Handle upgrading from the PL plugin

Author: aristath

activate.php

@@ -36,6 +36,18 @@ function sqlite_activation() {
 		return;
 	}
 	if ( isset( $_GET['confirm-install'] ) && wp_verify_nonce( $_GET['_wpnonce'], 'sqlite-install' ) ) {
+
+		// Handle upgrading from the performance-lab plugin.
+		if ( isset( $_GET['upgrade-from-pl'] ) ) {
+			// Delete the previous db.php file.
+			unlink( WP_CONTENT_DIR . '/db.php' );
+			// Deactivate the performance-lab SQLite module.
+			$pl_option_name = defined( 'PERFLAB_MODULES_SETTING' ) ? PERFLAB_MODULES_SETTING : 'perflab_modules_settings';
+			$pl_option      = get_option( $pl_option_name, array() );
+			unset( $pl_option['database/sqlite'] );
+			update_option( $pl_option_name, $pl_option );
+			remove_action( 'admin_notices', 'perflab_sqlite_plugin_admin_notice' ); // Remove the PL-plugin admin notices.
+		}
 		sqlite_plugin_copy_db_file();
 		// WordPress will automatically redirect to the install screen here.
 		wp_redirect( admin_url() );

admin-page.php

@@ -52,17 +52,40 @@ function sqlite_integration_admin_screen() {
 					<p><?php esc_html_e( 'We detected that the SQLite3 class is missing from your server. Please make sure that SQLite is enabled in your PHP installation before proceeding.', 'sqlite-database-integration' ); ?></p>
 				</div>
 			<?php elseif ( file_exists( WP_CONTENT_DIR . '/db.php' ) && ! defined( 'SQLITE_DB_DROPIN_VERSION' ) ) : ?>
-				<div class="notice notice-error">
+				<?php if ( defined( 'PERFLAB_SQLITE_DB_DROPIN_VERSION' ) ) : ?>
+					<div class="notice notice-warning">
 					<p>
 						<?php
 						printf(
 							/* translators: %s: db.php drop-in path */
-							esc_html__( 'The SQLite plugin cannot be activated because a different %s drop-in already exists.', 'sqlite-database-integration' ),
+							esc_html__( 'An older %s file was detected. Please click the button below to update the file.', 'sqlite-database-integration' ),
 							'<code>' . esc_html( basename( WP_CONTENT_DIR ) ) . '/db.php</code>'
 						);
 						?>
 					</p>
 				</div>
+				<a class="button button-primary" href="<?php echo esc_url( wp_nonce_url( admin_url( 'admin.php?page=sqlite-integration&confirm-install&upgrade-from-pl' ), 'sqlite-install' ) ); ?>">
+					<?php
+					printf(
+						/* translators: %s: db.php drop-in path */
+						esc_html__( 'Update %s file', 'sqlite-database-integration' ),
+						'<code>' . esc_html( basename( WP_CONTENT_DIR ) ) . '/db.php</code>'
+					);
+					?>
+				</a>
+				<?php else : ?>
+					<div class="notice notice-error">
+						<p>
+							<?php
+							printf(
+								/* translators: %s: db.php drop-in path */
+								esc_html__( 'The SQLite plugin cannot be activated because a different %s drop-in already exists.', 'sqlite-database-integration' ),
+								'<code>' . esc_html( basename( WP_CONTENT_DIR ) ) . '/db.php</code>'
+							);
+							?>
+						</p>
+					</div>
+				<?php endif; ?>
 			<?php elseif ( ! is_writable( WP_CONTENT_DIR ) ) : ?>
 				<div class="notice notice-error">
 					<p>