/*
 * Copyright 2025 CloudWeGo Authors
 *
 * 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.
 */

package agent

import (
	"errors"

	"github.com/cloudwego/eino/components/model"
	"github.com/cloudwego/eino/schema"
)

// ChatModelWithTools returns a chat model configured with tool schemas.
// If a ToolCallingChatModel is provided, it is used directly (and optionally
// configured with tools). Otherwise, a plain ChatModel is bound with tools.
func ChatModelWithTools(cm model.ChatModel, toolCallingModel model.ToolCallingChatModel, toolInfos []*schema.ToolInfo) (
	model.BaseChatModel, error) {

	if toolCallingModel != nil {
		if len(toolInfos) == 0 {
			return toolCallingModel, nil
		}
		return toolCallingModel.WithTools(toolInfos)
	}

	if cm != nil {
		if len(toolInfos) == 0 {
			return cm, nil
		}
		err := cm.BindTools(toolInfos)
		if err != nil {
			return nil, err
		}

		return cm, nil
	}

	return nil, errors.New("no chat model provided")
}