/*********************************************************************
 *   Copyright 2018, UCAR/Unidata
 *   See netcdf/COPYRIGHT file for copying and redistribution conditions.
 *********************************************************************/
#include "config.h"
#include "dapincludes.h"
#include <stddef.h>

#ifdef _WIN32
#include <crtdbg.h>
#include <math.h>
#endif

struct Value {
    long long llval;
    double dval;
};

/*Forward*/
static int cvtnumconst(const char* s, struct Value* val);
static int cvtdbl2int(struct Value* val);
static int cvtint2dbl(struct Value* val);
static int cvtint2int(nc_type dsttype, struct Value*);

NCerror
dapconvert(nc_type srctype, nc_type dsttype, char* memory0, char* value0, size_t count)
{
    NCerror ncstat = NC_NOERR;
    size_t i;
    char* memory = memory0;
    char* value = value0;
    /* In order to deal with the DAP upgrade problem,
	try to preserve the bit patterns
    */

    /* Provide space and pointer casts for intermediate results */
    signed char ncbyte;
    signed char* ncbytep;
    char ncchar;
    char* nccharp;
    short ncshort;
    short* ncshortp;
    int ncint;
    int* ncintp;
    float ncfloat;
    float* ncfloatp;
    double ncdouble;
    double* ncdoublep;
    unsigned char ncubyte;
    unsigned char* ncubytep;
    unsigned short ncushort;
    unsigned short* ncushortp;
    unsigned int ncuint;
    unsigned int* ncuintp;
    long long ncint64;
    long long* ncint64p;
    unsigned long long ncuint64;
    unsigned long long* ncuint64p;


#define CASE(nc1,nc2) (nc1*256+nc2)
#define CUT8(e) ((unsigned char)((e) & 0xff))
#define CUT16(e) ((unsigned short)((e) & 0xffff))
#define CUT32(e) ((unsigned int)((e) & 0xffffffff))
#define ARM(vs,ncs,ts,vd,ncd,td) \
case CASE(ncs,ncd):\
    vs##p = (ts *)value;\
    vs = *vs##p;\
    vd##p = (td *)memory;\
    *vd##p = (td)vs;\
    break;

