/*********************************************************************
 *   Copyright 2009, UCAR/Unidata
 *   See netcdf/COPYRIGHT file for copying and redistribution conditions.
 *********************************************************************/

#include "includes.h"
#include "nciter.h"
#include "odom.h"
#include "offsets.h"

/**************************************************/
/* Code for generating data lists*/
/**************************************************/
/* For datalist constant rules: see the rules on the man page */

/* Forward*/
static void generate_array(Symbol*,Bytebuffer*,Datalist*,Generator*,Writer);
static void generate_arrayr(Symbol*,Bytebuffer*,Datalist*,Odometer*,int,Datalist*,Generator*);
static void generate_primdata(Symbol*, Constant*, Bytebuffer*, Datalist* fillsrc, Generator*);
static void generate_fieldarray(Symbol*, Constant*, Dimset*, Bytebuffer*, Datalist* fillsrc, Generator*);

/* Mnemonics */
#define VLENLIST1
#define FIELDARRAY 1

/**************************************************/
/* Generator general procedures */

int
generator_getstate(Generator* generator ,void** statep)
{
    if(statep) *statep = (void*)generator->state;
    return 1;
}

int generator_reset(Generator* generator, void* state)
{
    generator->state = state;
    return 1;
}

#ifdef IGNORe
static void
checkodom(Odometer* odom)
{
    int i;
    for(i=0;i<odom->rank;i++) {
	ASSERT(odom->index[i] == odom->start[i]+odom->count[i]);
    }
}
#endif

/**************************************************/

void
generate_attrdata(Symbol* asym, Generator* generator, Writer writer, Bytebuffer* codebuf)
{
    Symbol* basetype = asym->typ.basetype;
    nc_type typecode = basetype->typ.typecode;

    if(typecode == NC_CHAR) {
	gen_charattr(asym->data,codebuf);
    } else {
	int uid;
	size_t count;
        generator->listbegin(generator,LISTATTR,asym->data->length,codebuf,&uid);
        for(count=0;count<asym->data->length;count++) {
	    Constant* con = datalistith(asym->data,count);
	    generator->list(generator,LISTATTR,uid,count,codebuf);
            generate_basetype(asym->typ.basetype,con,codebuf,NULL,generator);
	}
        generator->listend(generator,LISTATTR,uid,count,codebuf);
    }
    writer(generator,asym,codebuf,0,NULL,NULL);
}

void
generate_vardata(Symbol* vsym, Generator* generator, Writer writer, Bytebuffer* code)
{
    Dimset* dimset = &vsym->typ.dimset;
    int rank = dimset->ndims;
    Symbol* basetype = vsym->typ.basetype;
    Datalist* filler = getfiller(vsym);

    if(vsym->data == NULL) return;

    /* give the buffer a running start to be large enough*/
    bbSetalloc(code, nciterbuffersize);

    if(rank == 0) {/*scalar case*/
	Constant* c0 = datalistith(vsym->data,0);
        generate_basetype(basetype,c0,code,filler,generator);
        writer(generator,vsym,code,0,NULL,NULL);
    } else {/*rank > 0*/
	generate_array(vsym,code,filler,generator,writer);
    }
}
		
static void
generate_array(Symbol* vsym,
               Bytebuffer* code,
               Datalist* filler,
               Generator* generator,
	       Writer writer
              )
{
    Dimset* dimset = &vsym->typ.dimset;
    int rank = dimset->ndims;
    Symbol* basetype = vsym->typ.basetype;
    nc_type typecode = basetype->typ.typecode;
    Odometer* odom;
    nciter_t iter;

    ASSERT(rank > 0);

