#include <stdlib.h>
#include <string.h>
#include "symtab.h"


struct symtab* symtab_make() {
	struct symtab *symtab = malloc(sizeof(struct symtab));
	symtab->parent = NULL;
	symtab->cap = 16;
	symtab->len = 0;
	symtab->syms = malloc(symtab->cap * sizeof(struct symbol*));
	return symtab;
}

void symtab_delete_recursive(struct symtab *symtab) {
	free(symtab->syms);
	struct symtab *parent = symtab->parent;
	free(symtab);
	if (parent) symtab_delete_recursive(parent);
}

struct symbol* symtab_find(const struct symtab *symtab, const char *name) {
	struct symbol *sym = symtab_find_local(symtab, name);
	if (sym) return sym;
	else if (symtab->parent) return symtab_find(symtab->parent, name);
	else return NULL;
}

struct symbol* symtab_find_local(const struct symtab *symtab, const char *name) {
	for (int i = 0; i < symtab->len; i++) {
		if (strcmp(symtab->syms[i]->name, name) == 0) return symtab->syms[i];
	}
	return NULL;
}

void symtab_insert(struct symtab *symtab, struct symbol *sym) {
	if (symtab->len == symtab->cap) {
		symtab->cap *= 2;
		symtab->syms = realloc(symtab->syms, symtab->cap * sizeof(struct symbol*));
	}
	symtab->syms[symtab->len++] = sym;
}

struct symtab* symtab_root(struct symtab *symtab) {
	if (symtab->parent) return symtab_root(symtab->parent);
	else return symtab;
}

struct symtab* symtab_sub(struct symtab *symtab) {
	struct symtab *sub = symtab_make();
	sub->parent = symtab;
	return sub;
}

struct symtab* symtab_delete_get_parent(struct symtab *symtab) {
	struct symtab *parent = symtab->parent;
	symtab->parent = NULL;
	symtab_delete_recursive(symtab);
	return parent;
}