/*
  +----------------------------------------------------------------------+
  | parallel                                                             |
  +----------------------------------------------------------------------+
  | Copyright (c) Joe Watkins 2019-2024                                  |
  +----------------------------------------------------------------------+
  | This source file is subject to version 3.01 of the PHP license,      |
  | that is bundled with this package in the file LICENSE, and is        |
  | available through the world-wide-web at the following url:           |
  | http://www.php.net/license/3_01.txt                                  |
  | If you did not receive a copy of the PHP license and are unable to   |
  | obtain it through the world-wide-web, please send a note to          |
  | license@php.net so we can mail you a copy immediately.               |
  +----------------------------------------------------------------------+
  | Author: krakjoe                                                      |
  +----------------------------------------------------------------------+
 */
#ifndef HAVE_PARALLEL_FUTURE
#define HAVE_PARALLEL_FUTURE

#include "parallel.h"

zend_class_entry    *php_parallel_future_ce;
zend_object_handlers php_parallel_future_handlers;

zend_string         *php_parallel_future_string_runtime;

bool php_parallel_future_lock(php_parallel_future_t *future) { return php_parallel_monitor_lock(future->monitor); }

bool php_parallel_future_readable(php_parallel_future_t *future)
{
	return php_parallel_monitor_check(future->monitor, PHP_PARALLEL_READY);
}

static zend_always_inline void php_parallel_future_value_inline(php_parallel_future_t *future, zval *return_value)
{
	if (!php_parallel_monitor_check(future->monitor, PHP_PARALLEL_DONE)) {
		zval garbage = future->value;

		PARALLEL_ZVAL_COPY(&future->value, &garbage, 0);

		if (Z_OPT_REFCOUNTED(garbage)) {
			PARALLEL_ZVAL_DTOR(&garbage);
		}

		php_parallel_monitor_set(future->monitor, PHP_PARALLEL_DONE);
	}

	ZVAL_COPY(return_value, &future->value);
}

void php_parallel_future_value(php_parallel_future_t *future, zval *return_value)
{
	php_parallel_monitor_lock(future->monitor);

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_ERROR)) {
		ZVAL_OBJ(return_value, php_parallel_exceptions_restore(&future->value));
		php_parallel_monitor_unlock(future->monitor);
		return;
	} else if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_KILLED | PHP_PARALLEL_CANCELLED)) {
		ZVAL_NULL(return_value);
		php_parallel_monitor_unlock(future->monitor);
		return;
	}

	php_parallel_future_value_inline(future, return_value);

	php_parallel_monitor_unlock(future->monitor);
}

bool php_parallel_future_unlock(php_parallel_future_t *future) { return php_parallel_monitor_unlock(future->monitor); }

ZEND_BEGIN_ARG_INFO_EX(php_parallel_future_value_arginfo, 0, 0, 0)
ZEND_END_ARG_INFO()

PHP_METHOD(Parallel_Future, value)
{
	php_parallel_future_t *future = php_parallel_future_from(getThis());
	int32_t                state;

	PARALLEL_PARAMETERS_NONE(return);

	php_parallel_monitor_lock(future->monitor);

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_CANCELLED)) {
		php_parallel_exception_ex(php_parallel_future_error_cancelled_ce, "cannot retrieve value");
		php_parallel_monitor_unlock(future->monitor);
		return;
	}

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_KILLED)) {
		php_parallel_exception_ex(php_parallel_future_error_killed_ce, "cannot retrieve value");
		php_parallel_monitor_unlock(future->monitor);
		return;
	}

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_DONE)) {
		php_parallel_monitor_unlock(future->monitor);

		goto _php_parallel_future_value;
	} else {
		state = php_parallel_monitor_wait_locked(future->monitor,
		                                         PHP_PARALLEL_READY | PHP_PARALLEL_FAILURE | PHP_PARALLEL_ERROR);
		php_parallel_monitor_unlock(future->monitor);
	}

	if ((state == FAILURE) || (state & PHP_PARALLEL_FAILURE)) {
		php_parallel_exception_ex(php_parallel_future_error_ce, "cannot retrieve value");
		php_parallel_monitor_set(future->monitor, PHP_PARALLEL_READY | PHP_PARALLEL_FAILURE);
		return;
	}

	if ((state & PHP_PARALLEL_ERROR)) {
		zval exception;

		ZVAL_OBJ(&exception, php_parallel_exceptions_restore(&future->value));

		php_parallel_monitor_set(future->monitor, PHP_PARALLEL_READY | PHP_PARALLEL_ERROR);

		zend_throw_exception_object(&exception);
		return;
	}

	php_parallel_monitor_set(future->monitor, PHP_PARALLEL_READY);

_php_parallel_future_value:
	php_parallel_future_value_inline(future, return_value);
}

ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(php_parallel_future_cancel_arginfo, 0, 0, _IS_BOOL, 0)
ZEND_END_ARG_INFO()

PHP_METHOD(Parallel_Future, cancel)
{
	php_parallel_future_t *future = php_parallel_future_from(getThis());

	PARALLEL_PARAMETERS_NONE(return);

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_CANCELLED)) {
		php_parallel_exception_ex(php_parallel_future_error_cancelled_ce, "task was already cancelled");
		return;
	}

	if (php_parallel_monitor_check(future->monitor, PHP_PARALLEL_KILLED)) {
		php_parallel_exception_ex(php_parallel_future_error_killed_ce, "runtime executing task was killed");
		return;
	}

