feat(acl): ACL skeleton — OpenZaak default-fill (refs #5) (#45)

services/acl/Acl.Infrastructure/OpenZaakGateway.cs

@@ -0,0 +1,48 @@
+using System.Net.Http.Headers;
+using System.Net.Http.Json;
+using System.Text.Json.Serialization;
+using Acl.Application;
+
+namespace Acl.Infrastructure;
+
+/// <summary>The only code that talks to OpenZaak's Zaken API (ADR-0001).</summary>
+public sealed class OpenZaakGateway(HttpClient http, OpenZaakOptions options) : IZaakGateway
+{
+    public async Task<Uri> OpenZaakAsync(ZaakRequest request, CancellationToken ct = default)
+    {
+        ArgumentNullException.ThrowIfNull(request);
+
+        using var message = new HttpRequestMessage(
+            HttpMethod.Post, new Uri(options.BaseUrl, "/zaken/api/v1/zaken"))
+        {
+            Content = JsonContent.Create(new ZaakDto(
+                request.Bronorganisatie,
+                request.Zaaktype.ToString(),
+                request.VerantwoordelijkeOrganisatie,
+                request.Startdatum.ToString("yyyy-MM-dd"),
+                request.Vertrouwelijkheidaanduiding)),
+        };
+        message.Headers.Authorization =
+            new AuthenticationHeaderValue("Bearer", ZgwToken.Mint(options.ClientId, options.Secret));
+        // ZRC is a geo API; it requires the CRS headers.
+        message.Headers.Add("Accept-Crs", "EPSG:4326");
+        message.Content.Headers.Add("Content-Crs", "EPSG:4326");
+
+        using var response = await http.SendAsync(message, ct);
+        response.EnsureSuccessStatusCode();
+
+        var created = await response.Content.ReadFromJsonAsync<ZaakCreatedDto>(ct)
+            ?? throw new InvalidOperationException("OpenZaak returned an empty zaak response");
+        return new Uri(created.Url);
+    }
+
+    private sealed record ZaakDto(
+        [property: JsonPropertyName("bronorganisatie")] string Bronorganisatie,
+        [property: JsonPropertyName("zaaktype")] string Zaaktype,
+        [property: JsonPropertyName("verantwoordelijkeOrganisatie")] string VerantwoordelijkeOrganisatie,
+        [property: JsonPropertyName("startdatum")] string Startdatum,
+        [property: JsonPropertyName("vertrouwelijkheidaanduiding")] string Vertrouwelijkheidaanduiding);
+
+    private sealed record ZaakCreatedDto(
+        [property: JsonPropertyName("url")] string Url);
+}