#!/usr/bin/env node
'use strict';

const Config = require('../config/config');
const Blog = require('..');
const Minimist = require('minimist');

const internals = {
  blog: new Blog(Config),
  expectedKeys: ['add', 'update', 'publish'],

  // Application entry point. Reads arguments and calls the
  // corresponding method from the blog lib

  async main() {

    try {
      const parsedArguments = this._parseArguments();

      for (const argument in parsedArguments) {
        if (parsedArguments.hasOwnProperty(argument)) {

          const value = parsedArguments[argument];

          if (argument === 'add') {
            await internals.blog.add(value);
            return;
          }

          if (argument === 'update') {
            await internals.blog.update(value);
            return;
          }

          if (argument === 'publish') {
            await internals.blog.publish(value);
            return;
          }
        }
      }
      console.log('Not yet implemented');
    }
    catch (err) {
      console.error(err.message || err);
      this._printUsage();
      process.exit(1);
    }
  },

  // Parses arguments and returns them if valid. otherwise Throws

  _parseArguments() {

    const parsedArguments = Minimist(process.argv.slice(2));

    if (!this._areArgumentsValid(parsedArguments)) {
      throw new Error(internals.strings.invalidArguments);
    }

    return parsedArguments;
  },

  // Checks if the arguments are valid, returns a boolean value.

  _areArgumentsValid(parsedArguments) {

    const argumentKeys = Object.keys(parsedArguments);

    return argumentKeys.some((key) => internals.expectedKeys.indexOf(key) >= 0);
  },

  // Prints the usage to stderr

  _printUsage() {

    console.error('\nUsage:\n');
    console.error('blog --add path/to/blog_post\t\t(creates new blog post)');
    console.error('blog --update path/to/blog_post\t(updates latest blog post)');
    console.error('blog --publish \t\t\t(publishes the blog)');
  }
};

// Add the strings, added after declaration so they can consume the
// internals object.

internals.strings = {
  invalidArguments: `Invalid Arguments, expecting one of: ${internals.expectedKeys.join(', ')}`
};



internals.main();