/*
   PURPOSE: (Slave for master/slave synchronization)
 */

#include <iostream>
#include <iomanip> // for setprecision
#include <sstream>
#include <dlfcn.h>
#include <stdlib.h> // for getenv
#include <cstring>

#include "trick/Slave.hh"
#include "trick/exec_proto.h"
#include "trick/message_proto.h"
#include "trick/message_type.h"
#include "trick/CheckPointRestart_c_intf.hh" // for checkpoint
#include "trick/command_line_protos.h" // output dir get/set

Trick::Slave::Slave() {
    enabled = false ;
    reconnected = false ;
    activated = false;
    msg_published = false;
    sent_reconnect_cmd = false;
}

int Trick::Slave::set_connection_type(Trick::MSConnect * in_connection) {
    connection = in_connection ;
    return 0 ;
}

int Trick::Slave::process_sim_args() {
    /** @par Detailed Design */
    if ( connection != NULL ) {
        /** @li the return_value of Trick::MSConnect::process_sim_args() sets the enabled flag for the slave. */
        enabled = connection->process_sim_args() ;
    }

    return(0) ;
}

int Trick::Slave::init() {

    std::string rts_disable_name ;
    std::string ms_master_disable_name ;
    void* dlhandle ;
    int (*rts_disable)(void) = NULL ;
    int (*ms_master_disable)(void) = NULL ;
    long long software_frame_tics ;
    long long sync_wait_limit_tics ;
    int chkpnt_flag;

    /** @par Detailed Design */

    if ( enabled ) {

        /** @li Connect to the master by calling Trick::MSConnect::connect() */
        connection->connect() ;

        dlhandle = dlopen( NULL, RTLD_LAZY) ;

        /** @li Turn off RealtimeSync if it exists.  We are not assuming that the function even
                exists.  Search for the routine and execute it if it exists */
        rts_disable_name = "real_time_disable" ;
        rts_disable = (int (*)(void))dlsym( dlhandle , rts_disable_name.c_str()) ;
        if ( rts_disable != NULL ) {
            message_publish(MSG_INFO , "Slave synchronization starting.  Turning realtime synchronization off.\n") ;
            (*rts_disable)() ;
        }

        /** @li Turn off Master synchronization if it exists.  We are not assuming that the function even
                exists.  Search for the routine and execute it if it exists */
        ms_master_disable_name = "ms_master_disable" ;
        ms_master_disable = (int (*)(void))dlsym( dlhandle , ms_master_disable_name.c_str()) ;
        if ( ms_master_disable != NULL ) {
            message_publish(MSG_INFO , "Slave synchronization starting.  Turning master off.\n") ;
            (*ms_master_disable)() ;
        }

        /** @li Read and set the slave software frame and time tic value according to the master. */
        software_frame_tics = connection->read_time() ;
        exec_set_time_tic_value (connection->read_time());
        exec_set_software_frame (double (software_frame_tics) / double(exec_get_time_tic_value()) ) ;
        /** @li Read and set the sync_wait_limit according to the master. */
        sync_wait_limit_tics = connection->read_time() ;
        sync_wait_limit = double (sync_wait_limit_tics) / double(exec_get_time_tic_value()) ;
        connection->set_sync_wait_limit(sync_wait_limit) ;

        /** @li  Read the initial freeze command from the master. */
        exec_set_freeze_command(int(connection->read_command())) ;
        /** @li Read and set the pre_init, post_init, and end checkpoint flags according to the master. */
        chkpnt_flag = (int)connection->read_time();
        checkpoint_pre_init(chkpnt_flag>>2 & 0x1);
        checkpoint_post_init(chkpnt_flag>>1 & 0x1);
        checkpoint_end(chkpnt_flag & 0x1);

        dlclose(dlhandle) ;

        // Executive freezes are only allowed on freeze frame boundaries in Master/Slave
        exec_set_freeze_on_frame_boundary(true) ;

        activated = true;
    }

    return(0) ;
}

std::string Trick::Slave::get_checkpoint_name(MS_SIM_COMMAND command) {

    std::string dir;
    std::stringstream file_name_stream ;
    /** @par Detailed Design */
    /** @li Read the checkpoint name from master, it's in the form "dir/filename" */
    connection->read_name(chkpnt_name, sizeof(chkpnt_name)); // dir/filename
    /** @li Return the appropriate checkpoint name to use for given dump/load command */
    // ascii checkpoint() only wants a filename -- no dir path
    if (command == MS_ChkpntDumpAsciiCmd) {
        if (chkpnt_name[0] != MS_ERROR_NAME) {
            file_name_stream << strrchr(chkpnt_name, '/')+1; // filename only
            //std::cout << "----> Slave: parsed checkpoint file name: " << file_name_stream.str() << std::endl;
        } else { // create default name
            file_name_stream << "chkpnt_" << std::fixed << std::setprecision(2) << exec_get_sim_time() ;
        }
    }
    // ascii load_checkpoint() wants the dir/filename path
    if (command == MS_ChkpntLoadAsciiCmd) {
        dir = command_line_args_get_output_dir(); // run dir
        if (chkpnt_name[0] != MS_ERROR_NAME) {
            file_name_stream << dir << std::string(strrchr(chkpnt_name, '/')); // my run dir / filename
        } else { // create default name
            file_name_stream << dir << "/chkpnt_" << std::fixed << std::setprecision(2) << exec_get_sim_time() ;
        }
    }

    return(file_name_stream.str()) ;
}

int Trick::Slave::end_of_frame() {

    long long master_time ;
    MS_SIM_COMMAND command ;
    MS_SIM_COMMAND slave_command ;
    std::string chkpt_name_str;

