// Lib/api/feed was barely covered, and it is where a filter turns into a query string.
// FastAPI IGNORES a query parameter it does not know, so a misspelt or renamed key does not fail —
// the filter simply stops applying while its chip still shows. Locked two ways: what each filter
// emits, and that every key emitted is one the backend's feed endpoints actually read.
import { readFileSync } from "node:fs";
import { beforeEach, describe, expect, it, vi } from "vitest";
import { beacon, req } from "./core";
import { feedApi, type FeedFilters } from "./feed";

vi.mock("./core", () => ({ req: vi.fn(() => Promise.resolve({})), beacon: vi.fn() }));

const BASE: FeedFilters = {
  tags: [],
  tagModes: { language: "or", topic: "or", other: "or" },
  q: "",
  sort: "newest",
  scope: "my",
  includeNormal: true,
  includeShorts: false,
  includeLive: false,
  show: "unwatched",
  channelIds: [],
};

const lastUrl = () => new URL(vi.mocked(req).mock.lastCall![0] as string, "http://x");
const sent = (f: Partial<FeedFilters>, cursor: string | null = null) => {
  void feedApi.feed({ ...BASE, ...f }, cursor, 30);
  return lastUrl().searchParams;
};

beforeEach(() => vi.mocked(req).mockClear());

describe("feed filters on the wire", () => {
  it("the defaults: scope, content types, show, library source, sort and page size", () => {
    const p = sent({});
    expect(Object.fromEntries(p)).toEqual({
      scope: "my",
      show_normal: "true",
      include_shorts: "false",
      include_live: "false",
      show: "unwatched",
      library_source: "organic",
      sort: "newest",
      limit: "30",
    });
  });

  it("repeats tags and channels, and sends only the categories matched as ALL", () => {
    const p = sent({
      tags: [3, 9],
      tagModes: { language: "or", topic: "and", other: "or" },
      channelIds: ["UCa", "UCb"],
      untagged: true,
      q: "jazz",
    });
    expect(p.getAll("tags")).toEqual(["3", "9"]);
    expect(p.getAll("channel_ids")).toEqual(["UCa", "UCb"]);
    expect(p.get("tag_mode_topic")).toBe("and");
    expect(p.has("tag_mode_language") || p.has("tag_mode_other")).toBe(false);
    expect(p.get("untagged")).toBe("true");
    expect(p.get("q")).toBe("jazz");
  });

  it("a year is a whole-year range and wins over the other date narrowings", () => {
    const p = sent({ year: 2019, maxAgeDays: 7, dateFrom: "2024-01-01", dateTo: "2024-02-01" });
    expect(p.get("published_after")).toBe("2019-01-01");
    expect(p.get("published_before")).toBe("2019-12-31");
    expect(p.has("max_age_days")).toBe(false);

    const q = sent({ maxAgeDays: 7, dateFrom: "2024-01-01", dateTo: "2024-02-01" });
    expect([q.get("max_age_days"), q.get("published_after"), q.get("published_before")]).toEqual([
      "7",
      "2024-01-01",
      "2024-02-01",
    ]);
  });

  it("a zero-second duration bound is still a bound", () => {
    const p = sent({ minDuration: 0, maxDuration: 60 });
    expect([p.get("min_duration"), p.get("max_duration")]).toEqual(["0", "60"]);
  });

  it("the shuffle seed travels only with the shuffle sort; the cursor when paging", () => {
    expect(sent({ sort: "shuffle", seed: 42 }).get("seed")).toBe("42");
    expect(sent({ sort: "newest", seed: 42 }).has("seed")).toBe(false);
    expect(sent({}, "CUR").get("cursor")).toBe("CUR");
  });

  it("the summary and the year list see the same filters, without the paging", () => {
    void feedApi.feedSummary({ ...BASE, tags: [5] });
    expect(lastUrl().pathname).toBe("/api/feed/summary");
    expect(lastUrl().searchParams.getAll("tags")).toEqual(["5"]);
    expect(lastUrl().searchParams.has("limit")).toBe(false);
    void feedApi.feedYears({ ...BASE, year: 2020 });
    expect(lastUrl().pathname).toBe("/api/feed/years");
  });