    for(i=0;i<count;i++) {

        switch (CASE(srctype,dsttype)) {
ARM(ncchar,NC_CHAR,char,ncchar,NC_CHAR,char)
ARM(ncchar,NC_CHAR,char,ncbyte,NC_BYTE,signed char)
ARM(ncchar,NC_CHAR,char,ncubyte,NC_UBYTE,unsigned char)
ARM(ncchar,NC_CHAR,char,ncshort,NC_SHORT,short)
ARM(ncchar,NC_CHAR,char,ncushort,NC_USHORT,unsigned short)
ARM(ncchar,NC_CHAR,char,ncint,NC_INT,int)
ARM(ncchar,NC_CHAR,char,ncuint,NC_UINT,unsigned int)
ARM(ncchar,NC_CHAR,char,ncint64,NC_INT64,long long)
ARM(ncchar,NC_CHAR,char,ncuint64,NC_UINT64,unsigned long long)
ARM(ncchar,NC_CHAR,char,ncfloat,NC_FLOAT,float)
ARM(ncchar,NC_CHAR,char,ncdouble,NC_DOUBLE,double)
ARM(ncbyte,NC_BYTE,signed char,ncchar,NC_CHAR,char)
ARM(ncbyte,NC_BYTE,signed char,ncbyte,NC_BYTE,signed char)
ARM(ncbyte,NC_BYTE,signed char,ncubyte,NC_UBYTE,unsigned char)
ARM(ncbyte,NC_BYTE,signed char,ncshort,NC_SHORT,short)
ARM(ncbyte,NC_BYTE,signed char,ncushort,NC_USHORT,unsigned short)
ARM(ncbyte,NC_BYTE,signed char,ncint,NC_INT,int)
ARM(ncbyte,NC_BYTE,signed char,ncuint,NC_UINT,unsigned int)
ARM(ncbyte,NC_BYTE,signed char,ncint64,NC_INT64,long long)
ARM(ncbyte,NC_BYTE,signed char,ncuint64,NC_UINT64,unsigned long long)
ARM(ncbyte,NC_BYTE,signed char,ncfloat,NC_FLOAT,float)
ARM(ncbyte,NC_BYTE,signed char,ncdouble,NC_DOUBLE,double)
ARM(ncubyte,NC_UBYTE,unsigned char,ncchar,NC_CHAR,char)
ARM(ncubyte,NC_UBYTE,unsigned char,ncbyte,NC_BYTE,signed char)
ARM(ncubyte,NC_UBYTE,unsigned char,ncubyte,NC_UBYTE,unsigned char)
ARM(ncubyte,NC_UBYTE,unsigned char,ncshort,NC_SHORT,short)
ARM(ncubyte,NC_UBYTE,unsigned char,ncushort,NC_USHORT,unsigned short)
ARM(ncubyte,NC_UBYTE,unsigned char,ncint,NC_INT,int)
ARM(ncubyte,NC_UBYTE,unsigned char,ncuint,NC_UINT,unsigned int)
ARM(ncubyte,NC_UBYTE,unsigned char,ncint64,NC_INT64,long long)
ARM(ncubyte,NC_UBYTE,unsigned char,ncuint64,NC_UINT64,unsigned long long)
ARM(ncubyte,NC_UBYTE,unsigned char,ncfloat,NC_FLOAT,float)
ARM(ncubyte,NC_UBYTE,unsigned char,ncdouble,NC_DOUBLE,double)
ARM(ncshort,NC_SHORT,short,ncchar,NC_CHAR,char)
ARM(ncshort,NC_SHORT,short,ncbyte,NC_BYTE,signed char)
ARM(ncshort,NC_SHORT,short,ncubyte,NC_UBYTE,unsigned char)
ARM(ncshort,NC_SHORT,short,ncshort,NC_SHORT,short)
ARM(ncshort,NC_SHORT,short,ncushort,NC_USHORT,unsigned short)
ARM(ncshort,NC_SHORT,short,ncint,NC_INT,int)
ARM(ncshort,NC_SHORT,short,ncuint,NC_UINT,unsigned int)
ARM(ncshort,NC_SHORT,short,ncint64,NC_INT64,long long)
ARM(ncshort,NC_SHORT,short,ncuint64,NC_UINT64,unsigned long long)
ARM(ncshort,NC_SHORT,short,ncfloat,NC_FLOAT,float)
ARM(ncshort,NC_SHORT,short,ncdouble,NC_DOUBLE,double)
ARM(ncushort,NC_USHORT,unsigned short,ncchar,NC_CHAR,char)
ARM(ncushort,NC_USHORT,unsigned short,ncbyte,NC_BYTE,signed char)
ARM(ncushort,NC_USHORT,unsigned short,ncubyte,NC_UBYTE,unsigned char)
ARM(ncushort,NC_USHORT,unsigned short,ncshort,NC_SHORT,short)
ARM(ncushort,NC_USHORT,unsigned short,ncushort,NC_USHORT,unsigned short)
ARM(ncushort,NC_USHORT,unsigned short,ncint,NC_INT,int)
ARM(ncushort,NC_USHORT,unsigned short,ncuint,NC_UINT,unsigned int)
ARM(ncushort,NC_USHORT,unsigned short,ncint64,NC_INT64,long long)
ARM(ncushort,NC_USHORT,unsigned short,ncuint64,NC_UINT64,unsigned long long)
ARM(ncushort,NC_USHORT,unsigned short,ncfloat,NC_FLOAT,float)
ARM(ncushort,NC_USHORT,unsigned short,ncdouble,NC_DOUBLE,double)
ARM(ncint,NC_INT,int,ncchar,NC_CHAR,char)
ARM(ncint,NC_INT,int,ncbyte,NC_BYTE,signed char)
ARM(ncint,NC_INT,int,ncubyte,NC_UBYTE,unsigned char)
ARM(ncint,NC_INT,int,ncshort,NC_SHORT,short)
ARM(ncint,NC_INT,int,ncushort,NC_USHORT,unsigned short)
ARM(ncint,NC_INT,int,ncint,NC_INT,int)
