import { describe, expect, it } from "vitest";

import { buildIndexDocs, chunkDocId, dedupeToParent } from "./indexer.js";
import type { GrantSnapshot, IndexDocInput } from "./types.js";

const grants: GrantSnapshot = { public: false, workspace: true, user: false, teams: ["t1"], users: ["u1"] };

function input(partial: Partial<IndexDocInput> & Pick<IndexDocInput, "docId" | "type" | "id" | "body">): IndexDocInput {
  return {
    workspaceId: "ws1",
    title: "T",
    grants,
    archived: false,
    url: "/ws1/x",
    createdAt: "2025-01-01T00:00:00Z",
    updatedAt: "2025-01-02T00:00:00Z",
    ...partial,
  };
}

describe("chunkDocId", () => {
  it("appends #n to the parent id", () => {
    expect(chunkDocId("page:pg_1", 0)).toBe("page:pg_1#0");
    expect(chunkDocId("page:pg_1", 7)).toBe("page:pg_1#7");
  });
});

describe("buildIndexDocs", () => {
  it("indexes a scalar type (record) as a single doc", () => {
    const docs = buildIndexDocs(input({ docId: "record:r1", type: "record", id: "r1", body: "any length at all..." }));
    expect(docs).toHaveLength(1);
    expect(docs[0]!.docId).toBe("record:r1");
    expect(docs[0]!.parentDocId).toBeUndefined();
  });

  it("indexes a short page body as the parent doc itself (no #0)", () => {
    const docs = buildIndexDocs(input({ docId: "page:pg_1", type: "page", id: "pg_1", body: "short body" }));
    expect(docs).toHaveLength(1);
    expect(docs[0]!.docId).toBe("page:pg_1");
  });

  it("expands a long page into chunked docs with parentDocId", () => {
    const body = Array.from({ length: 30 }, (_, i) => `Paragraph ${i} with some text. ${"word ".repeat(20).trim()}`).join(
      "\n\n",
    );
    const docs = buildIndexDocs(
      input({ docId: "page:pg_1", type: "page", id: "pg_1", body, vector: [0.1, 0.2] }),
      { maxChars: 300, overlapChars: 0 },
    );
    expect(docs.length).toBeGreaterThan(1);
    for (const [i, doc] of docs.entries()) {
      expect(doc.docId).toBe(`page:pg_1#${i}`);
      expect(doc.parentDocId).toBe("page:pg_1");
      expect(doc.chunkIndex).toBe(i);
      expect(doc.grants).toBe(grants); // shared reference — same snapshot
      expect(doc.body.length).toBeLessThanOrEqual(300);
    }
    // the parent's single vector applies to chunk 0 only
    expect(docs[0]!.vector).toEqual([0.1, 0.2]);
    expect(docs[1]!.vector).toBeUndefined();
  });

  it("keeps grants/workspace/url on every chunk", () => {
    const body = Array.from({ length: 30 }, (_, i) => `Para ${i} ${"filler ".repeat(15).trim()}`).join("\n\n");
    const docs = buildIndexDocs(input({ docId: "page:pg_9", type: "page", id: "pg_9", body }), {
      maxChars: 200,
      overlapChars: 0,
    });
    for (const doc of docs) {
      expect(doc.workspaceId).toBe("ws1");
      expect(doc.url).toBe("/ws1/x");
      expect(doc.grants.workspace).toBe(true);
    }
  });
});

describe("dedupeToParent", () => {
  it("keeps the better-scoring of chunk vs parent and records the matched chunk", () => {
    const out = dedupeToParent([
      { docId: "page:pg_1#2", parentDocId: "page:pg_1", score: 5 },
      { docId: "page:pg_1", score: 3 },
      { docId: "page:pg_2#0", parentDocId: "page:pg_2", score: 9 },
    ]);
    expect(out).toHaveLength(2);
    expect(out[0]).toEqual({ docId: "page:pg_2", score: 9, matchedChunk: "page:pg_2#0" });
    expect(out[1]).toEqual({ docId: "page:pg_1", score: 5, matchedChunk: "page:pg_1#2" });
  });

  it("keeps the parent when it outranks its own chunks", () => {
    const out = dedupeToParent([
      { docId: "page:pg_1#0", parentDocId: "page:pg_1", score: 2 },
      { docId: "page:pg_1", score: 7 },
    ]);
    expect(out).toHaveLength(1);
    expect(out[0]).toEqual({ docId: "page:pg_1", score: 7, matchedChunk: undefined });
  });

  it("sorts by descending score", () => {
    const out = dedupeToParent([
      { docId: "page:a", score: 1 },
      { docId: "page:b", score: 4 },
      { docId: "page:c", score: 2 },
    ]);
    expect(out.map((d) => d.docId)).toEqual(["page:b", "page:c", "page:a"]);
  });
});