import { test } from "node:test";
import assert from "node:assert/strict";
import { buildSearchHandoff, type HandoffGroup } from "./aiHandoff";
import type { LayerHit } from "./search/leafPipeline";

function hit(start: number, text: string): LayerHit {
  return { leafId: "l1", scope: "transcripts", start, text };
}

function group(slug: string, hits: LayerHit[]): HandoffGroup {
  return { slug, title: `Title ${slug}`, channel: "Chan", uploadDate: "20200101", hits };
}

const refs: Record<string, { id: string; webpageUrl?: string }> = {
  "chan/aaa": { id: "aaa", webpageUrl: "https://x/aaa" },
  "chan/bbb": { id: "bbb", webpageUrl: "https://x/bbb" },
};
const lookup = (slug: string) => refs[slug];

test("buildSearchHandoff maps groups to videos with ids, urls, and clocks", () => {
  const h = buildSearchHandoff(
    [group("chan/aaa", [hit(65, "hello  world"), hit(0, "meta")])],
    lookup,
    ["graham platner"],
  );
  assert.equal(h.label, "graham platner");
  assert.equal(h.totalVideos, 1);
  assert.equal(h.truncated, false);
  assert.equal(h.videos.length, 1);
  const v = h.videos[0];
  assert.equal(v.key, "chan/aaa");
  assert.equal(v.videoId, "aaa");
  assert.equal(v.url, "https://x/aaa");
  assert.deepEqual(v.snippets[0], { clock: "1:05", seconds: 65, text: "hello world" });
  // start 0 → "0:00" clock, whitespace collapsed.
  assert.equal(v.snippets[1].clock, "0:00");
});

test("buildSearchHandoff joins multiple queries with AND, falls back when empty", () => {
  assert.equal(
    buildSearchHandoff([group("chan/aaa", [hit(1, "a")])], lookup, ["one", " two "]).label,
    "one AND two",
  );
  assert.equal(
    buildSearchHandoff([group("chan/aaa", [hit(1, "a")])], lookup, []).label,
    "your search",
  );
});

test("buildSearchHandoff caps videos and hits, flagging truncation", () => {
  const groups = Array.from({ length: 25 }, (_, i) =>
    group(`chan/${i}`, Array.from({ length: 10 }, (_, j) => hit(j, `h${j}`))),
  );
  const h = buildSearchHandoff(groups, lookup, ["q"], {
    maxVideos: 5,
    maxHitsPerVideo: 3,
  });
  assert.equal(h.videos.length, 5);
  assert.equal(h.totalVideos, 25);
  assert.equal(h.videos[0].snippets.length, 3);
  assert.equal(h.truncated, true); // both video cap and per-video hit overflow
});

test("buildSearchHandoff passes the whole set and tiers snippets (top full, tail indexed)", () => {
  const groups = Array.from({ length: 20 }, (_, i) =>
    group(`chan/${i}`, Array.from({ length: 5 }, (_, j) => hit(j, `h${j}`))),
  );
  const h = buildSearchHandoff(groups, () => undefined, ["q"], {
    fullExcerptVideos: 3,
    maxHitsPerVideo: 5,
  });
  // Default maxVideos no longer caps at 20 — the whole set is passed.
  assert.equal(h.videos.length, 20);
  // Top tier keeps full excerpts; the tail is indexed with a single snippet.
  assert.equal(h.videos[0].snippets.length, 5);
  assert.equal(h.videos[2].snippets.length, 5);
  assert.equal(h.videos[3].snippets.length, 1);
  assert.equal(h.videos[19].snippets.length, 1);
  // The intentional tail trim is not flagged as truncation.
  assert.equal(h.truncated, false);
});

test("buildSearchHandoff marks truncated when the search itself was capped", () => {
  const h = buildSearchHandoff([group("chan/aaa", [hit(1, "a")])], lookup, ["q"], {
    searchCapped: true,
  });
  assert.equal(h.truncated, true);
});

test("buildSearchHandoff falls back to slug when no summary ref is found", () => {
  const h = buildSearchHandoff([group("chan/unknown", [hit(1, "a")])], lookup, ["q"]);
  assert.equal(h.videos[0].videoId, "chan/unknown");
  assert.equal(h.videos[0].url, undefined);
});

test("buildSearchHandoff with no groups yields an empty, untruncated handoff", () => {
  const h = buildSearchHandoff([], lookup, ["q"]);
  assert.equal(h.videos.length, 0);
  assert.equal(h.totalVideos, 0);
  assert.equal(h.truncated, false);
});