<?php
/* For licensing terms, see /license.txt */
/**
 * @package chamilo.webservices
 */
require_once(dirname(__FILE__).'/../inc/global.inc.php');
$libpath = api_get_path(LIBRARY_PATH);
require_once(dirname(__FILE__).'/webservice.php');

/**
 * Web services available for the Course module. This class extends the WS class
 */
class WSCourse extends WS
{
	/**
	 * Deletes a course (helper method)
	 *
	 * @param string Course id field name
	 * @param string Course id value
	 * @return mixed True if the course was successfully deleted, WSError otherwise
	 */
	protected function deleteCourseHelper($course_id_field_name, $course_id_value) {
		$course_id = $this->getCourseId($course_id_field_name, $course_id_value);
		if($course_id instanceof WSError) {
			return $course_id;
		} else {
			$course_code = CourseManager::get_course_code_from_course_id($course_id);
			CourseManager::delete_course($course_code);
			return true;
		}
	}

	/**
	 * Deletes a course
	 *
	 * @param string API secret key
	 * @param string Course id field name
	 * @param string Course id value
	 */
	public function DeleteCourse($secret_key, $course_id_field_name, $course_id_value) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$result = $this->deleteCourseHelper($course_id_field_name, $course_id_value);
			if($result instanceof WSError) {
				$this->handleError($result);
			}
		}
	}

	/**
	 * Deletes multiple courses
	 *
	 * @param string API secret key
	 * @param array Array of courses with elements of the form array('course_id_field_name' => 'name_of_field', 'course_id_value' => 'value')
	 * @return array Array with elements like array('course_id_value' => 'value', 'result' => array('code' => 0, 'message' => 'Operation was successful')). Note that if the result array contains a code different
	 * than 0, an error occured
	 */
	public function DeleteCourses($secret_key, $courses) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$results = array();
			foreach($courses as $course) {
				$result_tmp = array();
				$result_op = $this->deleteCourseHelper($course['course_id_field_name'], $course['course_id_value']);
				$result_tmp['course_id_value'] = $course['course_id_value'];
				if($result_op instanceof WSError) {
					// Return the error in the results
					$result_tmp['result'] = $result_op->toArray();
				} else {
					$result_tmp['result'] = $this->getSuccessfulResult();
				}
				$results[] = $result_tmp;
			}
			return $results;
		}
	}

	/**
	 * Creates a course (helper method)
	 *
	 * @param string Title
	 * @param string Category code
	 * @param string Wanted code. If it's not defined, it will be generated automatically
	 * @param string Tutor name
	 * @param string Course admin user id field name
	 * @param string Course admin user id value
	 * @param string Course language
	 * @param string Course id field name
	 * @param string Course id value
	 * @param array Course extra fields
	 * @return mixed Generated id if creation was successful, WSError otherwise
	 */
	protected function createCourseHelper($title, $category_code, $wanted_code, $tutor_name, $course_admin_user_id_field_name, $course_admin_user_id_value, $language, $course_id_field_name, $course_id_value, $extras) {
		// Add the original course id field name and value to the extra fields if needed
		$extras_associative = array();
		if($course_id_field_name != "chamilo_course_id") {
			$extras_associative[$course_id_field_name] = $course_id_value;
		}
		foreach($extras as $extra) {
			$extras_associative[$extra['field_name']] = $extra['field_value'];
		}
		$course_admin_id = $this->getUserId($course_admin_user_id_field_name, $course_admin_user_id_value);
		if($course_admin_id instanceof WSError) {
			return $course_admin_id;
		}
		if($wanted_code == '') {
			$wanted_code = CourseManager::generate_course_code($title);
		}
		$result = create_course($wanted_code, $title, $tutor_name, $category_code, $language, $course_admin_id, $this->_configuration['db_prefix'], 0);
		if (!$result) {
			return new WSError(202, 'There was an error creating the course');
		} else {
			// Update extra fields
			foreach($extras_associative as $fname => $fvalue) {
				CourseManager::update_course_extra_field_value($result, $fname, $fvalue);
			}
			// Get course id
			$course_info = CourseManager::get_course_information($result);
			return $course_info['real_id'];
		}
	}

