feat(frontend): discord registration/login/linking

also moves the registration form found on the mastodon callback page
into a component so we're not repeating the same code for every auth method

Foxnouns.Frontend/src/routes/auth/callback/discord/+page.server.ts

@@ -0,0 +1,64 @@
+import { apiRequest } from "$api";
+import ApiError, { ErrorCode } from "$api/error";
+import type { AddAccountResponse, CallbackResponse } from "$api/models/auth";
+import { setToken } from "$lib";
+import createRegisterAction from "$lib/actions/register.js";
+import log from "$lib/log.js";
+import { isRedirect, redirect } from "@sveltejs/kit";
+
+export const load = async ({ url, parent, fetch, cookies }) => {
+	const code = url.searchParams.get("code") as string | null;
+	const state = url.searchParams.get("state") as string | null;
+	if (!code || !state) throw new ApiError(undefined, ErrorCode.BadRequest).obj;
+
+	const { meUser } = await parent();
+	if (meUser) {
+		try {
+			const resp = await apiRequest<AddAccountResponse>(
+				"POST",
+				"/auth/discord/add-account/callback",
+				{
+					isInternal: true,
+					body: { code, state },
+					fetch,
+					cookies,
+				},
+			);
+
+			return { hasAccount: true, isLinkRequest: true, newAuthMethod: resp };
+		} catch (e) {
+			if (e instanceof ApiError) return { isLinkRequest: true, error: e.obj };
+			log.error("error linking new discord account to user %s:", meUser.id, e);
+			throw e;
+		}
+	}
+
+	try {
+		const resp = await apiRequest<CallbackResponse>("POST", "/auth/discord/callback", {
+			body: { code, state },
+			isInternal: true,
+			fetch,
+		});
+
+		if (resp.has_account) {
+			setToken(cookies, resp.token!);
+			redirect(303, `/@${resp.user!.username}`);
+		}
+
+		return {
+			hasAccount: false,
+			isLinkRequest: false,
+			ticket: resp.ticket!,
+			remoteUser: resp.remote_username!,
+		};
+	} catch (e) {
+		if (isRedirect(e)) throw e;
+		if (e instanceof ApiError) return { isLinkRequest: false, error: e.obj };
+		log.error("error while requesting discord callback:", e);
+		throw e;
+	}
+};
+
+export const actions = {
+	default: createRegisterAction("/auth/discord/register"),
+};

Foxnouns.Frontend/src/routes/auth/callback/discord/+page.svelte

@@ -0,0 +1,31 @@
+<script lang="ts">
+	import Error from "$components/Error.svelte";
+	import NewAuthMethod from "$components/settings/NewAuthMethod.svelte";
+	import OauthRegistrationForm from "$components/settings/OauthRegistrationForm.svelte";
+	import { t } from "$lib/i18n";
+	import type { ActionData, PageData } from "./$types";
+
+	type Props = { data: PageData; form: ActionData };
+	let { data, form }: Props = $props();
+</script>
+
+<svelte:head>
+	<title>{$t("auth.register-with-discord")} • pronouns.cc</title>
+</svelte:head>
+
+<div class="container">
+	{#if data.error}
+		<h1>{$t("auth.register-with-discord")}</h1>
+		<Error error={data.error} />
+	{:else if data.isLinkRequest}
+		<NewAuthMethod method={data.newAuthMethod!} user={data.meUser!} />
+	{:else}
+		<OauthRegistrationForm
+			title={$t("auth.register-with-discord")}
+			remoteLabel={$t("auth.remote-discord-account-label")}
+			remoteUser={data.remoteUser!}
+			ticket={data.ticket!}
+			error={form?.error}
+		/>
+	{/if}
+</div>

Foxnouns.Frontend/src/routes/auth/callback/mastodon/[instance]/+page.server.ts

@@ -1,9 +1,9 @@
 import { apiRequest } from "$api";
-import ApiError, { ErrorCode, type RawApiError } from "$api/error";
-import type { AuthResponse, CallbackResponse } from "$api/models/auth.js";
+import ApiError, { ErrorCode } from "$api/error";
+import type { CallbackResponse } from "$api/models/auth.js";
 import { setToken } from "$lib";
-import log from "$lib/log.js";
-import { isRedirect, redirect } from "@sveltejs/kit";
+import createRegisterAction from "$lib/actions/register.js";
+import { redirect } from "@sveltejs/kit";
 
 export const load = async ({ parent, params, url, fetch, cookies }) => {
 	const { meUser } = await parent();
@@ -33,30 +33,5 @@ export const load = async ({ parent, params, url, fetch, cookies }) => {
 };
 
 export const actions = {
-	default: async ({ request, fetch, cookies }) => {
-		const data = await request.formData();
-		const username = data.get("username") as string | null;
-		const ticket = data.get("ticket") as string | null;
-
-		if (!username || !ticket)
-			return {
-				error: { message: "Bad request", code: ErrorCode.BadRequest, status: 403 } as RawApiError,
-			};
-
-		try {
-			const resp = await apiRequest<AuthResponse>("POST", "/auth/fediverse/register", {
-				body: { username, ticket },
-				isInternal: true,
-				fetch,
-			});
-
-			setToken(cookies, resp.token);
-			redirect(303, "/auth/welcome");
-		} catch (e) {
-			if (isRedirect(e)) throw e;
-			log.error("Could not sign up user with username %s:", username, e);
-			if (e instanceof ApiError) return { error: e.obj };
-			throw e;
-		}
-	},
+	default: createRegisterAction("/auth/fediverse/register"),
 };

Foxnouns.Frontend/src/routes/auth/callback/mastodon/[instance]/+page.svelte

@@ -1,9 +1,7 @@
 <script lang="ts">
-	import { Button, Input, Label } from "@sveltestrap/sveltestrap";
 	import type { ActionData, PageData } from "./$types";
 	import { t } from "$lib/i18n";
-	import { enhance } from "$app/forms";
-	import ErrorAlert from "$components/ErrorAlert.svelte";
+	import OauthRegistrationForm from "$components/settings/OauthRegistrationForm.svelte";
 
 	type Props = { data: PageData; form: ActionData };
 	let { data, form }: Props = $props();
@@ -14,22 +12,11 @@
 </svelte:head>
 
 <div class="container">
-	<h1>{$t("auth.register-with-mastodon")}</h1>
-
-	{#if form?.error}
-		<ErrorAlert error={form?.error} />
-	{/if}
-
-	<form method="POST" use:enhance>
-		<div class="mb-3">
-			<Label>{$t("auth.remote-fediverse-account-label")}</Label>
-			<Input type="text" readonly value={data.remoteUser} />
-		</div>
-		<div class="mb-3">
-			<Label>{$t("auth.register-username-label")}</Label>
-			<Input type="text" name="username" required />
-		</div>
-		<input type="hidden" name="ticket" value={data.ticket} />
-		<Button color="primary" type="submit">{$t("auth.register-button")}</Button>
-	</form>
+	<OauthRegistrationForm
+		title={$t("auth.register-with-mastodon")}
+		remoteLabel={$t("auth.remote-fediverse-account-label")}
+		remoteUser={data.remoteUser}
+		ticket={data.ticket}
+		error={form?.error}
+	/>
 </div>