feat(mattermost): add auth and send message to channel action

* feat: mattermost integration

* post review adjustments

packages/backend/src/apps/mattermost/auth/generate-auth-url.ts

@@ -0,0 +1,18 @@
+import { IGlobalVariable } from '@automatisch/types';
+import { URL, URLSearchParams } from 'url';
+import getBaseUrl from '../common/get-base-url';
+
+export default async function generateAuthUrl($: IGlobalVariable) {
+  const searchParams = new URLSearchParams({
+    client_id: $.auth.data.clientId as string,
+    redirect_uri: $.auth.data.oAuthRedirectUrl as string,
+    response_type: 'code',
+  });
+
+  const baseUrl = getBaseUrl($);
+  const path = `/oauth/authorize?${searchParams.toString()}`;
+
+  await $.auth.set({
+    url: new URL(path, baseUrl).toString(),
+  });
+}

packages/backend/src/apps/mattermost/auth/index.ts

@@ -0,0 +1,57 @@
+import generateAuthUrl from './generate-auth-url';
+import verifyCredentials from './verify-credentials';
+import isStillVerified from './is-still-verified';
+
+export default {
+  fields: [
+    {
+      key: 'oAuthRedirectUrl',
+      label: 'OAuth Redirect URL',
+      type: 'string' as const,
+      required: true,
+      readOnly: true,
+      value: '{WEB_APP_URL}/app/mattermost/connections/add',
+      placeholder: null,
+      description:
+        'When asked to input an OAuth callback or redirect URL in Mattermost OAuth, enter the URL above.',
+      clickToCopy: true,
+    },
+    {
+      key: 'instanceUrl',
+      label: 'Mattermost instance URL',
+      type: 'string' as const,
+      required: false,
+      readOnly: false,
+      value: null,
+      placeholder: null,
+      description: 'Your Mattermost instance URL',
+      clickToCopy: true,
+    },
+    {
+      key: 'clientId',
+      label: 'Client id',
+      type: 'string' as const,
+      required: true,
+      readOnly: false,
+      value: null,
+      placeholder: null,
+      description: null,
+      clickToCopy: false,
+    },
+    {
+      key: 'clientSecret',
+      label: 'Client secret',
+      type: 'string' as const,
+      required: true,
+      readOnly: false,
+      value: null,
+      placeholder: null,
+      description: null,
+      clickToCopy: false,
+    },
+  ],
+
+  generateAuthUrl,
+  verifyCredentials,
+  isStillVerified,
+};

packages/backend/src/apps/mattermost/auth/is-still-verified.ts

@@ -0,0 +1,9 @@
+import { IGlobalVariable } from '@automatisch/types';
+import getCurrentUser from '../common/get-current-user';
+
+const isStillVerified = async ($: IGlobalVariable) => {
+  const user = await getCurrentUser($);
+  return !!user.id;
+};
+
+export default isStillVerified;

packages/backend/src/apps/mattermost/auth/verify-credentials.ts

@@ -0,0 +1,44 @@
+import { IGlobalVariable } from '@automatisch/types';
+import getCurrentUser from '../common/get-current-user';
+
+const verifyCredentials = async ($: IGlobalVariable) => {
+  const oauthRedirectUrlField = $.app.auth.fields.find(
+    (field) => field.key == 'oAuthRedirectUrl'
+  );
+  const redirectUri = oauthRedirectUrlField.value as string;
+  const params = {
+    client_id: $.auth.data.clientId,
+    client_secret: $.auth.data.clientSecret,
+    code: $.auth.data.code,
+    grant_type: 'authorization_code',
+    redirect_uri: redirectUri,
+  };
+  const headers = {
+    'Content-Type': 'application/x-www-form-urlencoded', // This is not documented yet required
+  };
+  const response = await $.http.post('/oauth/access_token', null, {
+    params,
+    headers,
+  });
+
+  const {
+    data: { access_token, refresh_token, scope, token_type },
+  } = response;
+
+  $.auth.data.accessToken = response.data.access_token;
+
+  const currentUser = await getCurrentUser($);
+
+  await $.auth.set({
+    clientId: $.auth.data.clientId,
+    clientSecret: $.auth.data.clientSecret,
+    accessToken: access_token,
+    refreshToken: refresh_token,
+    scope: scope,
+    tokenType: token_type,
+    userId: currentUser.id,
+    screenName: currentUser.username,
+  });
+};
+
+export default verifyCredentials;