using Microsoft.Extensions.Options;
using System;
using System.Collections.Concurrent;
using System.Threading.Tasks;
using static StellaOps.Localization.T;

namespace StellaOps.Cryptography.Kms;

/// <summary>
/// AWS KMS implementation of <see cref="IKmsClient"/>.
/// </summary>
public sealed partial class AwsKmsClient : IKmsClient, IDisposable
{
    private readonly IAwsKmsFacade _facade;
    private readonly TimeProvider _timeProvider;
    private readonly TimeSpan _metadataCacheDuration;
    private readonly TimeSpan _publicKeyCacheDuration;
    private readonly ConcurrentDictionary<string, CachedMetadata> _metadataCache = new(StringComparer.Ordinal);
    private readonly ConcurrentDictionary<string, CachedPublicKey> _publicKeyCache = new(StringComparer.Ordinal);
    private bool _disposed;

    public AwsKmsClient(IAwsKmsFacade facade, AwsKmsOptions options, TimeProvider? timeProvider = null)
    {
        _facade = facade ?? throw new ArgumentNullException(nameof(facade));
        ArgumentNullException.ThrowIfNull(options);

        _timeProvider = timeProvider ?? TimeProvider.System;
        _metadataCacheDuration = options.MetadataCacheDuration;
        _publicKeyCacheDuration = options.PublicKeyCacheDuration;
    }

    public AwsKmsClient(IAwsKmsFacade facade, IOptions<AwsKmsOptions> options, TimeProvider timeProvider)
        : this(facade, options?.Value ?? new AwsKmsOptions(), timeProvider)
    {
    }

    public Task<KmsKeyMetadata> RotateAsync(string keyId, CancellationToken cancellationToken = default)
        => throw new NotSupportedException(_t("crypto.kms.rotation_via_policy", "AWS KMS", "AWS KMS"));

    public Task RevokeAsync(string keyId, CancellationToken cancellationToken = default)
        => throw new NotSupportedException(_t("crypto.kms.revocation_via_policy", "AWS KMS key", "AWS KMS"));

    public void Dispose()
    {
        if (_disposed)
        {
            return;
        }

        _disposed = true;
        _facade.Dispose();
    }
}