    /* Start by doing easy cases */

#ifdef CHARBUG
    if(typecode == NC_CHAR) { /* case: character typed variable, rank > 0 */
	Bytebuffer* charbuf = bbNew();
        gen_chararray(dimset,vsym->data,charbuf,filler);
	generator->charconstant(generator,code,charbuf);
	bbFree(charbuf);
        odom = newodometer(dimset,NULL,NULL);
        writer(generator,vsym,code,odom->rank,odom->start,odom->count);
    } else
#else /*!CHARBUG*/
    /* Case: char var && dim 1..n are not unlimited */
    if(findunlimited(dimset,1) == rank && typecode == NC_CHAR) {
	Bytebuffer* charbuf = bbNew();
	gen_leafchararray(dimset,0,vsym->data,charbuf,filler);
	generator->charconstant(generator,code,charbuf);
	bbFree(charbuf);
        odom = newodometer(dimset,NULL,NULL);
        writer(generator,vsym,code,odom->rank,odom->start,odom->count);
    } else
#endif
    /* Case 2: dim 1..n are not unlimited */
    if(findunlimited(dimset,1) == rank) {
	size_t offset = 0; /* where are we in the data list */
	size_t nelems = 0; /* # of data list items to read */
        /* Create an iterator and odometer and just walk the datalist */
        nc_get_iter(vsym,nciterbuffersize,&iter);
        odom = newodometer(dimset,NULL,NULL);
	for(;;offset+=nelems) {
	     int i,uid;
             nelems=nc_next_iter(&iter,odom->start,odom->count);
             if(nelems == 0) break;
	     bbClear(code);
             generator->listbegin(generator,LISTDATA,vsym->data->length,code,&uid);
	     for(i=0;i<nelems;i++) {
#ifdef ITERBUG
	 	Constant* con = datalistith(vsym->data,i);
#else
	 	Constant* con = datalistith(vsym->data,i+offset);
#endif	
                generator->list(generator,LISTDATA,uid,i,code);
#ifdef USE_NOFILL
		if(nofill_flag && con == NULL)
		    break;
		else
#endif
                    generate_basetype(basetype,con,code,filler,generator);
 	    }
	    generator->listend(generator,LISTDATA,uid,i,code);
#ifdef USE_NOFILL
            writer(generator,vsym,code,rank,odom->start,odom->index);
#else
            writer(generator,vsym,code,rank,odom->start,odom->count);
#endif
	}
    } else

    { /* Hard case: multiple unlimited dimensions */
        /* Setup iterator and odometer */
#ifdef CHARBUG
        nc_get_iter(vsym,nciterbuffersize,&iter);
#else
	nc_get_iter(vsym,NC_MAX_UINT,&iter); /* effectively infinite */
#endif
        odom = newodometer(dimset,NULL,NULL);
	for(;;) {/* iterate in nelem chunks */
	    /* get nelems count and modify odometer */
   	    size_t nelems=nc_next_iter(&iter,odom->start,odom->count);
	    if(nelems == 0) break;
            generate_arrayr(vsym,code,vsym->data,
			    odom,
                            /*dim index=*/0,
			    filler,generator
			   );
#ifdef USE_NOFILL
            writer(generator,vsym,code,odom->rank,odom->start,odom->index);
#else
            writer(generator,vsym,code,odom->rank,odom->start,odom->count);
#endif
        }
    }
    odometerfree(odom);
}

static void
generate_arrayr(Symbol* vsym,
               Bytebuffer* code,
               Datalist* list,
	       Odometer* odom,
               int dimindex,
               Datalist* filler,
               Generator* generator
              )
{
    Symbol* basetype = vsym->typ.basetype;
    Dimset* dimset = &vsym->typ.dimset;
    int rank = dimset->ndims;
    int lastunlimited;
    int typecode = basetype->typ.typecode;

    lastunlimited = findlastunlimited(dimset);
    if(lastunlimited == rank) lastunlimited = 0;

    ASSERT(rank > 0);
    ASSERT(dimindex >= 0 && dimindex < rank);

