initial port of dartantic_interface types

packages/genai_primitives/CHANGELOG.md

@@ -1 +1,5 @@
-TODO: describe initial version here
+# `genai_primitives` Changelog
+
+## 0.1.0
+
+- Initial release

packages/genai_primitives/example/main.dart

@@ -0,0 +1,120 @@
+// Copyright 2025 The Flutter Authors.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:convert';
+import 'dart:typed_data';
+
+import 'package:genai_primitives/genai_primitives.dart';
+import 'package:json_schema_builder/json_schema_builder.dart';
+
+void main() {
+  print('--- GenAI Primitives Example ---');
+
+  // 1. Define a Tool
+  final ToolDefinition<Object> getWeatherTool = ToolDefinition(
+    name: 'get_weather',
+    description: 'Get the current weather for a location',
+    inputSchema: Schema.object(
+      properties: {
+        'location': Schema.string(
+          description: 'The city and state, e.g. San Francisco, CA',
+        ),
+        'unit': Schema.string(
+          enumValues: ['celsius', 'fahrenheit'],
+          description: 'The unit of temperature',
+        ),
+      },
+      required: ['location'],
+    ),
+  );
+
+  print('\n[Tool Definition]');
+  print(const JsonEncoder.withIndent('  ').convert(getWeatherTool.toJson()));
+
+  // 2. Create a conversation history
+  final history = <ChatMessage>[
+    // System message
+    ChatMessage.system(
+      'You are a helpful weather assistant. '
+      'Use the get_weather tool when needed.',
+    ),
+
+    // User message asking for weather
+    ChatMessage.user('What is the weather in London?'),
+  ];
+
+  print('\n[Initial Conversation]');
+  for (final msg in history) {
+    print('${msg.role.name}: ${msg.text}');
+  }
+
+  // 3. Simulate Model Response with Tool Call
+  final modelResponse = ChatMessage.model(
+    '', // Empty text for tool call
+    parts: [
+      const TextPart('Thinking: User wants weather for London...'),
+      const ToolPart.call(
+        id: 'call_123',
+        name: 'get_weather',
+        arguments: {'location': 'London', 'unit': 'celsius'},
+      ),
+    ],
+  );
+  history.add(modelResponse);
+
+  print('\n[Model Response with Tool Call]');
+  if (modelResponse.hasToolCalls) {
+    for (final ToolPart call in modelResponse.toolCalls) {
+      print('Tool Call: ${call.name}(${call.arguments})');
+    }
+  }
+
+  // 4. Simulate Tool Execution & Result
+  final toolResult = ChatMessage.user(
+    '', // User role is typically used for tool results in many APIs
+    parts: [
+      const ToolPart.result(
+        id: 'call_123',
+        name: 'get_weather',
+        result: {'temperature': 15, 'condition': 'Cloudy'},
+      ),
+    ],
+  );
+  history.add(toolResult);
+
+  print('\n[Tool Result]');
+  print('Result: ${toolResult.toolResults.first.result}');
+
+  // 5. Simulate Final Model Response with Data (e.g. an image generated or
+  //    returned)
+  final finalResponse = ChatMessage.model(
+    'Here is a chart of the weather trend:',
+    parts: [
+      DataPart(
+        Uint8List.fromList([0x89, 0x50, 0x4E, 0x47]), // Fake PNG header
+        mimeType: 'image/png',
+        name: 'weather_chart.png',
+      ),
+    ],
+  );
+  history.add(finalResponse);
+
+  print('\n[Final Model Response with Data]');
+  print('Text: ${finalResponse.text}');
+  if (finalResponse.parts.any((p) => p is DataPart)) {
+    final DataPart dataPart = finalResponse.parts.whereType<DataPart>().first;
+    print(
+      'Attachment: ${dataPart.name} '
+      '(${dataPart.mimeType}, ${dataPart.bytes.length} bytes)',
+    );
+  }
+
+  // 6. Demonstrate JSON serialization of the whole history
+  print('\n[Full History JSON]');
+  print(
+    const JsonEncoder.withIndent(
+      '  ',
+    ).convert(history.map((m) => m.toJson()).toList()),
+  );
+}

packages/genai_primitives/lib/genai_primitives.dart

@@ -2,11 +2,9 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-/// Support for doing something awesome.
-///
-/// More dartdocs go here.
+/// A set of primitives for working with generative AI.
 library;
 
