class TaskJuggler::TaskScenario

# File lib/taskjuggler/TaskScenario.rb, line 24
def initialize(task, scenarioIdx, attributes)
  super
  # Attributed are only really created when they are accessed the first
  # time. So make sure some needed attributes really exist so we don't
  # have to check for existance each time we access them.
  %w( allocate assignedresources booking charge chargeset complete
      competitors criticalness depends duration
      effort effortdone effortleft end forward gauge length
      maxend maxstart minend minstart milestone pathcriticalness
      precedes priority projectionmode responsible
      scheduled shifts start status ).each do |attr|
    @property[attr, @scenarioIdx]
  end
  unless @property.parent
    # The projectionmode attributes is a scenario specific attribute that
    # can be inherited from the project. The normal inherit-from-project
    # mechanism does not support scenario specific inheritance. We have to
    # deal with this separately here. To make it look like a regularly
    # inherted value, we need to switch the AttributeBase mode and restore
    # it afterwards.
      mode = AttributeBase.mode
      AttributeBase.setMode(1)
      @property['projectionmode', @scenarioIdx] =
        @project.scenario(@scenarioIdx).get('projection')
      AttributeBase.setMode(mode)
  end

  # A list of all allocated leaf resources.
  @candidates = []
  @dCache = DataCache.instance
end

# File lib/taskjuggler/TaskScenario.rb, line 165
def Xref
  @depends.each do |dependency|
    depTask = checkDependency(dependency, 'depends')
    @startpreds.push([ depTask, dependency.onEnd ])
    depTask[dependency.onEnd ? 'endsuccs' : 'startsuccs', @scenarioIdx].
      push([ @property, false ])
  end

  @precedes.each do |dependency|
    predTask = checkDependency(dependency, 'precedes')
    @endsuccs.push([ predTask, dependency.onEnd ])
    predTask[dependency.onEnd ? 'endpreds' : 'startpreds', @scenarioIdx].
      push([@property, true ])
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1283
def addBooking(booking)
  # This append operation will not trigger a copy to sub-scenarios.
  # Bookings are only valid for the scenario they are defined in.
  @booking << booking
end

# File lib/taskjuggler/TaskScenario.rb, line 1730
def assignedResources(interval = nil)
  interval = Interval.new(a('start'), a('end')) unless interval
  list = []

  if @property.container?
    @property.kids.each do |task|
      list += task.assignedResources(@scenarioIdx, interval)
    end
    list.uniq!
  else
    @assignedresources.each do |resource|
      if resource.allocated?(@scenarioIdx, interval, @property)
        list << resource
      end
    end
  end

  list
end

# File lib/taskjuggler/TaskScenario.rb, line 824
def calcCriticalness
  @criticalness = 0.0
  @pathcriticalness = nil

  # Users feel that milestones are somewhat important. So we use an
  # arbitrary value larger than 0 for them. We make it priority dependent,
  # so the user has some control over it. Priority 0 is 0, 500 is 1.0 and
  # 1000 is 2.0. These values are pretty much randomly picked and probably
  # require some more tuning based on real projects.
  if @milestone
    @criticalness = @priority / 500.0
  end

  # Task without efforts of allocations are not critical.
  return if @effort <= 0 || @candidates.empty?

  # Determine the average criticalness of all allocated resources.
  criticalness = 0.0
  @candidates.each do |resource|
    criticalness += resource['criticalness', @scenarioIdx]
  end
  criticalness /= @candidates.length

  # The task criticalness is the product of effort and average resource
  # criticalness.
  @criticalness = @effort * criticalness
end

# File lib/taskjuggler/TaskScenario.rb, line 858
def calcPathCriticalness(atEnd = false)
  # If we have computed this already, just return the value. If we are only
  # at the end of the task, we do not include the criticalness of this task
  # as it is not really part of the path.
  if @pathcriticalness
    return @pathcriticalness - (atEnd ? 0 : @criticalness)
  end

  maxCriticalness = 0.0

  if atEnd
    # At the end, we only care about pathes through the successors of this
    # task or its parent tasks.
    if (criticalness = calcPathCriticalnessEndSuccs) > maxCriticalness
      maxCriticalness = criticalness
    end
  else
    # At the start of the task, we have two options.
    if @property.container?
      # For container tasks, we ignore all dependencies and check the pathes
      # through all the children.
      @property.children.each do |task|
        if (criticalness = task.calcPathCriticalness(@scenarioIdx, false)) >
          maxCriticalness
          maxCriticalness = criticalness
        end
      end
    else
      # For leaf tasks, we check all pathes through the start successors and
      # then the pathes through the end successors of this task and all its
      # parent tasks.
      @startsuccs.each do |task, onEnd|
        if (criticalness = task.calcPathCriticalness(@scenarioIdx, onEnd)) >
          maxCriticalness
          maxCriticalness = criticalness
        end
      end

      if (criticalness = calcPathCriticalnessEndSuccs) > maxCriticalness
        maxCriticalness = criticalness
      end

