<?php
namespace ILJ\Cache;

class Transient_Cache {

	const CACHE_PREFIX = 'ilj_filtered_content';
	const TRANSIENT_PREFIX = '_transient_';

	/**
	 * Set the cache.
	 *
	 * @param string $key   The cache key.
	 * @param string $value The cache value.
	 * @return void
	 */
	private static function set(string $key, string $value) {
		set_transient($key, $value, DAY_IN_SECONDS);
	}

	/**
	 * Delete all cache.
	 *
	 * @return void
	 */
	public static function delete_all() {
		global $wpdb;
		// phpcs:disable WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- We need to use a direct query here.
		$wpdb->query(
			$wpdb->prepare(
				"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
				$wpdb->esc_like(self::TRANSIENT_PREFIX . self::CACHE_PREFIX) . '%'
			)
		);
	}

	/**
	 * Delete cache for the supplied params.
	 *
	 * @param int    $id   The post/term id.
	 * @param string $type One of types 'post', 'term', 'post_meta', 'term_meta'
	 * @return string|false
	 */
	public static function delete_cache_for_content($id, $type) {
		global $wpdb;
		$key = self::build_cache_key($id, $type);
		$wpdb->query(
			$wpdb->prepare(
				"DELETE FROM {$wpdb->options} WHERE option_name LIKE %s",
				$wpdb->esc_like(self::TRANSIENT_PREFIX . $key) . '%'
			)
		);
	}

	/**
	 * Get the cache value.
	 *
	 * @param string $key
	 * @return string | false
	 */
	private static function get(string $key) {
		return get_transient($key);
	}

	/**
	 * Build cache key from the supplied parameters.
	 *
	 * @param int    $id            The post/term id.
	 * @param string $type          One of types 'post', 'term', 'post_meta', 'term_meta'
	 * @param string $input_content The input content.
	 * @return string
	 */
	private static function build_cache_key_for_content($id, $type, $input_content): string {
		return sprintf('%s_%d_%s_%s', self::CACHE_PREFIX, $id, $type, md5($input_content));
	}

	/**
	 * Build cache key from the supplied parameters.
	 *
	 * @param int    $id   The post/term id.
	 * @param string $type One of types 'post', 'term', 'post_meta', 'term_meta'
	 * @return string
	 */
	private static function build_cache_key($id, $type): string {
		return sprintf('%s_%d_%s', self::CACHE_PREFIX, $id, $type);
	}

	/**
	 * Set cache for the supplied parameters.
	 *
	 * @param int    $id     The post/term id.
	 * @param string $type   One of types 'post', 'term', 'post_meta', 'term_meta'
	 * @param string $input  The input content before linking, this will be hashed for generating cache key
	 * @param string $output The output content after linking.
	 * @return void
	 */
	public static function set_cache_for_content($id, $type, $input, $output) {
		self::set(self::build_cache_key_for_content($id, $type, $input), $output);
	}

	/**
	 * Get cache for the supplied params.
	 *
	 * @param int    $id            The post/term id.
	 * @param string $type          One of types 'post', 'term', 'post_meta', 'term_meta'
	 * @param string $input_content The input content.
	 * @return string|false
	 */
	public static function get_cache_for_content($id, $type, $input_content) {
		return self::get(self::build_cache_key_for_content($id, $type, $input_content));
	}
}