/**********
Copyright 1990 Regents of the University of California.  All rights reserved.
Author: 1987 Gary W. Ng
Modified: 2001 AlansFixes
**********/

/* Patch to noisean.c by Richard D. McRoberts.
 * Patched with modifications from Weidong Liu (2000)
 * Patched with modifications ftom Weidong Liu
 * in bsim4.1.0 code
 */

#include "ngspice/ngspice.h"
#include "ngspice/acdefs.h"
#include "ngspice/cktdefs.h"
#include "ngspice/iferrmsg.h"
#include "ngspice/noisedef.h"
#include "ngspice/sperror.h"
#include "vsrc/vsrcdefs.h"
#include "isrc/isrcdefs.h"


int
NOISEan (CKTcircuit *ckt, int restart)
{
    static Ndata *data; /* va, must be static, for continuation of 
                         * interrupted(Ctrl-C), longer lasting noise 
			 * analysis 
			 */
    double realVal;
    double imagVal;
    int error;
    int posOutNode;
    int negOutNode;
    int step;
    IFuid freqUid;
    double freqTol; /* tolerence parameter for finding final frequency; hack */

    NOISEAN *job = (NOISEAN *) ckt->CKTcurJob;

    posOutNode = (job->output) -> number;
    negOutNode = (job->outputRef) -> number;

    /* see if the source specified is AC */
    {
        GENinstance *inst = CKTfndDev(ckt, job->input);
        bool ac_given = FALSE;

        if (!inst || inst->GENmodPtr->GENmodType < 0) {
            SPfrontEnd->IFerrorf (ERR_WARNING,
                                 "Noise input source %s not in circuit",
                                 job->input);
            return E_NOTFOUND;
        }

        if (inst->GENmodPtr->GENmodType == CKTtypelook("Vsource")) {
            ac_given = ((VSRCinstance *)inst) -> VSRCacGiven;
        } else if(inst->GENmodPtr->GENmodType == CKTtypelook("Isource")) {
            ac_given = ((ISRCinstance *)inst) -> ISRCacGiven;
        } else {
            SPfrontEnd->IFerrorf (ERR_WARNING,
                                 "Noise input source %s is not of proper type",
                                 job->input);
            return E_NOTFOUND;
        }

        if (!ac_given) {
            SPfrontEnd->IFerrorf (ERR_WARNING,
                                 "Noise input source %s has no AC value",
                                 job->input);
            return E_NOACINPUT;
        }
    }

    if ( (job->NsavFstp == 0.0) || restart) { /* va, NsavFstp is double */
	switch (job->NstpType) {


        case DECADE:
            job->NfreqDelta = exp(log(10.0)/
                            job->NnumSteps);
            break;

        case OCTAVE:
            job->NfreqDelta = exp(log(2.0)/
	                    job->NnumSteps);
            break;

        case LINEAR:
            job->NfreqDelta = (job->NstopFreq - 
                            job->NstartFreq)/
			    (job->NnumSteps - 1);
            break;

        default:
            return(E_BADPARM);
        }

	/* error = DCop(ckt); */
	error = CKTop(ckt, (ckt->CKTmode & MODEUIC) | MODEDCOP | MODEINITJCT,
		(ckt->CKTmode & MODEUIC) | MODEDCOP | MODEINITFLOAT,
		ckt->CKTdcMaxIter);

	if (error) return(error);

	/* Patch to noisean.c by Richard D. McRoberts. */
	ckt->CKTmode = (ckt->CKTmode & MODEUIC) | MODEDCOP | MODEINITSMSIG;
     error = CKTload(ckt);
     if(error) return(error);
     
     data = TMALLOC(Ndata, 1);
	step = 0;
	data->freq = job->NstartFreq;
	data->outNoiz = 0.0;
	data->inNoise = 0.0;

	/* the current front-end needs the namelist to be fully
		declared before an OUTpBeginplot */

	SPfrontEnd->IFnewUid (ckt, &freqUid, NULL, "frequency", UID_OTHER, NULL);

	data->numPlots = 0;                /* we don't have any plots  yet */
        error = CKTnoise(ckt,N_DENS,N_OPEN,data);
        if (error) return(error);

	/*
	 * all names in the namelist have been declared. now start the
	 * plot
	 */

        error = SPfrontEnd->OUTpBeginPlot (ckt, ckt->CKTcurJob,
                                           "Noise Spectral Density Curves - (V^2 or A^2)/Hz",
                                           freqUid, IF_REAL,
                                           data->numPlots, data->namelist, IF_REAL,
                                           &(data->NplotPtr));
	if (error) return(error);

        if (job->NstpType != LINEAR) {
	    SPfrontEnd->OUTattributes (data->NplotPtr, NULL, OUT_SCALE_LOG, NULL);
	}