	RETURN_BOOL(php_parallel_scheduler_cancel(future));
}

ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(php_parallel_future_cancelled_arginfo, 0, 0, _IS_BOOL, 0)
ZEND_END_ARG_INFO()

PHP_METHOD(Parallel_Future, cancelled)
{
	php_parallel_future_t *future = php_parallel_future_from(getThis());

	PARALLEL_PARAMETERS_NONE(return);

	RETURN_BOOL(php_parallel_monitor_check(future->monitor, PHP_PARALLEL_CANCELLED));
}

ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(php_parallel_future_done_arginfo, 0, 0, _IS_BOOL, 0)
ZEND_END_ARG_INFO()

PHP_METHOD(Parallel_Future, done)
{
	php_parallel_future_t *future = php_parallel_future_from(getThis());

	RETURN_BOOL(php_parallel_monitor_check(future->monitor, PHP_PARALLEL_READY));
}

ZEND_BEGIN_ARG_INFO_EX(php_parallel_future_construct_arginfo, 0, 0, 0)
ZEND_END_ARG_INFO()

PHP_METHOD(Parallel_Future, __construct)
{
	php_parallel_future_t *future = php_parallel_future_from(getThis());

	php_parallel_exception_ex(php_parallel_future_error_ce, "construction of Future objects is not allowed");

	php_parallel_monitor_set(future->monitor, PHP_PARALLEL_READY | PHP_PARALLEL_DONE);
}

zend_function_entry php_parallel_future_methods[] = {
    PHP_ME(Parallel_Future, __construct, php_parallel_future_construct_arginfo,
           ZEND_ACC_PUBLIC) PHP_ME(Parallel_Future, value, php_parallel_future_value_arginfo, ZEND_ACC_PUBLIC)
        PHP_ME(Parallel_Future, done, php_parallel_future_done_arginfo, ZEND_ACC_PUBLIC)
            PHP_ME(Parallel_Future, cancel, php_parallel_future_cancel_arginfo, ZEND_ACC_PUBLIC)
                PHP_ME(Parallel_Future, cancelled, php_parallel_future_cancelled_arginfo, ZEND_ACC_PUBLIC) PHP_FE_END};

zend_object *php_parallel_future_create(zend_class_entry *type)
{
	php_parallel_future_t *future = ecalloc(1, sizeof(php_parallel_future_t) + zend_object_properties_size(type));

	zend_object_std_init(&future->std, type);

	future->std.handlers = &php_parallel_future_handlers;

	future->monitor = php_parallel_monitor_create();

	return &future->std;
}

void php_parallel_future_destroy(zend_object *o)
{
	php_parallel_future_t *future = php_parallel_future_fetch(o);

	php_parallel_monitor_lock(future->monitor);

	if (!php_parallel_monitor_check(future->monitor, PHP_PARALLEL_READY)) {
		php_parallel_monitor_wait_locked(future->monitor, PHP_PARALLEL_READY);
	}

	php_parallel_monitor_unlock(future->monitor);

	switch (Z_TYPE(future->value)) {
	case IS_PTR:
		php_parallel_exceptions_destroy(Z_PTR(future->value));
		break;

	default:
		if (Z_OPT_REFCOUNTED(future->value)) {
			PARALLEL_ZVAL_DTOR(&future->value);
		}
	}

	if (future->runtime) {
		OBJ_RELEASE(&future->runtime->std);
	}

	php_parallel_monitor_destroy(future->monitor);

	zend_object_std_dtor(o);
}

static HashTable *php_parallel_future_debug(zend_object *zo, int *temp)
{
	php_parallel_future_t *future = php_parallel_future_fetch(zo);
	HashTable             *debug;
	zval                   zdbg;

	ALLOC_HASHTABLE(debug);
	zend_hash_init(debug, 3, NULL, ZVAL_PTR_DTOR, 0);

	*temp = 1;

	GC_ADDREF(&future->runtime->std);

	ZVAL_OBJ(&zdbg, &future->runtime->std);

	zend_hash_add(debug, php_parallel_future_string_runtime, &zdbg);

	return debug;
}

PHP_MINIT_FUNCTION(PARALLEL_FUTURE)
{
	zend_class_entry ce;

	memcpy(&php_parallel_future_handlers, php_parallel_standard_handlers(), sizeof(zend_object_handlers));

	php_parallel_future_handlers.offset = offsetof(php_parallel_future_t, std);
	php_parallel_future_handlers.free_obj = php_parallel_future_destroy;
	php_parallel_future_handlers.get_debug_info = php_parallel_future_debug;

	INIT_NS_CLASS_ENTRY(ce, "parallel", "Future", php_parallel_future_methods);

	php_parallel_future_ce = zend_register_internal_class(&ce);
	php_parallel_future_ce->create_object = php_parallel_future_create;
	php_parallel_future_ce->ce_flags |= ZEND_ACC_FINAL;

#ifdef ZEND_ACC_NOT_SERIALIZABLE
	php_parallel_future_ce->ce_flags |= ZEND_ACC_NOT_SERIALIZABLE;
#else
	php_parallel_future_ce->serialize = zend_class_serialize_deny;
	php_parallel_future_ce->unserialize = zend_class_unserialize_deny;
#endif

	php_parallel_future_string_runtime = zend_string_init_interned(ZEND_STRL("runtime"), 1);

	return SUCCESS;
}

PHP_MSHUTDOWN_FUNCTION(PARALLEL_FUTURE)
{
	zend_string_release(php_parallel_future_string_runtime);

	return SUCCESS;
}
#endif
