using DigitalData.Core.Security.Cryptographer;

namespace DigitalData.Core.Security.Config
{
    public class AsymCryptParams : RSAFactoryParams
    {
        public string PemDirectory { get; init; } = string.Empty;

        /// <summary>
        /// Represents the separator used to concatenate the components of a file-related token string.
        /// </summary>
        /// <remarks>
        /// The resulting file-related token string is constructed as follows:
        /// <c>string.Join(FileNameSeparator, Issuer, Audience, Secret_version)</c>.
        /// If <c>Secret_version</c> is not null, it will be included in the concatenation.
        /// </remarks>
        /// <example>
        /// For example, if <c>FileNameSeparator = "_-_"</c>, the output might look like:
        /// <c>"Issuer_-_Audience_-_Secret_version"</c>.
        /// </example>
        public string FileNameSeparator { get; init; } = "_-_";

        /// <summary>
        /// Represents the separator used to concatenate the components of a key-related token string.
        /// </summary>
        /// <remarks>
        /// The resulting key-related token string is constructed as follows:
        /// <c>string.Join(KeyNameSeparator, Issuer, Audience, Secret_version)</c>.
        /// If <c>Secret_version</c> is not null, it will be included in the concatenation.
        /// </remarks>
        /// <example>
        /// For example, if <c>KeyNameSeparator = ":"</c>, the output might look like:
        /// <c>"Issuer:Audience:Secret_version"</c>.
        /// </example>
        public string KeyNameSeparator { get; init; } = ":";

        public IEnumerable<RSADecryptor> Decryptors { get; init; } = new List<RSADecryptor>();

        public override void OnDeserialized()
        {
            base.OnDeserialized();

            // Create root folder if it does not exist
            if (!Directory.Exists(PemDirectory))
                Directory.CreateDirectory(PemDirectory);

            foreach (var decryptor in Decryptors)
            {
                // set default path
                if (decryptor.IsPemNull)
                {
                    var file_name_params = new List<object> { decryptor.Issuer, decryptor.Audience };
                    if (decryptor.IsEncrypted)
                        file_name_params.Add(Secrets.Version);

                    var path = Path.Combine(PemDirectory, string.Join(FileNameSeparator, file_name_params));

                    if (File.Exists(path))
                        decryptor.SetPem(File.ReadAllText(path));
                    else
                    {
                        var pem = decryptor.IsEncrypted
                            ? Instance.RSAFactory.CreateEncryptedPrivateKeyPem(pbeParameters: PbeParameters, keySizeInBits: KeySizeInBits, password: Secrets.PBE_PASSWORD)
                            : Instance.RSAFactory.CreatePrivateKeyPem(keySizeInBits: KeySizeInBits);

                        decryptor.SetPem(File.ReadAllText(pem));

                        // Save file in background
                        Task.Run(async () => await File.WriteAllTextAsync(path: path, pem));
                    }
                }

                decryptor.Init();
            }
        }
    }
}