    } else {   /* we must have paused before.  pick up where we left off */
	step = (int)(job->NsavFstp);
	switch (job->NstpType) {

	case DECADE:
        case OCTAVE:
	    data->freq = job->NstartFreq * exp (step *
		     log (job->NfreqDelta));
            break;
            
        case LINEAR:
	    data->freq = job->NstartFreq + step *
		     job->NfreqDelta;
            break;

        default:
            return(E_BADPARM);

        }
	job->NsavFstp = 0;
	data->outNoiz = job->NsavOnoise;
	data->inNoise = job->NsavInoise;
	/* saj resume rawfile fix*/
        error = SPfrontEnd->OUTpBeginPlot (NULL, NULL,
                                           NULL,
                                           NULL, 0,
                                           666, NULL, 666,
                                           &(data->NplotPtr));
	/*saj*/
    }

    switch (job->NstpType) {
    case DECADE:
    case OCTAVE:
        freqTol = job->NfreqDelta * job->NstopFreq * ckt->CKTreltol;
        break;
    case LINEAR:
        freqTol = job->NfreqDelta * ckt->CKTreltol;
        break;
    default:
        return(E_BADPARM);
    }

    data->lstFreq = data->freq;

    /* do the noise analysis over all frequencies */

    while (data->freq <= job->NstopFreq + freqTol) {
        if(SPfrontEnd->IFpauseTest()) {
	    job->NsavFstp = step;   /* save our results */
	    job->NsavOnoise = data->outNoiz; /* up until now     */
	    job->NsavInoise = data->inNoise;
	    return (E_PAUSE);
        }
	ckt->CKTomega = 2.0 * M_PI * data->freq;
	ckt->CKTmode = (ckt->CKTmode & MODEUIC) | MODEAC;

	/*
	 * solve the original AC system to get the transfer
	 * function between the input and output
	 */

	NIacIter(ckt);
	realVal = ckt->CKTrhsOld [posOutNode]
		- ckt->CKTrhsOld [negOutNode];
	imagVal = ckt->CKTirhsOld [posOutNode]
		- ckt->CKTirhsOld [negOutNode];
	data->GainSqInv = 1.0 / MAX(((realVal*realVal)
		+ (imagVal*imagVal)),N_MINGAIN);
	data->lnGainInv = log(data->GainSqInv);

	/* set up a block of "common" data so we don't have to
	 * recalculate it for every device
	 */

	data->delFreq = data->freq - data->lstFreq;
	data->lnFreq = log(MAX(data->freq,N_MINLOG));
	data->lnLastFreq = log(MAX(data->lstFreq,N_MINLOG));
        data->delLnFreq = data->lnFreq - data->lnLastFreq;

	if ((job->NStpsSm != 0) && ((step % (job->NStpsSm)) == 0)) {
	    data->prtSummary = TRUE;
        } else {
	    data->prtSummary = FALSE;
        }

	/*
	data->outNumber = 1;       
	*/

	data->outNumber = 0;
	/* the frequency will NOT be stored in array[0]  as before; instead,
	 * it will be given in refVal.rValue (see later)
	 */

	NInzIter(ckt,posOutNode,negOutNode);   /* solve the adjoint system */

	/* now we use the adjoint system to calculate the noise
	 * contributions of each generator in the circuit
	 */

	error = CKTnoise(ckt,N_DENS,N_CALC,data);
	if (error) return(error);
	data->lstFreq = data->freq;

	/* update the frequency */

	switch (job->NstpType) {

	case DECADE:
	case OCTAVE:
	    data->freq *= job->NfreqDelta;
	    break;

        case LINEAR:
	    data->freq += job->NfreqDelta;
	    break;
        
	default:
	    return(E_INTERN);
        }
	step++;
    }

    error = CKTnoise(ckt,N_DENS,N_CLOSE,data);
    if (error) return(error);
    
    data->numPlots = 0;
    data->outNumber = 0;

    if (job->NstartFreq != job->NstopFreq) {
	error = CKTnoise(ckt,INT_NOIZ,N_OPEN,data);

	if (error) return(error);

        SPfrontEnd->OUTpBeginPlot (ckt, ckt->CKTcurJob,
                                   "Integrated Noise - V^2 or A^2",
                                   NULL, 0,
                                   data->numPlots, data->namelist, IF_REAL,
                                   &(data->NplotPtr));

	error = CKTnoise(ckt,INT_NOIZ,N_CALC,data);
	if (error) return(error);

	error = CKTnoise(ckt,INT_NOIZ,N_CLOSE,data);
	if (error) return(error);
    }

    FREE(data);
    return(OK);
}