feat: offer fediverse login on login page

frontend/src/routes/auth/login/+page.svelte

@@ -1,7 +1,53 @@
 <script lang="ts">
+  import { goto } from "$app/navigation";
+  import type { APIError } from "$lib/api/entities";
+  import { apiFetch } from "$lib/api/fetch";
+  import ErrorAlert from "$lib/components/ErrorAlert.svelte";
+  import { userStore } from "$lib/store";
+  import { addToast } from "$lib/toast";
+  import { onMount } from "svelte";
+  import {
+    Button,
+    Icon,
+    Input,
+    ListGroup,
+    ListGroupItem,
+    Modal,
+    ModalBody,
+    ModalFooter,
+  } from "sveltestrap";
   import type { PageData } from "./$types";
 
   export let data: PageData;
+
+  let error: APIError | null = null;
+  let instance = "";
+  let fediDisabled = false;
+
+  let modalOpen = false;
+  let toggleModal = () => (modalOpen = !modalOpen);
+
+  onMount(() => {
+    if ($userStore) {
+      addToast({ header: "Error", body: "You are already logged in." });
+      goto("/");
+    }
+  });
+
+  const fediLogin = async () => {
+    fediDisabled = true;
+    try {
+      const resp = await apiFetch<{ url: string }>(
+        `/auth/urls/fediverse?instance=${encodeURIComponent(instance)}`,
+        {},
+      );
+      window.location.assign(resp.url);
+    } catch (e) {
+      error = e as APIError;
+    } finally {
+      fediDisabled = false;
+    }
+  };
 </script>
 
 <svelte:head>
@@ -11,13 +57,35 @@
 <div class="container">
   <h1>Log in or sign up</h1>
   <div class="row">
-    <div class="col">
-      <p>
-        <a class="btn btn-primary" href={data.discord} role="button">Log in with Discord</a>
-      </p>
+    <div class="col-md-4">
+      <ListGroup>
+        <ListGroupItem tag="button" on:click={toggleModal}>
+          <Icon name="mastodon" /> Log in with Fediverse
+        </ListGroupItem>
+        <ListGroupItem tag="a" href={data.discord}>
+          <Icon name="discord" /> Log in with Discord
+        </ListGroupItem>
+      </ListGroup>
+      <Modal header="Pick an instance" isOpen={modalOpen} toggle={toggleModal}>
+        <ModalBody>
+          <Input placeholder="Instance (e.g. mastodon.social)" bind:value={instance} />
+          {#if error}
+            <div class="mt-2">
+              <ErrorAlert {error} />
+            </div>
+          {/if}
+        </ModalBody>
+        <ModalFooter>
+          <Button color="primary" disabled={fediDisabled || instance === ""} on:click={fediLogin}
+            >Fediverse login</Button
+          >
+        </ModalFooter>
+      </Modal>
     </div>
-    <div class="col">
-
+    <div class="col-md">
+      <p>
+        <b>Choose an authentication provider to get started.</b> You can add more providers later.
+      </p>
     </div>
   </div>
 </div>

frontend/src/routes/auth/login/discord/+page.svelte

@@ -8,6 +8,7 @@
   import { userStore } from "$lib/store";
   import type { PageData } from "./$types";
   import ErrorAlert from "$lib/components/ErrorAlert.svelte";
+  import { addToast } from "$lib/toast";
 
   interface SignupResponse {
     user: MeUser;
@@ -21,6 +22,7 @@
       localStorage.setItem("pronouns-token", data.token);
       localStorage.setItem("pronouns-user", JSON.stringify(data.user));
       userStore.set(data.user);
+      addToast({ header: "Logged in", body: "Successfully logged in!" });
       goto("/");
     }
   });
@@ -42,6 +44,7 @@
       localStorage.setItem("pronouns-token", resp.token);
       localStorage.setItem("pronouns-user", JSON.stringify(resp.user));
       userStore.set(resp.user);
+      addToast({ header: "Welcome!", body: "Signed up successfully!" });
       goto("/");
     } catch (e) {
       data.error = e as APIError;

frontend/src/routes/edit/profile/+page.svelte

@@ -33,6 +33,7 @@
   const MAX_AVATAR_BYTES = 1_000_000;
 
   if (!$userStore) {
+    addToast({ header: "Error", body: "You are not logged in." });
     goto("/");
   }
 
@@ -55,16 +56,9 @@
 
   let modified = false;
 
-  $: redirectIfNoAuth($userStore);
   $: modified = isModified(bio, display_name, links, names, pronouns, fields, avatar);
   $: getAvatar(avatar_files).then((b64) => (avatar = b64));
 
-  const redirectIfNoAuth = (user: MeUser | null) => {
-    if (!user) {
-      goto("/");
-    }
-  };
-
   const isModified = (
     bio: string,
     display_name: string,

frontend/src/routes/settings/+layout.svelte

@@ -4,6 +4,7 @@
   import { Button, ListGroup, ListGroupItem, Modal, ModalBody, ModalFooter } from "sveltestrap";
   import { userStore } from "$lib/store";
   import { goto } from "$app/navigation";
+  import { addToast } from "$lib/toast";
 
   export let data: LayoutData;
 
@@ -15,6 +16,8 @@
     localStorage.removeItem("pronouns-token");
     localStorage.removeItem("pronouns-user");
     toggle();
+
+    addToast({ header: "Logged out", body: "Successfully logged out!" });
     goto("/");
   };
 </script>

frontend/src/routes/settings/+page.svelte

@@ -5,6 +5,7 @@
   import ErrorAlert from "$lib/components/ErrorAlert.svelte";
   import FallbackImage from "$lib/components/FallbackImage.svelte";
   import { userStore } from "$lib/store";
+  import { addToast } from "$lib/toast";
   import { Button, Icon, Modal, ModalBody, ModalFooter, ModalHeader, Table } from "sveltestrap";
   import type { PageData } from "./$types";
 
@@ -39,6 +40,7 @@
       localStorage.removeItem("pronouns-token");
       localStorage.removeItem("pronouns-user");
       toggleDeleteOpen();
+      addToast({ header: "Deleted account", body: "Your account is now pending deletion." });
       goto("/");
     } catch (e) {
       deleteUsername = "";