import { execFile } from "node:child_process";
import { createHash } from "node:crypto";
import { lstat, readdir, readFile, realpath } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";
import { promisify } from "node:util";
import { verifyModulePackage } from "@ekklesia/core/modules";
import { afterEach, describe, expect, it } from "vitest";
import { packModule } from "../src/index.js";
import { cleanupFixtures, SOURCE_REVISION, scratchDirectory } from "./support/fixture-module.js";
import { fileEntries } from "./support/tar.js";

/**
 * The canonical template module, packaged end to end (ADR 0049): the real built template, the real
 * packager, and Core's real verifier. Turbo builds the template and the verifier before this suite
 * runs (both are development dependencies of this package), and runs the template's own tests, which
 * rebuild its UI in place, before this one (turbo.json).
 */

const execFileAsync = promisify(execFile);
const packageRoot = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const repositoryRoot = path.resolve(packageRoot, "..", "..");

afterEach(cleanupFixtures);

async function templateDirectory(): Promise<string> {
  return realpath(path.join(packageRoot, "node_modules", "@ekklesia", "module-template"));
}

async function readJson(file: string): Promise<Record<string, unknown>> {
  return JSON.parse(await readFile(file, "utf8")) as Record<string, unknown>;
}

async function platform() {
  const core = await readJson(path.join(repositoryRoot, "core", "package.json"));
  return {
    databaseRuntime: {
      "drizzle-orm": (core.dependencies as Record<string, string>)["drizzle-orm"] ?? "",
    },
    moduleSdkVersion: String(
      (await readJson(path.join(repositoryRoot, "packages", "module-sdk", "package.json"))).version,
    ),
    platformVersion: String((await readJson(path.join(repositoryRoot, "package.json"))).version),
  };
}

async function fingerprint(file: string): Promise<string> {
  try {
    return createHash("sha256")
      .update(await readFile(file))
      .digest("hex");
  } catch {
    return "absent";
  }
}

async function treeListing(directory: string): Promise<readonly string[]> {
  const entries = await readdir(directory, { recursive: true, withFileTypes: true });
  return entries
    .filter((entry) => !path.join(entry.parentPath, entry.name).includes(`${path.sep}node_modules`))
    .map((entry) => path.relative(directory, path.join(entry.parentPath, entry.name)))
    .sort();
}

async function packTemplate() {
  const outDirectory = await scratchDirectory("ekklesia-template-package-");
  const result = await packModule({
    moduleDirectory: await templateDirectory(),
    outDirectory,
    sourceRevision: SOURCE_REVISION,
    target: "any",
  });
  return { archive: await readFile(result.archivePath), result };
}

describe("the module template as a Module Package v1", () => {
  it("packs deterministically, without touching the workspace it was built in", async () => {
    const template = await templateDirectory();
    const watched = [
      path.join(repositoryRoot, "node_modules", ".pnpm-workspace-state-v1.json"),
      path.join(repositoryRoot, "node_modules", ".modules.yaml"),
      path.join(repositoryRoot, "pnpm-lock.yaml"),
    ];
    const before = await Promise.all(watched.map(fingerprint));
    const templateBefore = await treeListing(template);

    const first = await packTemplate();
    const second = await packTemplate();

    expect(first.result.sha256).toBe(second.result.sha256);
    expect(first.archive.equals(second.archive)).toBe(true);
    expect(path.basename(first.result.archivePath)).toMatch(
      /^example-\d+\.\d+\.\d+-any\.tar\.gz$/u,
    );
    expect(await Promise.all(watched.map(fingerprint))).toEqual(before);
    expect(await treeListing(template)).toEqual(templateBefore);
  });

  it("verifies against this platform and extracts to an unrelated directory that holds no link", async () => {
    const { result } = await packTemplate();
    const target = path.join(await scratchDirectory("ekklesia-installed-elsewhere-"), "example");
    const verified = await verifyModulePackage({
      archivePath: result.archivePath,
      expectedSha256: result.sha256,
      extractTo: target,
      platform: await platform(),
    });
    expect(verified).toMatchObject({ moduleId: "example", target: "any" });

    for (const entry of await readdir(target, { recursive: true, withFileTypes: true })) {
      const stats = await lstat(path.join(entry.parentPath, entry.name));
      expect(stats.isSymbolicLink(), entry.name).toBe(false);
      expect(stats.isFile() ? stats.nlink : 1, entry.name).toBe(1);
    }
    const listing = await treeListing(target);
    expect(listing).not.toContain("node_modules");
    expect(listing.some((file) => /(^|\/)(src|tests)(\/|$)|\.d\.ts$|\.map$/u.test(file))).toBe(
      false,
    );
  });

  it("loads from its new location without resolving anything outside itself", async () => {
    const { result } = await packTemplate();
    const target = path.join(await scratchDirectory("ekklesia-portable-"), "example");
    await verifyModulePackage({
      archivePath: result.archivePath,
      extractTo: target,
      platform: await platform(),
    });

    // Every specifier the backend resolves while loading, recorded by Node itself.
    const script = `
      import { registerHooks } from "node:module";
      import { pathToFileURL } from "node:url";
      const resolved = [];
      registerHooks({ resolve(specifier, context, next) { const result = next(specifier, context); resolved.push(result.url); return result; } });
      for (const file of ["dist/server/index.js", "dist/schema/index.js"]) {
        await import(pathToFileURL(${JSON.stringify(target)} + "/" + file).href);
      }
      process.stdout.write(JSON.stringify(resolved));
    `;
    const { stdout } = await execFileAsync(
      process.execPath,
      ["--input-type=module", "-e", script],
      {
        cwd: path.dirname(target),
        env: {},
      },
    );
    const resolved = JSON.parse(stdout) as string[];
    expect(resolved.length).toBeGreaterThan(0);
    for (const url of resolved) {
      const inside = url.startsWith(`file://${target}/`);
      expect(inside || url.startsWith("node:"), url).toBe(true);
    }
  });

  it("credits every third-party package its bundles say they contain", async () => {
    const { archive } = await packTemplate();
    const files = fileEntries(archive);
    const notices = files.get("example/THIRD_PARTY_NOTICES")?.toString("utf8") ?? "";
    const bundled = new Set<string>();
    for (const [file, data] of files) {
      if (file.endsWith(".js")) {
        // esbuild names every bundled source file in a path comment.
        for (const match of data
          .toString("utf8")
          .matchAll(/node_modules\/((?:@[^/]+\/)?[^/.][^/]*)\//gu)) {
          if (match[1] && !match[1].startsWith("@ekklesia/")) {
            bundled.add(match[1]);
          }
        }
      }
    }
    expect([...bundled]).toEqual(
      expect.arrayContaining(["drizzle-orm", "react", "react-dom", "zod"]),
    );
    for (const name of bundled) {
      expect(notices, name).toMatch(
        new RegExp(`^${name.replace(/[.*+?^${}()|[\]\\/]/gu, "\\$&")} \\S+$`, "mu"),
      );
    }
    const licence = await readFile(path.join(packageRoot, "licenses", "Apache-2.0.txt"));
    expect(createHash("sha256").update(licence).digest("hex")).toBe(
      "cfc7749b96f63bd31c3c42b5c471bf756814053e847c10f3eb003417bc523d30",
    );
  });

  it("refers to no absolute path of the checkout it was built in", async () => {
    const { archive } = await packTemplate();
    for (const [file, data] of fileEntries(archive)) {
      expect(data.toString("utf8"), file).not.toContain(repositoryRoot);
    }
  });
});