#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include "symtable.h"

#if 0
#define DD
#endif

struct symbol *tab_new(void)
{
	return SYMNULL;
}

struct symbol *tab_clone(struct symbol *tab)
{
	struct symbol *elm = tab;
	struct symbol *ntab = tab_new();
#ifdef DD
	fprintf(stderr, "tab_clone: tab(%08X)\n", tab);
#endif

	while(elm != SYMNULL) {
		ntab = tab_add_symbol(ntab, elm->ident, elm->type, 0, elm->param_index, elm->soffset);
		elm = elm->next;
	}
	return ntab;
}

struct symbol *tab_add_symbol(struct symbol *tab, char *ident, short type, short check, int param_index, int soffset)
{
	struct symbol *elm = tab;
	struct symbol *new_elm;
#ifdef DD
	fprintf(stderr, "tab_add_symbol: tab(%08X), ident(%s), type(%i), check(%i), param_index(%i), soffset(%i)\n", tab, ident, type, check, param_index, soffset);
#endif

#if 0
	/* kann statt return -3, -4 verursachen... (z.b. codea_ag_snafu_01.3) */
	if(param_index >= 6) {
		fprintf(stderr, "eine methode hat zu viele parameter (max. 6 inkl. this erlaubt)\n");
		exit(4);
	}
#endif

	if(tab_lookup(tab, ident, type) != SYMNULL || (type == S_VAR && tab_lookup(tab, ident, S_PARM) != SYMNULL)) {
		if(check) {
			fprintf(stderr, "Identifier doppelt vorhanden: \"%s\"\n", ident);
			exit(3);
		} else {
			tab = tab_remove_symbol(tab, ident, type);
		}
	}
	
	new_elm = (struct symbol *) malloc(sizeof(struct symbol));
	new_elm->next = SYMNULL;
	new_elm->ident = strdup(ident);
	new_elm->type = type;
	new_elm->param_index = param_index;
	new_elm->soffset = soffset;

	if(tab == SYMNULL) return new_elm;

	while(elm->next != SYMNULL) {
		elm = elm->next;
	}
	elm->next = new_elm;
	
	return tab;
}

struct symbol *tab_lookup(struct symbol *tab, char *ident, short type)
{
	struct symbol *elm = tab;

	if(tab == SYMNULL) return SYMNULL;

	do {
		if((elm->type & type) && (strcmp(elm->ident, ident) == 0)) {
			return elm;
		}
		elm = elm->next;
	} while(elm != SYMNULL);

	return SYMNULL;
}

struct symbol *tab_merge(struct symbol *tab, struct symbol *to_add, short check)
{
	struct symbol *elm = to_add;
	struct symbol *ntab = tab_clone(tab);
#ifdef DD
	fprintf(stderr, "tab_merge: tab(%08X), to_add(%08X), check(%i), ntab(%08X)\n", tab, to_add, check, ntab);
#endif
	
	while(elm != SYMNULL) {
		ntab = tab_add_symbol(ntab, elm->ident, elm->type, check, elm->param_index, elm->soffset);
		elm = elm->next;
	}

	return ntab;
}

struct symbol *tab_remove_symbol(struct symbol *tab, char *ident, short type)
{
	struct symbol *elm = tab;
	struct symbol *previous_elm = SYMNULL;

	while(elm != SYMNULL) {
		if((elm->type == type) && (strcmp(elm->ident, ident) == 0)) {
			if(previous_elm == SYMNULL) {
				tab = elm->next;
			} else {
				previous_elm->next = elm->next;
			}
			(void)free(elm->ident);
			(void)free(elm);
			break;
		}
		previous_elm = elm;
		elm = elm->next;
	}

	return tab;
}

void check(struct symbol *tab, char *ident, short type)
{
	struct symbol *elm;
#ifdef DD
	fprintf(stderr, "check: tab(%08X), ident(%s), type(%i), elm(%08X)\n", tab, ident, type, elm);
#endif

	if(type & (S_VAR | S_PARM)) {
		elm = tab_lookup(tab, ident, type);
		if(elm != SYMNULL) {
			return;
		}
	}

	/* keine passende variable gefunden?
	 * => vllt gibt es ja ein passenden feldnamen */
	elm = tab_lookup(tab, ident, S_FIELD);
	if(elm == SYMNULL) {
		fprintf(stderr, "Unbekannter Identifier: \"%s\"\n", ident);
		exit(3);
	}
}