<?php
/**
 * Stored settings and validation helpers.
 *
 * @package Clvrly
 */

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

/**
 * Reads, sanitises and validates the plugin's single option.
 */
class Clvrly_Settings {

	/**
	 * Post meta key for the per-page "hide the assistant" toggle.
	 */
	const HIDE_META = '_clvrly_hide';

	/**
	 * Default values for every setting.
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			'token'        => '',
			'enabled'      => 1,
			'audience'     => 'everyone', // 'everyone' or 'logged_out'.
			'excluded_ids' => '',
		);
	}

	/**
	 * Current settings merged over the defaults.
	 *
	 * @return array
	 */
	public static function get() {
		$saved = get_option( CLVRLY_OPTION, array() );
		return wp_parse_args( is_array( $saved ) ? $saved : array(), self::defaults() );
	}

	/**
	 * Whether the token is set in wp-config.php with the CLVRLY_TOKEN constant.
	 *
	 * @return bool
	 */
	public static function token_is_constant() {
		return defined( 'CLVRLY_TOKEN' ) && self::is_valid_token( CLVRLY_TOKEN );
	}

	/**
	 * The token in use: the CLVRLY_TOKEN constant if set, otherwise the saved one.
	 *
	 * @return string
	 */
	public static function token() {
		if ( self::token_is_constant() ) {
			return strtolower( CLVRLY_TOKEN );
		}
		$settings = self::get();
		return self::is_valid_token( $settings['token'] ) ? $settings['token'] : '';
	}

	/**
	 * Whether a valid token is available.
	 *
	 * @return bool
	 */
	public static function has_token() {
		return '' !== self::token();
	}

	/**
	 * Whether the assistant is switched on (it may still be hidden on some pages).
	 *
	 * @return bool
	 */
	public static function is_enabled() {
		$settings = self::get();
		return ! empty( $settings['enabled'] );
	}

	/**
	 * Clvrly tokens are hex strings (32 or 64 characters).
	 *
	 * @param string $token Token to check.
	 * @return bool
	 */
	public static function is_valid_token( $token ) {
		return (bool) preg_match( '/^[a-f0-9]{32,64}$/i', (string) $token );
	}

	/**
	 * Pull a token out of whatever was pasted: the bare token, or the whole install snippet.
	 *
	 * @param string $raw Raw input.
	 * @return string Token (lower case), or the trimmed input if no token was found.
	 */
	public static function extract_token( $raw ) {
		$raw = trim( (string) $raw );

		if ( preg_match( '/data-token\s*=\s*["\']?([a-f0-9]{32,64})/i', $raw, $m ) ) {
			return strtolower( $m[1] );
		}

		$bare = trim( $raw, " \t\n\r\0\x0B\"'" );
		return self::is_valid_token( $bare ) ? strtolower( $bare ) : $raw;
	}

	/**
	 * Turns "12, 40,abc,40" into array( 12, 40 ).
	 *
	 * @param string $value Comma-separated IDs.
	 * @return int[]
	 */
	public static function parse_ids( $value ) {
		$ids = array_map( 'absint', explode( ',', (string) $value ) );
		return array_values( array_unique( array_filter( $ids ) ) );
	}

	/**
	 * Whether the assistant is hidden on a given post, by ID list or by the editor toggle.
	 *
	 * @param int $post_id Post ID.
	 * @return bool
	 */
	public static function is_hidden_on( $post_id ) {
		$post_id = (int) $post_id;
		if ( ! $post_id ) {
			return false;
		}
		$settings = self::get();
		if ( in_array( $post_id, self::parse_ids( $settings['excluded_ids'] ), true ) ) {
			return true;
		}
		return (bool) get_post_meta( $post_id, self::HIDE_META, true );
	}

	/**
	 * Sanitise callback for register_setting().
	 *
	 * @param mixed $input Raw form input.
	 * @return array
	 */
	public static function sanitize( $input ) {
		$current = self::get();
		$input   = is_array( $input ) ? $input : array();
		$clean   = self::defaults();

		if ( ! array_key_exists( 'token', $input ) ) {
			// Token field not submitted (it is read-only when CLVRLY_TOKEN is set).
			$clean['token'] = $current['token'];
		} else {
			$token = self::extract_token( $input['token'] );
			$token = strtolower( sanitize_text_field( $token ) );

			if ( '' === $token || self::is_valid_token( $token ) ) {
				$clean['token'] = $token;
			} else {
				// Keep the previous token rather than saving a broken one.
				$clean['token'] = $current['token'];
				add_settings_error(
					CLVRLY_OPTION,
					'clvrly_invalid_token',
					__( 'That token doesn\'t look right. Copy it again from "Your Embed Code" in your Clvrly portal. You can paste the token on its own or the whole install snippet.', 'clvrly' )
				);
			}
		}

		$clean['enabled']      = empty( $input['enabled'] ) ? 0 : 1;
		$clean['audience']     = ( isset( $input['audience'] ) && 'logged_out' === $input['audience'] ) ? 'logged_out' : 'everyone';
		$clean['excluded_ids'] = implode( ', ', self::parse_ids( isset( $input['excluded_ids'] ) ? $input['excluded_ids'] : '' ) );

		return $clean;
	}
}