<?php
namespace YahnisElsts\PluginUpdateChecker\v5p1;

if ( !class_exists(StateStore::class, false) ):

	class StateStore {
		/**
		 * @var int Last update check timestamp.
		 */
		protected $lastCheck = 0;

		/**
		 * @var string Version number.
		 */
		protected $checkedVersion = '';

		/**
		 * @var Update|null Cached update.
		 */
		protected $update = null;

		/**
		 * @var string Site option name.
		 */
		private $optionName = '';

		/**
		 * @var bool Whether we've already tried to load the state from the database.
		 */
		private $isLoaded = false;

		public function __construct($optionName) {
			$this->optionName = $optionName;
		}

		/**
		 * Get time elapsed since the last update check.
		 *
		 * If there are no recorded update checks, this method returns a large arbitrary number
		 * (i.e. time since the Unix epoch).
		 *
		 * @return int Elapsed time in seconds.
		 */
		public function timeSinceLastCheck() {
			$this->lazyLoad();
			return time() - $this->lastCheck;
		}

		/**
		 * @return int
		 */
		public function getLastCheck() {
			$this->lazyLoad();
			return $this->lastCheck;
		}

		/**
		 * Set the time of the last update check to the current timestamp.
		 *
		 * @return $this
		 */
		public function setLastCheckToNow() {
			$this->lazyLoad();
			$this->lastCheck = time();
			return $this;
		}

		/**
		 * @return null|Update
		 */
		public function getUpdate() {
			$this->lazyLoad();
			return $this->update;
		}

		/**
		 * @param Update|null $update
		 * @return $this
		 */
		public function setUpdate(Update $update = null) {
			$this->lazyLoad();
			$this->update = $update;
			return $this;
		}

		/**
		 * @return string
		 */
		public function getCheckedVersion() {
			$this->lazyLoad();
			return $this->checkedVersion;
		}

		/**
		 * @param string $version
		 * @return $this
		 */
		public function setCheckedVersion($version) {
			$this->lazyLoad();
			$this->checkedVersion = strval($version);
			return $this;
		}

		/**
		 * Get translation updates.
		 *
		 * @return array
		 */
		public function getTranslations() {
			$this->lazyLoad();
			if ( isset($this->update, $this->update->translations) ) {
				return $this->update->translations;
			}
			return array();
		}

		/**
		 * Set translation updates.
		 *
		 * @param array $translationUpdates
		 */
		public function setTranslations($translationUpdates) {
			$this->lazyLoad();
			if ( isset($this->update) ) {
				$this->update->translations = $translationUpdates;
				$this->save();
			}
		}

		public function save() {
			$state = new \stdClass();

			$state->lastCheck = $this->lastCheck;
			$state->checkedVersion = $this->checkedVersion;

			if ( isset($this->update)) {
				$state->update = $this->update->toStdClass();

				$updateClass = get_class($this->update);
				$state->updateClass = $updateClass;
				$prefix = $this->getLibPrefix();
				if ( Utils::startsWith($updateClass, $prefix) ) {
					$state->updateBaseClass = substr($updateClass, strlen($prefix));
				}
			}

			update_site_option($this->optionName, $state);
			$this->isLoaded = true;
		}

		/**
		 * @return $this
		 */
		public function lazyLoad() {
			if ( !$this->isLoaded ) {
				$this->load();
			}
			return $this;
		}

		protected function load() {
			$this->isLoaded = true;

			$state = get_site_option($this->optionName, null);

			if (
				!is_object($state)
				//Sanity check: If the Utils class is missing, the plugin is probably in the process
				//of being deleted (e.g. the old version gets deleted during an update).
				|| !class_exists(Utils::class)
			) {
				$this->lastCheck = 0;
				$this->checkedVersion = '';
				$this->update = null;
				return;
			}

			$this->lastCheck = intval(Utils::get($state, 'lastCheck', 0));
			$this->checkedVersion = Utils::get($state, 'checkedVersion', '');
			$this->update = null;

			if ( isset($state->update) ) {
				//This mess is due to the fact that the want the update class from this version
				//of the library, not the version that saved the update.

				$updateClass = null;
				if ( isset($state->updateBaseClass) ) {
					$updateClass = $this->getLibPrefix() . $state->updateBaseClass;
				} else if ( isset($state->updateClass) ) {
					$updateClass = $state->updateClass;
				}

				$factory = array($updateClass, 'fromObject');
				if ( ($updateClass !== null) && is_callable($factory) ) {
					$this->update = call_user_func($factory, $state->update);
				}
			}
		}

		public function delete() {
			delete_site_option($this->optionName);

			$this->lastCheck = 0;
			$this->checkedVersion = '';
			$this->update = null;
		}

		private function getLibPrefix() {
			//This assumes that the current class is at the top of the versioned namespace.
			return __NAMESPACE__ . '\\';
		}
	}

endif;