trips) add local auth provider and login picker

src/lib/server/local-credentials.ts

@@ -0,0 +1,67 @@
+import { env } from '$env/dynamic/private';
+import argon2 from 'argon2';
+import { db } from './db/index.js';
+
+export interface LocalCredentialRecord {
+	userId: string;
+	username: string;
+	fullName: string;
+	email: string | null;
+	passwordHash: string;
+}
+
+export const LOCAL_AUTH_MIN_PASSWORD_LENGTH = 12;
+
+const getNumberEnv = (value: string | undefined, fallback: number): number => {
+	const parsed = Number.parseInt(value ?? '', 10);
+	return Number.isFinite(parsed) ? parsed : fallback;
+};
+
+export function getLocalCredentialByIdentifier(identifier: string): LocalCredentialRecord | null {
+	const normalized = identifier.trim();
+	if (!normalized) return null;
+	return (
+		db.get<LocalCredentialRecord>(
+			`SELECT
+				users.id as userId,
+				users.username as username,
+				users.full_name as fullName,
+				users.email as email,
+				local_credentials.password_hash as passwordHash
+			 FROM users
+			 INNER JOIN local_credentials ON local_credentials.user_id = users.id
+			 WHERE lower(users.username) = lower(?)
+				OR (users.email IS NOT NULL AND lower(users.email) = lower(?))
+			 LIMIT 1`,
+			[normalized, normalized]
+		) ?? null
+	);
+}
+
+export async function hashLocalPassword(password: string): Promise<string> {
+	const trimmed = password.trim();
+	if (trimmed.length < LOCAL_AUTH_MIN_PASSWORD_LENGTH) {
+		throw new Error(`Password must be at least ${LOCAL_AUTH_MIN_PASSWORD_LENGTH} characters`);
+	}
+	const memoryCost = getNumberEnv(env.LOCAL_AUTH_ARGON2_MEMORY_KB, 65536);
+	const timeCost = getNumberEnv(env.LOCAL_AUTH_ARGON2_TIME_COST, 3);
+	const parallelism = getNumberEnv(env.LOCAL_AUTH_ARGON2_PARALLELISM, 1);
+	return argon2.hash(trimmed, {
+		type: argon2.argon2id,
+		memoryCost,
+		timeCost,
+		parallelism
+	});
+}
+
+export async function setLocalCredentialPassword(userId: string, password: string): Promise<void> {
+	const passwordHash = await hashLocalPassword(password);
+	db.run(
+		`INSERT INTO local_credentials (user_id, password_hash)
+		 VALUES (?, ?)
+		 ON CONFLICT(user_id) DO UPDATE SET
+			password_hash = excluded.password_hash,
+			updated_at = datetime('now')`,
+		[userId, passwordHash]
+	);
+}