ai-utils/src/open-ai.ts

import {OpenAI as openAI} from 'openai';
import {findByProp, objectMap, JSONSanitize, JSONAttemptParse, clean} from '@ztimson/utils';
import {AbortablePromise, Ai} from './ai.ts';
import {LLMMessage, LLMRequest} from './llm.ts';
import {LLMProvider} from './provider.ts';

export class OpenAi extends LLMProvider {
	client!: openAI;

	constructor(public readonly ai: Ai, public readonly host: string | null, public readonly token: string, public model: string) {
		super();
		this.client = new openAI(clean({
			baseURL: host,
			apiKey: token
		}));
	}

	private toStandard(history: any[]): LLMMessage[] {
		for(let i = 0; i < history.length; i++) {
			const h = history[i];
			if(h.role === 'assistant' && h.tool_calls) {
				const tools = h.tool_calls.map((tc: any) => ({
					role: 'tool',
					id: tc.id,
					name: tc.function.name,
					args: JSONAttemptParse(tc.function.arguments, {}),
					timestamp: h.timestamp
				}));
				history.splice(i, 1, ...tools);
				i += tools.length - 1;
			} else if(h.role === 'tool' && h.content) {
				const record = history.find(h2 => h.tool_call_id == h2.id);
				if(record) {
					if(h.content.includes('"error":')) record.error = h.content;
					else record.content = h.content;
				}
				history.splice(i, 1);
				i--;
			}
			if(!history[i]?.timestamp) history[i].timestamp = Date.now();
		}
		return history;
	}

	private fromStandard(history: LLMMessage[]): any[] {
		return history.reduce((result, h) => {
			if(h.role === 'tool') {
				result.push({
					role: 'assistant',
					content: null,
					tool_calls: [{ id: h.id, type: 'function', function: { name: h.name, arguments: JSON.stringify(h.args) } }],
					refusal: null,
					annotations: []
				}, {
					role: 'tool',
					tool_call_id: h.id,
					content: h.error || h.content
				});
			} else {
				const {timestamp, ...rest} = h;
				result.push(rest);
			}
			return result;
		}, [] as any[]);
	}

	ask(message: string, options: LLMRequest = {}): AbortablePromise<string> {
		const controller = new AbortController();
		return Object.assign(new Promise<any>(async (res, rej) => {
			if(options.system && options.history?.[0]?.role != 'system') options.history?.splice(0, 0, {role: 'system', content: options.system, timestamp: Date.now()});
			let history = this.fromStandard([...options.history || [], {role: 'user', content: message, timestamp: Date.now()}]);
			const tools = options.tools || this.ai.options.llm?.tools || [];
			const requestParams: any = {
				model: options.model || this.model,
				messages: history,
				stream: !!options.stream,
				max_tokens: options.max_tokens || this.ai.options.llm?.max_tokens || 4096,
				temperature: options.temperature || this.ai.options.llm?.temperature || 0.7,
				tools: tools.map(t => ({
					type: 'function',
					function: {
						name: t.name,
						description: t.description,
						parameters: {
							type: 'object',
							properties: t.args ? objectMap(t.args, (key, value) => ({...value, required: undefined})) : {},
							required: t.args ? Object.entries(t.args).filter(t => t[1].required).map(t => t[0]) : []
						}
					}
				}))
			};

			let resp: any, isFirstMessage = true;
			do {
				resp = await this.client.chat.completions.create(requestParams).catch(err => {
					err.message += `\n\nMessages:\n${JSON.stringify(history, null, 2)}`;
					throw err;
				});

				if(options.stream) {
					if(!isFirstMessage) options.stream({text: '\n\n'});
					else isFirstMessage = false;
					resp.choices = [{message: {content: '', tool_calls: []}}];
					for await (const chunk of resp) {
						if(controller.signal.aborted) break;
						if(chunk.choices[0].delta.content) {
							resp.choices[0].message.content += chunk.choices[0].delta.content;
							options.stream({text: chunk.choices[0].delta.content});
						}
						if(chunk.choices[0].delta.tool_calls) {
							resp.choices[0].message.tool_calls = chunk.choices[0].delta.tool_calls;
						}
					}
				}

				const toolCalls = resp.choices[0].message.tool_calls || [];
				if(toolCalls.length && !controller.signal.aborted) {
					history.push(resp.choices[0].message);
					const results = await Promise.all(toolCalls.map(async (toolCall: any) => {
						const tool = tools?.find(findByProp('name', toolCall.function.name));
						if(options.stream) options.stream({tool: toolCall.function.name});
						if(!tool) return {role: 'tool', tool_call_id: toolCall.id, content: '{"error": "Tool not found"}'};
						try {
							const args = JSONAttemptParse(toolCall.function.arguments, {});
							const result = await tool.fn(args, options.stream, this.ai);
							return {role: 'tool', tool_call_id: toolCall.id, content: JSONSanitize(result)};
						} catch (err: any) {
							return {role: 'tool', tool_call_id: toolCall.id, content: JSONSanitize({error: err?.message || err?.toString() || 'Unknown'})};
						}
					}));
					history.push(...results);
					requestParams.messages = history;
				}
			} while (!controller.signal.aborted && resp.choices?.[0]?.message?.tool_calls?.length);
			history.push({role: 'assistant', content: resp.choices[0].message.content || ''});
			history = this.toStandard(history);

			if(options.stream) options.stream({done: true});
			if(options.history) options.history.splice(0, options.history.length, ...history);
			res(history.at(-1)?.content);
		}), {abort: () => controller.abort()});
	}
}