import { cp, mkdir, readFile, readdir, rm, writeFile } from "node:fs/promises";
import path from "node:path";
import { fileURLToPath } from "node:url";

const root = path.resolve(path.dirname(fileURLToPath(import.meta.url)), "..");
const publicDirectory = path.join(root, "public");
const required = [
  "LICENSE",
  "README.md",
  "CHANGELOG.md",
  "SOURCE.md",
  "THIRD_PARTY_NOTICES.md",
];

await mkdir(publicDirectory, { recursive: true });
for (const name of required) {
  const source = path.join(root, name);
  await readFile(source);
  await cp(source, path.join(publicDirectory, name));
}

const publicLicenses = path.join(publicDirectory, "LICENSES");
await rm(publicLicenses, { recursive: true, force: true });
await cp(path.join(root, "LICENSES"), publicLicenses, { recursive: true });
const publicDocs = path.join(publicDirectory, "docs");
await rm(publicDocs, { recursive: true, force: true });
await cp(path.join(root, "docs"), publicDocs, { recursive: true });

const lock = JSON.parse(
  await readFile(path.join(root, "package-lock.json"), "utf8"),
);
const runtimeLicenseSections = [];
for (const [location, locked] of Object.entries(lock.packages ?? {}).sort(
  ([left], [right]) => (left < right ? -1 : left > right ? 1 : 0),
)) {
  if (!location.includes("node_modules/") || locked.dev === true) continue;
  const packageDirectory = path.join(root, location);
  const details = JSON.parse(
    await readFile(path.join(packageDirectory, "package.json"), "utf8"),
  );
  const candidates = (await readdir(packageDirectory))
    .filter((name) => /^(?:licen[cs]e|copying|notice)(?:\.|$)/iu.test(name))
    .sort();
  const texts = [];
  for (const candidate of candidates) {
    try {
      texts.push(
        `--- ${candidate} ---\n${await readFile(path.join(packageDirectory, candidate), "utf8")}`,
      );
    } catch {
      // Ignore directories or non-text aliases; another matching file may exist.
    }
  }
  runtimeLicenseSections.push(
    [
      "=".repeat(78),
      `${details.name}@${details.version}`,
      `Declared licence: ${details.license ?? locked.license ?? "See upstream package"}`,
      `Installed from: ${location}`,
      "=".repeat(78),
      texts.length
        ? texts.join("\n\n")
        : "No package-local licence file was present; see THIRD_PARTY_NOTICES.md and the upstream source.",
    ].join("\n"),
  );
}
await writeFile(
  path.join(publicLicenses, "npm-runtime-licenses.txt"),
  `${runtimeLicenseSections.join("\n\n")}\n`,
);

const packageJson = JSON.parse(
  await readFile(path.join(root, "package.json"), "utf8"),
);
const rows = [
  "# Runtime dependency licences",
  "",
  "Generated from the exact lock used for this build.",
  "",
  "| Package | Version | Licence |",
  "| --- | --- | --- |",
];
for (const name of Object.keys(packageJson.dependencies).sort()) {
  const manifestPath = path.join(root, "node_modules", name, "package.json");
  const details = JSON.parse(await readFile(manifestPath, "utf8"));
  rows.push(
    `| \`${details.name}\` | ${details.version} | ${details.license ?? "See packaged notices"} |`,
  );
}
await writeFile(
  path.join(publicDirectory, "THIRD_PARTY_LICENSES.txt"),
  `${rows.join("\n")}\n`,
);

console.log("Prepared static release notices");