has_no_configured_zaaktype()
  {
    var options = new ZgwOptions { ZrcBaseUrl = ZrcBase, ZtcBaseUrl = ZtBase, ClientId = "c", Secret = "s" };
    var handler = new ZgwStubHandler(url => throw new InvalidOperationException($"no HTTP call expected, got {url}"));
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);
    var aanvraag = Given.Concept(type: "unknown-type", owner: "111222333")
        .Submitted()
        .WithZaakUrl($"{ZrcBase}/zaken/uuid-existing")
        .Build();
    var caller = new MedewerkerCaller("m1", new[] { MedewerkerRol.Behandelaar }, "Medewerker Test", PrincipalRole.Drafter);

    Assert.Throws<InvalidOperationException>(() => source.RecordBesluit(aanvraag, Besluit.Goedkeuren, null, DateTimeOffset.UtcNow, caller));
  }

  // --- WP-60: bounded retry in ZgwHttpClient, exercised through the create-zaak write path ---

  private static (ZgwOptions options, Aanvraag.Submitted aanvraag, CallerIdentity caller) CreateZaakFixture()
  {
    const string zaaktypeUrl = $"{ZtBase}/zaaktypen/zt-registratie";
    var options = new ZgwOptions
    {
      ZrcBaseUrl = ZrcBase,
      ZtcBaseUrl = ZtBase,
      ClientId = "c",
      Secret = "s",
      Bronorganisatie = "123443210",
      VerantwoordelijkeOrganisatie = "123443210",
      ZaaktypeUrls = new() { ["registratie"] = zaaktypeUrl },
    };
    var aanvraag = Given.Concept(type: "registratie", owner: "111222333").Submitted().Build();
    var caller = new ZorgverlenerCaller(aanvraag.Owner, "Dr. Test", PrincipalRole.Drafter);
    return (options, aanvraag, caller);
  }

  private static string RespondFor(string zaaktypeUrl, string url) => url switch
  {
    _ when url == $"{ZrcBase}/zaken" => $$"""
      { "url": "{{ZrcBase}}/zaken/uuid-new", "identificatie": "BIG-2026-000123",
        "zaaktype": "{{zaaktypeUrl}}", "startdatum": "2026-07-28",
        "einddatum": null, "registratiedatum": "2026-07-28" }
      """,
    _ when url.StartsWith($"{ZtBase}/statustypen") => """
      { "count": 1, "next": null,
        "results": [ { "url": "https://oz.example/catalogi/api/v1/statustypen/st-1", "volgnummer": 1 } ] }
      """,
    _ when url.StartsWith($"{ZtBase}/roltypen") => """
      { "count": 1, "next": null,
        "results": [ { "url": "https://oz.example/catalogi/api/v1/roltypen/rt-initiator" } ] }
      """,
    _ when url == $"{ZrcBase}/statussen" => "{}",
    _ when url == $"{ZrcBase}/rollen" => "{}",
    _ => throw new InvalidOperationException($"unexpected ZGW call {url}"),
  };

  [Fact]
  public void CreateZaak_retries_a_transient_failure_and_then_succeeds()
  {
    var (options, aanvraag, caller) = CreateZaakFixture();
    var zaaktypeUrl = options.ZaaktypeUrls["registratie"];
    var handler = new ZgwStubHandler(
        url => RespondFor(zaaktypeUrl, url),
        (url, attempt) => url == $"{ZrcBase}/zaken" && attempt == 0 ? HttpStatusCode.ServiceUnavailable : HttpStatusCode.OK);
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);

    var (referentie, _, zaakUrl) = source.CreateZaak(aanvraag, new DateTimeOffset(2026, 7, 28, 12, 0, 0, TimeSpan.Zero), caller);

    Assert.Equal("BIG-2026-000123", referentie);
    Assert.Equal($"{ZrcBase}/zaken/uuid-new", zaakUrl);
    Assert.Equal(2, handler.Requests.Count(r => r == $"{ZrcBase}/zaken"));
  }

  [Fact]
  public void CreateZaak_gives_up_after_three_attempts_on_a_persistent_transient_failure()
  {
    var (options, aanvraag, caller) = CreateZaakFixture();
    var zaaktypeUrl = options.ZaaktypeUrls["registratie"];
    var handler = new ZgwStubHandler(
        url => RespondFor(zaaktypeUrl, url),
        (url, _) => url == $"{ZrcBase}/zaken" ? HttpStatusCode.ServiceUnavailable : HttpStatusCode.OK);
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);

    var ex = Assert.Throws<HttpRequestException>(() => source.CreateZaak(aanvraag, DateTimeOffset.UtcNow, caller));

    Assert.Contains("503", ex.Message);
    Assert.Equal(3, handler.Requests.Count(r => r == $"{ZrcBase}/zaken"));
  }

  [Fact]
  public void CreateZaak_does_not_retry_a_permanent_rejection()
  {
    var (options, aanvraag, caller) = CreateZaakFixture();
    var zaaktypeUrl = options.ZaaktypeUrls["registratie"];
    var handler = new ZgwStubHandler(
        url => RespondFor(zaaktypeUrl, url),
        (url, _) => url == $"{ZrcBase}/statussen" ? HttpStatusCode.BadRequest : HttpStatusCode.OK);
    var source = new OpenZaakZaakSource(new HttpClient(handler), new ZgwTokenProvider(options), options);

    Assert.Throws<HttpRequestException>(() => source.CreateZaak(aanvraag, DateTimeOffset.UtcNow, caller));

    // No retry on 400, and — the property that makes the whole design safe — no duplicate
    // zaak was created by a retry that never should have happened.
    Assert.Equal(1, handler.Requests.Count(r => r == $"{ZrcBase}/statussen"));
    Assert.Equal(1, handler.Requests.Count(r => r == $"{ZrcBase}/zaken"));
  }
}