-export 'src/genai_primitives_base.dart';
-
-// TODO: Export any libraries intended for clients of this package.
+export 'src/chat_message.dart';
+export 'src/message_parts.dart';
+export 'src/tool_definition.dart';

packages/genai_primitives/lib/src/chat_message.dart

@@ -0,0 +1,133 @@
+// Copyright 2025 The Flutter Authors.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'package:meta/meta.dart';
+
+import 'message_parts.dart';
+import 'utils.dart';
+
+/// A message in a conversation between a user and a model.
+@immutable
+class ChatMessage {
+  /// Creates a new message.
+  const ChatMessage({
+    required this.role,
+    required this.parts,
+    this.metadata = const {},
+  });
+
+  /// Creates a message from a JSON-compatible map.
+  factory ChatMessage.fromJson(Map<String, dynamic> json) => ChatMessage(
+    role: ChatMessageRole.values.byName(json['role'] as String),
+    parts: (json['parts'] as List<dynamic>)
+        .map((p) => Part.fromJson(p as Map<String, dynamic>))
+        .toList(),
+    metadata: (json['metadata'] as Map<String, dynamic>?) ?? const {},
+  );
+
+  /// Creates a system message.
+  factory ChatMessage.system(
+    String text, {
+    List<Part> parts = const [],
+    Map<String, dynamic>? metadata,
+  }) => ChatMessage(
+    role: ChatMessageRole.system,
+    parts: [TextPart(text), ...parts],
+    metadata: metadata ?? const {},
+  );
+
+  /// Creates a user message with text.
+  factory ChatMessage.user(
+    String text, {
+    List<Part> parts = const [],
+    Map<String, dynamic>? metadata,
+  }) => ChatMessage(
+    role: ChatMessageRole.user,
+    parts: [TextPart(text), ...parts],
+    metadata: metadata ?? const {},
+  );
+
+  /// Creates a model message with text.
+  factory ChatMessage.model(
+    String text, {
+    List<Part> parts = const [],
+    Map<String, dynamic>? metadata,
+  }) => ChatMessage(
+    role: ChatMessageRole.model,
+    parts: [TextPart(text), ...parts],
+    metadata: metadata ?? const {},
+  );
+
+  /// The role of the message author.
+  final ChatMessageRole role;
+
+  /// The content parts of the message.
+  final List<Part> parts;
+
+  /// Optional metadata associated with this message.
+  /// Can include information like suppressed content, warnings, etc.
+  final Map<String, dynamic> metadata;
+
+  /// Gets the text content of the message by concatenating all text parts.
+  String get text => parts.whereType<TextPart>().map((p) => p.text).join();
+
+  /// Checks if this message contains any tool calls.
+  bool get hasToolCalls =>
+      parts.whereType<ToolPart>().any((p) => p.kind == ToolPartKind.call);
+
+  /// Gets all tool calls in this message.
+  List<ToolPart> get toolCalls => parts
+      .whereType<ToolPart>()
+      .where((p) => p.kind == ToolPartKind.call)
+      .toList();
+
+  /// Checks if this message contains any tool results.
+  bool get hasToolResults =>
+      parts.whereType<ToolPart>().any((p) => p.kind == ToolPartKind.result);
+
+  /// Gets all tool results in this message.
+  List<ToolPart> get toolResults => parts
+      .whereType<ToolPart>()
+      .where((p) => p.kind == ToolPartKind.result)
+      .toList();
+
+  /// Converts the message to a JSON-compatible map.
+  Map<String, dynamic> toJson() => {
+    'role': role.name,
+    'parts': parts.map((p) => p.toJson()).toList(),
+    'metadata': metadata,
+  };
+
+  @override
+  bool operator ==(Object other) =>
+      identical(this, other) ||
+      other is ChatMessage &&
+          runtimeType == other.runtimeType &&
+          role == other.role &&
+          listEquals(parts, other.parts) &&
+          mapEquals(metadata, other.metadata);
+
+  @override
+  int get hashCode => Object.hash(
+    role,
+    Object.hashAll(parts),
+    Object.hashAll(metadata.entries),
+  );
+
+  @override
+  String toString() =>
+      'Message(role: $role, parts: $parts, metadata: $metadata)';
+}
+
+/// The role of a message author.
+enum ChatMessageRole {
+  /// A message from the system that sets context or instructions.
+  system,
+
+  /// A message from the end user.
+  user,
+
+  /// A message from the model.
+  model,
+}