<?php
/**
 * Thrive Themes - https://thrivethemes.com
 *
 * @package thrive-dashboard
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Silence is golden
}

class TD_DB_Manager {

	/**
	 * Array of instances for each products
	 *
	 * @var TD_DB_Manager[]
	 */
	protected static $_instances = array();

	/**
	 * Path to migrations folder
	 *
	 * @var string path
	 */
	protected $_migrations_path;

	/**
	 * Version to which this class should run the migrations
	 *
	 * @var string
	 */
	protected $_required_version;

	/**
	 * Current version of DB; stored in wp_option
	 *
	 * @var string
	 */
	protected $_current_version;

	/**
	 * Option name which holds the version of DB
	 *
	 * @var string
	 */
	protected $_option_name;

	/**
	 * Product name to be included in the error message
	 *
	 * @var string
	 */
	protected $_product_name;

	/**
	 * Prefix to be used for tables
	 *
	 * @var string
	 */
	protected $_table_prefix;

	/**
	 * Reset option parameter name
	 *
	 * @var string
	 */
	protected $_reset_option_param = '';

	/**
	 * Holder for DB error
	 *
	 * @var string
	 */
	protected $_last_db_error;

	/**
	 * TD_DB_Manager constructor.
	 *
	 * @param string $path
	 * @param string $option_name
	 * @param string $required_version
	 * @param string $product_name
	 * @param string $table_prefix
	 * @param string $reset_option_param
	 *
	 * @throws Exception
	 */
	public function __construct( $path, $option_name, $required_version, $product_name = '', $table_prefix = '', $reset_option_param = '' ) {

		if ( is_dir( $path ) === false ) {
			throw new Exception( 'Path to migrations is invalid' );
		}

		if ( strpos( $option_name, '_db' ) !== false ) {
			$this->_option_name = $option_name;
		} else {
			throw new Exception( 'Unknown option name' );
		}

		$this->_migrations_path = trailingslashit( $path );
		$this->_required_version   = $required_version;
		$this->_current_version    = $this->_get_current_version();
		$this->_product_name       = $product_name;
		$this->_table_prefix       = $table_prefix;
		$this->_reset_option_param = $reset_option_param ? $reset_option_param : ( $this->_option_name . '_reset' );
	}

	protected function _get_current_version( $default = '0.0' ) {
		$this->_current_version = get_option( $this->_option_name, $default );

		return $this->_current_version;
	}

	/**
	 * Reset the wp_option so that all the migrations will run again at next check()
	 *
	 * @return bool
	 */
	protected function _reset() {

		$this->_current_version = '0.0';

		return delete_option( $this->_option_name );
	}

	protected function _update( $value ) {

		$this->_current_version = $value;

		return update_option( $this->_option_name, $value );
	}

	/**
	 * Compare the current db version with the required version and
	 * Runs all the scrips from current version until the required version
	 */
	public function check() {

		if ( is_admin() && ! empty( $_REQUEST[ $this->_reset_option_param ] ) ) {
			$this->_reset();
		}

		if ( version_compare( $this->_current_version, $this->_required_version, '<' ) ) {

			$scripts = $this->_get_scripts( $this->_current_version, $this->_required_version );

			if ( ! empty( $scripts ) ) {
				! defined( 'THRIVE_DB_UPGRADING' ) ? define( 'THRIVE_DB_UPGRADING', true ) : null;
			}

			/** @var $wpdb wpdb */
			global $wpdb;

			/**
			 * We only want to hide the errors not suppress them
			 * in case we need to log them somewhere
			 */
			$wpdb->hide_errors();
			$has_error = false;

			foreach ( $scripts as $file_path ) {
				$migration = new TD_DB_Migration( $this->_table_prefix, $file_path );
				$has_error = $migration->run() === false;

				if ( $has_error ) {
					/* ERROR: we don't change the DB version option and notify the user about the last error */
					break;
				}
			}

			if ( $has_error ) {
				$this->_last_db_error = $wpdb->last_error;
				add_action( 'admin_notices', array( $this, 'display_admin_error' ) );
			} else {
				$this->_update( $this->_required_version );
			}

			do_action( 'tve_after_db_migration', $this->_option_name );
		}
	}

	/**
	 * Get all DB update scripts from $from_version to $to_version.
	 *
	 * @param string $from_version from version.
	 * @param string $to_version   to version.
	 *
	 * @return array
	 */
	protected function _get_scripts( $from_version, $to_version ) {