      maxCriticalness += @criticalness
    end
  end

  @pathcriticalness = maxCriticalness
end

# File lib/taskjuggler/TaskScenario.rb, line 1079
def canInheritDate?(atEnd)
  # Inheriting a start or end date from the enclosing task or the project
  # is allowed for the following scenarios:
  #   -  --> -   inhS*1  -  <-- -   inhE*1
  #   -  --> |   inhS    |  <-- -   inhE
  #   -  x-> -   inhS    -  <-x -   inhE
  #   -  x-> |   inhS    |  <-x -   inhE
  #   -  x-> -D  inhS    -D <-x -   inhE
  #   -  x-> |D  inhS    |D <-x -   inhE
  #   -  --> -D  inhS    -D <-- -   inhE
  #   -  --> |D  inhS    |D <-- -   inhE
  #   -  <-- |   inhS    |  --> -   inhE
  #
  #   *1 when no bookings but allocations are present

  thisEnd, thatEnd = atEnd ? [ 'end', 'start' ] : [ 'start', 'end' ]
  # Return false if we already have a date for this end or if we have a
  # strong dependency for this end.
  return false if instance_variable_get('@' + thisEnd) ||
                  hasStrongDeps?(atEnd)

  # Containter task can inherit the date if they have no dependencies at
  # this end.
  return true if @property.container?

  hasThatSpec = !instance_variable_get('@' + thatEnd).nil? ||
                hasStrongDeps?(!atEnd)

  # Check for tasks that have no start and end spec, no duration spec but
  # allocates. They can inherit the start and end date.
  return true if hasThatSpec && !@hasDurationSpec && !@allocate.empty?

  if @forward ^ atEnd
    # the scheduling direction is pointing away from this end
    return true if @hasDurationSpec || !@booking.empty?

    return hasThatSpec
  else
    # the scheduling direction is pointing towards this end
    return !instance_variable_get('@' + thatEnd).nil? &&
           !@hasDurationSpec && @booking.empty? #&& @allocate.empty?
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 794
def candidates
  @candidates = []
  @allocate.each do |allocation|
    allocation.candidates.each do |candidate|
      candidate.allLeaves.each do |resource|
        @candidates << resource unless @candidates.include?(resource)
      end
    end
  end
  @candidates
end

# File lib/taskjuggler/TaskScenario.rb, line 627
def checkForLoops(path, atEnd, fromOutside, forward)
  # Check if we have been here before on this path.
  if path.include?([ @property, atEnd ])
    warning('loop_detected',
            "Dependency loop detected at #{atEnd ? 'end' : 'start'} " +
            "of task #{@property.fullId}", false)
    skip = true
    path.each do |t, e|
      if t == @property && e == atEnd
        skip = false
        next
      end
      next if skip
      info("loop_at_#{e ? 'end' : 'start'}",
           "Loop ctnd. at #{e ? 'end' : 'start'} of task #{t.fullId}",
           t.sourceFileInfo)
    end
    error('loop_end', "Aborting")
  end
  # Used for debugging only
  if false
    pathText = ''
    path.each do |t, e|
      pathText += "#{t.fullId}(#{e ? 'end' : 'start'}) -> "
    end
    pathText += "#{@property.fullId}(#{atEnd ? 'end' : 'start'})"
    puts pathText
  end
  return if @deadEndFlags[(atEnd ? 2 : 0) + (fromOutside ? 1 : 0)]
  path << [ @property, atEnd ]

  # To find loops we have to traverse the graph in a certain order. When we
  # enter a task we can either come from outside or inside. The following
  # graph explains these definitions:
  #
  #             |      /          \      |
  #  outside    v    /              \    v   outside
  #          +------------------------------+
  #          |    /        Task        \    |
  #       -->|  o   <---          --->   o  |<--
  #          |/ Start                  End \|
  #         /+------------------------------+\
  #       /     ^                        ^     \
  #             |         inside         |
  #
  # At the top we have the parent task. At the botton the child tasks.
  # The horizontal arrors are start predecessors or end successors.
  # As the graph is doubly-linked, we need to becareful to only find real
  # loops. When coming from outside, we only continue to the inside and vice
  # versa. Horizontal moves are only made when we are in a leaf task.
  unless atEnd
    if fromOutside
      if @property.container?
        #
        #         |
        #         v
        #       +--------
        #    -->| o--+
        #       +----|---
        #            |
        #            V
        #
        @property.children.each do |child|
          child.checkForLoops(@scenarioIdx, path, false, true, forward)
        end
      else
        #         |
        #         v
        #       +--------
        #    -->| o---->
        #       +--------
        #
        if (forward && @forward) || @milestone
          checkForLoops(path, true, false, true)
        end
      end
    else
      if @startpreds.empty?
        #
        #         ^
        #         |
        #       +-|------
        #       | o <--
        #       +--------
        #         ^
        #         |
        #
        if @property.parent
          @property.parent.checkForLoops(@scenarioIdx, path, false, false,
                                         forward)
        end
      else

