<?php
/**
 * Plugin settings.
 *
 * @package PageSpeedBenchmark
 */

namespace PageSpeedBenchmark;

defined( 'ABSPATH' ) || exit;

/**
 * Reads, validates and saves settings (one non-autoloaded option).
 */
class Settings {

	const OPTION = 'psbench_settings';

	/**
	 * Setting => default.
	 */
	const DEFAULTS = array(
		'enabled'             => true,
		'sample_rate'         => 5,
		'track_ajax'          => true,
		'track_admin'         => false,
		'retention_days'      => 30,
		'slow_threshold_ms'   => 700,
		'detail_threshold_ms' => 300,
		'excluded_paths'      => '',
		'delete_on_uninstall' => false,
	);

	/**
	 * Setting => array( min, max ) for integers.
	 */
	const LIMITS = array(
		'sample_rate'         => array( 1, 1000 ),
		'retention_days'      => array( 1, 365 ),
		'slow_threshold_ms'   => array( 50, 60000 ),
		'detail_threshold_ms' => array( 0, 60000 ),
	);

	/**
	 * Cached settings for the request.
	 *
	 * @var array|null
	 */
	private static ?array $cache = null;

	/**
	 * All settings merged over the defaults.
	 */
	public static function all(): array {
		if ( null === self::$cache ) {
			$stored      = get_option( self::OPTION, array() );
			self::$cache = array_merge( self::DEFAULTS, is_array( $stored ) ? $stored : array() );
		}

		return self::$cache;
	}

	/**
	 * One setting.
	 *
	 * @param string $key Setting name.
	 *
	 * @return mixed
	 */
	public static function get( string $key ) {
		return self::all()[ $key ] ?? null;
	}

	/**
	 * Validate and save settings from user input.
	 *
	 * @param array $input Raw input.
	 *
	 * @return array Saved settings.
	 */
	public static function save( array $input ): array {
		$clean = self::all();
		foreach ( self::DEFAULTS as $key => $default ) {
			if ( ! array_key_exists( $key, $input ) ) {
				continue;
			}
			if ( is_bool( $default ) ) {
				$clean[ $key ] = filter_var( $input[ $key ], FILTER_VALIDATE_BOOLEAN );
			} elseif ( is_int( $default ) ) {
				[ $min, $max ] = self::LIMITS[ $key ];
				$clean[ $key ] = min( $max, max( $min, (int) $input[ $key ] ) );
			} else {
				$clean[ $key ] = sanitize_textarea_field( (string) $input[ $key ] );
			}
		}

		update_option( self::OPTION, $clean, false );
		self::$cache = $clean;

		return $clean;
	}

	/**
	 * Store defaults on first activation.
	 */
	public static function ensure_defaults(): void {
		if ( false === get_option( self::OPTION ) ) {
			add_option( self::OPTION, self::DEFAULTS, '', false );
		}
	}

	/**
	 * Excluded path prefixes, one per line.
	 *
	 * @return string[]
	 */
	public static function excluded_paths(): array {
		return array_values( array_filter( array_map( 'trim', explode( "\n", (string) self::get( 'excluded_paths' ) ) ) ) );
	}
}