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// Name        :
// Author      : Avi
// Revision    : $Revision: #30 $ 
//
// Copyright 2009-2020 ECMWF.
// This software is licensed under the terms of the Apache Licence version 2.0 
// which can be obtained at http://www.apache.org/licenses/LICENSE-2.0. 
// In applying this licence, ECMWF does not waive the privileges and immunities 
// granted to it by virtue of its status as an intergovernmental organisation 
// nor does it submit to any jurisdiction. 
//
// Description :
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#include <stdexcept>
#include <boost/algorithm/string/trim.hpp>

#include "ClientToServerCmd.hpp"
#include "AbstractServer.hpp"
#include "AbstractClientEnv.hpp"
#include "Log.hpp"
#include "CtsApi.hpp"
#include "Str.hpp"
#include "Defs.hpp"

using namespace ecf;
using namespace std;
using namespace boost;
namespace po = boost::program_options;


LogCmd::LogCmd(LogApi a, int get_last_n_lines)
: api_(a), get_last_n_lines_(get_last_n_lines)
{
   if (get_last_n_lines_ == 0) get_last_n_lines_ = Log::get_last_n_lines_default();
}


LogCmd::LogCmd()
: get_last_n_lines_(Log::get_last_n_lines_default()) {}


LogCmd::LogCmd(const std::string& path)
: api_(NEW),get_last_n_lines_(Log::get_last_n_lines_default()),new_path_(path)
{
   // ECFLOW-154, If path to new log file is specified, it should only be checked by the server,
   //             as that could be on a different machine.
   // ECFLOW-174, Never get the full log, as this can make server consume to much memory
   //             default taken from get_last_n_lines_default
   // ECFLOW-377, should remove leading/trailing spaces from path
   boost::algorithm::trim(new_path_);
}

void LogCmd::print(std::string& os) const
{
    switch (api_) {
      case LogCmd::GET:   user_cmd(os,CtsApi::to_string(CtsApi::getLog(get_last_n_lines_)));  break;
      case LogCmd::CLEAR: user_cmd(os,CtsApi::clearLog()); break;
      case LogCmd::FLUSH: user_cmd(os,CtsApi::flushLog()); break;
      case LogCmd::NEW:   user_cmd(os,CtsApi::to_string(CtsApi::new_log(new_path_)));  break;
      case LogCmd::PATH:  user_cmd(os,CtsApi::get_log_path()); break;
      default : throw std::runtime_error( "LogCmd::print: Unrecognised log api command,") ;
   }
}
void LogCmd::print_only(std::string& os) const
{
    switch (api_) {
      case LogCmd::GET:   os += CtsApi::to_string(CtsApi::getLog(get_last_n_lines_));  break;
      case LogCmd::CLEAR: os += CtsApi::clearLog(); break;
      case LogCmd::FLUSH: os += CtsApi::flushLog(); break;
      case LogCmd::NEW:   os += CtsApi::to_string(CtsApi::new_log(new_path_));  break;
      case LogCmd::PATH:  os += CtsApi::get_log_path(); break;
      default : throw std::runtime_error( "LogCmd::print: Unrecognised log api command,") ;
   }
}

bool LogCmd::equals(ClientToServerCmd* rhs) const
{
	auto* the_rhs = dynamic_cast< LogCmd* > ( rhs );
	if ( !the_rhs ) return false;
	if (api_ != the_rhs->api()) return false;
	if (get_last_n_lines_ != the_rhs->get_last_n_lines()) return false;
	if (new_path_ != the_rhs->new_path()) return false;
	return UserCmd::equals(rhs);
}

// changed for release 4.1.0
bool LogCmd::isWrite() const
{
   switch (api_) {
      case LogCmd::GET:   return false; break;
      case LogCmd::CLEAR: return false; break;
      case LogCmd::FLUSH: return false; break;
      case LogCmd::NEW:   return true;  break;
      case LogCmd::PATH:  return false; break;
      default : throw std::runtime_error( "LogCmd::isWrite: Unrecognised log api command,") ;
   }
   return false;
}

STC_Cmd_ptr LogCmd::doHandleRequest(AbstractServer* as) const
{
	as->update_stats().log_cmd_++;

	switch (api_) {
	case LogCmd::GET:   return PreAllocatedReply::string_cmd( Log::instance()->contents(get_last_n_lines_) );
	case LogCmd::CLEAR: Log::instance()->clear(); break;
	case LogCmd::FLUSH: Log::instance()->flush(); break;
	case LogCmd::NEW:   {
		if (!new_path_.empty()) {
			Log::instance()->new_path(new_path_); // will throw for errors

			// *NOTE* calling --log=new <path> should be treated the *SAME* as editing ECF_LOG in the GUI
			//        This is done adding it as a *USER* variable. This overloads the server variables
			//        It also allows us to see the change in GUI. Note: Defs/server_variables are not synced
			// ECFLOW-376
			as->defs()->set_server().add_or_update_user_variables(Str::ECF_LOG(),Log::instance()->path());
		}
		else {
			// User could have overridden ECF_LOG variable
			// *FIRST* look at user variables, then look at *server* variables.
			std::string log_file_name = as->defs()->server().find_variable(Str::ECF_LOG());

			// ECFLOW-377 should remove leading/trailing spaces from path
			boost::algorithm::trim(log_file_name);

