<?php

/**
 * Secure option storage helper (encrypt-at-rest).
 *
 * @package AfroIT_Messaging_WorkflowAutomations
 */

namespace AfroIT\Messaging\WorkflowAutomations\Security;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class SecureOptions {

	/**
	 * @var string
	 */
	private $option_name = 'afromewo_options';

	/**
	 * @var Encryptor
	 */
	private $encryptor;

    protected $gotten = [];

    private static $instance;

    public static function get_instance() {
        if (self::$instance === null) {
            self::$instance = new self();
        }
        return self::$instance;
    }

	public function __construct() {
		$this->encryptor = new Encryptor();
	}

	/**
	 * Get option value (decrypted).
	 *
	 * @param string $key Key.
	 * @param mixed  $default Default.
	 * @return mixed
	 */
	public function get( $key, $default = null ) {
		if ( isset( $this->gotten[ $key ] ) ) {
			return $this->gotten[ $key ];
		}

		$all = get_option( $this->option_name, array() );
		if ( ! is_array( $all ) || ! array_key_exists( $key, $all ) ) {
			return $default;
		}

		$value = $all[ $key ];
		if ( ! is_string( $value ) ) {
			return $default;
		}

		$decrypted = $this->encryptor->decrypt( $value );
		$this->gotten[ $key ] = $decrypted;
		return $decrypted;
	}

	/**
	 * Set option value (encrypted).
	 *
	 * @param string $key Key.
	 * @param string $value Plain value.
	 * @return void
	 */
	public function set( $key, $value ) {
		$all = get_option( $this->option_name, array() );
		if ( ! is_array( $all ) ) {
			$all = array();
		}

		$all[ $key ] = $this->encryptor->encrypt( (string) $value );
		unset( $this->gotten[ $key ] );
		update_option( $this->option_name, $all, false );
	}

	/**
	 * Set multiple option values (encrypted) from an associative array.
	 *
	 * @param array $pairs Associative array of key => plain value.
	 * @return void
	 */
	public function set_multi( $pairs ) {
		if ( ! is_array( $pairs ) ) {
			return;
		}

		$all = get_option( $this->option_name, array() );
		if ( ! is_array( $all ) ) {
			$all = array();
		}

		foreach ( $pairs as $key => $value ) {
			$all[ $key ] = $this->encryptor->encrypt( (string) $value );
			unset( $this->gotten[ $key ] );
		}

		update_option( $this->option_name, $all, false );
	}

    public function facebook_user_access_token_is_valid() {
        // FIXME: if there is already a valud system user token, return true
        if ( $this->get( 'system_user_token', '' ) ) {
            return true;
        }

        $expires_at = $this->get( 'user_access_token_expires_at', 0 );
        if ( $expires_at < time() ) {
            return false;
        }
        return true;
    }

    public function get_selected_business(): array|null {
        $business = $this->get( 'selected_business', '' );
        if ( $business === '' ) {
            return null;
        }

        $business_parts = explode(',', $business);
        if ( count( $business_parts ) !== 3 ) {
            return null;
        }

        return [
            'business_id' => $business_parts[0],
            'waba_id' => $business_parts[1],
            'phone_id' => $business_parts[2],
        ];
    }

    public function delete($key) {
        $all = get_option( $this->option_name, array() );
        if ( ! is_array( $all ) ) {
            $all = array();
        }
        unset( $all[ $key ], $this->gotten[ $key ] );
        delete_option( $this->option_name );
        add_option( $this->option_name, $all );
    }

    public function delete_all() {
        delete_option( $this->option_name );
    }
}