#ifdef CHARBUG
    ASSERT(typecode != NC_CHAR); 
#else /*!CHARBUG*/
    if(dimindex == lastunlimited && typecode == NC_CHAR) {
	Bytebuffer* charbuf = bbNew();
	gen_leafchararray(dimset,dimindex,list,charbuf,filler);
	generator->charconstant(generator,code,charbuf);
	bbFree(charbuf);
    } else
#endif /*!CHARBUG*/
    if(dimindex == lastunlimited) {
	int uid,i;
	Odometer* slabodom;
	/* build a special odometer to walk the last few dimensions
	   (similar to case 2 above)
	*/
        slabodom = newsubodometer(odom,dimset,dimindex,rank);
	/* compute the starting offset in our datalist 
	   (Assumes that slabodom->index[i] == slabodom->start[i])
        */
        generator->listbegin(generator,LISTDATA,list->length,code,&uid);
	for(i=0;odometermore(slabodom);i++) {
	    size_t offset = odometeroffset(slabodom);
	    Constant* con = datalistith(list,offset);
#ifdef USE_NOFILL
	    if(nofill_flag && con == NULL)
		break;
#endif
            generator->list(generator,LISTDATA,uid,i,code);
            generate_basetype(basetype,con,code,filler,generator);
	    odometerincr(slabodom);
        }
        generator->listend(generator,LISTDATA,uid,i,code);
	odometerfree(slabodom);
    } else {
        /* If we are strictly to the left of the next unlimited
           then our datalist is a list of compounds representing
           the next unlimited; so walk the subarray from this index
	   upto next unlimited.
        */
	int i;
	Odometer* slabodom;
        int nextunlimited = findunlimited(dimset,dimindex+1);
	ASSERT((dimindex < lastunlimited
                && (dimset->dimsyms[dimindex]->dim.isunlimited)));
	/* build a sub odometer */
        slabodom = newsubodometer(odom,dimset,dimindex,nextunlimited);
	/* compute the starting offset in our datalist 
	   (Assumes that slabodom->index[i] == slabodom->start[i])
        */
	for(i=0;odometermore(slabodom);i++) {
	    size_t offset = odometeroffset(slabodom);
	    Constant* con = datalistith(list,offset);
#ifdef USE_NOFILL
	    if(nofill_flag && con == NULL)
		break;
#endif
	    if(con == NULL || con->nctype == NC_FILL) {
	        generate_arrayr(vsym,code,filler,odom,nextunlimited,NULL,generator);
		
	    } else if(!islistconst(con))
	        semwarn(constline(con),"Expected {...} representing unlimited list");
	    else {
	        Datalist* sublist = con->value.compoundv;
	        generate_arrayr(vsym,code,sublist,odom,nextunlimited,filler,generator);
	    }
	    odometerincr(slabodom);
        }
	odometerfree(slabodom);
    }
    return;
}


/* Generate an instance of the basetype */
void
generate_basetype(Symbol* tsym, Constant* con, Bytebuffer* codebuf, Datalist* filler, Generator* generator)
{
    Datalist* data;

    switch (tsym->subclass) {

    case NC_ENUM:
    case NC_OPAQUE:
    case NC_PRIM:
	if(islistconst(con)) {
	    semerror(constline(con),"Expected primitive found {..}");
	}
	generate_primdata(tsym,con,codebuf,filler,generator);
	break;

    case NC_COMPOUND: {
	int i,uid;
	if(con == NULL || isfillconst(con)) {
	    Datalist* fill = (filler==NULL?getfiller(tsym):filler);
	    ASSERT(fill->length == 1);
	    con = &fill->data[0];
	    if(!islistconst(con))
	        semerror(con->lineno,"Compound data fill value is not enclosed in {..}");
	}
	if(!islistconst(con)) {/* fail on no compound*/
	    semerror(constline(con),"Compound data must be enclosed in {..}");
        }
	data = con->value.compoundv;
	generator->listbegin(generator,LISTCOMPOUND,listlength(tsym->subnodes),codebuf,&uid);
        for(i=0;i<listlength(tsym->subnodes);i++) {
            Symbol* field = (Symbol*)listget(tsym->subnodes,i);
	    con = datalistith(data,i);
	    generator->list(generator,LISTCOMPOUND,uid,i,codebuf);
            generate_basetype(field,con,codebuf,NULL,generator);
	}
	generator->listend(generator,LISTCOMPOUND,uid,i,codebuf);
	} break;

    case NC_VLEN: {
	Bytebuffer* vlenbuf;
        int uid;
	size_t count;

	if(con == NULL || isfillconst(con)) {
	    Datalist* fill = (filler==NULL?getfiller(tsym):filler);
	    ASSERT(fill->length == 1);
	    con = &fill->data[0];
	    if(con->nctype != NC_COMPOUND) {
	        semerror(con->lineno,"Vlen data fill value is not enclosed in {..}");
	    }
	}