	/**
	 * Creates a course
	 *
	 * @param string API secret key
	 * @param string Title
	 * @param string Category code
	 * @param string Wanted code. If it's not defined, it will be generated automatically
	 * @param string Tutor name
	 * @param string Course admin user id field name
	 * @param string Course admin user id value
	 * @param string Course language
	 * @param string Course id field name
	 * @param string Course id value
	 * @param array Course extra fields
	 * @return int Course id generated
	 */
	public function CreateCourse($secret_key, $title, $category_code, $wanted_code, $tutor_name, $course_admin_user_id_field_name, $course_admin_user_id_value, $language, $course_id_field_name, $course_id_value, $extras) {
		// First, verify the secret key
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$result = $this->createCourseHelper($title, $category_code, $wanted_code, $tutor_name, $course_admin_user_id_field_name, $course_admin_user_id_value, $language, $course_id_field_name, $course_id_value, $extras);
			if($result instanceof WSError) {
				$this->handleError($result);
			} else {
				return $result;
			}
		}
	}

	/**
	 * Create multiple courses
	 *
	 * @param string API secret key
	 * @param array Courses to be created, with elements following the structure presented in CreateCourse
	 * @return array Array with elements of the form array('course_id_value' => 'original value sent', 'course_id_generated' => 'value_generated', 'result' => array('code' => 0, 'message' => 'Operation was successful'))
	 */
	public function CreateCourses($secret_key, $courses) {
		// First, verify the secret key
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$results = array();
			foreach($courses as $course) {
				$result_tmp = array();
                // re-initialize variables just in case
                $title = $category_code = $wanted_code = $tutor_name = $course_admin_user_id_field_name = $course_admin_user_id_value = $language = $course_id_field_name = $course_id_value = $extras = 0;
				extract($course);
				$result = $this->createCourseHelper($title, $category_code, $wanted_code, $tutor_name, $course_admin_user_id_field_name, $course_admin_user_id_value, $language, $course_id_field_name, $course_id_value, $extras);
				if($result instanceof WSError) {
					$result_tmp['result'] = $result->toArray();
					$result_tmp['course_id_value'] = $course_id_value;
					$result_tmp['course_id_generated'] = 0;
				} else {
					$result_tmp['result'] = $this->getSuccessfulResult();
					$result_tmp['course_id_value'] = $course_id_value;
					$result_tmp['course_id_generated'] = $result;
				}
				$results[] = $result_tmp;
			}
			return $results;
		}
	}

	/**
	 * Edits a course (helper method)
	 *
	 * @param string Course id field name
	 * @param string Course id value
	 * @param string Title
	 * @param string Category code
	 * @param string Department name
	 * @param string Department url
	 * @param string Course language
	 * @param int Visibility
	 * @param int Subscribe (0 = denied, 1 = allowed)
	 * @param int Unsubscribe (0 = denied, 1 = allowed)
	 * @param string Visual code
	 * @param array Course extra fields
	 * @return mixed True in case of success, WSError otherwise
	 */
	protected function editCourseHelper($course_id_field_name, $course_id_value, $title, $category_code, $department_name, $department_url, $language, $visibility, $subscribe, $unsubscribe, $visual_code, $extras) {
		$course_id = $this->getCourseId($course_id_field_name, $course_id_value);
		if($course_id instanceof WSError) {
			return $course_id;
		} else {
			$attributes = array();
			if(!is_empty($title)) {
				$attributes['title'] = $title;
			}
			if(!is_empty($category_code)) {
				$attributes['category_code'] = $category_code;
			}
			if(!is_empty($department_name)) {
				$attributes['department_name'] = $department_name;
			}
			if(!is_empty($department_url)) {
				$attributes['department_url'] = $department_url;
			}
			if(!is_empty($language)) {
				$attributes['course_language'] = $language;
			}
			if($visibility != '') {
				$attributes['visibility'] = (int)$visibility;
			}
			if($subscribe != '') {
				$attributes['subscribe'] = (int)$subscribe;
			}
			if($unsubscribe != '') {
				$attributes['unsubscribe'] = (int)$unsubscribe;
			}
			if(!is_empty($visual_code)) {
				$attributes['visual_code'] = $visual_code;
			}
			if(!is_empty($attributes)) {
				CourseManager::update_attributes($course_id, $attributes);
			}
			if(!empty($extras)) {
				$course_code = CourseManager::get_course_code_from_course_id($course_id);
				$extras_associative = array();
				foreach($extras as $extra) {
					$extras_associative[$extra['field_name']] = $extra['field_value'];
				}
				foreach($extras_associative as $fname => $fvalue) {
					CourseManager::update_extra_field_value($course_code, $fname, $fvalue);
				}
			}
			return true;
		}
	}

