(function() {
  'use strict';

  var page = require('webpage').create();
  var args = require('system').args;
  var params = {};
  var regexp = /^([^=]+)=([^$]+)/;

  args.forEach(function(arg) {
    var parts = arg.match(regexp);
    if (!parts) {
      return;
    }
    params[parts[1]] = parts[2];
  });

  var usage = 'url=<url> png=<filename> width=<width> height=<height> renderKey=<key>';

  if (!params.url || !params.png || !params.renderKey || !params.domain) {
    console.log(usage);
    phantom.exit();
  }

  phantom.addCookie({
    name: 'renderKey',
    value: params.renderKey,
    domain: params.domain,
  });

  page.viewportSize = {
    width: params.width || '800',
    height: params.height || '400',
  };

  var timeoutMs = (parseInt(params.timeout) || 10) * 1000;
  var waitBetweenReadyCheckMs = 50;
  var totalWaitMs = 0;

  page.open(params.url, function(status) {
    console.log('Loading a web page: ' + params.url + ' status: ' + status, timeoutMs);

    page.onError = function(msg, trace) {
      var msgStack = ['ERROR: ' + msg];
      if (trace && trace.length) {
        msgStack.push('TRACE:');
        trace.forEach(function(t) {
          msgStack.push(' -> ' + t.file + ': ' + t.line + (t.function ? ' (in function "' + t.function + '")' : ''));
        });
      }
      console.error(msgStack.join('\n'));
    };

    function checkIsReady() {
      var panelsRendered = page.evaluate(function() {
        var panelCount = document.querySelectorAll('plugin-component').length;
        return window.panelsRendered >= panelCount;
      });

      if (panelsRendered || totalWaitMs > timeoutMs) {
        var bb = page.evaluate(function() {
          var container = document.getElementsByClassName('dashboard-container');
          if (container.length == 0) {
            container = document.getElementsByClassName('panel-container');
          }
          return container[0].getBoundingClientRect();
        });

        // reset viewport to render full page
        page.viewportSize = {
          width: bb.width,
          height: bb.height,
        };

        setTimeout(function() {
          page.render(params.png);
          phantom.exit();
        }, 5);
      } else {
        totalWaitMs += waitBetweenReadyCheckMs;
        setTimeout(checkIsReady, waitBetweenReadyCheckMs);
      }
    }

    setTimeout(checkIsReady, waitBetweenReadyCheckMs);
  });
})();
