import {
  apply,
  chain,
  MergeStrategy,
  mergeWith,
  move,
  Rule,
  SchematicContext,
  Tree,
  url
} from '@angular-devkit/schematics';
import { NodePackageInstallTask } from '@angular-devkit/schematics/tasks';

import { addPackage, removePackage } from '../utils';
import { PluginOptions } from './interface';

function fixPackage(options: PluginOptions): Rule {
  return (tree: Tree) => {
    (options.type === 'add' ? addPackage : removePackage)(
      tree,
      ['ng-alain-sts@^0.0.2'],
      'devDependencies'
    );
  };
}

function fixFiles(): Rule {
  return chain([mergeWith(apply(url('./files/sts'), [move('/_cli-tpl')]), MergeStrategy.Overwrite)]);
}

function installPackages(): (_tree: Tree, context: SchematicContext) => void {
  return (_tree: Tree, context: SchematicContext) => {
    context.addTask(new NodePackageInstallTask());
  };
}

export function pluginSTS(options: PluginOptions): Rule[] {
  return [fixPackage(options), fixFiles(), installPackages()];
}