add password change form.

frontend/src/routes/login.svelte

@@ -6,17 +6,42 @@
 
   let username = '';
   let password = '';
+  let newPassword = '';
+  let newPassword2 = '';
   let error: string;
   let loading = false;
+  let changeMode = false;
+  let changeUser = null;
 
   async function handleSignIn() {
     error = void(0);
     loading = true;
 
+    if (newPassword !== newPassword2) {
+      error = "The two passwords do not match, please re-enter."
+      return
+    }
+
     try {
-      const res = await Auth.signIn(username, password);
+      if (changeMode) {
+        const res = await Auth.completeNewPassword(changeUser, newPassword)
+        console.log(res);
+
+        changeMode = false;
+        password = "";
+      } else {
+        const res = await Auth.signIn(username, password);
+        console.log(res);
+
+        if (res.challengeName == "NEW_PASSWORD_REQUIRED") {
+          newPassword = "";
+          newPassword2 = "";
+          changeMode = true
+          changeUser = res
+        }
 
-      goto('/', {replaceState: true});
+        goto('/', {replaceState: true});
+      }
     } catch (err) {
       error = err?.toString() || err;
     }
@@ -30,8 +55,15 @@
     <ModalBody>
       <label for="name">Username</label>
       <input type="text" bind:value={username} />
-      <label for="name">Password</label>
-      <input type="password" bind:value={password} />
+      {#if changeMode}
+        <label for="name">New Password</label>
+        <input type="password" bind:value={newPassword} />
+        <label for="name">Confirm New Password</label>
+        <input type="password" bind:value={newPassword2} />
+      {:else}
+        <label for="name">Password</label>
+        <input type="password" bind:value={password} />
+      {/if}
     </ModalBody>
   </Modal>
 </form>