#include "catalog.h"
#include "query.h"
#include <stdlib.h>
#include "stdio.h"


// forward declaration
const Status ScanSelect(const string & result, 
			const int projCnt, 
			const AttrDesc projNames[],
			const AttrDesc *attrDesc, 
			const Operator op, 
			const char *filter,
			const int reclen);

/*
 * Selects records from the specified relation.
 *
 * Returns:
 * 	OK on success
 * 	an error code otherwise
 */

const Status QU_Select(const string & result, 
		       const int projCnt, 
		       const attrInfo projNames[],
		       const attrInfo *attr, 
		       const Operator op, 
		       const char *attrValue)
{
   // Qu_Select sets up things and then calls ScanSelect to do the actual work
    cout << "Doing QU_Select " << endl;
    Status status;
    
    //go through the projection list and look up each in attrcat 
    //to get an AttrDesc structure (for offset, length)
    AttrDesc attrDesc[projCnt];
    for (int i=0; i<projCnt; i++){
	status = attrCat->getInfo(projNames[i].relName,
			          projNames[i].attrName,
			  	  attrDesc[i]);
	if(status != OK) return status;
    }
    
    //get AtrDesc structure for the first selection attrbute
    AttrDesc attrDesc1;
    status = attrCat->getInfo(attr->relName,
			      attr->attrName,
			      attrDesc1);
    if(status != OK) return status;

    //get output record length from attrDesc structures
    int reclen = 0;
    for (int i=0;i<projCnt; i++){
	reclen = reclen + attrDesc[i].attrLen;
    }
    const char* value;
    if(((Datatype)attrDesc1.attrType) == INTEGER){
        int temp = atoi(attrValue);
	int *val = &temp;
	value = (char*) val;
    }
    else if ((Datatype)attrDesc1.attrType == FLOAT){
	cout<<"Reached Inside Float"<<endl;
	float fTemp  = (float)atof(attrValue);
	float *fval = &fTemp;
	value = (char*)fval;
    }
    else
	value = attrValue;	
    
    status = ScanSelect(result,
			projCnt,
			attrDesc,
			&attrDesc1,
			op,
			value,
			reclen);
   if(status != OK) return status;
   return OK;			      
}


const Status ScanSelect(const string & result, 
			const int projCnt, 
			const AttrDesc projNames[],
			const AttrDesc *attrDesc, 
			const Operator op, 
			const char *filter,
			const int reclen)
{
    Status status;
    cout << "Doing HeapFileScan Selection using ScanSelect()" << endl;
    InsertFileScan resultRel(result, status);
    if(status != OK) return status;

    HeapFileScan hfs((string)attrDesc->relName, status);
    if(status != OK) return status;
    status = hfs.startScan(attrDesc->attrOffset,
			   attrDesc->attrLen,
			   (Datatype) attrDesc->attrType,
			   filter,
			   op);

    if(status != OK) return status;
    char outputData[reclen];
    Record outputRec;
    outputRec.data = (void *)outputData;
    outputRec.length = reclen;
    RID rid;
    while(hfs.scanNext(rid) == OK){
	Record rec;
	status = hfs.getRecord(rec);
	if(status != OK) return status;
	int outputOffset = 0;
	for(int i=0 ; i<projCnt; i++){
		memcpy(outputData+outputOffset, (char*)rec.data +projNames[i].attrOffset, projNames[i].attrLen);
		outputOffset = outputOffset + projNames[i].attrLen;
	}
	
	RID outRid;
        status = resultRel.insertRecord(outputRec, outRid);
	if(status != OK) return status;	
    }
    return OK;   
}