models.ts

import { BaseChatModel } from '@langchain/core/language_models/chat_models';
import { ChatOpenAI } from '@langchain/openai';
import { ChatOllama } from '@langchain/ollama';

export type ChatProvider = 'ollama' | 'openai';

export type ChatModelWithTools = BaseChatModel & {
    bindTools: (tools: any[]) => any;
};



export interface ChatModelOptions {
    provider: ChatProvider;
    temperature?: number;
    modelName?: string;
    verbose?: boolean;
}


const chatModelConstructors: Record<ChatProvider, (options: ChatModelOptions) => ChatModelWithTools > = {
    openai: ({ modelName, temperature = 0.7, verbose = false }) =>
        new ChatOpenAI({
            modelName: modelName ?? 'gpt-4o-mini',
            temperature,
            streaming: true,
            openAIApiKey: process.env.OPENAI_API_KEY!,
            verbose,
        }),
    ollama: ({ modelName, temperature = 0.7, verbose = false }) =>
        new ChatOllama({
            model: modelName ?? 'llama3',
            temperature,
            verbose,
        }),
};

export class ChatModelFactory {
    static create(options: ChatModelOptions): ChatModelWithTools {
        const { provider } = options;
        const constructor = chatModelConstructors[provider];
        if (!constructor) {
            throw new Error(`Unsupported provider: ${provider}`);
        }
        return constructor(options);
    }
}