First pass at DAP resolution (#3)

* first pass at dap resolution

* add `collection` dep to use `firstWhereOrNull()`

* remove all force unwrapping

---------

Co-authored-by: Ethan Lee <[email protected]>

lib/src/dap_resolver.dart

@@ -1,6 +1,11 @@
-import 'package:dap/dap.dart';
+import 'dart:convert';
+
+import 'package:dap/src/dap.dart';
+import 'package:dap/src/registration_request.dart';
+import 'package:dap/src/money_address.dart';
 import 'package:http/http.dart' as http;
 import 'package:web5/web5.dart';
+import 'package:collection/collection.dart';
 
 class DapResolver {
   http.Client client;
@@ -9,11 +14,157 @@ class DapResolver {
   DapResolver(this.didResolver, {http.Client? client})
       : client = client ?? http.Client();
 
-  Future<void> getMoneyAddresses(Dap dap) async {}
+  Future<List<MoneyAddress>> getMoneyAddresses(Dap dap) async {
+    throw UnimplementedError();
+  }
+
+  Future<DapResolutionResult> resolve(Dap dap) async {
+    final registryDidResolution = await didResolver.resolveDid(dap.registryDid);
+    if (registryDidResolution.hasError()) {
+      throw DapResolutionException(
+          'Failed to resolve registry DID: ${registryDidResolution.didResolutionMetadata.error}');
+    }
+
+    final dapRegistryService = registryDidResolution.didDocument?.service
+        ?.firstWhereOrNull((service) => service.type == 'DAPRegistry');
+
+    if (dapRegistryService == null) {
+      throw DapResolutionException(
+          'Registry DID does not have a DAPRegistry service');
+    }
+
+    final serviceEndpoint = dapRegistryService.serviceEndpoint.firstOrNull;
+
+    if (serviceEndpoint == null) {
+      throw DapResolutionException(
+          'DAPRegistry service does not have a service endpoint');
+    }
+
+    Uri registryEndpoint;
+
+    try {
+      registryEndpoint = Uri.parse(serviceEndpoint);
+    } on FormatException {
+      throw DapResolutionException(
+          'Invalid service endpoint in DAPRegistry service');
+    }
+
+    final dereferenceUrl =
+        registryEndpoint.replace(path: '/daps/${dap.handle}');
+
+    http.Response dereferenceResponse;
+    try {
+      dereferenceResponse = await client.get(dereferenceUrl);
+    } on Exception catch (e) {
+      throw DapResolutionException('Failed to dereference DAP handle: $e');
+    }
+
+    if (dereferenceResponse.statusCode != 200) {
+      throw DapResolutionException(
+          'Failed to dereference DAP handle: (${dereferenceResponse.statusCode}) ${dereferenceResponse.body}');
+    }
+
+    DereferencedHandle dereferencedDap;
+    try {
+      dereferencedDap = DereferencedHandle.fromJson(dereferenceResponse.body);
+    } on FormatException catch (e) {
+      throw DapResolutionException(
+          'Failed to parse dereferenced DAP handle: $e');
+    }
+
+    final dapDidResolution =
+        await didResolver.resolveDid(dereferencedDap.did.uri);
+
+    if (dapDidResolution.hasError()) {
+      throw DapResolutionException(
+          'Failed to resolve DAP DID: ${dapDidResolution.didResolutionMetadata.error}');
+    }
+
+    final dapDidServices = dapDidResolution.didDocument?.service ?? [];
+    List<MoneyAddress> moneyAddresses = [];
+
+    for (var service in dapDidServices) {
+      if (service.type == 'MoneyAddress') {
+        try {
+          var address = MoneyAddress.parse(service.serviceEndpoint.first);
+          moneyAddresses.add(address);
+        } catch (e) {
+          print(
+              'Error parsing MoneyAddress for service: ${service.serviceEndpoint.first}, error: $e');
+        }
+      }
+    }
+
+    return DapResolutionResult(
+      dap: dap,
+      dapDid: dereferencedDap.did,
+      dapDidDocument: dapDidResolution.didDocument ??
+          DidDocument(id: dereferencedDap.did.uri),
+      registryDidDocument: registryDidResolution.didDocument ??
+          DidDocument(id: dereferencedDap.did.uri),
+      registryEndpoint: registryEndpoint,
+      moneyAddresses: moneyAddresses,
+    );
+  }
+}
+
+class DapResolutionResult {
+  final Dap dap;
+  final Did dapDid;
+  final DidDocument dapDidDocument;
+  final DidDocument registryDidDocument;
+  final Uri registryEndpoint;
+  final List<MoneyAddress> moneyAddresses;
+
+  DapResolutionResult({
+    required this.dap,
+    required this.dapDid,
+    required this.dapDidDocument,
+    required this.registryDidDocument,
+    required this.registryEndpoint,
+    required this.moneyAddresses,
+  });
+}
+
+class DapResolutionException implements Exception {
+  final String message;
+
+  DapResolutionException(this.message);
+
+  @override
+  String toString() {
+    return "DapResolutionException: $message";
+  }
+}
+
+/// Response from dereferencing a DAP handle from a DAP registry.
+/// More info [here](https://github.com/TBD54566975/dap?tab=readme-ov-file#dap-resolution)
+class DereferencedHandle {
+  final Did did;
+  final RegistrationRequest proof;
+
+  DereferencedHandle({required this.did, required this.proof});
+
+  // Factory constructor to create an instance from a JSON string
+  factory DereferencedHandle.fromJson(String source) =>
+      DereferencedHandle.fromMap(jsonDecode(source));
+
+  // Factory constructor to create an instance from a map
+  factory DereferencedHandle.fromMap(Map<String, dynamic> map) {
+    return DereferencedHandle(
+      did: Did.parse(map['did']),
+      proof: RegistrationRequest.fromMap(map['proof']),
+    );
+  }
+
+  // Converts the instance into a map
+  Map<String, dynamic> toMap() {
+    return {
+      'did': did.uri,
+      'proof': proof.toMap(),
+    };
+  }
 
