// Copyright 2026 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import Foundation

/// An internal data model for `FunctionCallingConfig`.
///
/// ### Gemini Developer API
///
/// Type: `GoogleAiGenerativelanguageV1betaFunctionCallingConfig`
///
/// Configuration for specifying function calling behavior.
///
/// ### Gemini Enterprise API
///
/// Type: `GoogleCloudAiplatformV1beta1FunctionCallingConfig`
///
/// Function calling config.
package struct FunctionCallingConfig: Codable, Sendable, Equatable, Hashable {
  /// Optional. Specifies the mode in which function calling should execute. If
  ///
  /// ### Gemini Developer API
  ///
  /// Optional. Specifies the mode in which function calling should execute. If
  /// unspecified, the default value will be set to AUTO.
  ///
  /// ### Gemini Enterprise API
  ///
  /// Optional. Function calling mode.
  package let mode: Mode?

  /// Optional. A set of function names that, when provided, limits the functions the model
  ///
  /// ### Gemini Developer API
  ///
  /// Optional. A set of function names that, when provided, limits the functions the model
  /// will call.
  ///
  /// This should only be set when the Mode is ANY or VALIDATED. Function names
  /// should match [FunctionDeclaration.name]. When set, model will
  /// predict a function call from only allowed function names.
  ///
  /// ### Gemini Enterprise API
  ///
  /// Optional. Function names to call. Only set when the Mode is ANY. Function names
  /// should match FunctionDeclaration.name. With mode set to ANY, model will
  /// predict a function call from the set of function names provided.
  package let allowedFunctionNames: [String]?

  /// Optional. When set to true, arguments of a single function call will be streamed out
  ///
  /// ### Gemini Developer API
  ///
  /// > Important: This property is not supported in the Gemini Developer API.
  ///
  /// ### Gemini Enterprise API
  ///
  /// Optional. When set to true, arguments of a single function call will be streamed out
  /// in multiple parts/contents/responses. Partial parameter results will be
  /// returned in the `FunctionCall.partial_args` field.
  package let streamFunctionCallArguments: Bool?

  /// Creates a new `FunctionCallingConfig`.
  ///
  /// - Parameters:
  ///   - mode: Optional. Specifies the mode in which function calling should execute. If (behavior varies by backend). For more details, see ``mode``.
  ///   - allowedFunctionNames: Optional. A set of function names that, when provided, limits the functions the model (behavior varies by backend). For more details, see ``allowedFunctionNames``.
  ///   - streamFunctionCallArguments: Optional. When set to true, arguments of a single function call will be streamed out (Gemini Enterprise API only). For more details, see ``streamFunctionCallArguments``.
  package init(
    mode: Mode? = nil,
    allowedFunctionNames: [String]? = nil,
    streamFunctionCallArguments: Bool? = nil
  ) {
    self.mode = mode
    self.allowedFunctionNames = allowedFunctionNames
    self.streamFunctionCallArguments = streamFunctionCallArguments
  }
  enum CodingKeys: String, CodingKey {
    case mode = "mode"
    case allowedFunctionNames = "allowedFunctionNames"
    case streamFunctionCallArguments = "streamFunctionCallArguments"
  }
}