import { describe, expect, it } from "vitest";
import { recordFetch } from "./record.js";
import type { FetchLike, HttpExchangeFixture } from "./types.js";

function fakeResponse(body: string, init?: ResponseInit): Response {
	return new Response(body, {
		status: 200,
		statusText: "OK",
		headers: { "content-type": "application/json" },
		...init,
	});
}

describe("recordFetch", () => {
	it("onExchange receives fixture matching request+response", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse('{"ok":true}');
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		await recorded("https://api.example.com/v1/chat", {
			method: "POST",
			headers: { "content-type": "application/json" },
			body: '{"prompt":"hi"}',
		});

		expect(fixtures).toHaveLength(1);
		const fx = fixtures[0] as HttpExchangeFixture;
		expect(fx.request.method).toBe("POST");
		expect(fx.request.url).toBe("https://api.example.com/v1/chat");
		expect(fx.request.headers["content-type"]).toBe("application/json");
		expect(fx.request.body).toBe('{"prompt":"hi"}');
		expect(fx.response.status).toBe(200);
		expect(fx.response.statusText).toBe("OK");
		expect(fx.response.headers["content-type"]).toBe("application/json");
		expect(fx.response.body).toBe('{"ok":true}');
	});

	it("response returned to caller is still fully readable after recording", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse("full body content");
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		const res = await recorded("https://x");
		expect(await res.text()).toBe("full body content");
	});

	it("response body can be read even after fixture is captured", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse("stream data");
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		const res = await recorded("https://x");
		expect(fixtures[0]?.response.body).toBe("stream data");
		expect(await res.text()).toBe("stream data");
	});

	it("captures Request object input with method", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse("ok");
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		const req = new Request("https://from-req.com/path", { method: "PUT" });
		await recorded(req);

		expect(fixtures[0]?.request.url).toBe("https://from-req.com/path");
		expect(fixtures[0]?.request.method).toBe("PUT");
	});

	it("defaults method to GET", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse("ok");
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		await recorded("https://x");
		expect(fixtures[0]?.request.method).toBe("GET");
	});

	it("captures null request body", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () => fakeResponse("ok");
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		await recorded("https://x", { method: "GET" });
		expect(fixtures[0]?.request.body).toBeNull();
	});

	it("captures response error status", async () => {
		const fixtures: HttpExchangeFixture[] = [];
		const fakeFetch: FetchLike = async () =>
			new Response('{"error":"bad request"}', {
				status: 400,
				statusText: "Bad Request",
			});
		const recorded = recordFetch(fakeFetch, (fx) => fixtures.push(fx));

		const res = await recorded("https://x");
		expect(fixtures[0]?.response.status).toBe(400);
		expect(res.status).toBe(400);
	});

	it("passes through to real fetch", async () => {
		let called = false;
		const fakeFetch: FetchLike = async () => {
			called = true;
			return new Response("from fake", { status: 201 });
		};
		const recorded = recordFetch(fakeFetch, () => {});
		const res = await recorded("https://x");
		expect(called).toBe(true);
		expect(res.status).toBe(201);
	});
});