-  /// can construct yourself for mocking purposes etc.
-  /// getRegistryEndpoint() -> resolve registry did, find DAPRegistry service endpoint
-  /// dereferenceHandle() -> makes GET request to registry endpoint to get DAP's DID
-  /// resolveDid() -> resolve DAP's DID, get back did document
-  /// getMoneyAddresses(dap) -> getRegistryEndpoint() -> dereferenceHandle() -> resolveDid() -> parse out money addresses from did document -> return list of money addrrsses
+  // Converts the instance to a JSON string
+  String toJson() => jsonEncode(toMap());
 }

lib/src/registration_request.dart

@@ -0,0 +1,47 @@
+import 'dart:convert';
+
+class RegistrationRequest {
+  final String id;
+  final String handle;
+  final String did;
+  final String domain;
+  final String signature;
+
+  RegistrationRequest({
+    required this.id,
+    required this.handle,
+    required this.did,
+    required this.domain,
+    required this.signature,
+  });
+
+  factory RegistrationRequest.fromJson(String source) =>
+      RegistrationRequest.fromMap(jsonDecode(source));
+
+  factory RegistrationRequest.fromMap(Map<String, dynamic> map) {
+    return RegistrationRequest(
+      id: map['id'],
+      handle: map['handle'],
+      did: map['did'],
+      domain: map['domain'],
+      signature: map['signature'],
+    );
+  }
+
+  // Converts the instance into a map
+  Map<String, dynamic> toMap() {
+    return {
+      'id': id,
+      'handle': handle,
+      'did': did,
+      'domain': domain,
+      'signature': signature,
+    };
+  }
+
+  // Converts the instance to a JSON string
+  String toJson() => jsonEncode(toMap());
+
+  @override
+  String toString() => toJson();
+}

pubspec.yaml

@@ -8,6 +8,7 @@ environment:
 
 # Add regular dependencies here.
 dependencies:
+  collection: ^1.18.0
   http: ^1.2.0
   typeid: ^1.0.1
   web5: ^0.2.0

test/dap_resolver_test.dart

@@ -0,0 +1,24 @@
+import 'package:dap/dap.dart';
+import 'package:dap/src/dap_resolver.dart';
+import 'package:test/test.dart';
+import 'package:web5/web5.dart';
+
+void main() {
+  group('DapResolver.resolve', () {
+    test('should resolve DAP', () async {
+      final dap = Dap.parse('@moegrammer/didpay.me');
+
+      // TODO: use mocks
+      final resolver = DapResolver(DidResolver(
+        methodResolvers: [DidWebResolver()],
+      ));
+
+      final result = await resolver.resolve(dap);
+
+      expect(result.dap.handle, 'moegrammer');
+      expect(result.dap.domain, 'didpay.me');
+      expect(result.dap.registryDid, 'did:web:didpay.me');
+      expect(result.moneyAddresses.length, 1);
+    });
+  });
+}