add best effort migration for pages

packages/backend/migration/1659335999000-pages-to-plaintext.js

@@ -0,0 +1,81 @@
+export class pagesToPlaintext1659335999000 {
+	name = 'pagesToPlaintext1659335999000'
+
+	async up(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "page" ADD "text" text`);
+
+		async function noteUrl(noteId) {
+			const note = await queryRunner.query(`SELECT "uri", "userHost" FROM "note" WHERE "id" = $1`, [noteId]);
+			if (note.uri) return note.uri;
+			// don't really have access to the configuration here so just guess
+			else return `https://${note.userHost}/notes/${noteId}`;
+		}
+
+		async function fileUrl(fileId) {
+			const file = await queryRunner.query(`SELECT "url" from "drive_file" WHERE "id" = $1`, [fileId]);
+			return file.url;
+		}
+
+		async function convertBlock(block) {
+			switch (block.type) {
+				case 'note':
+					if (block.note) return noteUrl(block.note);
+					else break;
+				case 'section':
+					return block.children.map(convertBlock).join('\n');
+				case 'text':
+					return block.text;
+				case 'textarea':
+					return '```\n' + block.text + '```';
+				case 'image':
+					if (block.fileId) return '![image](' + fileUrl(block.fileId) + ')';
+					else break;
+				case 'if': // no idea how to convert these
+				case 'post': // new note form, why?
+				case 'canvas': // there is some aiscript api for these but dont think anyone ever used it
+				// interactive elements can also not be converted
+				case 'button':
+				case 'numberInput':
+				case 'textInput':
+				case 'switch':
+				case 'radioButton':
+				case 'counter':
+					break;
+			}
+
+			return `(There was a/an ${block.type} here in a previous version but it is no longer supported.)`;
+		}
+
+		await queryRunner.query(`SELECT id, "content" FROM "page"`)
+		.then(pages => Promise.all(pages.map(page => {
+			let text = page.content.map(convertBlock).join('\n');
+
+			return queryRunner.query(`UPDATE "page" SET "text" = $1 WHERE "id" = $2`, [text, page.id]);
+		})));
+
+		await queryRunner.query(`ALTER TABLE "page" DROP COLUMN "content"`);
+		await queryRunner.query(`ALTER TABLE "page" DROP COLUMN "variables"`);
+		await queryRunner.query(`ALTER TABLE "page" DROP COLUMN "script"`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "page" ADD "content" jsonb default '[]'::jsonb`);
+		await queryRunner.query(`ALTER TABLE "page" ADD "variables" jsonb default '[]'::jsonb`);
+		await queryRunner.query(`ALTER TABLE "page" ADD "script" character varying(16384) default ''`);
+
+		// The conversion from the previous page content to text is lossy,
+		// so we can just convert it back to a big text block.
+		await queryRunner.query(`SELECT "id", "text" FROM "page"`)
+		.then(pages => Promise.all(pages.map(page => {
+			const content = [{
+				// just a random UUID to keep the data structure
+				id: '0730b23f-ab5b-4d56-8bd1-f4ead3f72af7',
+				type: 'text',
+				text: page.text,
+			}];
+			return queryRunner.query(`UPDATE "page" SET "content" = $1 WHERE "id" = $2`, [JSON.stringify(content), page.id]);
+		})));
+
+		await queryRunner.query(`ALTER TABLE "page" DROP COLUMN "text"`);
+	}
+}