<?php
/**
 * Plugin settings with defaults and sanitization.
 *
 * @package Unbreak
 */

namespace Unbreak\Support;

defined( 'ABSPATH' ) || exit;

/**
 * Single option-backed settings store.
 */
final class Settings {

	public const OPTION = 'unbreak_settings';

	/**
	 * Capabilities an administrator may delegate the plugin screen to.
	 */
	public const ALLOWED_CAPABILITIES = array( 'manage_options', 'edit_others_posts', 'publish_posts' );

	/**
	 * Default browser-like User-Agent. Many sites reject obvious bot agents.
	 */
	public const DEFAULT_USER_AGENT = 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0.0.0 Safari/537.36';

	/**
	 * Per-request cache of the merged settings.
	 *
	 * @var array<string,mixed>|null
	 */
	private static $cache = null;

	/**
	 * Default values.
	 *
	 * @return array<string,mixed>
	 */
	public static function defaults(): array {
		return array(
			'check_interval_days' => 7,
			'rate_limit_per_hour' => 600,
			'concurrency'         => 2,
			'sources'             => array(
				'post_content' => true,
				'elementor'    => true,
				'menu'         => true,
				'widget'       => true,
				'comment'      => false,
			),
			'include_images'      => true,
			'user_agent'          => self::DEFAULT_USER_AGENT,
			'extra_allowlist'     => array(),
			'internal_fast_path'  => false,
			'email_digest'        => false,
			'capability'          => 'manage_options',
			'log_404'             => false,
			'redirect_query'      => 'ignore',
			'retention_days'      => 90,
		);
	}

	/**
	 * All settings merged over defaults.
	 *
	 * @return array<string,mixed>
	 */
	public static function all(): array {
		if ( null === self::$cache ) {
			$stored = get_option( self::OPTION, array() );
			if ( ! is_array( $stored ) ) {
				$stored = array();
			}
			$defaults          = self::defaults();
			$merged            = array_merge( $defaults, $stored );
			$merged['sources'] = array_merge( $defaults['sources'], is_array( $merged['sources'] ) ? $merged['sources'] : array() );
			self::$cache       = $merged;
		}
		return self::$cache;
	}

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

	/**
	 * Whether a content source is enabled.
	 *
	 * @param string $source Source type.
	 */
	public static function source_enabled( string $source ): bool {
		$sources = self::get( 'sources' );
		return is_array( $sources ) && ! empty( $sources[ $source ] );
	}

	/**
	 * Sanitize and save a (partial) settings array.
	 *
	 * @param array<string,mixed> $input Raw input.
	 * @return array<string,mixed> The saved settings.
	 */
	public static function update( array $input ): array {
		$clean = self::sanitize( array_merge( self::all(), $input ) );
		update_option( self::OPTION, $clean, true ); // Autoloaded: read on front-end 404s and redirects.
		self::$cache = null;
		return self::all();
	}

	/**
	 * Clear the per-request cache (used after external option changes).
	 */
	public static function flush(): void {
		self::$cache = null;
	}

	/**
	 * Sanitize a full settings array.
	 *
	 * @param array<string,mixed> $in Raw values.
	 * @return array<string,mixed>
	 */
	public static function sanitize( array $in ): array {
		$d   = self::defaults();
		$out = array();

		$out['check_interval_days'] = self::clamp_int( $in['check_interval_days'] ?? $d['check_interval_days'], 1, 30 );
		$out['rate_limit_per_hour'] = self::clamp_int( $in['rate_limit_per_hour'] ?? $d['rate_limit_per_hour'], 10, 20000 );
		$out['concurrency']         = self::clamp_int( $in['concurrency'] ?? $d['concurrency'], 1, 4 );

		$out['sources'] = array();
		$sources_in     = isset( $in['sources'] ) && is_array( $in['sources'] ) ? $in['sources'] : array();
		foreach ( $d['sources'] as $source => $default ) {
			$out['sources'][ $source ] = isset( $sources_in[ $source ] ) ? (bool) $sources_in[ $source ] : (bool) $default;
		}

		$out['include_images']     = (bool) ( $in['include_images'] ?? $d['include_images'] );
		$out['internal_fast_path'] = (bool) ( $in['internal_fast_path'] ?? $d['internal_fast_path'] );
		$out['email_digest']       = (bool) ( $in['email_digest'] ?? $d['email_digest'] );
		$out['log_404']            = (bool) ( $in['log_404'] ?? $d['log_404'] );

		$ua                = sanitize_text_field( (string) ( $in['user_agent'] ?? '' ) );
		$out['user_agent'] = '' !== $ua ? substr( $ua, 0, 500 ) : $d['user_agent'];

		$allow = $in['extra_allowlist'] ?? array();
		if ( is_string( $allow ) ) {
			$allow = preg_split( '/[\s,]+/', $allow );
		}
		$out['extra_allowlist'] = array();
		foreach ( (array) $allow as $host ) {
			$host = strtolower( trim( sanitize_text_field( (string) $host ) ) );
			$host = preg_replace( '#^https?://#', '', $host );
			$host = preg_replace( '#[/:].*$#', '', (string) $host );
			if ( is_string( $host ) && '' !== $host && preg_match( '/^[a-z0-9.*-]+$/', $host ) ) {
				$out['extra_allowlist'][] = $host;
			}
		}
		$out['extra_allowlist'] = array_values( array_unique( $out['extra_allowlist'] ) );

		$cap               = (string) ( $in['capability'] ?? $d['capability'] );
		$out['capability'] = in_array( $cap, self::ALLOWED_CAPABILITIES, true ) ? $cap : $d['capability'];

		$rq                    = (string) ( $in['redirect_query'] ?? $d['redirect_query'] );
		$out['redirect_query'] = in_array( $rq, array( 'ignore', 'exact', 'pass' ), true ) ? $rq : $d['redirect_query'];

		$out['retention_days'] = self::clamp_int( $in['retention_days'] ?? $d['retention_days'], 7, 3650 );

		return $out;
	}

	/**
	 * Integer clamped to a range.
	 *
	 * @param mixed $value Raw value.
	 * @param int   $min   Minimum.
	 * @param int   $max   Maximum.
	 */
	private static function clamp_int( $value, int $min, int $max ): int {
		$value = is_numeric( $value ) ? (int) $value : $min;
		return max( $min, min( $max, $value ) );
	}

	/**
	 * Capability required to use the plugin screen. Filterable.
	 */
	public static function capability(): string {
		$cap = (string) self::get( 'capability' );
		/**
		 * Filters the capability required to use Unbreak's admin screen and REST API.
		 *
		 * @param string $cap Capability name.
		 */
		return (string) apply_filters( 'unbreak_capability', '' !== $cap ? $cap : 'manage_options' );
	}
}