add: endpoint /timeline & /frame/:id in backend server

improve: simplify the migration code

src/electron/backend/migrate/index.ts

@@ -12,26 +12,23 @@ function migrateTo(version: number, db: Database) {
 	}
 }
 
+function getVersion(db: Database): number {
+	const stmt = db.prepare(`SELECT value FROM config WHERE key = 'version';`);
+	const data = stmt.get() as { value: string };
+	const version = data.value;
+	return parseInt(version);
+}
+
 export function migrate(db: Database) {
 	const configTableExists =
-		db.prepare(`SELECT name FROM sqlite_master WHERE type='table' AND name='config';`).get()
+		db.prepare(`SELECT name FROM sqlite_master WHERE type='table' AND name='config';`).get() !==
-		!== undefined;
+		undefined;
 	if (!configTableExists) {
 		migrateToV2(db);
 	}
-	let databaseVersion = parseInt(
+	let databaseVersion = getVersion(db);
-		(
-			db.prepare(`SELECT value FROM config WHERE key = 'version';`).get() as
-				{ value: any }
-		).value
-	);
 	while (databaseVersion < CURRENT_VERSION) {
 		migrateTo(databaseVersion, db);
-		databaseVersion = parseInt(
+		databaseVersion = getVersion(db);
-			(
-				db.prepare(`SELECT value FROM config WHERE key = 'version';`).get() as
-					{ value: any }
-			).value
-		);
 	}
 }

src/electron/index.ts

@@ -96,6 +96,7 @@ app.on("ready", () => {
 		setInterval(processEncodingTasks, 10000, db);
 		setInterval(deleteEncodedScreenshots, 5000, db);
 		dbConnection = db;
+		cache.put("server:dbConnection", dbConnection);
 	});
 	mainWindow = createMainWindow(port, () => (mainWindow = null));
 	settingsWindow = createSettingsWindow(port, () => (settingsWindow = null));
@@ -107,6 +108,8 @@ app.on("ready", () => {
 
 app.on("will-quit", () => {
 	dbConnection?.close();
+	if (screenshotInterval)
+		clearInterval(screenshotInterval);
 });
 
 // app.on("window-all-closed", () => {

src/electron/server/index.ts

@@ -1,17 +1,75 @@
-import { Hono } from 'hono'
+import { Hono } from "hono";
 import cache from "memory-cache";
+import { join } from "path";
+import fs from "fs";
+import { Database } from "better-sqlite3";
+import type { Frame } from "../backend/schema";
+import { getScreenshotsDir } from "../utils/backend.js";
 
 const app = new Hono();
 
 app.use(async (c, next) => {
 	const key = cache.get("server:APIKey");
 	if (key && c.req.header("x-api-key") !== key) {
-		c.res = undefined
+		c.res = undefined;
 		c.res = c.json({ error: "Invalid API key" }, 401);
 	}
 	await next();
-})
+});
 
-app.get('/ping', (c) => c.text('pong'))
+app.get("/ping", (c) => c.text("pong"));
+
+app.get("/timeline", async (c) => {
+	const { offset = 0, limit = 50 } = c.req.query();
+	const db = cache.get("server:dbConnection");
+
+	const frames = db
+		.prepare(
+			`
+    SELECT id, createdAt, imgFilename, videoPath, videoFrameIndex 
+    FROM frame 
+    ORDER BY createdAt DESC
+    LIMIT ? OFFSET ?
+  `
+		)
+		.all(limit, offset);
+
+	return c.json(frames);
+});
+
+app.get("/frame/:id", async (c) => {
+	const { id } = c.req.param();
+	const db: Database = cache.get("server:dbConnection");
+
+	const frame = db
+		.prepare(
+			`
+    SELECT imgFilename, videoPath, videoFrameIndex 
+    FROM frame 
+    WHERE id = ?
+  `
+		)
+		.get(id) as Frame;
+
+	if (!frame) {
+		return c.json({ error: "Frame not found" }, 404);
+	}
+
+	// If frame is from video, decode and return frame
+	if (frame.videoPath) {
+		// TODO: Implement video frame extraction
+		return c.json({ error: "Video frame extraction not implemented" }, 501);
+	}
+
+	// Return image file
+	const imagePath = join(getScreenshotsDir(), frame.imgFilename);
+	const imageBuffer = fs.readFileSync(imagePath);
+	return new Response(imageBuffer, {
+		status: 200,
+		headers: {
+			"Content-Type": "image/png"
+		}
+	});
+});
 
 export default app;