var redis = require('redis');
var redisClient = redis.createClient();

var SERVICE_KEY = 'DASHBOARD_COUNTER';

// Set to true to disable the service's server-side component.
exports.disabled = false;

// Jobs are simply functions that are executed at some date or time interval.
exports.jobs = [
  {
    cron: '1 0 0 * * *', // every night at midnight EST
    callback: resetCounter,
    timeZone: 'America/New_York'
  },
  {
    cron: '* * * * * *', // every second
    callback: updateCounter
  }
];

// args is an object passed to the server via the `requestData` parameter.
// responseToClient sends data back to the client which gets passed
// to the `render` function.
exports.serve = function (args, responseToClient) {
  redisClient.get(SERVICE_KEY, function (err, data) {
    responseToClient(data ? data : 0);
  });
};

function resetCounter() {
  redisClient.set(SERVICE_KEY, 0);
}

function updateCounter() {
  updateKey(SERVICE_KEY, function (count) {
    count = parseFloat(count) || 0;
    count += (Math.random() * 10);
    return count;
  });
}

function updateKey(key, updateFn) {
  redisClient.get(key, function (err, data) {
    data = updateFn(data);
    redisClient.set(key, data);
  });
}

Dashboard.Service.add({
  // The unique id of this service.
  id: 'Counter',
  // The name in the service selector.
  name: 'Counter',
  // Disabled services don't show up in the service selector.
  disabled: false,
  // The url to ask for data. The URL should map to the service name (i.e. app/services/counter).
  url: '/service/counter',
  // How often to poll the server for new data, in milliseconds.
  interval: 1000,
  // Data to be sent to the server. Can be an object or a function.
  requestData: function () { },
  // Function called once, during service init.
  init: function () { },
  // Function called before a different service is initialized.
  tearDown: function () { },
  // Function called when we get data from the server.
  render: function (data) {
    // Assumes a my_template.html file exists in this or another service directory.
    Dashboard.View.render('my_template', data);
  },
  // Options that can be used to interact with the rendered data.
  // Use Dashboard.Service.option(service_id, option_key) to get the selected value.
  options: {
    lookback: {
      name: 'Granularity',
      control: 'slider',
      value: 15,
      min: 1,
      max: 30
    },
    scaleType: {
      name: 'Scale Type',
      control: 'dropdown',
      value: 'linear',
      values: [
        { name: 'Linear', value: 'linear' },
        { name: 'Square Root', value: 'sqrt' }
      ]
    },
    filter: {
      name: 'Filter',
      control: 'filter',
      key: 'name'
    }
  }
});