ARM(ncint,NC_INT,int,ncuint,NC_UINT,unsigned int)
ARM(ncint,NC_INT,int,ncint64,NC_INT64,long long)
ARM(ncint,NC_INT,int,ncuint64,NC_UINT64,unsigned long long)
ARM(ncint,NC_INT,int,ncfloat,NC_FLOAT,float)
ARM(ncint,NC_INT,int,ncdouble,NC_DOUBLE,double)
ARM(ncuint,NC_UINT,unsigned int,ncchar,NC_CHAR,char)
ARM(ncuint,NC_UINT,unsigned int,ncbyte,NC_BYTE,signed char)
ARM(ncuint,NC_UINT,unsigned int,ncubyte,NC_UBYTE,unsigned char)
ARM(ncuint,NC_UINT,unsigned int,ncshort,NC_SHORT,short)
ARM(ncuint,NC_UINT,unsigned int,ncushort,NC_USHORT,unsigned short)
ARM(ncuint,NC_UINT,unsigned int,ncint,NC_INT,int)
ARM(ncuint,NC_UINT,unsigned int,ncuint,NC_UINT,unsigned int)
ARM(ncuint,NC_UINT,unsigned int,ncint64,NC_INT64,long long)
ARM(ncuint,NC_UINT,unsigned int,ncuint64,NC_UINT64,unsigned long long)
ARM(ncuint,NC_UINT,unsigned int,ncfloat,NC_FLOAT,float)
ARM(ncuint,NC_UINT,unsigned int,ncdouble,NC_DOUBLE,double)
ARM(ncint64,NC_INT64,long long,ncchar,NC_CHAR,char)
ARM(ncint64,NC_INT64,long long,ncbyte,NC_BYTE,signed char)
ARM(ncint64,NC_INT64,long long,ncubyte,NC_UBYTE,unsigned char)
ARM(ncint64,NC_INT64,long long,ncshort,NC_SHORT,short)
ARM(ncint64,NC_INT64,long long,ncushort,NC_USHORT,unsigned short)
ARM(ncint64,NC_INT64,long long,ncint,NC_INT,int)
ARM(ncint64,NC_INT64,long long,ncuint,NC_UINT,unsigned int)
ARM(ncint64,NC_INT64,long long,ncint64,NC_INT64,long long)
ARM(ncint64,NC_INT64,long long,ncuint64,NC_UINT64,unsigned long long)
ARM(ncint64,NC_INT64,long long,ncfloat,NC_FLOAT,float)
ARM(ncint64,NC_INT64,long long,ncdouble,NC_DOUBLE,double)
ARM(ncuint64,NC_UINT64,unsigned long long,ncchar,NC_CHAR,char)
ARM(ncuint64,NC_UINT64,unsigned long long,ncbyte,NC_BYTE,signed char)
ARM(ncuint64,NC_UINT64,unsigned long long,ncubyte,NC_UBYTE,unsigned char)
ARM(ncuint64,NC_UINT64,unsigned long long,ncshort,NC_SHORT,short)
ARM(ncuint64,NC_UINT64,unsigned long long,ncushort,NC_USHORT,unsigned short)
ARM(ncuint64,NC_UINT64,unsigned long long,ncint,NC_INT,int)
ARM(ncuint64,NC_UINT64,unsigned long long,ncuint,NC_UINT,unsigned int)
ARM(ncuint64,NC_UINT64,unsigned long long,ncint64,NC_INT64,long long)
ARM(ncuint64,NC_UINT64,unsigned long long,ncuint64,NC_UINT64,unsigned long long)
ARM(ncuint64,NC_UINT64,unsigned long long,ncfloat,NC_FLOAT,float)
ARM(ncuint64,NC_UINT64,unsigned long long,ncdouble,NC_DOUBLE,double)
ARM(ncfloat,NC_FLOAT,float,ncchar,NC_CHAR,char)
ARM(ncfloat,NC_FLOAT,float,ncbyte,NC_BYTE,signed char)
ARM(ncfloat,NC_FLOAT,float,ncubyte,NC_UBYTE,unsigned char)
ARM(ncfloat,NC_FLOAT,float,ncshort,NC_SHORT,short)
ARM(ncfloat,NC_FLOAT,float,ncushort,NC_USHORT,unsigned short)
ARM(ncfloat,NC_FLOAT,float,ncint,NC_INT,int)
ARM(ncfloat,NC_FLOAT,float,ncuint,NC_UINT,unsigned int)
ARM(ncfloat,NC_FLOAT,float,ncint64,NC_INT64,long long)
ARM(ncfloat,NC_FLOAT,float,ncuint64,NC_UINT64,unsigned long long)
ARM(ncfloat,NC_FLOAT,float,ncfloat,NC_FLOAT,float)
ARM(ncfloat,NC_FLOAT,float,ncdouble,NC_DOUBLE,double)
ARM(ncdouble,NC_DOUBLE,double,ncchar,NC_CHAR,char)
ARM(ncdouble,NC_DOUBLE,double,ncbyte,NC_BYTE,signed char)
ARM(ncdouble,NC_DOUBLE,double,ncubyte,NC_UBYTE,unsigned char)
ARM(ncdouble,NC_DOUBLE,double,ncshort,NC_SHORT,short)
ARM(ncdouble,NC_DOUBLE,double,ncushort,NC_USHORT,unsigned short)
ARM(ncdouble,NC_DOUBLE,double,ncint,NC_INT,int)
ARM(ncdouble,NC_DOUBLE,double,ncuint,NC_UINT,unsigned int)
ARM(ncdouble,NC_DOUBLE,double,ncint64,NC_INT64,long long)
ARM(ncdouble,NC_DOUBLE,double,ncuint64,NC_UINT64,unsigned long long)
ARM(ncdouble,NC_DOUBLE,double,ncfloat,NC_FLOAT,float)
ARM(ncdouble,NC_DOUBLE,double,ncdouble,NC_DOUBLE,double)
	
