#include <stdlib.h>
#include <string.h>
#include "compiler-expressions.h"
#include "compiler-statements.h"
#include "compiler-util.h"

/* BEGIN FORWARD DECLARATIONS */

// Miscelaneous
LINE* popthat();
LINE* pushtemp();
char* mkcondlabel(char* name, int count);

// Handling individual statements
LINEBLOCK* compileret(SCOPE* s, STATEMENT* st);
LINEBLOCK* compileif(SCOPE* s, STATEMENT* st);
LINEBLOCK* compilewhile(SCOPE* s, STATEMENT* st);
LINEBLOCK* compilelet(SCOPE* s, STATEMENT* st);
LINEBLOCK* compilestatement(SCOPE* s, STATEMENT* st);

/* END FORWARD DECLARATIONS */



// Miscelaneous
LINE* popthat() {
	char* popthat[] = { "pop", "that", "0" };
	return mkln(popthat);
}

LINE* pushtemp() {
	char* pushtemp[] = { "push", "temp", "0" };
	return mkln(pushtemp);
}

char* mkcondlabel(char* name, int count) {
	int sz = (strlen(name) + countplaces(count) + 1) * sizeof(char);
	char* result = (char*)malloc(sz);
	sprintf(result, "%s%i", name, count);
	return result;
}

// Handling individual statements
LINEBLOCK* compileret(SCOPE* s, STATEMENT* st) {
	TERM* e = st->retstatement;
	LINE* ret = onetoken("return");
	LINEBLOCK* blk = mklnblk(ret);

	// void subroutdecs return 0
	if(e == NULL) {
		char* tokens[] = { "push", "constant", "0" };
		appendlnbefore(blk, mkln(tokens));
	} else
		blk = mergelnblks(compileexpression(s, st->debug, e), blk);

	return blk;
}

LINEBLOCK* compileif(SCOPE* s, STATEMENT* st) {
	IFSTATEMENT* ifst = st->ifstatement;
	LINEBLOCK* blk = compileexpression(s, st->debug, ifst->base->expression);

	pthread_mutex_lock(&(s->compiler->ifmutex));
	static int ifcount = 0;
	int mycount = ifcount;
	ifcount++;
	pthread_mutex_unlock(&(s->compiler->ifmutex));
	
	char* truelabel = mkcondlabel("IF_TRUE", mycount);
	char* ifgoto[] = { "if-goto", truelabel };
	appendln(blk, mkln(ifgoto));
	
	char* falselabel = mkcondlabel("IF_FALSE", mycount);
	char* gotofalse[] = { "goto", falselabel };
	appendln(blk, mkln(gotofalse));

	char* truelabelln[] = { "label", truelabel };
	appendln(blk, mkln(truelabelln));

	blk = mergelnblks(blk, compilestatements(s, ifst->base->statements));

	char* endlabel;
	bool haselse = ifst->elsestatements != NULL;
	if(haselse) {
		endlabel = mkcondlabel("IF_END", mycount);
		char* endgoto[] = { "goto", endlabel };
		appendln(blk, mkln(endgoto));
	}

	char* falselabelln[] = { "label", falselabel};
	appendln(blk, mkln(falselabelln));

	if(haselse) {
		blk = mergelnblks(blk, compilestatements(s, ifst->elsestatements));
		char* endlabelln[] = { "label", endlabel };
		appendln(blk, mkln(endlabelln));
		free(endlabel);
	}

	free(falselabel);
	free(truelabel);

	return blk;
}

LINEBLOCK* compilewhile(SCOPE* s, STATEMENT* st) {
	CONDSTATEMENT* w = st->whilestatement;
	LINEBLOCK* blk = compileexpression(s, st->debug, w->expression);

	pthread_mutex_lock(&(s->compiler->whilemutex));
	static int whilecount = 0;
	int mycount = whilecount;
	whilecount++;
	pthread_mutex_unlock(&(s->compiler->whilemutex));

	char* explabel = mkcondlabel("WHILE_EXP", mycount);
	char* explabelln[] = { "label", explabel };
	appendlnbefore(blk, mkln(explabelln));

	appendln(blk, onetoken("not"));

	char* endlabel = mkcondlabel("WHILE_END", mycount);
	char* ifgoto[] = { "if-goto", endlabel };
	appendln(blk, mkln(ifgoto));

	blk = mergelnblks(blk, compilestatements(s, w->statements));

	char* gotoln[] = { "goto", explabel };
	appendln(blk, mkln(gotoln));

	char* endlabelln[] = { "label", endlabel };
	appendln(blk, mkln(endlabelln));

	free(explabel);
	free(endlabel);

	return blk;
}

LINEBLOCK* compilelet(SCOPE* s, STATEMENT* st) {
	LETSTATEMENT* l = st->letstatement;
	LINEBLOCK* blk = compileexpression(s, st->debug, l->expression);

	if(l->arrayind != NULL) {
		appendlnbefore(blk, onetoken("add"));
		appendlnbefore(blk, pushvar(s, st->debug, l->varname));
		blk = mergelnblks(compileexpression(s, st->debug, l->arrayind), blk);

		appendln(blk, poptemp());
		appendln(blk, popthatadd());
		appendln(blk, pushtemp());
		appendln(blk, popthat());
	}
	else
		appendln(blk, popvar(s, st->debug, l->varname));
	return blk;
}

LINEBLOCK* compilestatement(SCOPE* s, STATEMENT* st) {
	s->currdebug = st->debug;
	if(st->type == dostatement) return compilesubroutcall(s, st->dostatement);
	if(st->type == returnstatement) return compileret(s, st);
	if(st->type == ifstatement) return compileif(s, st);
	if(st->type == whilestatement) return compilewhile(s, st);
	return compilelet(s, st);
}

LINEBLOCK* compilestatements(SCOPE* s, STATEMENT* sts) {
	LINEBLOCK* head = NULL;
	while(sts != NULL) {
		head = mergelnblks(head, compilestatement(s, sts));
		sts = sts->next;
	}
	return head;
}

LINEBLOCK* compilestatementsretlast(SCOPE* s, STATEMENT* sts, STATEMENT** retlast) {
	LINEBLOCK* head = NULL;
	STATEMENT* last = NULL;
	while(sts != NULL) {
		head = mergelnblks(head, compilestatement(s, sts));
		last = sts;
		sts = sts->next;
	}
	*retlast = last;
	return head;
}