allow users to change their password

Closes #13

src/db/users.ts

@@ -1,7 +1,7 @@
 import { config } from "$lib/configuration";
 import { generateRandomToken } from "$lib/randomToken";
 import type { Email, Password, VerificationCode } from "$lib/types";
-import { hash } from "@node-rs/argon2";
+import { hash, verify } from "@node-rs/argon2";
 import { db } from ".";
 import { usersTable } from "./schema";
 import { eq } from "drizzle-orm";
@@ -36,6 +36,22 @@ export async function createNewUser(email: Email, password: Password): Promise<{
     }
 }
 
+export async function loadUser(id: number) {
+    const user = await db.select().from(usersTable).where(eq(usersTable.id, id)).limit(1);
+    if (user.length === 0) {
+        return null;
+    }
+    return {
+        id: user[0].id,
+        email: user[0].email as Email,
+        password_hash: user[0].password_hash
+    }
+}
+
+export async function verifyPassword(password: Password, password_hash: string) {
+    return await verify(password_hash, password);
+}
+
 export enum VerificationError {
     InvalidVerificationCode = 'Invalid verification code',
     VerificationCodeExpired = 'Verification code expired'

src/lib/components/PasswordSetterFormPart.svelte

@@ -0,0 +1,27 @@
+<script lang="ts">
+	type Props = {
+		password: string;
+		password_repeat: string;
+	};
+
+	let { password = $bindable(), password_repeat = $bindable() } = $props();
+</script>
+
+<label for="password" class="justify-self-end">Password</label>
+<input
+	type="password"
+	name="password"
+	id="password"
+	class="justify-self-start"
+	required
+	bind:value={password}
+/>
+<label for="password_repeat" class="justify-self-end">Password (repeat)</label>
+<input
+	type="password"
+	name="password_repeat"
+	id="password_repeat"
+	class="justify-self-start"
+	required
+	bind:value={password_repeat}
+/>

src/lib/components/icons/ProfileIcon.svelte

@@ -0,0 +1,14 @@
+<svg
+	xmlns="http://www.w3.org/2000/svg"
+	fill="none"
+	viewBox="0 0 24 24"
+	stroke-width="1.5"
+	stroke="currentColor"
+	class="size-6"
+>
+	<path
+		stroke-linecap="round"
+		stroke-linejoin="round"
+		d="M17.982 18.725A7.488 7.488 0 0 0 12 15.75a7.488 7.488 0 0 0-5.982 2.975m11.963 0a9 9 0 1 0-11.963 0m11.963 0A8.966 8.966 0 0 1 12 21a8.966 8.966 0 0 1-5.982-2.275M15 9.75a3 3 0 1 1-6 0 3 3 0 0 1 6 0Z"
+	/>
+</svg>

src/routes/(app)/+page.svelte

@@ -6,9 +6,30 @@
 	import Navbar from '$lib/components/Navbar.svelte';
 	import CheckIcon from '$lib/components/icons/CheckIcon.svelte';
 	import DuplicateIcon from '$lib/components/icons/DuplicateIcon.svelte';
+	import { page } from '$app/state';
+	import { toast } from '@zerodevx/svelte-toast';
+	import { goto } from '$app/navigation';
+	import ProfileIcon from '$lib/components/icons/ProfileIcon.svelte';
+
+	$effect(() => {
+		if (page.url.searchParams.get('pwd_updated') === 'true') {
+			toast.push('Password update successful', {
+				theme: {
+					'--toastProgressBackground': 'green'
+				},
+				onpop: () => {
+					goto('/');
+				}
+			});
+		}
+	});
 </script>
 
-<Navbar title="Dashboard" />
+<Navbar title="Dashboard">
+	<div class="w-30 flex flex-row justify-self-end">
+		<a href="passwordChange" title="Change password"><ProfileIcon /></a>
+	</div>
+</Navbar>
 
 <div class="p-4">
 	<h2 class="text-2xl">Surveys you own</h2>

src/routes/(app)/passwordChange/+page.server.ts

@@ -0,0 +1,33 @@
+import type { Email, Password } from "$lib/types";
+import { error, redirect, type Actions } from "@sveltejs/kit";
+import { db } from "../../../db";
+import { usersTable } from "../../../db/schema";
+import { loadUser, verifyPassword } from "../../../db/users";
+import { hash } from "@node-rs/argon2";
+import { eq } from "drizzle-orm";
+
+export const actions = {
+    default: async (event) => {
+        const formData = await event.request.formData();
+        const old_password = formData.get('old_password')?.toString() as Password | undefined;
+        const password = formData.get('password')?.toString() as Password | undefined;
+
+        if (!password || !old_password) {
+            error(400, 'Old and new password is required');
+        }
+
+        if (event.locals.userId === null) {
+            error(403, 'User is not logged in');
+        }
+        // load and verify the old credentials and update the password hash
+        const user = await loadUser(event.locals.userId);
+        if (!user) {
+            error(403, 'User does not exist');
+        }
+        if (await verifyPassword(old_password, user.password_hash)) {
+            await db.update(usersTable).set({ password_hash: await hash(password) }).where(eq(usersTable.id, event.locals.userId));
+        }
+
+        redirect(303, '/?pwd_updated=true');
+    }
+} satisfies Actions;

src/routes/(app)/passwordChange/+page.svelte

@@ -0,0 +1,36 @@
+<script>
+	import Navbar from '$lib/components/Navbar.svelte';
+	import PasswordSetterFormPart from '$lib/components/PasswordSetterFormPart.svelte';
+
+	let password = $state();
+	let password_repeat = $state();
+</script>
+
+<Navbar title="Update password" />
+
+<p class="m-4 text-center">
+	Please provide your old password and the new password twice to update your password.
+</p>
+<form method="post" class="grid grid-cols-2 gap-1">
+	<label for="old_password" class="justify-self-end">Old password</label>
+	<input
+		type="password"
+		name="old_password"
+		id="old_password"
+		class="justify-self-start"
+		required
+	/>
+
+	<PasswordSetterFormPart bind:password bind:password_repeat />
+	<button
+		type="submit"
+		class="col-span-2 w-40 justify-self-center bg-slate-200"
+		disabled={password !== password_repeat || password === ''}
+	>
+		{#if password !== password_repeat}
+			New passwords don't match
+		{:else}
+			Update password
+		{/if}
+	</button>
+</form>

src/routes/register/+page.svelte

@@ -1,8 +1,9 @@
 <script lang="ts">
 	import Navbar from '$lib/components/Navbar.svelte';
+	import PasswordSetterFormPart from '$lib/components/PasswordSetterFormPart.svelte';
 
-	let password = $state('');
-	let password_repeat = $state('');
+	let password = $state();
+	let password_repeat = $state();
 
 	const { data } = $props();
 </script>
@@ -19,24 +20,7 @@
 			{/if}
 		</label>
 		<input type="email" name="email" id="email" class="justify-self-start" required />
-		<label for="password" class="justify-self-end">Password</label>
-		<input
-			type="password"
-			name="password"
-			id="password"
-			class="justify-self-start"
-			required
-			bind:value={password}
-		/>
-		<label for="password_repeat" class="justify-self-end">Password</label>
-		<input
-			type="password"
-			name="password_repeat"
-			id="password_repeat"
-			class="justify-self-start"
-			required
-			bind:value={password_repeat}
-		/>
+		<PasswordSetterFormPart bind:password bind:password_repeat />
 		<button
 			type="submit"
 			class="col-span-2 w-40 justify-self-center bg-slate-200"