    /** @par Detailed Design */
    if ( (enabled) and (activated) ){

        /** @li write the current slave exec_command to the master */
        slave_command = (MS_SIM_COMMAND)exec_get_exec_command();

        // send a special command so master knows to print a "we reconnected" message
        if (reconnected) {
            slave_command = MS_ReconnectCmd;

            if (msg_published)
                reconnected = false;
            else
                sent_reconnect_cmd = true;
        }

        //printf("DEBUG slave write %d command to master\n", slave_command); fflush(stdout);
        connection->write_command(slave_command) ;

        /** @li read the simulation time according to the master */
        master_time = connection->read_time() ;

        if ( master_time == MS_ERROR_TIME ) {

            if ( sync_error_terminate == true ) {
                /** @li if reading the master time returned an error exit the sim if sync_error_terminate == true */
                message_publish(MSG_ERROR , "Slave lost sync with master. sync_error_terminate is true: Slave is terminating.\n") ;
                exec_terminate_with_return(-1, __FILE__, __LINE__ , "Slave lost sync with master") ;
            }
            else {
                if (slave_command != MS_FreezeCmd){
                    /** @li if reading the master time returned an error freeze the sim if sync_error_terminate == false */
                    activated = false;
                    message_publish(MSG_ERROR , "Slave lost sync with master. sync_error_terminate is false: Slave is entering Freeze mode.\n") ;
                    exec_set_exec_command(FreezeCmd) ;
                    connection->write_command(MS_FreezeCmd) ;
                    return(0);
                }
            }
        }

        /** @li read the master mode command */
        command = connection->read_command() ;
        //printf("DEBUG slave read %d command from master\n", command); fflush(stdout);

        switch ( command ) {
            case (MS_ErrorCmd):
                if ( sync_error_terminate == true ) {
                    /** @li if reading the master mode command returned an error exit the sim if sync_error_terminate == true */
                    message_publish(MSG_ERROR , "Slave lost sync with master. sync_error_terminate is true: Slave is terminating.\n") ;
                    exec_terminate_with_return(-1, __FILE__, __LINE__ , "Slave lost sync with master") ;
                }
                else {
                    if (slave_command != MS_FreezeCmd) {
                        /** @li if reading the master mode command returned an error freeze the sim if sync_error_terminate == false */
                        activated = false;
                        message_publish(MSG_ERROR , "Slave lost sync with master. sync_error_terminate is false: Slave is entering Freeze mode.\n") ;
                        exec_set_exec_command(FreezeCmd) ;
                        connection->write_command(MS_FreezeCmd) ;
                        return(0);
                    }
                }
                break;
            /** @li if reading the master mode command returned a checkpoint dump command, dump a checkpoint */
            case (MS_ChkpntDumpAsciiCmd):   // Master tells slave to dump an ascii checkpoint
                message_publish(MSG_WARNING , "Slave received Checkpoint Dump command from master.\n") ;
                chkpt_name_str = get_checkpoint_name(MS_ChkpntDumpAsciiCmd);
                checkpoint(chkpt_name_str.c_str());
                break;
            /** @li if reading the master mode command returned a checkpoint load command, load a checkpoint */
            case (MS_ChkpntLoadAsciiCmd):  // Master tells slave to load an ascii checkpoint
                message_publish(MSG_WARNING , "Slave received Checkpoint Load command from master.\n") ;
                chkpt_name_str = get_checkpoint_name(MS_ChkpntLoadAsciiCmd);
                load_checkpoint(chkpt_name_str.c_str()); // load done in freeze or end_of_frame job
                //load_checkpoint_job(); // do the load NOW
                break;
            default:
                /** @li if reading the master mode command returned an Executive mode, set the slave mode command to the master mode command */
                exec_set_exec_command((SIM_COMMAND)command) ;
                if (reconnected) {
                    message_publish(MSG_INFO , "Slave has reconnected to master.\n") ;
                    if (sent_reconnect_cmd)
                        reconnected = false;
                    else
                        msg_published = true;
                }
                break;
        }
    }

    return(0) ;
}

int Trick::Slave::freeze_init() {
    /** @par Detailed Design */
    if ( enabled ) {
        /** @li Set the connection sync_wait_limit to infinite upon entering freeze */
        connection->set_sync_wait_limit(-1.0) ;
    }
    return(0) ;
}

int Trick::Slave::freeze() {
    /** @par Detailed Design */
    /** @li Call Trick::Slave::end_of_frame() */

    if ( enabled ) {
        exec_set_exec_command(NoCmd) ; // so master won't keep reading freeze command during freeze
        end_of_frame() ;
    }
    return(0) ;
}

int Trick::Slave::unfreeze() {
    /** @par Detailed Design */
    if ( enabled ) {
        /** @li Set the connection sync_wait_limit to the default upon exiting freeze */
        connection->set_sync_wait_limit(sync_wait_limit) ;
    }
    return(0) ;
}

int Trick::Slave::shutdown() {
    /** @par Detailed Design */
    if ( enabled ) {
        /** @li write the exit mode command to the master when the slave is shutting down */
        connection->write_command(MS_ExitCmd) ;
    }
    return(0) ;
}