#!/usr/bin/env node

import { readdirSync, readFileSync, writeFileSync, existsSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { dirname, join, resolve } from "node:path";

const __dirname = dirname(fileURLToPath(import.meta.url));
const repoRoot = resolve(__dirname, "..");
const manifestPath = join(repoRoot, "scripts", "release-package-manifest.json");
const roots = ["packages", "server", "ui", "cli"];

function readJson(filePath) {
  return JSON.parse(readFileSync(filePath, "utf8"));
}

function discoverPublicPackages() {
  const packages = [];

  function walk(relDir) {
    const absDir = join(repoRoot, relDir);
    if (!existsSync(absDir)) return;

    const pkgPath = join(absDir, "package.json");
    if (existsSync(pkgPath)) {
      const pkg = readJson(pkgPath);
      if (!pkg.private) {
        packages.push({
          dir: relDir,
          pkgPath,
          name: pkg.name,
          version: pkg.version,
          pkg,
        });
      }
      return;
    }

    for (const entry of readdirSync(absDir, { withFileTypes: true })) {
      if (!entry.isDirectory()) continue;
      if (entry.name === "node_modules" || entry.name === "dist" || entry.name === ".git") continue;
      walk(join(relDir, entry.name));
    }
  }

  for (const rel of roots) {
    walk(rel);
  }

  return packages;
}

function loadReleaseManifest() {
  const manifest = readJson(manifestPath);

  if (!Array.isArray(manifest)) {
    throw new Error(`expected ${manifestPath} to contain an array.`);
  }

  return manifest.map((entry, index) => {
    if (!entry || typeof entry !== "object" || Array.isArray(entry)) {
      throw new Error(`manifest entry ${index + 1} in ${manifestPath} must be an object.`);
    }

    if (typeof entry.dir !== "string" || entry.dir.length === 0) {
      throw new Error(`manifest entry ${index + 1} in ${manifestPath} is missing a non-empty "dir".`);
    }

    if (typeof entry.name !== "string" || entry.name.length === 0) {
      throw new Error(`manifest entry ${index + 1} in ${manifestPath} is missing a non-empty "name".`);
    }

    if (typeof entry.publishFromCi !== "boolean") {
      throw new Error(
        `manifest entry ${index + 1} (${entry.dir}) in ${manifestPath} must set boolean "publishFromCi".`,
      );
    }

    return entry;
  });
}

function buildReleasePackagePlan() {
  const discoveredPackages = discoverPublicPackages();
  const manifestEntries = loadReleaseManifest();
  const packageByDir = new Map(discoveredPackages.map((pkg) => [pkg.dir, pkg]));
  const manifestByDir = new Map();
  const problems = [];

  for (const entry of manifestEntries) {
    if (manifestByDir.has(entry.dir)) {
      problems.push(`duplicate manifest entry for ${entry.dir}`);
      continue;
    }

    manifestByDir.set(entry.dir, entry);
    const pkg = packageByDir.get(entry.dir);

    if (!pkg) {
      problems.push(`${entry.dir} is listed in ${manifestPath} but is not a public package in this repo`);
      continue;
    }

    if (pkg.name !== entry.name) {
      problems.push(
        `${entry.dir} is listed as ${entry.name} in ${manifestPath}, but package.json declares ${pkg.name}`,
      );
    }
  }

  for (const pkg of discoveredPackages) {
    if (!manifestByDir.has(pkg.dir)) {
      problems.push(
        `${pkg.dir} (${pkg.name}) is public but missing from ${manifestPath}; add it with publishFromCi true or false`,
      );
    }
  }

  if (problems.length > 0) {
    throw new Error(`release package manifest validation failed:\n- ${problems.join("\n- ")}`);
  }

  const packages = discoveredPackages.map((pkg) => ({
    ...pkg,
    publishFromCi: manifestByDir.get(pkg.dir).publishFromCi,
  }));

  return packages;
}

function sortTopologically(packages) {
  const byName = new Map(packages.map((pkg) => [pkg.name, pkg]));
  const visited = new Set();
  const visiting = new Set();
  const ordered = [];

