const fs = require('fs');
const yargs = require('yargs');

const { Argv } = yargs;
const { promisify } = require('util');
const { resolve } = require('path');

const exists = promisify(fs.exists);
const readFile = promisify(fs.readFile);
const writeFile = promisify(fs.writeFile);

const argv = yargs.options({
  appFolder: {
    demandOption: true,
    description: 'app name',
    type: 'string',
  },
  appVersion: {
    default: '1.0.0',
    description: 'version number',
    type: 'string',
  },
  rootPath: {
    default: resolve(__dirname, '..'),
    description: 'project root path',
    type: 'string',
  },
  docker: {
    default: false,
    type: 'boolean',
    description: 'Running in docker?',
  },
}).argv;

const root = argv.rootPath;
const distRoot = resolve(root, 'dist');

interface PackageJson {
  dependencies: Record<string, string>;
}

interface ProjectDependency {
  type: 'static' | 'implicit';
  target: string;
}

interface NxDeps {
  projectGraph: {
    dependencies: Record<string, Array<ProjectDependency>>;
  };
}

const generatePackageJson = (
  name: string,
  dependencies: Record<string, string>,
  version: string
): string =>
  JSON.stringify(
    {
      name,
      version,
      dependencies,
    },
    null,
    2
  );

const getDependencies = (
  rootPackage: PackageJson,
  deps: NxDeps,
  pack: string
): Record<string, string> => {
  const dependencies = deps.projectGraph.dependencies[pack];
  const directDependencies = dependencies.reduce<Record<string, string>>(
    (depsAcc: Record<string, string>, dep, index) => {
      const depName = dep.target.split(':').pop();
      const version = rootPackage.dependencies[depName];
      if (dep.type === 'static') {
        if (version) {
          depsAcc[depName] = version;
        } else {
          return {
            ...depsAcc,
            ...getDependencies(rootPackage, deps, depName),
          };
        }
      }
      return depsAcc;
    },
    {}
  );

  return directDependencies;
};

const run = async (appFolder: any, version: any, docker: boolean) => {
  const app = appFolder.split('/').join('-');
  const appDir = docker ? [distRoot] : [distRoot, 'apps', appFolder];
  const rootPackageBuffer = await readFile(
    resolve(root, docker ? 'package-base.json' : 'package.json')
  );
  const rootPackage = JSON.parse(rootPackageBuffer.toString('utf-8'));

  const depsBuffer = await readFile(
    resolve(docker ? root : distRoot, 'nxdeps.json')
  );
  const deps = JSON.parse(depsBuffer.toString('utf-8')) as NxDeps;

  console.log(`Checking ${appFolder}`);

  const doesExist = await exists(resolve(...appDir));

  if (doesExist && Reflect.has(deps.projectGraph.dependencies, app)) {
    console.log(`Generating package.json at ${appDir.join('/')}/package.json`);
    const dependencies = getDependencies(rootPackage, deps, app);
    const appPackageJson = generatePackageJson(app, dependencies, version);

    await writeFile(resolve(...appDir, 'package.json'), appPackageJson);
    console.log('Done');
  } else {
    console.log('App not found');
  }
};

if (argv.appFolder) {
  run(argv.appFolder, argv.appVersion, argv.docker).then(() => process.exit(0));
}