using System.Security.Cryptography;
using IdentityShroud.Core.Contracts;
using IdentityShroud.Core.Helpers;
using IdentityShroud.Core.Messages.Realm;
using IdentityShroud.Core.Model;
using IdentityShroud.Core.Security.Keys;
using IdentityShroud.Core.Security.Keys.Rsa;
using Microsoft.EntityFrameworkCore;

namespace IdentityShroud.Core.Services;

public record RealmCreateResponse(Guid Id, string Slug, string Name);

public class RealmService(
    Db db,
    IKeyService keyService) : IRealmService
{
    public async Task<Realm?> FindById(Guid id, CancellationToken ct = default)
    {
        return await db.Realms
            .SingleOrDefaultAsync(r => r.Id == id, ct);
    }

    public async Task<Realm?> FindBySlug(string slug, CancellationToken ct = default)
    {
        return await db.Realms
            .SingleOrDefaultAsync(r => r.Slug == slug, ct);
    }

    public async Task<Result<RealmCreateResponse>> Create(RealmCreateRequest request, CancellationToken ct = default)
    {
        Realm realm = new()
        {
            Id = request.Id ?? Guid.CreateVersion7(),
            Slug = request.Slug ?? SlugHelper.GenerateSlug(request.Name),
            Name = request.Name,
        };
        
        realm.Keys.Add(keyService.CreateKey(GetKeyPolicy(realm)));

        db.Add(realm);
        await db.SaveChangesAsync(ct);
        
        return new RealmCreateResponse(
            realm.Id, realm.Slug, realm.Name);
    }

    /// <summary>
    /// Place holder for getting policies from the realm and falling back to sane defaults when no policies have been set.
    /// </summary>
    /// <param name="_"></param>
    /// <returns></returns>
    private KeyPolicy GetKeyPolicy(Realm _) => new RsaKeyPolicy();
    

    public async Task LoadActiveKeys(Realm realm)
    {
        await db.Entry(realm).Collection(r => r.Keys)
            .Query()
            .Where(k => k.RevokedAt == null)
            .LoadAsync();
        
    }
}