class TaskJuggler::GanttChart

# File lib/taskjuggler/reports/GanttChart.rb, line 46
def initialize(now, weekStartsMonday, columnDef, table = nil, markdate = nil)
  # The start and end dates of the reported interval.
  @start = nil
  @end = nil
  @now = now
  @columnDef = columnDef
  @table = table
  @markdate = markdate

  # This defines the possible horizontal scales that the Gantt chart can
  # have. The scales differ in their resolution and the amount of detail
  # that is displayed. A scale is defined by its name. The _name_ must be
  # unique and can be used to select the scale. The _stepSize_ defines the
  # width of a scale step in pixels. The _stepsToFunc_ is a TjTime method
  # that determines the number of steps between 2 dates. _minTimeOff_
  # defines the minimum required length of an time-off interval that is
  # displayed in this scale.
  @@scales = [
    { 'name' => 'hour', 'stepSize' => 20, 'stepsToFunc' => :hoursTo,
      'minTimeOff' => 5 * 60 },
    { 'name' => 'day', 'stepSize' => 20, 'stepsToFunc' => :daysTo,
      'minTimeOff' => 6 * 60 * 60 },
    { 'name' => 'week', 'stepSize' => 20, 'stepsToFunc' => :weeksTo,
      'minTimeOff' => 24 * 60 * 60 },
    { 'name' => 'month', 'stepSize' => 35, 'stepsToFunc' => :monthsTo,
      'minTimeOff' => 5 * 24 * 60 * 60 },
    { 'name' => 'quarter', 'stepSize' => 28, 'stepsToFunc' => :quartersTo,
      'minTimeOff' => -1 },
    { 'name' => 'year', 'stepSize' => 20, 'stepsToFunc' => :yearsTo,
      'minTimeOff' => -1 }
  ]
  # This points to one of the scales above and marks the current scale.
  @scale = nil
  # The height of the chart (without the header)
  @height = 0
  # The width of the chart in pixels.
  @width = 0
  # The width of the view that the chart is presented in. If it's nil, the
  # view will be adapted to the width of the chart.
  @viewWidth = nil
  # True of the week starts on a Monday.
  @weekStartsMonday = weekStartsMonday

  # Reference to the GanttHeader object that models the chart header.
  @header = nil
  # The GanttLine objects that model the lines of the chart.
  @lines = []
  # The router for dependency lines.
  @router = nil
  # This dictionary stores primary task lines indexed by their task. To
  # handle multiple scenarios, the dictionary stored the lines in an Array.
  # This is used to generate dependency arrows.
  @tasks = {}
  # This is a list of the dependency lines. Each entry is an Array of [x, y]
  # coordinate pairs.
  @depArrows = []
  # This is the list of arrow heads used for the dependency arrows. It
  # contains an Array of [ x, y ] coordinates that mark the tip of the
  # arrow.
  @arrowHeads = []
end

# File lib/taskjuggler/reports/GanttChart.rb, line 110
def addTask(task, line)
  if @tasks.include?(task)
    # Append the line to the existing lines.
    @tasks[task] << line
  else
    # Add a new Array for this tasks and store the first line.
    @tasks[task] = [ line ]
  end
end

# File lib/taskjuggler/reports/GanttChart.rb, line 211
def dateToX(date)
  ((@width / (@end - @start)) * (date - @start)).to_i
end

# File lib/taskjuggler/reports/GanttChart.rb, line 132
def generateByScale(periodStart, periodEnd, scaleName)
  @start = periodStart
  @end = periodEnd
  @scale = scaleByName(scaleName)
  @stepSize = @scale['stepSize']
  steps = @start.send(@scale['stepsToFunc'], @end)
  @width = @stepSize * steps

  @header = GanttHeader.new(@columnDef, self)
end

# File lib/taskjuggler/reports/GanttChart.rb, line 121
def generateByWidth(periodStart, periodEnd, width)
  @start = periodStart
  @end = periodEnd
  @width = width
  # TODO
end

# File lib/taskjuggler/reports/GanttChart.rb, line 225
def hasScrollbar?
  @viewWidth && (@viewWidth < @width)
end

# File lib/taskjuggler/reports/GanttChart.rb, line 204
def to_csv(csv, startColumn)
  # Can't put a Gantt chart into a CSV file.
  0
end

# File lib/taskjuggler/reports/GanttChart.rb, line 144
def to_html
  completeChart

  # The chart is rendered into a cell that extends over the full height of
  # the table. No other cells for this column will be generated. In case
  # there is a scrollbar, the table will have an extra line to hold the
  # scrollbar.
  td = XMLElement.new('td',
    'rowspan' => "#{2 + @lines.length + (hasScrollbar? ? 1 : 0)}",
    'style' => 'padding:0px; vertical-align:top;')
  # Now we generate two 'div's nested into each other. The first div is the
  # view. It may contain a scrollbar if the second div is wider than the
  # first one. In case we need a scrollbar The outer div is
  # SCROLLBARHEIGHT pixels heigher to hold the scrollbar. Unfortunately
  # this must be a hardcoded value even though the height of the scrollbar
  # varies from system to system. This value should be good enough for
  # most systems.
  td << (scrollDiv = XMLElement.new('div', 'class' => 'tabback',
    'style' => 'position:relative; ' +
               "overflow:auto; " +
               "width:#{hasScrollbar? ? @viewWidth : @width}px; " +
               "height:#{@height +
                         (hasScrollbar? ? SCROLLBARHEIGHT : 0)}px;"))
  scrollDiv << (div = XMLElement.new('div',
    'style' => "margin:0px; padding:0px; " +
               "position:absolute; overflow:hidden; " +
               "top:0px; left:0px; " +
               "width:#{@width}px; " +
               "height:#{@height}px; " +
               "font-size:10px;"))
  # Add the header.
  div << @header.to_html
  # These are the lines of the chart.
  @lines.each do |line|
    div << line.to_html
  end

  # This is used for debugging and testing only.
  #div << @router.to_html

  # Render the dependency lines.
  @depArrows.each do |arrow|
    xx = yy = nil
    arrow.each do |x, y|
      if xx
        div << lineToHTML(xx, yy, x, y, 'depline')
      end
      xx = x
      yy = y
    end
  end
  # And the corresponsing arrow heads.
  @arrowHeads.each do |x, y|
    div << arrowHeadToHTML(x, y)
  end

  td
end