        default: ncstat = NC_EINVAL; THROWCHK(ncstat); goto fail;
        }
        value += nctypesizeof(srctype);
        memory += nctypesizeof(dsttype);
    }

fail:
    return THROW(ncstat);
}

/**
Convert an attribute value string to a specific type.
If the conversion fails, then return NC_EBADTYPE.
If we need an int and the string value is out of range, return NC_ERANGE.
@param etype the target type
@param dst the memory into which to put the converted constants
@param src list of constants as strings
*/
NCerror
dapcvtattrval(nc_type etype, void* dst, NClist* src, NCattribute* att)
{
    size_t i;
    NCerror  ncstat = NC_NOERR;
    size_t memsize = nctypesizeof(etype);
    size_t nvalues = nclistlength(src);
    char* dstmem = (char*)dst;

    for(i=0;i<nvalues;i++) {
	/* Convert numeric looking constants to either double
           or signed long long and conforming to etype*/
	char* s;
	size_t slen;

	s = (char*)nclistget(src,i);
        slen = strlen(s);
	if(etype <= NC_DOUBLE && etype != NC_CHAR) {
	    struct Value val;
	    int stype;
	    /* Target types */
	    unsigned char* u8p;
	    short* i16p;
	    unsigned short* u16p;
	    int* i32p;
	    unsigned int* u32p;
	    float* fp;
	    double* dp;

