Added createPublisher end-point (#2630)

* Added createPublisher end-point

* Added tests for createPublisher

Author: jonasfj

app/lib/frontend/handlers/pubapi.client.dart

@@ -11,7 +11,6 @@ import 'account.dart';
 import 'custom_api.dart';
 import 'listing.dart';
 import 'package.dart';
-import 'publisher.dart';
 
 part 'pubapi.g.dart';
 
@@ -101,8 +100,12 @@ class PubApi {
 
   /// Starts publisher creation flow.
   @EndPoint.post('/api/publishers/<publisherId>')
-  Future<Response> createPublisher(Request request, String publisherId) =>
-      createPublisherApiHandler(request, publisherId);
+  Future<PublisherInfo> createPublisher(
+    Request request,
+    String publisherId,
+    CreatePublisherRequest body,
+  ) =>
+      publisherBackend.createPublisher(publisherId, body);
 
   /// Returns publisher data in a JSON form.
   @EndPoint.get('/api/publishers/<publisherId>')

app/lib/frontend/handlers/pubapi.dart

@@ -13,10 +13,3 @@ Future<shelf.Response> createPublisherPageHandler(shelf.Request request) async {
   // TODO: implement
   return notFoundHandler(request);
 }
-
-/// Handles requests for POST /api/publisher/<publisherId>
-Future<shelf.Response> createPublisherApiHandler(
-    shelf.Request request, String publisherId) async {
-  // TODO: implement
-  return notFoundHandler(request);
-}

app/lib/frontend/handlers/pubapi.g.dart

@@ -12,6 +12,7 @@ import '../account/backend.dart';
 import '../account/consent_backend.dart';
 import '../shared/email.dart';
 import '../shared/exceptions.dart';
+import 'domain_verifier.dart' show domainVerifier;
 
 import 'models.dart';
 
@@ -60,6 +61,87 @@ class PublisherBackend {
     });
   }
 
+  /// Create publisher.
+  Future<api.PublisherInfo> createPublisher(
+    String publisherId,
+    api.CreatePublisherRequest body,
+  ) async {
+    // Sanity check that domains are:
+    //  - lowercase (because we want that in pub.dev)
+    //  - consist of a-z, 0-9 and dashes
+    // We do not care if they end in dash, as such domains can't be verified.
+    InvalidInputException.checkMatchPattern(
+      publisherId,
+      'publisherId',
+      RegExp(r'^[a-z0-9-]{1,63}\.[a-z0-9-]{1,63}$'),
+    );
+    InvalidInputException.checkStringLength(
+      publisherId,
+      'publisherId',
+      maximum: 255, // Some upper limit for sanity.
+    );
+    InvalidInputException.checkNotNull(body.accessToken, 'accessToken');
+    InvalidInputException.checkStringLength(
+      body.accessToken,
+      'accessToken',
+      minimum: 1,
+      maximum: 4096,
+    );
+
+    // Verify ownership of domain.
+    final isOwner = await domainVerifier.verifyDomainOwnership(
+      publisherId,
+      body.accessToken,
+    );
+    if (!isOwner) {
+      throw AuthorizationException.userIsNotDomainOwner(publisherId);
+    }
+
+    // Create the publisher
+    final now = DateTime.now().toUtc();
+    await _db.withTransaction((tx) async {
+      final key = _db.emptyKey.append(Publisher, id: publisherId);
+      final p = (await tx.lookup<Publisher>([key])).single;
+      if (p != null) {
+        // Check that publisher is the same as what we would create.
+        if (p.created.isBefore(now.subtract(Duration(minutes: 10))) ||
+            p.updated.isBefore(now.subtract(Duration(minutes: 10))) ||
+            p.contactEmail != authenticatedUser.email ||
+            p.description != '' ||
+            p.websiteUrl != 'https://$publisherId') {
+          throw ConflictException.publisherAlreadyExists(publisherId);
+        }
+        // Avoid creating the same publisher again, this end-point is idempotent
+        // if we just do nothing here.
+        return;
+      }
+
+      // Create publisher
+      tx.queueMutations(inserts: [
+        Publisher()
+          ..parentKey = _db.emptyKey
+          ..id = publisherId
+          ..created = now
+          ..description = ''
+          ..contactEmail = authenticatedUser.email
+          ..updated = now
+          ..websiteUrl = 'https://$publisherId',
+        PublisherMember()
+          ..parentKey = _db.emptyKey.append(Publisher, id: publisherId)
+          ..id = authenticatedUser.userId
+          ..created = now
+          ..updated = now
+          ..role = PublisherMemberRole.admin
+      ]);
+      await tx.commit();
+    });
+
+    // Return publisher as it was created
+    final key = _db.emptyKey.append(Publisher, id: publisherId);
+    final p = (await _db.lookup<Publisher>([key])).single;
+    return _asPublisherInfo(p);
+  }
+
   /// Gets the publisher data
   Future<api.PublisherInfo> getPublisher(String publisherId) async {
     final p = await _getPublisher(publisherId);