	/**
	 * Edits a course
	 *
	 * @param string API secret key
	 * @param string Course id field name
	 * @param string Course id value
	 * @param string Title
	 * @param string Category code
	 * @param string Department name
	 * @param string Department url
	 * @param string Course language
	 * @param int Visibility
	 * @param int Subscribe (0 = denied, 1 = allowed)
	 * @param int Unsubscribe (0 = denied, 1 = allowed)
	 * @param string Visual code
	 * @param array Course extra fields
	 */
	public function EditCourse($secret_key, $course_id_field_name, $course_id_value, $title, $category_code, $department_name, $department_url, $language, $visibility, $subscribe, $unsubscribe, $visual_code, $extras) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$result = $this->editCourseHelper($course_id_field_name, $course_id_value, $title, $category_code, $department_name, $department_url, $language, $visibility, $subscribe, $unsubscribe, $visual_code, $extras);
			if($result instanceof WSError) {
				$this->handleError($result);
			}
		}
	}

	/**
	 * List courses
	 *
	 * @param string API secret key
	 * @param string A list of visibility filter we want to apply
	 * @return array An array with elements of the form ('id' => 'Course internal id', 'code' => 'Course code', 'title' => 'Course title', 'language' => 'Course language', 'visibility' => 'Course visibility',
	 * 'category_name' => 'Name of the category of the course', 'number_students' => 'Number of students in the course', 'external_course_id' => 'External course id')
	 */
	public function ListCourses($secret_key, $visibility = 'public,public-registered,private,closed') {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
            $visibilities = split(',',$visibility);
            $vis = array('public' => '3', 'public-registered' => '2', 'private' => '1', 'closed' => '0');
            foreach ($visibilities as $p => $visibility) {
                $visibilities[$p] = $vis[$visibility];
            }
			$courses_result = array();
			$category_names = array();

			$courses = CourseManager::get_courses_list();
			foreach($courses as $course) {
                //skip elements that do not match required visibility
                if (!in_array($course['visibility'],$visibilities)) { continue; }
				$course_tmp = array();
				$course_tmp['id'] = $course['id'];
				$course_tmp['code'] = $course['code'];
				$course_tmp['title'] = $course['title'];
				$course_tmp['language'] = $course['course_language'];
				$course_tmp['visibility'] = $course['visibility'];

				// Determining category name
				if($category_names[$course['category_code']]) {
					$course_tmp['category_name'] = $category_names[$course['category_code']];
				} else {
					$category = CourseManager::get_course_category($course['category_code']);
					$category_names[$course['category_code']] = $category['name'];
					$course_tmp['category_name'] = $category['name'];
				}

				// Determining number of students registered in course
				$user_list = CourseManager::get_user_list_from_course_code($course['code'], 0);
				$course_tmp['number_students'] = count($user_list);

				// Determining external course id - this code misses the external course id field name
				// $course_tmp['external_course_id'] = CourseManager::get_course_extra_field_value($course_field_name, $course['code']);


				$courses_result[] = $course_tmp;
			}

			return $courses_result;
		}
	}

	/**
	 * Subscribe or unsubscribe user to a course (helper method)
	 *
	 * @param string Course id field name. Use "chamilo_course_id" to use internal id
	 * @param string Course id value.
	 * @param string User id field name. Use "chamilo_user_id" to use internal id
	 * @param string User id value
	 * @param int Set to 1 to subscribe, 0 to unsubscribe
	 * @param int Status (STUDENT or TEACHER) Used for subscription only
	 * @return mixed True if subscription or unsubscription was successful, false otherwise
	 */
	protected function changeUserSubscription($course_id_field_name, $course_id_value, $user_id_field_name, $user_id_value, $state, $status = STUDENT) {
		$course_id = $this->getCourseId($course_id_field_name, $course_id_value);
		if($course_id instanceof WSError) {
			return $course_id;
		} else {
			$user_id = $this->getUserId($user_id_field_name, $user_id_value);
			if($user_id instanceof WSError) {
				return $user_id;
			} else {
				$course_code = CourseManager::get_course_code_from_course_id($course_id);
				if($state == 0) {
					// Unsubscribe user
					CourseManager::unsubscribe_user($user_id, $course_code);
					return true;
				} else {
					// Subscribe user
					if(CourseManager::subscribe_user($user_id, $course_code, $status)) {
						return true;
					} else {
						return new WSError(203, 'An error occured subscribing to this course');
					}
				}
			}
		}
	}

