// SPDX-License-Identifier: MIT
// Copyright (c) 2023 John Watts and the LuminaSensum contributors

#include "error.h"
#include "object.h"
#include <stdlib.h>

static struct object_class num_class;

struct number {
	struct object obj;
	int value;
};

Object number_create(int value) {
	struct number *num = malloc(sizeof(struct number));
	abort_if(!num, "unable to allocate number");
	num->obj.class_data = &num_class;
	num->obj.ref_count = 1;
	num->value = value;
	return (Object)num;
}

static void number_cleanup(Object obj) {
	abort_if(obj->class_data != &num_class,
		"number_cleanup obj is not a number");
	struct number *num = (struct number *)obj;
	free(num);
}

int number_value(Object obj) {
	abort_if(obj->class_data != &num_class,
		"number_value obj is not a number");
	struct number *num = (struct number *)obj;
	return num->value;
}

static void number_add(VmState state, Object obj) {
	int arg_count = vm_stack_depth(state);
	abort_if(arg_count != 2, "number_add called without 2 arguments");
	Object arg1 = vm_stack_get(state, 1);
	abort_if(!arg1, "number_add arg is NULL");
	abort_if(arg1->class_data != &num_class,
		"number_add arg is not a number");
	struct number *numA = (struct number *)obj;
	struct number *numB = (struct number *)arg1;
	int added = numA->value + numB->value;
	vm_stack_set(state, 0, number_create(added));
	vm_stack_drop(state, 1);
	object_drop(&arg1);
	numB = NULL;
}

static void number_minus(VmState state, Object obj) {
	int arg_count = vm_stack_depth(state);
	abort_if(arg_count != 2, "number_minus called without 2 arguments");
	Object arg1 = vm_stack_get(state, 1);
	abort_if(!arg1, "number_minus arg is NULL");
	abort_if(arg1->class_data != &num_class,
		"number_minus arg is not a number");
	struct number *numA = (struct number *)obj;
	struct number *numB = (struct number *)arg1;
	int subbed = numA->value - numB->value;
	vm_stack_set(state, 0, number_create(subbed));
	vm_stack_drop(state, 1);
	object_drop(&arg1);
	numB = NULL;
}

static struct object_call calls[] = {{.name = "Add", .handler = number_add},
	{.name = "Minus", .handler = number_minus}, {.name = NULL, /* end */}};

static struct object_class num_class = {
	.cleanup = number_cleanup,
	.calls = &calls[0],
};