import { describe, it, expect } from "vitest";
import { handleForcedSSEToJson } from "../../open-sse/handlers/chatCore/sseToJsonHandler.js";

const encoder = new TextEncoder();
const sseResponse = (chunks) => {
	const body = new ReadableStream({
		start(c) {
			for (const ch of chunks)
				c.enqueue(encoder.encode(`data: ${JSON.stringify(ch)}\n\n`));
			c.enqueue(encoder.encode("data: [DONE]\n\n"));
			c.close();
		},
	});
	return new Response(body, {
		status: 200,
		headers: { "content-type": "text/event-stream" },
	});
};

const mkChunk = (content, finish = null) => ({
	id: "x",
	object: "chat.completion.chunk",
	created: 1,
	model: "m",
	choices: [
		{ index: 0, delta: content ? { content } : {}, finish_reason: finish },
	],
});

const baseCtx = {
	provider: "fakeprovider",
	model: "m",
	body: { stream: false },
	stream: true,
	translatedBody: null,
	finalBody: null,
	requestStartTime: Date.now(),
	connectionId: "c1",
	apiKey: null,
	clientRawRequest: null,
	onRequestSuccess: null,
	pxpipe: null,
	reqTag: "",
	log: null,
	trackDone: () => {},
	appendLog: () => {},
	reqLogger: null,
	toolNameMap: null,
	sourceFormat: "openai",
};

describe("Layer 1 — non-streaming stream error patterns", () => {
	it("returns a 502 error result when content matches a configured pattern", async () => {
		const result = await handleForcedSSEToJson({
			...baseCtx,
			streamErrorPatterns: { fakeprovider: ["Network connection lost"] },
			providerResponse: sseResponse([
				mkChunk("Network connection lost."),
				mkChunk(null, "stop"),
			]),
		});
		expect(result.success).toBe(false);
		expect(result.status).toBe(502);
		expect(result.error).toContain("Network connection lost");
	});

	it("succeeds when content does not match", async () => {
		const result = await handleForcedSSEToJson({
			...baseCtx,
			streamErrorPatterns: { fakeprovider: ["Network connection lost"] },
			providerResponse: sseResponse([
				mkChunk("hello world"),
				mkChunk(null, "stop"),
			]),
		});
		expect(result.success).toBe(true);
	});

	it("ignores patterns for other providers", async () => {
		const result = await handleForcedSSEToJson({
			...baseCtx,
			streamErrorPatterns: { otherprovider: ["hello"] },
			providerResponse: sseResponse([
				mkChunk("hello world"),
				mkChunk(null, "stop"),
			]),
		});
		expect(result.success).toBe(true);
	});
});