<?php
/**
 * Settings and secrets.
 *
 * @package AJSM
 */

namespace AJSM;

defined( 'ABSPATH' ) || exit;

/**
 * Option access with wp-config constant overrides.
 */
class Options {

	const KEY     = 'ajsm_settings';
	const SECRETS = 'ajsm_secrets';
	const ERRORS  = 'ajsm_errors';

	/**
	 * Defaults.
	 *
	 * @return array
	 */
	public static function defaults() {
		return array(
			'mailer'           => 'php',
			'from_email'       => '',
			'force_from_email' => 1,
			'from_name'        => '',
			'force_from_name'  => 0,
			'return_path'      => 1,
			'reply_to'         => '',
			'smtp_host'        => '',
			'smtp_port'        => 465,
			'smtp_encryption'  => 'ssl',
			'smtp_autotls'     => 1,
			'smtp_auth'        => 1,
			'smtp_user'        => '',
			'uninstall_delete' => 0,
		);
	}

	/**
	 * Map of setting => constant name.
	 *
	 * @return array
	 */
	public static function constant_map() {
		return apply_filters(
			'ajsm_constant_map',
			array(
				'mailer'          => 'AJSM_MAILER',
				'from_email'      => 'AJSM_FROM_EMAIL',
				'from_name'       => 'AJSM_FROM_NAME',
				'reply_to'        => 'AJSM_REPLY_TO',
				'smtp_host'       => 'AJSM_SMTP_HOST',
				'smtp_port'       => 'AJSM_SMTP_PORT',
				'smtp_encryption' => 'AJSM_SMTP_ENCRYPTION',
				'smtp_auth'       => 'AJSM_SMTP_AUTH',
				'smtp_user'       => 'AJSM_SMTP_USER',
				'smtp_pass'       => 'AJSM_SMTP_PASS',
			)
		);
	}

	/**
	 * Constant name for a key if defined.
	 *
	 * @param string $key Setting key.
	 * @return string Constant name or ''.
	 */
	public static function constant_for( $key ) {
		$map  = self::constant_map();
		$name = isset( $map[ $key ] ) ? $map[ $key ] : 'AJSM_' . strtoupper( $key );
		return defined( $name ) ? $name : '';
	}

	/**
	 * Raw saved settings merged with defaults (no constants).
	 *
	 * @return array
	 */
	public static function saved() {
		$s = get_option( self::KEY, array() );
		return array_merge( self::defaults(), apply_filters( 'ajsm_default_settings', array() ), is_array( $s ) ? $s : array() );
	}

	/**
	 * All settings with constants applied.
	 *
	 * @return array
	 */
	public static function all() {
		$s = self::saved();
		foreach ( array_keys( $s ) as $k ) {
			$c = self::constant_for( $k );
			if ( $c ) {
				$s[ $k ] = constant( $c );
			}
		}
		if ( defined( 'AJSM_ON' ) && ! AJSM_ON ) {
			$s['mailer'] = 'php';
		}
		return $s;
	}

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

	/**
	 * Save settings.
	 *
	 * @param array $values Clean values.
	 * @return bool
	 */
	public static function update( array $values ) {
		$new = array_merge( self::saved(), $values );
		if ( get_option( self::KEY ) === $new ) {
			return true;
		}
		return update_option( self::KEY, $new, true );
	}

	/**
	 * Secret field keys (free + add-ons).
	 *
	 * @return string[]
	 */
	public static function secret_keys() {
		return (array) apply_filters( 'ajsm_secret_keys', array( 'smtp_pass' ) );
	}

	/**
	 * Decrypted secret, constant first.
	 *
	 * @param string $key Key.
	 * @return string
	 */
	public static function secret( $key ) {
		$c = self::constant_for( $key );
		if ( $c ) {
			return (string) constant( $c );
		}
		$all = get_option( self::SECRETS, array() );
		return isset( $all[ $key ] ) ? Crypto::decrypt( $all[ $key ] ) : '';
	}

	/**
	 * Whether a secret is stored or defined.
	 *
	 * @param string $key Key.
	 * @return bool
	 */
	public static function has_secret( $key ) {
		if ( self::constant_for( $key ) ) {
			return true;
		}
		$all = get_option( self::SECRETS, array() );
		return ! empty( $all[ $key ] );
	}

	/**
	 * Store (or clear with '') a secret.
	 *
	 * @param string $key Key.
	 * @param string $value Plain value.
	 * @return bool
	 */
	public static function set_secret( $key, $value ) {
		$all = get_option( self::SECRETS, array() );
		$all = is_array( $all ) ? $all : array();
		if ( '' === (string) $value ) {
			unset( $all[ $key ] );
		} else {
			$enc = Crypto::encrypt( $value );
			if ( '' === $enc ) {
				return false;
			}
			$all[ $key ] = $enc;
		}
		if ( get_option( self::SECRETS, null ) === null ) {
			return add_option( self::SECRETS, $all, '', false );
		}
		if ( get_option( self::SECRETS ) === $all ) {
			return true;
		}
		return update_option( self::SECRETS, $all, false );
	}

	/**
	 * All secret plain values, for masking.
	 *
	 * @return string[]
	 */
	public static function secret_values() {
		$out = array();
		foreach ( self::secret_keys() as $k ) {
			$v = self::secret( $k );
			if ( strlen( $v ) >= 3 ) {
				$out[] = $v;
			}
		}
		return $out;
	}

	/**
	 * Replace any secret (plain or base64 forms) with ****.
	 *
	 * @param string $text Text.
	 * @return string
	 */
	public static function mask( $text ) {
		$text = (string) $text;
		$user = (string) self::get( 'smtp_user', '' );
		foreach ( self::secret_values() as $v ) {
			// phpcs:disable WordPress.PHP.DiscouragedPHPFunctions.obfuscation_base64_encode -- masking the encoded forms SMTP AUTH uses.
			$forms = array( $v, base64_encode( $v ), base64_encode( "\0" . $user . "\0" . $v ), base64_encode( $user . "\0" . $user . "\0" . $v ) );
			// phpcs:enable
			foreach ( $forms as $f ) {
				$text = str_replace( $f, '********', $text );
			}
		}
		return $text;
	}

	/**
	 * Record an error (last 20).
	 *
	 * @param string $message Message.
	 * @param array  $context to/subject/mailer.
	 */
	public static function log_error( $message, array $context = array() ) {
		$list = get_option( self::ERRORS, array() );
		$list = is_array( $list ) ? $list : array();
		array_unshift(
			$list,
			array(
				'time'    => time(),
				'message' => self::mask( wp_strip_all_tags( (string) $message ) ),
				'to'      => isset( $context['to'] ) ? sanitize_text_field( implode( ', ', (array) $context['to'] ) ) : '',
				'subject' => isset( $context['subject'] ) ? sanitize_text_field( (string) $context['subject'] ) : '',
				'mailer'  => isset( $context['mailer'] ) ? sanitize_key( $context['mailer'] ) : '',
			)
		);
		$list = array_slice( $list, 0, 20 );
		if ( false === get_option( self::ERRORS, false ) ) {
			add_option( self::ERRORS, $list, '', false );
		} else {
			update_option( self::ERRORS, $list, false );
		}
	}

	/**
	 * Recent errors.
	 *
	 * @return array
	 */
	public static function errors() {
		$l = get_option( self::ERRORS, array() );
		return is_array( $l ) ? $l : array();
	}
}