using System.Net.Http.Json;

namespace Bff.Api;

/// <summary>What the self-service submit returns to the portal (the domain's registration id + status).</summary>
public sealed record SubmitAccepted(string RegistrationId, string Status);

/// <summary>A projection row as the projection-api serves it. <c>Bsn</c>/<c>NaamPlaceholder</c> are
/// read but never surfaced by the openbaar endpoint (public-safe filtering, ADR-0010/S-09).
/// <c>Reference</c> is the public-safe citizen reference (the zaak identificatie, #78).</summary>
public sealed record ProjectionEntry(string Id, string Status, string? Reference, string? Bsn, string? NaamPlaceholder);

/// <summary>A public-safe openbaar register row — only non-sensitive fields leave the BFF.</summary>
public sealed record OpenbaarEntry(string Id, string Status, string? Reference);

/// <summary>Port to the Domain Service (§8.3: the BFF is the portals' only backend; it fans out).</summary>
public interface IDomainClient
{
    Task<SubmitAccepted> SubmitRegistrationAsync(string bsn, CancellationToken ct = default);
}

/// <summary>Port to the read projection.</summary>
public interface IProjectionClient
{
    Task<IReadOnlyList<ProjectionEntry>> GetRegisterAsync(CancellationToken ct = default);
}

/// <summary>Calls the Domain Service's <c>POST /registrations</c>.</summary>
public sealed class DomainClient(HttpClient http) : IDomainClient
{
    public async Task<SubmitAccepted> SubmitRegistrationAsync(string bsn, CancellationToken ct = default)
    {
        using var response = await http.PostAsJsonAsync("registrations", new { bsn }, ct);
        response.EnsureSuccessStatusCode();
        var dto = await response.Content.ReadFromJsonAsync<DomainResponse>(ct)
            ?? throw new InvalidOperationException("The Domain Service returned an empty registration response.");
        return new SubmitAccepted(dto.RegistrationId, dto.Status);
    }

    private sealed record DomainResponse(string RegistrationId, string Status, string? ZaakUrl);
}

/// <summary>Calls the projection-api's <c>GET /register</c>.</summary>
public sealed class ProjectionClient(HttpClient http) : IProjectionClient
{
    public async Task<IReadOnlyList<ProjectionEntry>> GetRegisterAsync(CancellationToken ct = default)
        => await http.GetFromJsonAsync<List<ProjectionEntry>>("register", ct) ?? [];
}