  it("every key it sends is a parameter the backend's feed endpoints read", () => {
    const routes = readFileSync(
      new URL("../../../../backend/app/routes/feed.py", import.meta.url),
      "utf-8",
    );
    const block = routes.match(/def _feed_params\(([\s\S]*?)\) -> dict:/);
    expect(block, "routes/feed.py no longer defines _feed_params").toBeTruthy();
    const known = new Set(
      [...(block?.[1] ?? "").matchAll(/^\s{4}(\w+):/gm)].flatMap((m) => (m[1] ? [m[1]] : [])),
    );
    known.add("sort").add("seed").add("cursor").add("limit"); // read by /feed itself
    // Every field set (Required: a new filter field fails tsc here until it has a value, so its key
    // is checked too). `year` wins over the other date filters, so the set goes out once with it
    // and once without.
    const all: Required<FeedFilters> = {
      tags: [1],
      tagModes: { language: "and", topic: "and", other: "and" },
      q: "x",
      sort: "shuffle",
      seed: 1,
      scope: "all",
      includeNormal: false,
      includeShorts: true,
      includeLive: true,
      show: "all",
      librarySource: "search",
      untagged: true,
      channelIds: ["UC"],
      maxAgeDays: 3,
      minDuration: 1,
      maxDuration: 2,
      dateFrom: "2024-01-01",
      dateTo: "2024-01-02",
      year: 2020,
    };
    const everything = [...sent(all, "C").keys(), ...sent({ ...all, year: undefined }, "C").keys()];
    const unknown = [...new Set(everything)].filter((k) => !known.has(k));
    expect(unknown).toEqual([]);
    expect(known.has("tag_mode_topic")).toBe(true); // the parse found the real list
  });
});

describe("watch state and progress", () => {
  it("progress is saved in whole seconds, and the unload beacon escapes the id", () => {
    void feedApi.saveProgress("abc", 61.9, 600.4);
    const [url, init, opts] = vi.mocked(req).mock.lastCall!;
    expect(url).toBe("/api/videos/abc/progress");
    expect(JSON.parse((init as RequestInit).body as string)).toEqual({
      position_seconds: 61,
      duration_seconds: 600,
    });
    expect(opts).toEqual({ idempotent: true });

    feedApi.saveProgressBeacon("a/b", 10.5, 20.5);
    expect(vi.mocked(beacon)).toHaveBeenLastCalledWith("/api/videos/a%2Fb/progress", {
      position_seconds: 10,
      duration_seconds: 20,
    });
  });

  it("the live search is quiet, so its panel can show a quota error inline", () => {
    void feedApi.searchYoutube("cats & dogs", "NEXT", 10);
    const [url, , opts] = vi.mocked(req).mock.lastCall!;
    const u = new URL(url as string, "http://x");
    expect(u.pathname).toBe("/api/search/youtube");
    expect(Object.fromEntries(u.searchParams)).toEqual({
      q: "cats & dogs",
      cursor: "NEXT",
      limit: "10",
    });
    expect(opts).toEqual({ quiet: true });
  });

  it("a related list is quiet too, and sends its region and cursor", () => {
    void feedApi.related("a/b", "hu", "CUR1");
    const [url, , opts] = vi.mocked(req).mock.lastCall!;
    const u = new URL(url as string, "http://x");
    expect(u.pathname).toBe("/api/search/related/a%2Fb");
    expect(Object.fromEntries(u.searchParams)).toEqual({ region: "hu", cursor: "CUR1" });
    expect(opts).toEqual({ quiet: true });

    void feedApi.related("abc", "topical", null);
    const first = new URL(vi.mocked(req).mock.lastCall![0] as string, "http://x");
    expect(Object.fromEntries(first.searchParams)).toEqual({ region: "topical" });
  });
});