<?php

class WPBDP__Manual_Upgrade_Helper {

	private $installer;
	private $manual_upgrades = array();
	private $callback;
	private $config_callback = null;

	public function __construct( $installer ) {
		$this->installer = $installer;

		$this->load_manual_upgrades();
		$this->prepare_manual_upgrade_callbacks();

		add_action( 'admin_notices', array( &$this, 'upgrade_required_notice' ) );
		add_action( 'admin_menu', array( &$this, 'add_upgrade_page' ) );
		add_action( 'admin_enqueue_scripts', array( &$this, 'enqueue_scripts' ) );
		add_action( 'wp_ajax_wpbdp-manual-upgrade', array( &$this, 'handle_ajax' ) );
	}

	private function prepare_manual_upgrade_callbacks() {
		$versions = array_keys( $this->manual_upgrades );

		$this->current_version = reset( $versions );
		$this->current_upgrade = reset( $this->manual_upgrades[ $this->current_version ] );

		if ( isset( $this->current_upgrade['callback'] ) ) {
			$this->callback = $this->get_callback( $this->current_upgrade['callback'] );
		} else {
			$this->callback = $this->get_callback( $this->current_upgrade );
		}

		if ( isset( $this->current_upgrade['config_callback'] ) ) {
			$this->config_callback = $this->get_configuration_callback( $this->current_upgrade['config_callback'] );
		} else {
			$this->config_callback = null;
		}
	}

	private function get_callback( $params ) {
		$callback = $this->get_migration_callback( $params );

		if ( ! is_callable( $callback ) ) {
			throw new Exception( 'Invalid upgrade callback provided.' );
		}

		return $callback;
	}

	private function get_migration_callback( $params ) {
		if ( is_array( $params ) ) {
			$classname = $params[0];
			$method    = $params[1];

			$migration = $this->installer->load_migration_class( $classname );

			$callback = array( $migration, $method );
		} else {
			$callback = $params;
		}

		return $callback;
	}

	private function get_configuration_callback( $params ) {
		$callback = $this->get_migration_callback( $params );

		if ( ! is_callable( $callback ) ) {
			throw new Exception( 'Invalid upgrade config callback provided.' );
		}

		return $callback;
	}

	public function upgrade_required_notice() {
		global $pagenow;

		$page = wpbdp_get_var( array( 'param' => 'page' ) );
		if ( in_array( $pagenow, array( 'admin.php', 'edit.php' ) ) && 'wpbdp-upgrade-page' === $page ) {
			return;
		}

		if ( ! wpbdp_user_is_admin() ) {
			return;
		}

		print '<div class="error"><p>';
		print '<strong>' . __( 'Business Directory - Manual Upgrade Required', 'business-directory-plugin' ) . '</strong>';
		print '<br />';
		esc_html_e( 'Business Directory features are currently disabled because the plugin needs to perform a manual upgrade before continuing.', 'business-directory-plugin' );
		print '<br /><br />';
		printf(
			'<a class="button button-primary" href="%s">%s</a>',
			esc_url( admin_url( 'admin.php?page=wpbdp-upgrade-page' ) ),
			esc_html__( 'Perform Manual Upgrade', 'business-directory-plugin' )
		);
		print '</p></div>';
	}

	public function add_upgrade_page() {
		global $submenu;

		// Make "Directory" menu items point to upgrade page.
		$menu_id = 'edit.php?post_type=' . WPBDP_POST_TYPE;
		if ( isset( $submenu[ $menu_id ] ) ) {
			foreach ( $submenu[ $menu_id ] as &$item ) {
				$item[2] = admin_url( 'admin.php?page=wpbdp-upgrade-page' );
			}
		}

		add_submenu_page(
			'options.php',
			__( 'Business Directory - Manual Upgrade', 'business-directory-plugin' ),
			__( 'Business Directory - Manual Upgrade', 'business-directory-plugin' ),
			'manage_options',
			'wpbdp-upgrade-page',
			array( &$this, 'upgrade_page' )
		);
	}

	public function enqueue_scripts() {
		wp_enqueue_style(
			'wpbdp-admin',
			WPBDP_ASSETS_URL . 'css/admin.min.css',
			array(),
			WPBDP_VERSION
		);

		wp_enqueue_style(
			'wpbdp-manual-upgrade-css',
			WPBDP_ASSETS_URL . 'css/admin-manual-upgrade.min.css',
			array(),
			WPBDP_VERSION
		);

		wp_enqueue_script(
			'wpbdp-manual-upgrade',
			WPBDP_ASSETS_URL . 'js/admin-manual-upgrade.min.js',
			array(),
			WPBDP_VERSION,
			true
		);
	}

	private function is_configured() {
		if ( ! $this->config_callback ) {
			return true;
		}

