/*
 * Copyright (c) 2026 Nakidai Perumenei <nakidai at disroot dot org>
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 */

#include "thac.h"

#include <ctype.h>
#include <stdlib.h>
#include <string.h>


long
findvar(char *name, struct scope **scope)
{
	struct var *var;
	ulong i;

	for (; *scope; *scope = (*scope)->parent) for (i = 0; i < (*scope)->len; ++i)
	{
		var = &(*scope)->vars[i];
		if (!strcmp(var->name, name))
			return i;
	}

	return -1;
}

ulong
assignvar(char *name, struct val val, struct scope **scope)
{
	struct scope *lscope;
	long i;

	lscope = *scope;
	i = findvar(name, &lscope);
	if (i < 0)
	{
		/* TODO: add cap and increment like in lex.c */
		(*scope)->vars = realloc(
			(*scope)->vars,
			sizeof(*(*scope)->vars) * ++(*scope)->len
		);
		if (!(*scope)->vars)
			dieno(1, "realloc()");
		i = (*scope)->len - 1;
	} else
	{
		scope = &lscope;
	}
	(*scope)->vars[i].name = name;
	(*scope)->vars[i].val = val;
	return i;
}

int
varnextchar(struct scope *scope)
{
	struct var *var;
	ulong i;
	int c;

	for (c = -1; scope; scope = scope->parent) for (i = 0; i < scope->len; ++i)
	{
		var = &scope->vars[i];
		if (var->name[0] == '@' && islower(var->name[1]))
			c = max(c, var->name[1]);

		if (c == -1)
			continue;

		if (c == 'z')
			return -1;
		return var->name[1] + 1;
	}

	return 'a';
}

ulong
varnextnum(struct scope *scope)
{
	struct var *var;
	ulong i;

	for (; scope; scope = scope->parent) for (i = 0; i < scope->len; ++i)
	{
		var = &scope->vars[i];
		if (var->name[0] == '@' && isdigit(var->name[1]))
			return atoll(&var->name[1]) + 1;
	}

	return 0;
}

void
delvarscope(struct scope *scope, ulong i)
{
	freeval(scope->vars[i].val);
	scope->vars[i] = scope->vars[--scope->len];
}