  function visit(pkg) {
    if (visited.has(pkg.name)) return;
    if (visiting.has(pkg.name)) {
      throw new Error(`cycle detected in release package graph at ${pkg.name}`);
    }

    visiting.add(pkg.name);

    const dependencySections = [
      pkg.pkg.dependencies ?? {},
      pkg.pkg.optionalDependencies ?? {},
      pkg.pkg.peerDependencies ?? {},
    ];

    for (const deps of dependencySections) {
      for (const depName of Object.keys(deps)) {
        const dep = byName.get(depName);
        if (dep) visit(dep);
      }
    }

    visiting.delete(pkg.name);
    visited.add(pkg.name);
    ordered.push(pkg);
  }

  for (const pkg of [...packages].sort((a, b) => a.dir.localeCompare(b.dir))) {
    visit(pkg);
  }

  return ordered;
}

function getReleasePackages() {
  return sortTopologically(buildReleasePackagePlan().filter((pkg) => pkg.publishFromCi));
}

function replaceWorkspaceDeps(deps, version) {
  if (!deps) return deps;
  const next = { ...deps };

  for (const [name, value] of Object.entries(next)) {
    if (!name.startsWith("@paperclipai/")) continue;
    if (typeof value !== "string" || !value.startsWith("workspace:")) continue;
    next[name] = version;
  }

  return next;
}

function setVersion(version) {
  const packages = getReleasePackages();

  for (const pkg of packages) {
    const nextPkg = {
      ...pkg.pkg,
      version,
      dependencies: replaceWorkspaceDeps(pkg.pkg.dependencies, version),
      optionalDependencies: replaceWorkspaceDeps(pkg.pkg.optionalDependencies, version),
      peerDependencies: replaceWorkspaceDeps(pkg.pkg.peerDependencies, version),
      devDependencies: replaceWorkspaceDeps(pkg.pkg.devDependencies, version),
    };

    writeFileSync(pkg.pkgPath, `${JSON.stringify(nextPkg, null, 2)}\n`);
  }

  const cliEntryPath = join(repoRoot, "cli/src/index.ts");
  const cliEntry = readFileSync(cliEntryPath, "utf8");
  const nextCliEntry = cliEntry.replace(
    /\.version\("([^"]+)"\)/,
    `.version("${version}")`,
  );

  if (cliEntry !== nextCliEntry) {
    writeFileSync(cliEntryPath, nextCliEntry);
    return;
  }

  if (!cliEntry.includes(".version(cliVersion)")) {
    throw new Error("failed to rewrite CLI version string in cli/src/index.ts");
  }
}

function listPackages() {
  const packages = getReleasePackages();
  for (const pkg of packages) {
    process.stdout.write(`${pkg.dir}\t${pkg.name}\t${pkg.version}\n`);
  }
}

function checkConfiguration() {
  const packages = buildReleasePackagePlan();
  const enabledCount = packages.filter((pkg) => pkg.publishFromCi).length;
  const disabledCount = packages.length - enabledCount;

  if (enabledCount === 0) {
    throw new Error(`no packages are enabled for CI publishing in ${manifestPath}`);
  }

  process.stdout.write(
    `Release package manifest OK: ${enabledCount} enabled for CI publish, ${disabledCount} disabled pending bootstrap.\n`,
  );
}

function usage() {
  process.stderr.write(
    [
      "Usage:",
      "  node scripts/release-package-map.mjs list",
      "  node scripts/release-package-map.mjs check",
      "  node scripts/release-package-map.mjs set-version <version>",
      "",
    ].join("\n"),
  );
}

const [command, arg] = process.argv.slice(2);
const isDirectRun = process.argv[1] && resolve(process.argv[1]) === fileURLToPath(import.meta.url);

if (isDirectRun) {
  if (command === "list") {
    listPackages();
    process.exit(0);
  }

  if (command === "check") {
    checkConfiguration();
    process.exit(0);
  }

  if (command === "set-version") {
    if (!arg) {
      usage();
      process.exit(1);
    }
    setVersion(arg);
    process.exit(0);
  }

  usage();
  process.exit(1);
}

export {
  buildReleasePackagePlan,
  checkConfiguration,
  discoverPublicPackages,
  getReleasePackages,
  loadReleaseManifest,
};