<?php
/**
 * Server-side management API credentials for the WordPress dashboard.
 *
 * The public tracking key stays in Causewise_Settings. This option is separate
 * so the tracker cannot read or print the management key.
 *
 * @package CauseWise_Analytics
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Stores the management API key and optional site ID.
 */
class Causewise_Credentials {
	const OPTION_NAME = 'causewise_analytics_api';

	/**
	 * Register the option.
	 */
	public static function init() {
		add_action( 'admin_init', array( __CLASS__, 'register_setting' ) );
		add_action( 'add_option_' . self::OPTION_NAME, array( __CLASS__, 'disable_autoload' ) );
		add_action( 'update_option_' . self::OPTION_NAME, array( __CLASS__, 'disable_autoload' ) );
	}

	/**
	 * Keep the management key off the autoloaded options cache.
	 */
	public static function disable_autoload() {
		if ( ! isset( $GLOBALS['wpdb'] ) || ! is_object( $GLOBALS['wpdb'] ) ) {
			return;
		}

		$wpdb = $GLOBALS['wpdb'];
		if ( empty( $wpdb->options ) || ! method_exists( $wpdb, 'update' ) ) {
			return;
		}

		$wpdb->update( // phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery -- Sets autoload without rewriting the stored key.
			$wpdb->options,
			array( 'autoload' => 'no' ),
			array( 'option_name' => self::OPTION_NAME )
		);

		if ( function_exists( 'wp_cache_delete' ) ) {
			wp_cache_delete( 'alloptions', 'options' );
		}
	}

	/**
	 * Register with the same settings group as the tracking option.
	 */
	public static function register_setting() {
		register_setting(
			Causewise_Settings::OPTION_GROUP,
			self::OPTION_NAME,
			array(
				'type'              => 'array',
				'sanitize_callback' => array( __CLASS__, 'sanitize' ),
				'default'           => self::defaults(),
				'show_in_rest'      => false,
			)
		);
	}

	/**
	 * Default stored values. The key is empty until an administrator saves one.
	 *
	 * @return array{api_key: string, site_id: string}
	 */
	public static function defaults() {
		return array(
			'api_key' => '',
			'site_id' => '',
		);
	}

	/**
	 * Saved credentials. Call this only from server-side dashboard code.
	 *
	 * @return array{api_key: string, site_id: string}
	 */
	public static function get() {
		$stored = get_option( self::OPTION_NAME, array() );
		if ( ! is_array( $stored ) ) {
			$stored = array();
		}

		$settings = array_merge( self::defaults(), $stored );
		$api_key  = self::normalize_api_key( $settings['api_key'] );
		$site_id  = self::normalize_site_id( $settings['site_id'] );

		return array(
			'api_key' => self::is_valid_api_key( $api_key ) ? $api_key : '',
			'site_id' => self::is_valid_site_id( $site_id ) ? $site_id : '',
		);
	}

	/**
	 * Whether a management key is stored.
	 *
	 * @return bool
	 */
	public static function has_api_key() {
		$credentials = self::get();
		return '' !== $credentials['api_key'];
	}

	/**
	 * Remove whitespace from a pasted key.
	 *
	 * @param mixed $key Raw value.
	 * @return string
	 */
	public static function normalize_api_key( $key ) {
		$key = preg_replace( '/\s+/', '', (string) $key );
		if ( ! is_string( $key ) ) {
			return '';
		}
		return $key;
	}

	/**
	 * Management keys are cw_api_ plus a base64url secret.
	 *
	 * @param mixed $key Candidate.
	 * @return bool
	 */
	public static function is_valid_api_key( $key ) {
		return 1 === preg_match( '/^cw_api_[A-Za-z0-9_-]{10,200}$/', self::normalize_api_key( $key ) );
	}

	/**
	 * Trim a site ID.
	 *
	 * @param mixed $site_id Raw value.
	 * @return string
	 */
	public static function normalize_site_id( $site_id ) {
		return trim( (string) $site_id );
	}

	/**
	 * Site IDs are opaque URL-safe identifiers, not tracking or API keys.
	 *
	 * @param mixed $site_id Candidate.
	 * @return bool
	 */
	public static function is_valid_site_id( $site_id ) {
		$site_id = self::normalize_site_id( $site_id );
		if ( '' === $site_id ) {
			return false;
		}
		if ( 0 === strpos( $site_id, 'cw_' ) ) {
			return false;
		}
		return 1 === preg_match( '/^[A-Za-z0-9_-]{8,64}$/', $site_id );
	}

	/**
	 * Sanitize the dashboard credential form.
	 *
	 * An empty key field keeps the stored key. The clear checkbox removes it.
	 * Invalid values are not written.
	 *
	 * @param mixed $input Posted value.
	 * @return array{api_key: string, site_id: string}
	 */
	public static function sanitize( $input ) {
		$previous = self::get();

		if ( ! current_user_can( Causewise_Settings::CAPABILITY ) ) {
			return $previous;
		}

		if ( ! is_array( $input ) ) {
			return $previous;
		}

		$api_key = $previous['api_key'];
		if ( ! empty( $input['clear_api_key'] ) ) {
			$api_key = '';
		} else {
			$posted = self::normalize_api_key( isset( $input['api_key'] ) ? wp_unslash( $input['api_key'] ) : '' );
			if ( '' !== $posted ) {
				if ( self::is_valid_api_key( $posted ) ) {
					$api_key = $posted;
				} else {
					add_settings_error(
						self::OPTION_NAME,
						'causewise_invalid_api_key',
						__( 'Enter the management API key from CauseWise. The public tracking key cannot show analytics in WordPress.', 'causewise-analytics' ),
						'error'
					);
				}
			}
		}

		$site_id = $previous['site_id'];
		if ( array_key_exists( 'site_id', $input ) ) {
			$posted_site = self::normalize_site_id( wp_unslash( $input['site_id'] ) );
			if ( '' === $posted_site ) {
				$site_id = '';
			} elseif ( self::is_valid_site_id( $posted_site ) ) {
				$site_id = $posted_site;
			} else {
				add_settings_error(
					self::OPTION_NAME,
					'causewise_invalid_site_id',
					__( 'Enter the site ID from CauseWise, or leave it blank.', 'causewise-analytics' ),
					'error'
				);
			}
		}

		return array(
			'api_key' => $api_key,
			'site_id' => $site_id,
		);
	}
}