/**
 *  PNG\JPEG exporter for C3.js, version 0.2
 *  (c) 2014 Yuval Bar-On
 *
 * usage: path/to/phantomjs output options [WxH]
 *
 */

// useful python-styled string formatting, "hello {0}! Javascript is {1}".format("world", "awesome");
if (!String.prototype.format) {
  String.prototype.format = function() {
    var args = arguments
    return this.replace(/{(\d+)}/g, function(match, number) {
      return typeof args[number] != 'undefined' ? args[number] : match
    })
  }
}

// defaults
var page = require('webpage').create(),
  fs = require('fs'),
  system = require('system'),
  config = JSON.parse(fs.read('config.json')),
  output,
  size

if (system.args.length < 3) {
  console.log('Usage: phantasm.js filename html [WxH]')
  phantom.exit(1)
} else {
  out = system.args[1]
  opts = JSON.parse(system.args[2])

  if (system.args[3]) {
    var dimensions = system.args[3].split('x'),
      width = dimensions[0],
      height = dimensions[1]

    function checkNum(check) {
      check = parseInt(check)
      if (!isNaN(check)) return check
      return false
    }

    width = checkNum(width)
    height = checkNum(height)

    if (width && height) {
      page.viewportSize = {
        height: height,
        width: width
      }
    }

    // fit chart size to img size, if undefined
    if (!opts.size) {
      opts.size = {
        height: height,
        width: width
      }
    }
  } else {
    // check if size is defined in chart,
    // else apply defaults
    page.viewportSize = {
      height: opts.size && opts.size.height ? opts.size.height : 320,
      width: opts.size && opts.size.width ? opts.size.width : 710
    }
  }
}

page.onResourceRequested = function(requestData, request) {
  console.log('::loading resource ', requestData['url'])
}

// helpful debug functions
page.onConsoleMessage = function(msg) {
  console.log(msg)
}

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'))
}

// render page
function injectVerify(script) {
  var req = page.injectJs(script)
  if (!req) {
    console.log('\nError!\n' + script + ' not found!\n')
    phantom.exit(1)
  }
}

page.onLoadFinished = function() {
  console.log('::rendering')

  for (var j in config.js) {
    injectVerify(config.js[j])
  }

  page.evaluate(function(chartoptions) {
    // phantomjs doesn't know how to handle .bind, so we override
    Function.prototype.bind =
      Function.prototype.bind ||
      function(thisp) {
        var fn = this
        return function() {
          return fn.apply(thisp, arguments)
        }
      }

    // generate chart
    c3.generate(chartoptions)
  }, opts)

  // setting transition to 0 has proven not to work thus far, but 300ms isn't much
  // so this is acceptable for now
  setTimeout(function() {
    page.render(out)
    phantom.exit()
  }, 300)
}

//  apply css inline because that usually renders better
var css = ''
for (var i in config.css) {
  css += fs.read(config.css[i])
}
page.content = config.template.format(css)