app/lib/frontend/handlers/publisher.dart

@@ -0,0 +1,62 @@
+import 'package:gcloud/service_scope.dart' as ss;
+import 'package:googleapis_auth/auth.dart' as auth;
+import 'package:googleapis/webmasters/v3.dart' as wmx;
+import 'package:http/http.dart' as http;
+import 'package:retry/retry.dart' show retry;
+
+import '../shared/exceptions.dart' show AuthorizationException;
+
+/// Sets the [DomainVerifier] service.
+void registerDomainVerifier(DomainVerifier domainVerifier) =>
+    ss.register(#_domainVerifier, domainVerifier);
+
+/// The active [DomainVerifier] service.
+DomainVerifier get domainVerifier =>
+    ss.lookup(#_domainVerifier) as DomainVerifier;
+
+/// Service that can verify ownership of a domain by asking Search Console
+/// through Webmaster API v3.
+///
+/// Please obtain instances of this from [domainVerifier], as this allows for
+/// dependency injection during testing.
+class DomainVerifier {
+  /// Verify ownership of [domain] using [accessToken] which has the read-only
+  /// scope for Search Console API.
+  Future<bool> verifyDomainOwnership(String domain, String accessToken) async {
+    // Create client for talking to Webmasters API:
+    // https://developers.google.com/webmaster-tools/search-console-api-original/v3/parameters
+    final client = auth.authenticatedClient(
+      http.Client(),
+      auth.AccessCredentials(
+        auth.AccessToken(
+          'Bearer',
+          accessToken,
+          DateTime.now().toUtc().add(Duration(minutes: 20)), // avoid refresh
+        ),
+        null,
+        [wmx.WebmastersApi.WebmastersReadonlyScope],
+      ),
+    );
+    try {
+      // Request list of sites/domains from the Search Console API.
+      final sites = await retry(
+        () => wmx.WebmastersApi(client).sites.list(),
+        maxAttempts: 3,
+        maxDelay: Duration(milliseconds: 500),
+        retryIf: (e) => e is! auth.AccessDeniedException,
+      );
+      // Determine if the user is in fact owner of the domain in question.
+      // Note. domains are prefixed 'sc-domain:' and 'siteOwner' is the only
+      //       permission that ensures the user actually did DNS verification.
+      return sites.siteEntry.any(
+        (s) =>
+            s.siteUrl.toLowerCase() == 'sc-domain:$domain' &&
+            s.permissionLevel == 'siteOwner', // must be 'siteOwner'!
+      );
+    } on auth.AccessDeniedException {
+      throw AuthorizationException.missingSearchConsoleReadAccess();
+    } finally {
+      client.close();
+    }
+  }
+}

app/lib/publisher/backend.dart

@@ -165,7 +165,7 @@ class AuthenticationException extends ResponseException
 ///
 /// Example:
 ///  * Modifying a package for which the user doesn't have permissions,
-///  * Creating a package without domain validation.
+///  * Creating a publisher without domain validation.
 class AuthorizationException extends ResponseException
     implements UnauthorizedAccessException {
   AuthorizationException._(String message)
@@ -201,6 +201,39 @@ class AuthorizationException extends ResponseException
         'package `$publisher`.',
       );
 
