add sqlite cache schema, thread/message storage

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/db/index.test.ts

@@ -0,0 +1,51 @@
+import { describe, expect, test, beforeEach } from "bun:test";
+import { createDatabase, insertThread, insertMessage, getThreads, getMessagesForThread } from "./index";
+import type { Database } from "bun:sqlite";
+
+let db: Database;
+
+beforeEach(() => {
+	db = createDatabase(":memory:");
+});
+
+describe("threads", () => {
+	test("insert and retrieve threads", () => {
+		insertThread(db, {
+			threadId: "t001",
+			subject: "Q1 Planning",
+			authors: "Alice, Bob",
+			totalMessages: 3,
+			tags: "inbox,unread",
+			timestamp: 1709884532,
+			accountId: "personal",
+		});
+
+		const threads = getThreads(db, "personal");
+		expect(threads).toHaveLength(1);
+		expect(threads[0].threadId).toBe("t001");
+		expect(threads[0].subject).toBe("Q1 Planning");
+	});
+});
+
+describe("messages", () => {
+	test("insert and retrieve messages for a thread", () => {
+		insertMessage(db, {
+			messageId: "msg001@example.com",
+			threadId: "t001",
+			fromHeader: "Alice <alice@example.com>",
+			toHeader: "user@example.com",
+			subject: "Q1 Planning",
+			date: "2024-03-08T10:15:32+01:00",
+			inReplyTo: "",
+			body: "Hey, let's plan Q1.",
+			tags: "inbox,unread",
+			timestamp: 1709884532,
+			accountId: "personal",
+		});
+
+		const messages = getMessagesForThread(db, "t001");
+		expect(messages).toHaveLength(1);
+		expect(messages[0].messageId).toBe("msg001@example.com");
+		expect(messages[0].body).toBe("Hey, let's plan Q1.");
+	});
+});

backend/src/db/index.ts

@@ -0,0 +1,90 @@
+import { Database } from "bun:sqlite";
+import { SCHEMA } from "./schema";
+
+export function createDatabase(path: string): Database {
+	const db = new Database(path, { create: true });
+	db.run("PRAGMA journal_mode = WAL");
+	db.exec(SCHEMA);
+	return db;
+}
+
+export interface ThreadRow {
+	threadId: string;
+	subject: string;
+	authors: string;
+	totalMessages: number;
+	tags: string;
+	timestamp: number;
+	accountId: string;
+}
+
+export interface MessageRow {
+	messageId: string;
+	threadId: string;
+	fromHeader: string;
+	toHeader: string;
+	subject: string;
+	date: string;
+	inReplyTo: string;
+	body: string;
+	tags: string;
+	timestamp: number;
+	accountId: string;
+}
+
+export function insertThread(db: Database, thread: ThreadRow): void {
+	db.prepare(`
+		INSERT OR REPLACE INTO threads
+		(thread_id, account_id, subject, authors, total_messages, tags, timestamp)
+		VALUES ($threadId, $accountId, $subject, $authors, $totalMessages, $tags, $timestamp)
+	`).run({
+		$threadId: thread.threadId,
+		$accountId: thread.accountId,
+		$subject: thread.subject,
+		$authors: thread.authors,
+		$totalMessages: thread.totalMessages,
+		$tags: thread.tags,
+		$timestamp: thread.timestamp,
+	});
+}
+
+export function insertMessage(db: Database, msg: MessageRow): void {
+	db.prepare(`
+		INSERT OR REPLACE INTO messages
+		(message_id, thread_id, account_id, from_header, to_header, subject, date, in_reply_to, body, tags, timestamp)
+		VALUES ($messageId, $threadId, $accountId, $fromHeader, $toHeader, $subject, $date, $inReplyTo, $body, $tags, $timestamp)
+	`).run({
+		$messageId: msg.messageId,
+		$threadId: msg.threadId,
+		$accountId: msg.accountId,
+		$fromHeader: msg.fromHeader,
+		$toHeader: msg.toHeader,
+		$subject: msg.subject,
+		$date: msg.date,
+		$inReplyTo: msg.inReplyTo,
+		$body: msg.body,
+		$tags: msg.tags,
+		$timestamp: msg.timestamp,
+	});
+}
+
+export function getThreads(db: Database, accountId: string): ThreadRow[] {
+	return db.prepare(`
+		SELECT thread_id as threadId, subject, authors, total_messages as totalMessages,
+		       tags, timestamp, account_id as accountId
+		FROM threads
+		WHERE account_id = $accountId
+		ORDER BY timestamp DESC
+	`).all({ $accountId: accountId }) as ThreadRow[];
+}
+
+export function getMessagesForThread(db: Database, threadId: string): MessageRow[] {
+	return db.prepare(`
+		SELECT message_id as messageId, thread_id as threadId, from_header as fromHeader,
+		       to_header as toHeader, subject, date, in_reply_to as inReplyTo, body, tags,
+		       timestamp, account_id as accountId
+		FROM messages
+		WHERE thread_id = $threadId
+		ORDER BY timestamp ASC
+	`).all({ $threadId: threadId }) as MessageRow[];
+}

backend/src/db/schema.ts

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+export const SCHEMA = `
+	CREATE TABLE IF NOT EXISTS threads (
+		thread_id TEXT NOT NULL,
+		account_id TEXT NOT NULL,
+		subject TEXT NOT NULL,
+		authors TEXT NOT NULL,
+		total_messages INTEGER NOT NULL,
+		tags TEXT NOT NULL DEFAULT '',
+		timestamp INTEGER NOT NULL,
+		updated_at TEXT NOT NULL DEFAULT (datetime('now')),
+		PRIMARY KEY (thread_id, account_id)
+	);
+
+	CREATE TABLE IF NOT EXISTS messages (
+		message_id TEXT PRIMARY KEY,
+		thread_id TEXT NOT NULL,
+		account_id TEXT NOT NULL,
+		from_header TEXT NOT NULL,
+		to_header TEXT NOT NULL,
+		subject TEXT NOT NULL,
+		date TEXT NOT NULL,
+		in_reply_to TEXT NOT NULL DEFAULT '',
+		body TEXT NOT NULL DEFAULT '',
+		tags TEXT NOT NULL DEFAULT '',
+		timestamp INTEGER NOT NULL,
+		updated_at TEXT NOT NULL DEFAULT (datetime('now'))
+	);
+
+	CREATE INDEX IF NOT EXISTS idx_messages_thread ON messages(thread_id);
+	CREATE INDEX IF NOT EXISTS idx_threads_account ON threads(account_id);
+	CREATE INDEX IF NOT EXISTS idx_threads_timestamp ON threads(timestamp DESC);
+`;