	/**
	 * Subscribe user to a course
	 *
	 * @param string API secret key
	 * @param string Course id field name. Use "chamilo_course_id" to use internal id
	 * @param string Course id value.
	 * @param string User id field name. Use "chamilo_user_id" to use internal id
	 * @param string User id value
	 * @param int Status (1 = Teacher, 5 = Student)
	 */
	public function SubscribeUserToCourse($secret_key, $course_id_field_name, $course_id_value, $user_id_field_name, $user_id_value, $status) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$result = $this->changeUserSubscription($course_id_field_name, $course_id_value, $user_id_field_name, $user_id_value, 1, $status);
			if($result instanceof WSError) {
				$this->handleError($result);
			}
		}
	}

	/**
	 * Unsusbscribe user from course
	 *
	 * @param string API secret key
	 * @param string Course id field name. Use "chamilo_course_id" to use internal id
	 * @param string Course id value.
	 * @param string User id field name. Use "chamilo_user_id" to use internal id
	 * @param string User id value
	 */
	public function UnsubscribeUserFromCourse($secret_key, $course_id_field_name, $course_id_value, $user_id_field_name, $user_id_value) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$result = $this->changeUserSubscription($course_id_field_name, $course_id_value, $user_id_field_name, $user_id_value, 0);
			if($result instanceof WSError) {
				$this->handleError($result);
			}
		}
	}

	/**
	 * Returns the descriptions of a course, along with their id
	 *
	 * @param string API secret key
	 * @param string Course id field name
	 * @param string Course id value
	 * @return array Returns an array with elements of the form ('course_desc_id' => 1, 'course_desc_title' => 'Title', 'course_desc_content' => 'Content')
	 */
	public function GetCourseDescriptions($secret_key, $course_id_field_name, $course_id_value) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$course_id = $this->getCourseId($course_id_field_name, $course_id_value);
			if($course_id instanceof WSError) {
				return $course_id;
			} else {
				// Course exists, get its descriptions
				$descriptions = CourseDescription::get_descriptions($course_id);
				$results = array();
				foreach($descriptions as $description) {
					$results[] = array('course_desc_id' => $description->get_description_type(),
										'course_desc_title' => $description->get_title(),
										'course_desc_content' => $description->get_content());
				}
				return $results;
			}
		}
	}


	/**
	 * Edit course description
	 *
	 * @param string API secret key
	 * @param string Course id field name
	 * @param string Course id value
	 * @param int Category id from course description
	 * @param string Description title
	 * @param string Course description content
	 */
	public function EditCourseDescription($secret_key, $course_id_field_name, $course_id_value, $course_desc_id, $course_desc_title, $course_desc_content) {
		$verifKey = $this->verifyKey($secret_key);
		if($verifKey instanceof WSError) {
			$this->handleError($verifKey);
		} else {
			$course_id = $this->getCourseId($course_id_field_name, $course_id_value);
			if($course_id instanceof WSError) {
				return $course_id;
			} else {
				// Create the new course description
				$cd = new CourseDescription();
				$cd->set_description_type($course_desc_id);
				$cd->set_title($course_desc_title);
				$cd->set_content($course_desc_content);
				$cd->set_session_id(0);
				// Get course info
				$course_info = CourseManager::get_course_information(CourseManager::get_course_code_from_course_id($course_id));
                $cd->set_course_id($course_info['real_id']);
				// Check if this course description exists
				$descriptions = CourseDescription::get_descriptions($course_id);
				$exists = false;
				foreach($descriptions as $description) {
					if($description->get_description_type() == $course_desc_id) {
						$exists = true;
					}
				}
				if (!$exists) {
					$cd->set_progress(0);
					$cd->insert();
				} else {
					$cd->update();
				}
			}
		}
	}
}