using System.Text.Json.Serialization;
using BigRegister.Api.Contracts;

namespace BigRegister.Api.Zgw;

/// <summary>
/// The subset of a ZGW Zaak (Zaken API / ZRC) the read slice needs. The full resource has
/// dozens of fields; we bind only what maps to <see cref="ApplicationSummaryDto"/>. Note the
/// two ZGW traits that force an anti-corruption layer: <see cref="Url"/> is the resource's
/// identity (not a bare id), and <see cref="Zaaktype"/> is a URL <em>into another service</em>
/// (Catalogi/ZTC) that must be resolved to a human label.
/// </summary>
public sealed record ZgwZaak(
    [property: JsonPropertyName("url")] string Url,
    [property: JsonPropertyName("identificatie")] string Identificatie,
    [property: JsonPropertyName("zaaktype")] string Zaaktype,
    [property: JsonPropertyName("startdatum")] DateOnly Startdatum,
    [property: JsonPropertyName("einddatum")] DateOnly? Einddatum,
    [property: JsonPropertyName("registratiedatum")] DateOnly? Registratiedatum);

/// <summary>
/// Anti-corruption map: ZGW Zaak → the existing <see cref="ApplicationSummaryDto"/> the FE
/// already renders (WP-49). This is where "URL as identity" and the cross-service zaaktype
/// join get flattened away, so nothing downstream (the FE) sees ZGW shapes.
/// </summary>
public static class ZgwZaakMapper
{
  /// <summary>Last path segment of a ZGW resource URL — the uuid that identifies it.</summary>
  public static string Uuid(string url) => url.TrimEnd('/').Split('/').Last();

  public static ApplicationSummaryDto ToSummaryDto(ZgwZaak z, string zaaktypeLabel)
  {
    // ponytail: coarse status map — an open zaak (no einddatum) is In behandeling, a closed
    // one is Goedgekeurd. Real fidelity (statustype/resultaat lookups) is a later slice; the
    // Afgewezen path needs the resultaat resource. Enough to prove the seam end-to-end.
    var status = z.Einddatum is null
        ? new AanvraagStatusDto("InBehandeling", Referentie: z.Identificatie, Manual: true)
        : new AanvraagStatusDto("Goedgekeurd", Referentie: z.Identificatie);

    var created = Iso(z.Registratiedatum ?? z.Startdatum);
    var updated = Iso(z.Einddatum ?? z.Registratiedatum ?? z.Startdatum);

    return new ApplicationSummaryDto(
        Id: Uuid(z.Url),
        Type: zaaktypeLabel,
        Status: status,
        DocumentIds: Array.Empty<string>(),   // zaak↔document links arrive with WP-51 (DRC)
        CreatedAt: created,
        UpdatedAt: updated,
        SubmittedAt: created,
        Owner: z.Identificatie);              // real initiator (rol/BSN) needs a rollen lookup — later slice
  }

  // Keep the wire shape identical to the local source (round-trip datetime): a ZGW date
  // becomes midnight UTC so the FE's date parsing sees the same format either backend.
  private static string Iso(DateOnly d) =>
      d.ToDateTime(TimeOnly.MinValue, DateTimeKind.Utc).ToString("o");
}