/**
 * Copyright (c) 2015-present, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 */
'use strict';

const Promise = require('promise');

const chalk = require('chalk');
const copyProjectTemplateAndReplace = require('../generator/copyProjectTemplateAndReplace');
const fs = require('fs');
const path = require('path');
const printRunInstructions = require('../generator/printRunInstructions');
const semver = require('semver');
const yarn = require('../util/yarn');

/**
 * Migrate application to a new version of React Native.
 * See http://facebook.github.io/react-native/docs/upgrading.html
 *
 * IMPORTANT: Assumes the cwd() is the project directory.
 * The code here must only be invoked via the CLI:
 * $ cd MyAwesomeApp
 * $ react-native upgrade
 */
function validateAndUpgrade() {
  const projectDir = process.cwd();

  const packageJSON = JSON.parse(
      fs.readFileSync(path.resolve(projectDir, 'package.json'), 'utf8')
  );

  const projectName = packageJSON.name;
  if (!projectName) {
    warn(
      "Your project needs to have a name, declared in package.json, " +
      "such as \"name\": \"AwesomeApp\". Please add a project name. Aborting."
    );
    return;
  }

  const version = packageJSON.dependencies['react-native'];
  if (!version) {
    warn(
      "Your 'package.json' file doesn't seem to declare 'react-native' as " +
      "a dependency. Nothing to upgrade. Aborting."
    );
    return;
  }

  if (version === 'latest' || version === '*') {
    warn(
      "Some major releases introduce breaking changes.\n" +
      "Please use a caret version number in your 'package.json' file \n" +
      "to avoid breakage. Use e.g. react-native: ^0.38.0. Aborting."
    );
    return;
  }

  const installed = JSON.parse(
    fs.readFileSync(
      path.resolve(projectDir, 'node_modules/react-native/package.json'),
      'utf8'
    )
  );

  if (!semver.satisfies(installed.version, version)) {
    warn(
      "react-native version in 'package.json' doesn't match the installed version in 'node_modules'.\n" +
      "Try running 'npm install' to fix this. Aborting."
    );
    return;
  }

  const v = version.replace(/^(~|\^|=)/, '').replace(/x/i, '0');

  if (!semver.valid(v)) {
    warn(
      "A valid version number for 'react-native' is not specified in your " +
      "'package.json' file. Aborting."
    );
    return;
  }

  console.log(
    'Upgrading project to react-native v' + installed.version + '\n' +
    'Check out the release notes and breaking changes: ' +
    'https://github.com/facebook/react-native/releases/tag/v' + semver.major(v) + '.' + semver.minor(v) + '.0'
  );

  // >= v0.21.0, we require react to be a peer dependency
  if (semver.gte(v, '0.21.0') && !packageJSON.dependencies.react) {
    warn(
      "Your 'package.json' file doesn't seem to have 'react' as a dependency.\n" +
      "'react' was changed from a dependency to a peer dependency in react-native v0.21.0.\n" +
      "Therefore, it's necessary to include 'react' in your project's dependencies.\n" +
      "Please run 'npm install --save react', then re-run 'react-native upgrade'.\n"
    );
    return;
  }

  if (semver.satisfies(v, '~0.26.0')) {
    warn(
      "React Native 0.26 introduced some breaking changes to the native files on iOS. You can\n" +
      "perform them manually by checking the release notes or use \'rnpm\' to do it automatically.\n" +
      "Just run:\n" +
      "\'npm install -g rnpm && npm install rnpm-plugin-upgrade@0.26 --save-dev\', then run \'rnpm upgrade\'"
    );
  }

  return new Promise((resolve) => {
    upgradeProjectFiles(projectDir, projectName);
    console.log(
      'Successfully upgraded this project to react-native v' + installed.version
    );
    resolve();
  });
}

/**
 * Once all checks passed, upgrade the project files.
 */
function upgradeProjectFiles(projectDir, projectName) {
  // Just owerwrite
  copyProjectTemplateAndReplace(
    path.resolve('node_modules', 'react-native', 'local-cli', 'templates', 'HelloWorld'),
    projectDir,
    projectName,
    {upgrade: true}
  );
}

function warn(message) {
  console.warn(chalk.yellow(message));
}

const upgradeCommand = {
  name: 'upgrade',
  description: 'upgrade your app\'s template files to the latest version; run this after ' +
    'updating the react-native version in your package.json and running npm install',
  func: validateAndUpgrade,
};

module.exports = upgradeCommand;