// ===================================================================
// Contains many common helpers.
// ===================================================================

// Load by default a window in the ui/views folder.
// If options.isString is equals to true, a marshalling component can
// be used.
//
// Supported options: isString, exitHandler.
//
// If exitHandler is used, window must implement exitStatus signal.
function openWindow (window, parent, options) {
  var object

  if (options && options.isString) {
    object = Qt.createQmlObject(window, parent)
  } else {
    var component = Qt.createComponent(
      'qrc:/ui/views/' + window + '.qml'
    )

    if (component.status !== Component.Ready) {
      console.debug('Window not ready.')
      if (component.status === Component.Error) {
        console.debug('Error:' + component.errorString())
      }
      return // Error.
    }

    object = component.createObject(parent)
  }

  object.closing.connect(object.destroy.bind(object))

  if (options && options.exitHandler) {
    object.exitStatus.connect(
      // Bind to access parent properties.
      options.exitHandler.bind(parent)
    )
  }

  object.show()

  return object
}

// -------------------------------------------------------------------

// Display a simple ConfirmDialog component.
// Wrap the openWindow function.
function openConfirmDialog (parent, options) {
  return openWindow(
    'import QtQuick 2.7;' +
      'import Common 1.0;' +
      'ConfirmDialog {' +
      'descriptionText: \'' + options.descriptionText + '\';' +
      'title: \'' + options.title + '\'' +
      '}',
    parent, {
      isString: true,
      exitHandler: options.exitHandler
    }
  )
}

// -------------------------------------------------------------------

function _computeOptimizedCb (func, context) {
  return (context != null)
    ? (function () {
      return func.apply(context, arguments)
    }) : func
}

// -------------------------------------------------------------------

// Convert a snake_case string to a lowerCamelCase string.
function snakeToCamel (s) {
  return s.replace(/(\_\w)/g, function (matches) {
    return matches[1].toUpperCase()
  })
}

// -------------------------------------------------------------------

// A copy of `Window.setTimeout` from js.
// delay is in milliseconds.
function setTimeout (parent, delay, cb) {
  var timer = new (function (parent) {
    return Qt.createQmlObject('import QtQuick 2.7; Timer { }', parent)
  })(parent)

  timer.interval = delay
  timer.repeat = false
  timer.triggered.connect(cb)
  timer.start()

  return timer
}

// Destroy timeout.
function clearTimeout (timer) {
  timer.stop() // NECESSARY.
  timer.destroy()
}

// -------------------------------------------------------------------

// Returns the top (root) parent of one object.
function getTopParent (object) {
  function _getTopParent (object) {
    return object.$parent || object.parent
  }

  var parent = _getTopParent(object)

  while (_getTopParent(parent) != null) {
    parent = _getTopParent(parent)
  }

  return parent
}

// -------------------------------------------------------------------

// Test the type of a qml object.
// Warning: this function is probably not portable
// on new versions of Qt.
//
// So, if you want to use it on a specific `className`, please to add
// a test in `test_qmlTypeof_data` of `utils.spec.qml`.
function qmlTypeof (object, className) {
  var str = object.toString()

  return (
    str.indexOf(className + '(') == 0 ||
    str.indexOf(className + '_QML') == 0
  )
}

// -------------------------------------------------------------------

// Test if a point is in a item.
//
// `source` is the item that generated the point.
// `target` is the item to test.
// `point` is the point to test.
function pointIsInItem (source, target, point) {
  point = source.mapToItem(target.parent, point.x, point.y)

  return (
    point.x >= target.x &&
    point.y >= target.y &&
    point.x < target.x + target.width &&
    point.y < target.y + target.height
  )
}

// -------------------------------------------------------------------

// Invoke a `cb` function with each value of the interval: `[0, n[`.
// Return a mapped array created with the returned values of `cb`.
function times (n, cb, context) {
  var arr = Array(Math.max(0, n))
  cb = _computeOptimizedCb(cb, context, 1)

  for (var i = 0; i < n; i++) {
    arr[i] = cb(i)
  }

  return arr
}

// -------------------------------------------------------------------

// Test if a var is a string.
function isString (string) {
  return typeof string === 'string' || string instanceof String
}

// -------------------------------------------------------------------

// Generate a random number in the [min, max[ interval.
// Uniform distrib.
function genRandomNumber (min, max) {
  return Math.random() * (max - min) + min
}

// -------------------------------------------------------------------

// Generate a random number between a set of intervals.
// The `intervals` param must be orderer like this:
// `[ [ 1, 4 ], [ 8, 16 ], [ 22, 25 ] ]`
function genRandomNumberBetweenIntervals (intervals) {
  if (intervals.length === 1) {
    return genRandomNumber(intervals[0][0], intervals[0][1])
  }

  // Compute the intervals size.
  var size = 0
  intervals.forEach(function (interval) {
    size += interval[1] - interval[0]
  })

  // Generate a value in the interval: `[0, size[`
  var n = genRandomNumber(0, size)

  // Map the value in the right interval.
  n += intervals[0][0]
  for (var i = 0; i < intervals.length - 1; i++) {
    if (n < intervals[i][1]) {
      break
    }

    n += intervals[i + 1][0] - intervals[i][1]
  }

  return n
}