			Log::instance()->new_path(log_file_name);  // will throw for errors
		}

		as->stats().ECF_LOG_ = Log::instance()->path();  // do NOT update number of requests
		break;
	}
	case LogCmd::PATH:  return PreAllocatedReply::string_cmd(  Log::instance()->path() );
	default : throw std::runtime_error( "Unrecognised log api command,") ;
	}
	return PreAllocatedReply::ok_cmd();
}

const char* LogCmd::arg() { return "log";}
const char* LogCmd::desc() {
   return  "Get,clear,flush or create a new log file.\n"
            "The user must ensure that a valid path is specified.\n"
            "Specifying '--log=get' with a large number of lines from the server,\n"
            "can consume a lot of **memory**. The log file can be a very large file,\n"
            "hence we use a default of 100 lines, optionally the number of lines can be specified.\n"
            " arg1 = [ get | clear | flush | new | path ]\n"
            "  get -   Outputs the log file to standard out.\n"
            "          defaults to return the last 100 lines\n"
            "          The second argument can specify how many lines to return\n"
            "  clear - Clear the log file of its contents.\n"
            "  flush - Flush and close the log file. (only temporary) next time\n"
            "          server writes to log, it will be opened again. Hence it best\n"
            "          to halt the server first\n"
            "  new -   Flush and close the existing log file, and start using the\n"
            "          the path defined for ECF_LOG. By changing this variable\n"
            "          a new log file path can be used\n"
            "          Alternatively an explicit path can also be provided\n"
            "          in which case ECF_LOG is also updated\n"
            "  path -  Returns the path name to the existing log file\n"
            " arg2 = [ new_path | optional last n lines ]\n"
            "         if get specified can specify lines to get. Value must be convertible to an integer\n"
            "         Otherwise if arg1 is 'new' then the second argument must be a path\n"
            "Usage:\n"
            "  --log=get                        # Write the last 100 lines of the log file to standard out\n"
            "  --log=get 200                    # Write the last 200 lines of the log file to standard out\n"
            "  --log=clear                      # Clear the log file. The log is now empty\n"
            "  --log=flush                      # Flush and close log file, next request will re-open log file\n"
            "  --log=new /path/to/new/log/file  # Close and flush log file, and create a new log file, updates ECF_LOG\n"
            "  --log=new                        # Close and flush log file, and create a new log file using ECF_LOG variable\n"
            ;
}

void LogCmd::addOption(boost::program_options::options_description& desc) const {
	desc.add_options()( LogCmd::arg(), po::value< vector<string> >()->multitoken(), LogCmd::desc() );
}

void LogCmd::create( 	Cmd_ptr& cmd,
						boost::program_options::variables_map& vm,
						AbstractClientEnv* ac) const
{
	vector<string> args = vm[ arg() ].as< vector<string> >();

	if (ac->debug()) dumpVecArgs(LogCmd::arg(),args);

	if (!args.empty() && args[0] == "get")  {

		if ( args.size() != 1 && args.size() != 2) {
			std::stringstream ss;
			ss << "LogCmd: Please use '--log==get 100' to get the log file contents from the server\n";
			ss << "optionally an integer can be provide to specify the last number of lines\n";
			throw std::runtime_error( ss.str() );
		}

		if (args.size() == 1 ) {
			// This will retrieve Log::get_last_n_lines_default() lines from the log file.
			cmd = Cmd_ptr( new LogCmd( LogCmd::GET , Log::get_last_n_lines_default() ) );
			return;
		}

 		int value = Log::get_last_n_lines_default();
 		if (args.size() == 2) {
 			try { value = boost::lexical_cast<int>(args[1]); }
 			catch (boost::bad_lexical_cast& e) {
 				throw std::runtime_error( "LogCmd: Second argument must be a integer, i.e. --log get 100\n" );
 			}
 		}

	 	cmd = std::make_shared<LogCmd>( LogCmd::GET, value);
	 	return ;
	}

 	if (!args.empty() && args[0] == "clear")   {

		if (args.size() != 1 ) {
			std::stringstream ss;
			ss << "LogCmd: Too many arguments. Please use " << CtsApi::clearLog() << " to clear the log file\n";
 			throw std::runtime_error( ss.str() );
		}
 		cmd = std::make_shared<LogCmd>( LogCmd::CLEAR );
 		return;
 	}
 	if (!args.empty() && args[0] == "flush")   {

		if (args.size() != 1 ) {
			std::stringstream ss;
			ss << "LogCmd: Too many arguments. Please use " << CtsApi::flushLog() << " to flush the log file\n";
 			throw std::runtime_error( ss.str() );
		}
 		cmd = std::make_shared<LogCmd>( LogCmd::FLUSH );
 		return;
 	}
   if (!args.empty() && args[0] == "path")   {

      if (args.size() != 1 ) {
         std::stringstream ss;
         ss << "LogCmd: Too many arguments. Please use " << CtsApi::get_log_path() << " to get the log file path\n";
         throw std::runtime_error( ss.str() );
      }
      cmd = std::make_shared<LogCmd>( LogCmd::PATH ) ;
      return;
   }
   if (!args.empty() && args[0] == "new")   {

      if (args.size() > 2 ) {
         std::stringstream ss;
         ss << "LogCmd: Too many arguments.  Expected --log=new   OR   --log=new /path/to/newlog/file\n";
         throw std::runtime_error( ss.str() );
      }
      std::string path;
      if ( args.size() == 2 ) {
         path = args[1];
      }
      cmd = std::make_shared<LogCmd>( path ) ;
      return;
   }

 	std::stringstream ss;
 	ss << "LogCmd: The arguments have not been specified correctly\n" << LogCmd::desc();
   throw std::runtime_error( ss.str() );
}

std::ostream& operator<<(std::ostream& os, const LogCmd& c) { std::string ret; c.print(ret); os << ret; return os;}