		$scripts = array();
		$dir     = new DirectoryIterator( $this->_migrations_path );

		foreach ( $dir as $file ) {
			/**
			 * DirectoryIterator
			 *
			 * @var $file
			 */
			if ( $file->isDot() ) {
				continue;
			}
			$script_version = $this->_get_script_version( $file->getFilename() );
			if ( empty( $script_version ) ) {
				continue;
			}
			if ( version_compare( $script_version, $from_version, '>' ) && version_compare(
				$script_version, $to_version, '<=' ) ) {
                $script_key = $this->_generate_script_key( $script_version, $scripts );
				$scripts[ $script_key ] = $file->getPathname();
			}
		}

		/**
		 * Sort the scripts in the correct version order
		 */
		uksort( $scripts, 'version_compare' );

		return $scripts;
	}

    /**
     * Generate a key for script if there is multiple migration file name with same version.
     *
     * @param string $script_version migration file name's version.
     * @param array $scripts  list of scripts.
     *
     * @return string
     */
    protected function _generate_script_key( $script_version, $scripts ) {
        if ( ! isset( $scripts[ $script_version ] ) ) {
            return $script_version;
        }

        return $script_version . '.0';
    }

	/**
	 * Parse the script_ame and returns its version
	 *
	 * @param string $script_name in the following format {name}-{[\d+].[\d+]}.php.
	 *
	 * @return string
	 */
	protected function _get_script_version( $script_name ) {

		if ( ! preg_match( '/(.+?)-(\d+)\.(\d+)(.\d+)?\.php/', $script_name, $m ) ) {
			return false;
		}

		return $m[2] . '.' . $m[3] . ( ! empty( $m[4] ) ? $m[4] : '' );
	}

	/**
	 * Display a WP Notification with last db error
	 */
	public function display_admin_error() {

		if ( ! $this->_last_db_error ) {
			return;
		}

		// @codingStandardsIgnoreStart
		echo '<div class="notice notice-error is-dismissible"><p>' .
		     sprintf(
			     __( 'There was an error while updating the database tables%s. Detailed error message: %s. If you continue seeing this message, please contact %s', 'thrive-dash' ),
			     $this->_product_name ? " ({$this->_product_name})" : '',
			     '<strong>' . $this->_last_db_error . '</strong>',
			     '<a target="_blank" href="https://thrivethemes.com/forums/">' . __( 'Thrive Themes Support', 'thrive-dash' ) . '</a>'
		     ) .
		     '</p></div>';
		// @codingStandardsIgnoreEnd
	}

	/**
	 * Collect all thrive db managers
	 * Each plugin should hook into the 'thrive_prepare_migrations' hook
	 */
	public static function collect_migration_managers() {
		/**
		 * Action hook.
		 * Executed during the WP 'init' hook
		 *
		 * @since 2.0.49
		 */
		try {
			do_action( 'thrive_prepare_migrations' );
		} catch ( Exception $exception ) {
			/* do nothing for now. better safe than sorry. each plugin should catch errors */
		}

		foreach ( static::$_instances as $instance ) {
			$instance->check();
		}
	}

	/**
	 * @param string $path               Path to the migrations folder
	 * @param string $option_name        db wp_options table option name
	 * @param string $required_version   version to check against
	 * @param string $product_name       optional, a string used to display a nice product name to the user in case of errors
	 * @param string $table_prefix       optional, table prefix - can be used inside the migration file to automatically prepend it to table names
	 * @param string $reset_option_param query parameter name for resetting the option holding the version
	 *
	 * @throws Exception
	 */
	public static function add_manager( $path, $option_name, $required_version, $product_name = '', $table_prefix = '', $reset_option_param = '' ) {
		static::$_instances [] = new static( $path, $option_name, $required_version, $product_name, $table_prefix, $reset_option_param );
	}
}