+  static final _domainVerificationUrl =
+      Uri.parse('https://www.google.com/webmasters/verification/verification');
+
+  /// Signaling that the user is not a verified owner of the [domain] for which
+  /// the user is trying to create a publisher.
+  factory AuthorizationException.userIsNotDomainOwner(String domain) =>
+      AuthorizationException._([
+        'Insufficient permissions to create publisher `$domain`, to create ',
+        'this publisher the domain `$domain` must be _verified_ in the ',
+        '[search console](https://search.google.com/search-console/welcome).',
+        '',
+        'It is not sufficient to be granted access to the domain, the domain ',
+        'must be verified with the Google account used to created the ',
+        'publisher. It is also insufficient to verify a URL or URL prefix,',
+        'the domain must be verified with a **DNS record**.',
+        '',
+        '<b><a href="${_domainVerificationUrl.replace(queryParameters: {
+          "domain": domain
+        })}" target="_blank">Open domain verification flow.</a></b>',
+        '',
+        'Note, once the publisher is created the domain verification need not',
+        'remain in place. This is only required for publisher creation.',
+      ].join('\n'));
+
+  /// Signaling that the user did not grant read-only access to the
+  /// search console, making it impossible for the server to verify the users
+  /// domain ownership.
+  factory AuthorizationException.missingSearchConsoleReadAccess() =>
+      AuthorizationException._([
+        'Read-only access to Search Console data was not granted, preventing',
+        '`pub.dev` from verifying that you own the domain.',
+      ].join('\n'));
+
   @override
   String toString() => '$code: $message'; // used by package:pub_server
 }
@@ -225,6 +258,11 @@ class ConflictException extends ResponseException {
   /// The active user can't update their own role.
   factory ConflictException.cantUpdateOwnRole() =>
       ConflictException._('User can\'t update their own role.');
+
+  /// The user is trying to create a publisher that already exists.
+  factory ConflictException.publisherAlreadyExists(String domain) =>
+      ConflictException._(
+          'A publisher with the domain `$domain` already exists');
 }
 
 /// Thrown when the analysis for a package is not done yet.

app/lib/publisher/domain_verifier.dart

@@ -14,6 +14,7 @@ import '../frontend/search_service.dart';
 import '../history/backend.dart';
 import '../job/backend.dart';
 import '../publisher/backend.dart';
+import '../publisher/domain_verifier.dart';
 import '../scorecard/backend.dart';
 import '../search/backend.dart';
 import '../search/index_simple.dart';
@@ -71,6 +72,7 @@ Future<void> withPubServices(FutureOr<void> Function() fn) async {
       PopularityStorage(await getOrCreateBucket(
           storageService, activeConfiguration.popularityDumpBucketName)),
     );
+    registerDomainVerifier(DomainVerifier());
     registerPublisherBackend(PublisherBackend(dbService));
     registerScoreCardBackend(ScoreCardBackend(dbService));
     registerSearchBackend(SearchBackend(dbService));

app/lib/shared/exceptions.dart

@@ -33,6 +33,55 @@ void main() {
       });
     });
 
+    group('Create publisher', () {
+      testWithServices('verified.com', () async {
+        final api = createPubApiClient(authToken: hansAuthenticated.userId);
+
+        // Check that we can create the publisher
+        final r1 = await api.createPublisher(
+          'verified.com',
+          CreatePublisherRequest(accessToken: 'dummy-token-for-testing'),
+        );
+        expect(r1.contactEmail, hansAuthenticated.email);
+
+        // Check that creating again idempotently works too
+        final r2 = await api.createPublisher(
+          'verified.com',
+          CreatePublisherRequest(accessToken: 'dummy-token-for-testing'),
+        );
+        expect(r2.contactEmail, hansAuthenticated.email);
+
+        // Check that we can update the description
+        final r3 = await api.updatePublisher(
+          'verified.com',
+          UpdatePublisherRequest(description: 'hello-world'),
+        );
+        expect(r3.description, 'hello-world');
+
+        // Check that we get a sane result from publisherInfo
+        final r4 = await api.publisherInfo('verified.com');
+        expect(r4.toJson(), {
+          'description': 'hello-world',
+          'contactEmail': hansAuthenticated.email,
+        });
+      });
+
+      testWithServices('notverified.com', () async {
+        final api = createPubApiClient(authToken: hansAuthenticated.userId);
+
+        // Check that we can create the publisher
+        final rs = api.createPublisher(
+          'notverified.com',
+          CreatePublisherRequest(accessToken: 'dummy-token-for-testing'),
+        );
+        await expectApiException(
+          rs,
+          status: 403,
+          code: 'InsufficientPermissions',
+        );
+      });
+    });
+
     group('Update description', () {
       _testAdminAuthIssues(
         (client) => client.updatePublisher(