// A collection of useful methods that are essentially utils but are
// specific to the application and require access to the app object.
module.exports.createHelpers = function createHelpers(app) {
  return {
    // Proxied access to the Application#set() method.
    set: app.set.bind(app),

    // Proxied access to the Application#render() method.
    render: app.render.bind(app),

    // Check to see if the app is in production.
    production: app.set('env') === app.PRODUCTION,

    // Renders the analytics snippet. Accepts a callback that recieves
    // and error and html object.
    analytics: function (render, fn) {
      if (typeof render === 'function') {
        fn = render;
        render = false;
      }

      // separate the tracking of the application over rendered pages
      if (render) {
        app.render('analytics-render', {id: app.set('analytics render-id')}, fn);
      } else {
        app.render('analytics', {id: app.set('analytics id')}, fn);
      }
    },

    // Generates a url for the path provided including prefix. If the second
    // full parameter is provided then a full url including domain and
    // protocol will be returned.
    url: function (path, full) {
      var root = '';

      if (full) {
        root = app.set('url full');
      } else {
        root = app.set('url prefix');
      }

      // Remove preceding slash if one exists.
      if (path && path[0] === '/') {
        path = path.slice(1);
      }

      return path ? root  + '/' + path : root;
    },

    // matches the format used in the client side code (jsbin.js)
    jsbinURL: function (bin) {
      var url = app.set('url full');

      if (bin.url) {
        url += '/' + bin.url;

        if (bin.revision && bin.revision !== 1) {
          url += '/' + bin.revision;
        }
      }
      return url;
    },

    // Same as helper.url() but creates a url for the bin object provided.
    urlForBin: function (bin, full) {
      var url = [];

      if (bin.url) {
        url.push(bin.url);

        if (bin.revision) {
          url.push(bin.revision);
        }
      }

      return this.url(url.join('/'), full);
    },

    // Same as helper.urlForBin() but returns an url for the edit page.
    editUrlForBin: function (bin, full) {
      return this.urlForBin(bin, full) + '/edit';
    },

    // Returns a url for a static resource.
    urlForStatic: function (path) {
      if (path && path[0] === '/') {
        path = path.slice(1);
      }

      var root = app.set('static url');
      return path ? root + '/' + (path || '') : root;
    }
  };
};