using Microsoft.AspNetCore.Mvc;
using ServiceShared.Database;
using ServiceOutside.Filter;
using ServiceShared;
using ServiceShared.Crypto;
using System.Text.Json;
using ServiceShared.Models.Response;

namespace ServiceOutside.Controllers
{
    [TrustedHeader]
    public class BaseController : ControllerBase
    {
        /// <summary>
        /// Current LogType from the configuration
        /// </summary>
        private static Log.Types _LogType = Log.Types.INFO;

        /// <summary>
        /// Configuration from appsettings.json
        /// </summary>
        private readonly IConfiguration _configuration = null;
        
        /// <summary>
        /// dbContext
        /// </summary>
        private readonly DbContext _dbContext = null;

        /// <summary>
        /// Server asymetric KeyPair(PrivateKey, PublicKey)
        /// It changes evrytime when the server is restarting
        /// </summary>
        protected readonly KeyPair _KeyPair = null;

        /// <summary>
        /// Maintenance Flag
        /// </summary>
        protected readonly bool Maintenance = false;

        /// <summary>
        /// Constructor of BaseController, that getting instance of configuration, dbcontext and KeyPair
        /// </summary>
        /// <param name="_configuration">Configuration from appsettings.json</param>
        /// <param name="dbContext">DbContext</param>
        /// <param name="keyPair">Server Curve25519 KeyPair</param>
        public BaseController(IConfiguration _configuration, DbContext dbContext, KeyPair keyPair)
        {
            this._configuration = _configuration;
            this._dbContext = dbContext;
            this._KeyPair = keyPair;
            this.Maintenance = this._dbContext.GetMaintenance();
        }

        /// <summary>
        /// Sets the log type
        /// </summary>
        /// <param name="Log.Types">Log.Types</param>
        public static void SetLog(Log.Types logType)
        {
            _LogType = logType;
        }

        /// <summary>
        /// Signature public key of server for the trusted response
        /// </summary>
        /// <returns>Returns server signature public key</returns>
        public string GetServerSignatureKey()
        {
            return this._KeyPair.SigningPublicKey;
        }

        /// <summary>
        /// Signature of server for the trusted response
        /// <paramref name="response">Response text, that sould be signied by server</paramref>
        /// </summary>
        /// <returns>Returns signature of response</returns>
        public string GetServerSignature(String response)
        {
            return this._KeyPair.GetSignature(response);
        }

        /// <summary>
        /// Client public key
        /// </summary>
        /// <returns>Returns client public key from the header (base64)</returns>
        protected string GetClientPublicKey()
        {
            return this.HttpContext.Request.Headers["Client-Key"].ToString();
        }

        /// <summary>
        /// Client signature of trusted request
        /// </summary>
        /// <returns>Returns client signature of request from the header (base64)</returns>
        protected string GetClientSignature()
        {
            return this.HttpContext.Request.Headers["Client-Signature"].ToString();
        }

        /// <summary>
        /// Client public signature key for the trusted request
        /// </summary>
        /// <returns>Returns client signature public key of trusted request from the header (base64), that was used in the signature</returns>
        protected string GetClientSignatureKey()
        {
            return this.HttpContext.Request.Headers["Client-Signature-Key"].ToString();
        }

        /// <summary>
        /// Server public key for shared key(Encryption)
        /// </summary>
        /// <returns>Returns server public key for shared key</returns>
        public string GetServerPublicKey()
        {
            return this._KeyPair.PublicKey;
        }

        /// <summary>
        /// Returns client shared key
        /// </summary>
        /// <returns>HKDF.DeriveKey(SHA512)</returns>
        protected byte[] GetClientSharedKey()
        {
            return this._KeyPair.GetSharedKey(this.GetClientPublicKey());
        }

        /// <summary>
        /// Logs object with type in debug mode
        /// </summary>
        /// <param name="obj">Logging object</param>
        /// <param name="type">Type of logging object</param>
        protected void Debug(object obj, string type)
        {
            if(_LogType == Log.Types.DEBUG)
            {
                if(obj != null)
                {
                    try
                    {
                        Log.Debug("[" + type + "]" + JsonSerializer.Serialize(obj));
                    }
                    catch (Exception ex)
                    {
                        Log.Critical(ex, "ServiceOutside.Controllers.BaseController", "Debug");
                    }
                }
            }
        }
    }
}