		$latest_data = (array) get_option( 'wpbdp-manual-upgrade-pending', array() );
		return ! empty( $latest_data['configured'] );
	}

	public function upgrade_page() {
		echo wpbdp_admin_header(
			array(
				'title'   => __( 'Directory Manual Upgrade', 'business-directory-plugin' ),
				'id'      => 'manual-upgrade',
				'sidebar' => false,
			)
		);
		echo '<div class="wpbdp-manual-upgrade-wrapper">';

		if ( ! $this->is_configured() ) {
			ob_start();
			call_user_func( $this->config_callback );
			$output = ob_get_contents();
			ob_end_clean();

			/** @phpstan-ignore-next-line */
			if ( ! $this->is_configured() ) {
				// is_configured can change during the config_callback.
				echo '<form action="" method="post">';
				echo '<div class="wpbdp-manual-upgrade-configuration">';
				echo $output;
				echo '<div class="cf"><input type="submit" class="right button button-primary" value="' . esc_attr__( 'Continue', 'business-directory-plugin' ) . '"/></div>';
				echo '</div>';
				echo '</form>';
			}
		}

		if ( $this->is_configured() ) {
			echo '<div class="step-upgrade">';
			echo '<p>';
			esc_html_e( 'Business Directory features are currently disabled because the plugin needs to perform a manual upgrade before it can be used.', 'business-directory-plugin' );
			echo '<br />';
			esc_html_e( 'Click "Start Upgrade" and wait until the process finishes.', 'business-directory-plugin' );
			echo '</p>';
			echo '<p>';
			echo '<a href="#" class="start-upgrade button button-primary">' . esc_html_x( 'Start Upgrade', 'manual-upgrade', 'business-directory-plugin' ) . '</a>';
			echo ' ';
			echo '<a href="#" class="pause-upgrade button">' . esc_html_x( 'Pause Upgrade', 'manual-upgrade', 'business-directory-plugin' ) . '</a>';
			echo '</p>';
			echo '<textarea id="manual-upgrade-progress" rows="20" style="width: 90%; font-family: courier, monospaced; font-size: 12px;" readonly="readonly"></textarea>';
			echo '</div>';

			echo '<div class="step-done" style="display: none;">';
			echo '<p>' . esc_html_x( 'The upgrade was successfully performed. Business Directory Plugin is now available.', 'manual-upgrade', 'business-directory-plugin' ) . '</p>';
			printf(
				'<a href="%s" class="button button-primary">%s</a>',
				esc_url( admin_url( 'edit.php?post_type=wpbdp_listing' ) ),
				esc_html_x( 'Go to "Directory Admin"', 'manual-upgrade', 'business-directory-plugin' )
			);
			echo '</div>';
		}

		echo '</div>';
		echo wpbdp_admin_footer();
	}

	/* Ajax Handlers */

	public function handle_ajax() {
		if ( ! wpbdp_user_is_admin() ) {
			return;
		}

		$response = call_user_func( $this->callback );

		// Migration routines can request additional manual upgrades
		$this->load_manual_upgrades();

		if ( $response['done'] ) {
			$this->remove_upgrade_for_version( $this->current_version, $this->current_upgrade );
		}

		if ( $this->is_upgrade_complete_for_version( $this->current_version ) ) {
			$this->installer->update_installed_version( $this->current_version );
		}

		if ( ! $this->is_upgrade_complete() ) {
			$response['done'] = false;
		}

		print wp_json_encode( $response );

		exit();
	}

	/* Manual Upgrades */

	private function load_manual_upgrades() {
		$this->manual_upgrades = $this->installer->get_manual_upgrades();
	}

	private function update_pending_manual_upgrades() {
		if ( empty( $this->manual_upgrades ) ) {
			delete_option( 'wpbdp-manual-upgrade-pending' );
		} else {
			update_option( 'wpbdp-manual-upgrade-pending', $this->manual_upgrades );
		}
	}

	private function remove_upgrade_for_version( $version, $upgrade ) {
		$index = array_search( $upgrade, $this->manual_upgrades[ $version ] );

		if ( false !== $index ) {
			unset( $this->manual_upgrades[ $version ][ $index ] );
		}

		if ( empty( $this->manual_upgrades[ $version ] ) ) {
			unset( $this->manual_upgrades[ $version ] );
		}

		$this->update_pending_manual_upgrades();
	}

	private function is_upgrade_complete_for_version( $version ) {
		return empty( $this->manual_upgrades[ $version ] );
	}

	private function is_upgrade_complete() {
		return empty( $this->manual_upgrades );
	}
}