	if(!islistconst(con)) {
	    semerror(constline(con),"Vlen data must be enclosed in {..}");
        }
        data = con->value.compoundv;
        /* generate the nc_vlen_t instance*/
	vlenbuf = bbNew();	
	if(tsym->typ.basetype->typ.typecode == NC_CHAR) {
	    gen_charvlen(data,vlenbuf);
	    generator->vlenstring(generator,vlenbuf,&uid,&count);
	} else {
    	    generator->listbegin(generator,LISTVLEN,data->length,codebuf,&uid);
            for(count=0;count<data->length;count++) {
   	        generator->list(generator,LISTVLEN,uid,count,vlenbuf);
                generate_basetype(tsym->typ.basetype,datalistith(data,count),vlenbuf,NULL,generator);
	    }
   	    generator->listend(generator,LISTVLEN,uid,count,codebuf,(void*)vlenbuf);
	}
	generator->vlendecl(generator,codebuf,tsym,uid,count,vlenbuf);
	bbFree(vlenbuf);
        } break;

    case NC_FIELD:
	if(tsym->typ.dimset.ndims > 0) {
	    /* Verify that we have a sublist (or fill situation) */
	    if(con != NULL && !isfillconst(con) && !islistconst(con)) 
		semerror(constline(con),"Dimensioned fields must be enclose in {...}");
            generate_fieldarray(tsym->typ.basetype,con,&tsym->typ.dimset,codebuf,filler,generator);
	} else {
	    generate_basetype(tsym->typ.basetype,con,codebuf,NULL,generator);
	}
	break;

    default: PANIC1("generate_basetype: unexpected subclass %d",tsym->subclass);
    }
}

/* Used only for structure field arrays*/
static void
generate_fieldarray(Symbol* basetype, Constant* con, Dimset* dimset,
		 Bytebuffer* codebuf, Datalist* filler, Generator* generator)
{
    int i;
    int chartype = (basetype->typ.typecode == NC_CHAR);
    Datalist* data;

    ASSERT(dimset->ndims > 0);

    if(con != NULL && !isfillconst(con))
        data = con->value.compoundv;
    else
	data = NULL;

    if(chartype) {
	/* Collect the char field in a separate buffer */
	Bytebuffer* charbuf = bbNew();
        gen_chararray(dimset,data,charbuf,filler);	
	generator->charconstant(generator,codebuf,charbuf);
	bbFree(charbuf);
    } else {
	int uid;
	size_t xproduct = crossproduct(dimset,0,0); /* compute total number of elements */
        generator->listbegin(generator,LISTFIELDARRAY,xproduct,codebuf,&uid);
        for(i=0;i<xproduct;i++) {
	    con = (data == NULL ? NULL : datalistith(data,i));
	    generator->list(generator,LISTFIELDARRAY,uid,i,codebuf);
            generate_basetype(basetype,con,codebuf,NULL,generator);
	}
        generator->listend(generator,LISTFIELDARRAY,uid,i,codebuf);
    }
}

static void
generate_primdata(Symbol* basetype, Constant* prim, Bytebuffer* codebuf,
		  Datalist* filler, Generator* generator)
{
    Constant target;

    if(prim == NULL || isfillconst(prim)) {
	Datalist* fill = (filler==NULL?getfiller(basetype):filler);
	ASSERT(fill->length == 1);
	prim = datalistith(fill,0);
    }

    ASSERT(prim->nctype != NC_COMPOUND);

    target.nctype = basetype->typ.typecode;

    if(target.nctype != NC_ECONST) {
	convert1(prim,&target);
    }

    switch (target.nctype) {
    case NC_ECONST:
        if(basetype->subclass != NC_ENUM) {
	    semerror(constline(prim),"Conversion to enum not supported (yet)");
	} break;
     case NC_OPAQUE:
	setprimlength(&target,basetype->typ.size*2);
	break;
    default:
	break;
    }
    generator->constant(generator,&target,codebuf);
    
    return;
}