src/lib/server/endpoints/openai/endpointOai.ts

import { z } from "zod";
import { openAICompletionToTextGenerationStream } from "./openAICompletionToTextGenerationStream";
import { openAIChatToTextGenerationStream } from "./openAIChatToTextGenerationStream";
import type { CompletionCreateParamsStreaming } from "openai/resources/completions";
import type { ChatCompletionCreateParamsStreaming } from "openai/resources/chat/completions";
import { buildPrompt } from "$lib/buildPrompt";
import { env } from "$env/dynamic/private";
import type { Endpoint } from "../endpoints";
import type OpenAI from "openai";
import { createImageProcessorOptionsValidator, makeImageProcessor } from "../images";
import type { MessageFile } from "$lib/types/Message";
import type { EndpointMessage } from "../endpoints";

export const endpointOAIParametersSchema = z.object({
	weight: z.number().int().positive().default(1),
	model: z.any(),
	type: z.literal("openai"),
	baseURL: z.string().url().default("https://api.openai.com/v1"),
	apiKey: z.string().default(env.OPENAI_API_KEY ?? "sk-"),
	completion: z
		.union([z.literal("completions"), z.literal("chat_completions")])
		.default("chat_completions"),
	defaultHeaders: z.record(z.string()).optional(),
	defaultQuery: z.record(z.string()).optional(),
	extraBody: z.record(z.any()).optional(),
	multimodal: z
		.object({
			image: createImageProcessorOptionsValidator({
				supportedMimeTypes: [
					"image/png",
					"image/jpeg",
					"image/webp",
					"image/avif",
					"image/tiff",
					"image/gif",
				],
				preferredMimeType: "image/webp",
				maxSizeInMB: Infinity,
				maxWidth: 4096,
				maxHeight: 4096,
			}),
		})
		.default({}),
});

export async function endpointOai(
	input: z.input<typeof endpointOAIParametersSchema>
): Promise<Endpoint> {
	const {
		baseURL,
		apiKey,
		completion,
		model,
		defaultHeaders,
		defaultQuery,
		multimodal,
		extraBody,
	} = endpointOAIParametersSchema.parse(input);

	/* eslint-disable-next-line no-shadow */
	let OpenAI;
	try {
		OpenAI = (await import("openai")).OpenAI;
	} catch (e) {
		throw new Error("Failed to import OpenAI", { cause: e });
	}

	const openai = new OpenAI({
		apiKey: apiKey ?? "sk-",
		baseURL,
		defaultHeaders,
		defaultQuery,
	});

	const imageProcessor = makeImageProcessor(multimodal.image);

	if (completion === "completions") {
		return async ({ messages, preprompt, continueMessage, generateSettings }) => {
			const prompt = await buildPrompt({
				messages,
				continueMessage,
				preprompt,
				model,
			});

			const parameters = { ...model.parameters, ...generateSettings };
			const body: CompletionCreateParamsStreaming = {
				model: model.id ?? model.name,
				prompt,
				stream: true,
				max_tokens: parameters?.max_new_tokens,
				stop: parameters?.stop,
				temperature: parameters?.temperature,
				top_p: parameters?.top_p,
				frequency_penalty: parameters?.repetition_penalty,
			};

			const openAICompletion = await openai.completions.create(body, {
				body: { ...body, ...extraBody },
			});

			return openAICompletionToTextGenerationStream(openAICompletion);
		};
	} else if (completion === "chat_completions") {
		return async ({ messages, preprompt, generateSettings }) => {
			let messagesOpenAI: OpenAI.Chat.Completions.ChatCompletionMessageParam[] =
				await prepareMessages(messages, imageProcessor);

			if (messagesOpenAI?.[0]?.role !== "system") {
				messagesOpenAI = [{ role: "system", content: "" }, ...messagesOpenAI];
			}

			if (messagesOpenAI?.[0]) {
				messagesOpenAI[0].content = preprompt ?? "";
			}

			const parameters = { ...model.parameters, ...generateSettings };
			const body: ChatCompletionCreateParamsStreaming = {
				model: model.id ?? model.name,
				messages: messagesOpenAI,
				stream: true,
				max_tokens: parameters?.max_new_tokens,
				stop: parameters?.stop,
				temperature: parameters?.temperature,
				top_p: parameters?.top_p,
				frequency_penalty: parameters?.repetition_penalty,
			};

			const openChatAICompletion = await openai.chat.completions.create(body, {
				body: { ...body, ...extraBody },
			});

			return openAIChatToTextGenerationStream(openChatAICompletion);
		};
	} else {
		throw new Error("Invalid completion type");
	}
}

async function prepareMessages(
	messages: EndpointMessage[],
	imageProcessor: ReturnType<typeof makeImageProcessor>
): Promise<OpenAI.Chat.Completions.ChatCompletionMessageParam[]> {
	return Promise.all(
		messages.map(async (message) => {
			if (message.from === "user") {
				return {
					role: message.from,
					content: [
						...(await prepareFiles(imageProcessor, message.files ?? [])),
						{ type: "text", text: message.content },
					],
				};
			}
			return {
				role: message.from,
				content: message.content,
			};
		})
	);
}

async function prepareFiles(
	imageProcessor: ReturnType<typeof makeImageProcessor>,
	files: MessageFile[]
): Promise<OpenAI.Chat.Completions.ChatCompletionContentPartImage[]> {
	const processedFiles = await Promise.all(files.map(imageProcessor));
	return processedFiles.map((file) => ({
		type: "image_url" as const,
		image_url: {
			url: `data:${file.mime};base64,${file.image.toString("base64")}`,
		},
	}));
}