import { describe, expect, test } from "bun:test";
import { createHttpClient, HttpError } from "../src/http.ts";
import { collect, createFixtureHttp, createTestContext } from "../src/testing.ts";
import { definePlugin } from "../src/types.ts";

const res = (status: number, body: unknown = {}, headers: Record<string, string> = {}) =>
  new Response(JSON.stringify(body), { status, headers });

function seq(...responses: Response[]) {
  const reqs: Request[] = [];
  const fetchImpl = (async (input: RequestInfo | URL, init?: RequestInit) => {
    reqs.push(new Request(input, init));
    return responses.shift()!;
  }) as typeof fetch;
  return { fetchImpl, reqs };
}

describe("http client", () => {
  test("retries 429 honouring Retry-After", async () => {
    const { fetchImpl } = seq(res(429, {}, { "Retry-After": "2" }), res(200, { ok: 1 }));
    const sleeps: number[] = [];
    const http = createHttpClient({ userAgent: "t/1", fetchImpl, sleep: async (ms) => void sleeps.push(ms) });
    expect(await http.json<{ ok: number }>("https://x.test/a")).toEqual({ ok: 1 });
    expect(sleeps).toEqual([2000]);
  });

  test("honours Retry-After as HTTP date and X-RateLimit-Reset-In", async () => {
    const t0 = Date.UTC(2026, 0, 1, 0, 0, 0);
    const date = new Date(t0 + 5000).toUTCString();
    const { fetchImpl } = seq(
      res(503, {}, { "Retry-After": date }),
      res(429, {}, { "X-RateLimit-Reset-In": "3" }),
      res(200, {}),
    );
    const sleeps: number[] = [];
    const http = createHttpClient({ userAgent: "t/1", fetchImpl, now: () => t0, sleep: async (ms) => void sleeps.push(ms) });
    await http.json("https://x.test/a");
    expect(sleeps).toEqual([5000, 3000]);
  });

  test("exponential backoff without headers", async () => {
    const { fetchImpl } = seq(res(500), res(500), res(200));
    const sleeps: number[] = [];
    const http = createHttpClient({ userAgent: "t/1", fetchImpl, sleep: async (ms) => void sleeps.push(ms) });
    await http.json("https://x.test/a");
    expect(sleeps.length).toBe(2);
    expect(sleeps[1]!).toBeGreaterThan(sleeps[0]!);
  });

  test("gives up after maxRetries with HttpError", async () => {
    const { fetchImpl, reqs } = seq(res(500, { e: 1 }), res(500, { e: 2 }), res(500, { e: 3 }));
    const http = createHttpClient({ userAgent: "t/1", maxRetries: 2, fetchImpl, sleep: async () => {} });
    const err = (await http.json("https://x.test/a").catch((e) => e)) as HttpError;
    expect(err).toBeInstanceOf(HttpError);
    expect(err).toBeInstanceOf(Error);
    expect(err.status).toBe(500);
    expect(err.body).toBe('{"e":3}');
    expect(reqs.length).toBe(3);
  });

  test("non-retryable errors throw immediately from json", async () => {
    const { fetchImpl, reqs } = seq(res(404, { nope: true }));
    const http = createHttpClient({ userAgent: "t/1", fetchImpl, sleep: async () => {} });
    const err = (await http.json("https://x.test/a").catch((e) => e)) as HttpError;
    expect(err).toBeInstanceOf(HttpError);
    expect(err.status).toBe(404);
    expect(reqs.length).toBe(1);
  });

  test("json sends Accept, User-Agent and appends query", async () => {
    const { fetchImpl, reqs } = seq(res(200, {}));
    const http = createHttpClient({ userAgent: "sttracker/1", fetchImpl, sleep: async () => {} });
    await http.json("https://x.test/a?z=1", { query: { q: "a b", n: 2, skip: undefined } });
    const r = reqs[0]!;
    expect(r.headers.get("accept")).toBe("application/json");
    expect(r.headers.get("user-agent")).toBe("sttracker/1");
    const u = new URL(r.url);
    expect(u.searchParams.get("z")).toBe("1");
    expect(u.searchParams.get("q")).toBe("a b");
    expect(u.searchParams.get("n")).toBe("2");
    expect(u.searchParams.has("skip")).toBe(false);
  });

  test("rate limits to ratePerMinute", async () => {
    let clock = 1_000_000;
    const sleeps: number[] = [];
    const { fetchImpl } = seq(res(200), res(200), res(200));
    const http = createHttpClient({
      userAgent: "t/1",
      ratePerMinute: 60,
      burst: 1,
      fetchImpl,
      now: () => clock,
      sleep: async (ms) => {
        sleeps.push(ms);
        clock += ms;
      },
    });
    await http.json("https://x.test/1");
    await http.json("https://x.test/2");
    await http.json("https://x.test/3");
    expect(sleeps.length).toBe(2);
    for (const s of sleeps) expect(Math.abs(s - 1000)).toBeLessThanOrEqual(5);
  });
});

describe("testing harness", () => {
  test("fixture routes match by full url or url without query; unknown throws", async () => {
    const fx = createFixtureHttp({
      "GET https://x.test/a": { a: 1 },
      "GET https://x.test/b?id=2": { b: 2 },
      "POST https://x.test/c": (req: Request) => ({ method: req.method }),
    });
    expect(await (await fx.fetch("https://x.test/a?q=1")).json()).toEqual({ a: 1 });
    expect(await (await fx.fetch("https://x.test/b?id=2")).json()).toEqual({ b: 2 });
    expect(await (await fx.fetch("https://x.test/c", { method: "POST" })).json()).toEqual({ method: "POST" });
    expect(fx.calls.length).toBe(3);
    await expect(fx.fetch("https://x.test/zzz")).rejects.toThrow();
  });

  test("createTestContext wires http, credentials and cursor", async () => {
    const fx = createFixtureHttp({ "GET https://x.test/a": { a: 1 } });
    const ctx = createTestContext({ fetch: fx.fetch });
    expect(await ctx.http.json("https://x.test/a")).toEqual({ a: 1 });
    expect(await ctx.credentials.get()).toBeNull();
    await ctx.credentials.save({ token: "t" });
    expect(await ctx.credentials.get()).toEqual({ token: "t" });
    await ctx.cursor.set("c1");
    expect(await ctx.cursor.get()).toBe("c1");
    expect(ctx.saved).toEqual({ credentials: [{ token: "t" }], cursor: ["c1"] });
    async function* gen() {
      yield 1;
      yield 2;
    }
    expect(await collect(gen())).toEqual([1, 2]);
  });
});

describe("definePlugin", () => {
  const manifest = { id: "p", name: "P", version: "1", sdkVersion: 1 as const, mediaTypes: [], capabilities: [], config: [] };
  test("identity for valid manifest", () => {
    const p = { manifest };
    expect(definePlugin(p)).toBe(p);
  });
  test("rejects bad sdkVersion or empty id", () => {
    expect(() => definePlugin({ manifest: { ...manifest, sdkVersion: 2 as never } })).toThrow();
    expect(() => definePlugin({ manifest: { ...manifest, id: "" } })).toThrow();
  });
});