#include "rmanager.h"

#include <QDebug>

#include <locale.h>
#include <Rinternals.h>

#include <Rembedded.h>
#ifndef _WIN32
#include <Rinterface.h>     // For Linux.
#endif

#include <R_ext/RStartup.h>
#include <R_ext/Parse.h>
#include <R.h>



RManager::RManager(QObject *parent) : QObject(parent)
{
    const char *argv[] = {"RConsole"};
    int argc = sizeof(argv) / sizeof(argv[0]);

    setlocale(LC_NUMERIC, "C"); // Required by Rembedded.

#ifndef _WIN32
    R_SignalHandlers = 0;               // Don't let R set up its own signal handlers
#endif

    Rf_initEmbeddedR(argc, (char**)argv);
    // Assign all callbacks. None in this reduced bug illustration.
    Rf_endEmbeddedR(0);
}



/**
 * @brief RManager::parseEval is the core of this console, sending commands to R.
 * @param line
 * @return
 */
int RManager::parseEval(const QString &line) {
    ParseStatus status;
    SEXP cmdSexp, cmdexpr, ret = R_NilValue;
    int i, errorOccurred, retVal=0;

    // Convert the command line to SEXP
    PROTECT(cmdSexp = Rf_allocVector(STRSXP, 1));
    SET_STRING_ELT(cmdSexp, 0, Rf_mkChar(line.toLocal8Bit().data()));
    cmdexpr = PROTECT(R_ParseVector(cmdSexp, -1, &status, R_NilValue));

    switch (status){
    case PARSE_OK:      // In this toy program, that's the only case that occurs.
		// Loop is needed here as EXPSEXP might be of length > 1
        for(i = 0; ((i < Rf_length(cmdexpr)) && (retVal==0)); i++){
            PROTECT(ret = R_tryEval(VECTOR_ELT(cmdexpr, i), R_GlobalEnv, &errorOccurred));
            if (errorOccurred) {
                qDebug() << "An error occured during eval of" << line ;
                retVal = -1;
            }
            else {
                qDebug() << "No error occured during eval of" << line ;
                printf("EXAMPLE #1 Output: ");
                for (i=0; i<length(ret); i++){
                    QString resultAsString ;
                    switch( TYPEOF(ret) ) {
                    case REALSXP:
                        resultAsString = QString::number(REAL(ret)[0]) ;
                    break;
                    case INTSXP:
                        resultAsString = QString::number(INTEGER(ret)[0]) ;
                    break;
                    case STRSXP:
                        resultAsString = QString(CHAR(STRING_ELT(ret, 0))) ;
                    break;
                    default:
                        resultAsString = QString("Can't recognize this data") ;
                    }
                    qDebug() << "Result is: " << resultAsString ;
                }
                printf("\n");
                UNPROTECT(1); // Clear 'ret'
            }
        }
        break;
    case PARSE_INCOMPLETE:
        // need to read another line
		retVal = 1;
        break;
    case PARSE_NULL:
		Rf_warning(tr("%s: Etat d'analyse de commande : NULL (%d)\n").toStdString().data(), "RPPConsole", status);
        retVal = -2;
        break;
    case PARSE_ERROR:
		Rf_warning(tr("Erreur d'analyse de la commande : \"%s\"\n").toStdString().data(), line.toStdString().c_str());
        retVal = -2;
        break;
    case PARSE_EOF:
		Rf_warning(tr("%s: Etat d'analyse de commande : EOF (%d)\n").toStdString().data(), "RPPConsole", status);
        break;
    default:
		Rf_warning(tr("%s: Etat d'analyse de commande non documenté %d\n").toStdString().data(), "RPPConsole", status);
        retVal = -2;
        break;
    }
    UNPROTECT(2);
    return retVal;
}