using System;
using System.Collections;
using System.Text;
using System.Threading;
using sscs.verbs;
using sscs.common;
using sscs.cache;
using sscs.constants;

namespace sscs.verbs 
{
    
   /*
    * This class is implementation of IsSecretPersistent call.
    * There will be one instance existing for every call made by the client.  
    */

    class IsSecretPersistent : SSVerb
    {
        private ushort msgId = 0;
        private uint inMsgLen  = 0;
        private uint outMsgLen = 0;
        private uint keyChainIdLen = 0;
        private uint secretIdLen = 0;
        private int ssFlags = 0;
        private int retCode = 0;
        private string keyChainId;
        private string secretId;
        
        private byte[] inBuf;
        private byte[] outBuf;

        /*
        * This method sets the class member with the byte array received.
        */
 
        public void SetMessageContent(byte[] ipcBytes)
        {
           CSSSLogger.ExecutionTrace(this);
           inBuf = ipcBytes;                   
        }

       /*
        * This method does the actual implementation of IsSecretPersistent 
        *   
        */

        public byte[] ProcessRequest(UserIdentifier userId)
        {
            CSSSLogger.ExecutionTrace(this);
            // Message Format decipher - Start
            msgId          = BitConverter.ToUInt16(inBuf,0);
            inMsgLen       = BitConverter.ToUInt32(inBuf,2);
            ssFlags        = BitConverter.ToInt32(inBuf,6);
            if( inMsgLen != inBuf.Length )
                throw new FormatException(" MsgLen sent does not match the length of the message received.");
            if(ssFlags == 0)
            {
                keyChainIdLen  = BitConverter.ToUInt32(inBuf,10);
                byte[] keyChainIdArr = new byte[keyChainIdLen];
                Array.Copy(inBuf,14,keyChainIdArr,0,keyChainIdLen);
                keyChainId     = Encoding.UTF8.GetString(keyChainIdArr);

                secretIdLen    = BitConverter.ToUInt32(inBuf,
                                 (14 + (int)keyChainIdLen ));
 
                byte[] secretIdArr = new byte[secretIdLen];
                Array.Copy(inBuf,(14+keyChainIdLen+4),secretIdArr,0,secretIdLen);
                secretId = Encoding.UTF8.GetString(secretIdArr);

            }
            try
            {
                KeyChain keyChain = null;
                SecretStore ssStore = SessionManager.GetUserSecretStore(userId);
                if(ssFlags != 0)
                {
                    if(ssStore.IsStorePersistent())
                        retCode = IPCRetCodes.SSCS_STORE_IS_PERSISTENT;
                    else
                        retCode = IPCRetCodes.SSCS_STORE_IS_NOT_PERSISTENT;


                }
                else
                {
                    if( ssStore.CheckIfKeyChainExists(keyChainId) )
                    {
                        keyChain = ssStore.GetKeyChain(keyChainId);
                        if( keyChain.CheckIfSecretExists(secretId) == false)
                        {
                            if(ssStore.IsStorePersistent())
                                retCode = IPCRetCodes.SSCS_SECRET_IS_PERSISTENT;
                            else
                                retCode = IPCRetCodes.SSCS_SECRET_IS_NOT_PERSISTENT;
                        }
                        else
                        {
                            retCode = IPCRetCodes.SSCS_E_SECRETID_DOES_NOT_EXIST;
                        }
                    }
                    else
                    {
                        retCode = IPCRetCodes.SSCS_E_KEYCHAIN_DOES_NOT_EXIST;
                    }
                }
    
            }
            catch(UserNotInSessionException)
            { 
                CSSSLogger.DbgLog("In " + CSSSLogger.GetExecutionPath(this) + " Unable to get user's secretstore" );
                retCode = IPCRetCodes.SSCS_E_SYSTEM_ERROR;                
            }   
            catch(Exception e )
            {
                CSSSLogger.ExpLog(e.ToString());
                retCode = IPCRetCodes.SSCS_E_SYSTEM_ERROR;
            }

            try
            {
                msgId = 19;
                outMsgLen = 10;
                outBuf = new byte[10];
                byte[] t = new byte[10];

                t = BitConverter.GetBytes((ushort)msgId);
                Array.Copy(t,0,outBuf,0,2);

                t = BitConverter.GetBytes((uint)outMsgLen);
                Array.Copy(t,0,outBuf,2,4);

                t = BitConverter.GetBytes(retCode);
                Array.Copy(t,0,outBuf,6,4);
            }
            catch(Exception e)
            {
                CSSSLogger.ExpLog(e.ToString());
                throw new FormatException("Unable to form the response " + e.ToString());
            }

            return outBuf;
        }


        /*
         * Gives the name of operation performed. Will be used in case 
         * of error. 
         */
        public string GetVerbName()
        {
            CSSSLogger.ExecutionTrace(this);
            return this.ToString(); 
        }
    }
}