import { mkdtemp, rm, writeFile } from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import {
  PROJECT_SUMMARY_MAX_LENGTH,
  readProjectSummary,
  summarizeProjectFiles,
} from "./project-summary.js";

describe("summarizeProjectFiles", () => {
  it("takes the README's first prose paragraph and skips headings, badges and code", () => {
    const readme = [
      "# Sugar Rush",
      "",
      "[![CI](https://ci.example/badge.svg)](https://ci.example)",
      "",
      "```sh",
      "pnpm install",
      "```",
      "",
      "A **candy** shop game for [kids](https://example.com),",
      "built with React.",
      "",
      "## Setup",
    ].join("\n");
    expect(summarizeProjectFiles({ readme })).toBe("A candy shop game for kids, built with React.");
  });

  it("falls back to a manifest description", () => {
    expect(
      summarizeProjectFiles({ readme: "# Title only", packageJson: '{"description":"A CLI"}' }),
    ).toBe("A CLI");
    expect(summarizeProjectFiles({ pyproject: '[project]\ndescription = "Data tools"\n' })).toBe(
      "Data tools",
    );
    expect(summarizeProjectFiles({ cargoToml: '[package]\ndescription = "Fast parser"' })).toBe(
      "Fast parser",
    );
  });

  it("returns null when nothing describes the project", () => {
    expect(summarizeProjectFiles({})).toBeNull();
    expect(summarizeProjectFiles({ readme: "# Title", packageJson: "not json" })).toBeNull();
  });

  it("clamps long descriptions", () => {
    const summary = summarizeProjectFiles({ readme: "word ".repeat(400) });
    expect(summary?.length).toBe(PROJECT_SUMMARY_MAX_LENGTH);
    expect(summary?.endsWith("…")).toBe(true);
  });
});

describe("readProjectSummary", () => {
  let directory: string | undefined;
  afterEach(async () => {
    if (directory) await rm(directory, { recursive: true, force: true });
    directory = undefined;
  });

  it("reads the README of a folder", async () => {
    directory = await mkdtemp(path.join(tmpdir(), "project-summary-"));
    await writeFile(path.join(directory, "README.md"), "# App\n\nTracks habits.\n");
    expect(await readProjectSummary(directory)).toBe("Tracks habits.");
  });

  it("returns null for an empty folder", async () => {
    directory = await mkdtemp(path.join(tmpdir(), "project-summary-"));
    expect(await readProjectSummary(directory)).toBeNull();
  });
});