	    /* Convert string to a number */
	    stype = cvtnumconst(s,&val);
	    if(stype == NC_NAT) {
	        nclog(NCLOGERR,"Unexpected attribute value: %s = %s",att->name,s);
	        ncstat = NC_EBADTYPE;
                goto next;
            }
	    /* Force conformance with etype */
	    /* Do Specific conversions */
	    if(stype == NC_DOUBLE && etype < NC_FLOAT) {/* double->integer-type */
		if((ncstat = cvtdbl2int(&val))) goto next;
		stype = NC_INT; /* pretend */
	    }else if(stype == NC_INT && etype >= NC_FLOAT) {/*integer-type -> float type*/
		if((ncstat = cvtint2dbl(&val))) goto next;
		stype = NC_DOUBLE; /* pretend */
	    }
	    if(stype == NC_INT && etype < NC_FLOAT) {/* integer-type -> integer-type */
	        if((ncstat = cvtint2int(etype,&val))) goto next;
	    }
	    switch (etype) {
	    case NC_BYTE:
		/* Note that in DAP2, this is unsigned 8-bit integer */
		u8p = (unsigned char*)dstmem;
		*u8p = (unsigned char)(val.llval);
		break;	
	    case NC_SHORT:
		i16p = (short*)dstmem;
		*i16p = (short)(val.llval);
		break;	
	    case NC_USHORT:
		u16p = (unsigned short*)dstmem;
		*u16p = (unsigned short)(val.llval);
		break;	
	    case NC_INT:
		i32p = (int*)dstmem;
		*i32p = (int)(val.llval);
		break;	
	    case NC_UINT:
		u32p = (unsigned int*)dstmem;
		*u32p = (unsigned int)(val.llval);
		break;	
	    case NC_FLOAT:
		fp = (float*)dstmem;
		*fp = (float)(val.dval);
		break;	
	    case NC_DOUBLE:
		dp = (double*)dstmem;
		*dp = (double)(val.dval);
		break;	
	    default: return NC_EINTERNAL;
	    }
	} else if(etype == NC_CHAR) {
	    char* p = (char*)dstmem;
	    int nread;
	    int count = sscanf(s,"%c%n",p,&nread);
	    if(count != 1 || nread != slen)
	        {ncstat = NC_EBADTYPE; goto next;}
	} else if(etype == NC_STRING || etype == NC_URL) {
	    char** p = (char**)dstmem;
	    *p = nulldup(s);
	} else {
   	    PANIC1("unexpected nc_type: %d",(int)etype);
	}
next: /* inside loop */
        if(ncstat == NC_ERANGE)
	    nclog(NCLOGERR,"Attribute value out of range: %s = %s",att->name,s);
        else if(ncstat == NC_EBADTYPE)
	    nclog(NCLOGERR,"Unexpected attribute type or untranslatable value: %s",att->name);
	ncstat = NC_NOERR;
	dstmem += memsize;
    }
    return THROW(ncstat);
}

/**
@param val resulting converted numeric value
@return NC_INT || NC_DOUBLE || NC_NAT (failure)
*/
static int
cvtnumconst(const char* s, struct Value* val)
{
    size_t slen = strlen(s);
    int nread; /* # of chars read */
    /* Try to convert to integer first */
    int count = sscanf(s,"%lld%n",&val->llval,&nread);
    if(count == 1 && nread == slen)
	return NC_INT;
    /* Try to convert to float second */
#ifdef _WIN32
    if (!_strnicmp(s, "NaN", 3)) {count = 1; nread = 3; val->dval = NAN;} else
#endif
    {
	count = sscanf(s,"%lg%n",&val->dval,&nread);
    }
    if(count == 1 && nread == slen)
	    return NC_DOUBLE;
    return NC_INT;
}

/**
Convert a struct Value.dval field to a long in struct Value.llval field.
Report if the result is out of range wrt NC_MAX/MIN_INT.
 @param val store original and converted value
@return NC_NOERR | NC_ERANGE
*/
static int
cvtdbl2int(struct Value* val)
{
    /* Inter-convert */
#ifdef _WIN32
    if(isnan(val->dval)) return NC_ERANGE;
#endif
    val->llval = (long long)val->dval;
    if(val->llval < NC_MIN_INT || val->llval > NC_MAX_INT)
	return NC_ERANGE;
    return NC_NOERR;
}

/**
Convert a struct Value.llval field to double in struct Value.dval field.
@return NC_NOERR
*/
static int
cvtint2dbl(struct Value* val)
{
    /* Inter-convert */
    val->dval = (double)val->llval;
    return NC_NOERR;
}

/**
Convert long long bit pattern to conform to a given
integer type.
@param dsttype target integer type
@param valp pointer to long long value to convert
@return NC_NOERR | NC_EBADTYPE
*/
static int
cvtint2int(nc_type dsttype, struct Value* val)
{
    /* assert dsttype < NC_FLOAT && dsttype != NC_CHAR */

    /* We do not actually do much in the way of range checking,
       we just truncate the bit pattern to the proper size, taking
       signedness into account */

    switch (dsttype) {
    case NC_BYTE:
	val->llval = (long long)((signed char)(val->llval));
        break;
    case NC_UBYTE:
	val->llval = (long long)(val->llval & 0xFF);
        break;
    case NC_SHORT:
	val->llval = (long long)((short)(val->llval));
        break;
    case NC_USHORT:
	val->llval = (long long)(val->llval & 0xFFFF);
        break;
    case NC_INT:
	val->llval = (long long)((int)(val->llval));
        break;
    case NC_UINT:
	val->llval = (long long)(val->llval & 0xFFFFFFFF);
        break;
    default: return NC_EBADTYPE;
    }
    return NC_NOERR;
}