/*
   +----------------------------------------------------------------------+
   | Copyright © The PHP Group and Contributors.                          |
   +----------------------------------------------------------------------+
   | This source file is subject to the Modified BSD License that is      |
   | bundled with this package in the file LICENSE, and is available      |
   | through the World Wide Web at <https://www.php.net/license/>.        |
   |                                                                      |
   | SPDX-License-Identifier: BSD-3-Clause                                |
   +----------------------------------------------------------------------+
   | Authors: Gustavo Lopes <cataphract@php.net>                          |
   +----------------------------------------------------------------------+
*/

#include "../intl_cppshims.h"

#include <limits>

#include <unicode/calendar.h>
#include <unicode/gregocal.h>

#include "dateformat_helpers.h"

extern "C" {
#include "../php_intl.h"
#include <Zend/zend_operators.h>
#define USE_CALENDAR_POINTER 1
#include "../calendar/calendar_class.h"
}

// Artificial value to set for a pure proleptic gregorian calendar (until icu provides it eventually)
#define UCAL_PHP_PROLEPTIC_GREGORIAN -16

using icu::GregorianCalendar;

zend_result datefmt_process_calendar_arg(
	zend_object *calendar_obj, zend_long calendar_long, bool calendar_is_null, Locale const& locale,
	intl_error *err, Calendar*& cal, zend_long& cal_int_type, bool& calendar_owned
) {
	UErrorCode status = UErrorCode();

	if (calendar_is_null) {
		// default requested
		cal = new GregorianCalendar(locale, status);
		calendar_owned = true;

		cal_int_type = UCAL_GREGORIAN;

	} else if (!calendar_obj) {
		zend_long v = calendar_long;
		if (v != (zend_long)UCAL_TRADITIONAL && v != (zend_long)UCAL_GREGORIAN &&
		    v != (zend_long)UCAL_PHP_PROLEPTIC_GREGORIAN) {
			intl_errors_set(err, U_ILLEGAL_ARGUMENT_ERROR,
				"Invalid value for calendar type; it must be one of "
				"IntlDateFormatter::TRADITIONAL (locale's default calendar) or"
				" IntlDateFormatter::GREGORIAN or IntlDateFormatter::PROLEPTIC_GREGORIAN."
			        " Alternatively, it can be an "
				"IntlCalendar object");
			return FAILURE;
		} else if (v == (zend_long)UCAL_TRADITIONAL) {
			cal = Calendar::createInstance(locale, status);
		} else { //UCAL_GREGORIAN
			GregorianCalendar *gcal = new GregorianCalendar(locale, status);
			if (v == (zend_long)UCAL_PHP_PROLEPTIC_GREGORIAN) {
				// set the Julian to gregorian cutover date to -infinity
				// to make it a proleptic gregorian calendar
				// TODO: consider making it default behavior over typical "gregorian" icu like calendar
				gcal->setGregorianChange(-std::numeric_limits<double>::infinity(), status);
			}
			cal = gcal;
		}

		calendar_owned = true;

		cal_int_type = calendar_long;
	} else if (calendar_obj) {
		cal = calendar_fetch_native_calendar(calendar_obj);
		if (cal == NULL) {
			intl_errors_set(err, U_ILLEGAL_ARGUMENT_ERROR, "Found unconstructed IntlCalendar object");
			return FAILURE;
		}
		calendar_owned = false;

		cal_int_type = -1;

	} else {
		intl_errors_set(err, U_ILLEGAL_ARGUMENT_ERROR,
			"Invalid calendar argument; should be an integer or an IntlCalendar instance");
		return FAILURE;
	}

	if (cal == NULL && !U_FAILURE(status)) {
		status = U_MEMORY_ALLOCATION_ERROR;
	}
	if (U_FAILURE(status)) {
		intl_errors_set(err, U_ILLEGAL_ARGUMENT_ERROR, "Failure instantiating calendar");
		return FAILURE;
	}

	return SUCCESS;
}