        #       +--------
        #    <---- o <--
        #       +--------
        #          ^
        #          |
        #
        @startpreds.each do |task, targetEnd|
          task.checkForLoops(@scenarioIdx, path, targetEnd, true, forward)
        end
      end
    end
  else
    if fromOutside
      if @property.container?
        #
        #          |
        #          v
        #    --------+
        #       +--o |<--
        #    ---|----+
        #       |
        #       v
        #
        @property.children.each do |child|
          child.checkForLoops(@scenarioIdx, path, true, true, forward)
        end
      else
        #          |
        #          v
        #    --------+
        #     <----o |<--
        #    --------+
        #
        if (!forward && !@forward) || @milestone
          checkForLoops(path, false, false, false)
        end
      end
    else
      if @endsuccs.empty?
        #
        #          ^
        #          |
        #    ------|-+
        #      --> o |
        #    --------+
        #          ^
        #          |
        #
        if @property.parent
          @property.parent.checkForLoops(@scenarioIdx, path, true, false,
                                         forward)
        end
      else
        #    --------+
        #      --> o---->
        #    --------+
        #          ^
        #          |
        #
        @endsuccs.each do |task, targetEnd|
          task.checkForLoops(@scenarioIdx, path, targetEnd, true, forward)
        end
      end
    end
  end

  path.pop
  @deadEndFlags[(atEnd ? 2 : 0) + (fromOutside ? 1 : 0)] = true
  # puts "Finished with #{@property.fullId} #{atEnd ? 'end' : 'start'} " +
  #      "#{fromOutside ? 'outside' : 'inside'}"
end

# File lib/taskjuggler/TaskScenario.rb, line 1622
def collectTimeOffIntervals(iv, minDuration)
  # This function is often called recursively for the same parameters. We
  # store the results in the cache to avoid repeated computations of the
  # same results.
  @dCache.cached(self, :TaskScenarioCollectTimeOffIntervals, iv,
                 minDuration) do
    il = IntervalList.new
    il << TimeInterval.new(@project['start'], @project['end'])
    if @property.leaf?
      unless (resources = @assignedresources).empty?
        # The task has assigned resources, so we can use their common time
        # off intervals.
        resources.each do |resource|
          il &= resource.collectTimeOffIntervals(@scenarioIdx, iv,
                                                 minDuration)
        end
      else
        # The task has no assigned resources. We simply use the global time
        # off intervals.
        il &= @project.collectTimeOffIntervals(iv, minDuration)
      end
    else
      @property.kids.each do |task|
        il &= task.collectTimeOffIntervals(@scenarioIdx, iv, minDuration)
      end
    end

    il
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 810
def countResourceAllocations
  return if @candidates.empty? || @effort <= 0

  avgEffort = @effort / @candidates.length
  @candidates.each do |resource|
    resource['alloctdeffort', @scenarioIdx] += avgEffort
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1172
def earliestStart
  # This is the date that we will return.
  startDate = nil
  @depends.each do |dependency|
    potentialStartDate =
      dependency.task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
    return nil if potentialStartDate.nil?

    # Determine the end date of a 'length' gap.
    dateAfterLengthGap = potentialStartDate
    gapLength = dependency.gapLength
    while gapLength > 0 && dateAfterLengthGap < @project['end'] do
      if @project.isWorkingTime(dateAfterLengthGap)
        gapLength -= 1
      end
      dateAfterLengthGap += @project['scheduleGranularity']
    end

    # Determine the end date of a 'duration' gap.
    if dateAfterLengthGap > potentialStartDate + dependency.gapDuration
      potentialStartDate = dateAfterLengthGap
    else
      potentialStartDate += dependency.gapDuration
    end

    startDate = potentialStartDate if startDate.nil? ||
                                      startDate < potentialStartDate
  end

  # If any of the parent tasks has an explicit start date, the task must
  # start at or after this date.
  task = @property
  while (task = task.parent) do
    if task['start', @scenarioIdx] &&
       (startDate.nil? || task['start', @scenarioIdx] > startDate)
      startDate = task['start', @scenarioIdx]
      break
    end
  end

  # When the computed start date is after the already determined end date
  # of the task, the start dependencies were too weak. This happens when
  # task B depends on A and they are specified this way:
  # task A: | --> D-
  # task B: -D <-- |
  if @end && (startDate.nil? || startDate > @end)
    error('impossible_start_dep',
          "Task #{@property.fullId} has start date dependencies " +
          "that conflict with the end date #{@end}.")
  end

  startDate
end

# File lib/taskjuggler/TaskScenario.rb, line 409
def finishScheduling
  # Recursively descend into all child tasks.
  @property.children.each do |task|
    task.finishScheduling(@scenarioIdx)
  end

  @property.parents.each do |pTask|
    # Add the assigned resources to the parent task's list.
    @assignedresources.each do |resource|
      unless pTask['assignedresources', @scenarioIdx].include?(resource)
        pTask['assignedresources', @scenarioIdx] << resource
      end
    end
  end

  # These lists are no longer needed, so let's save some memory. Set it to
  # nil so we can detect accidental use.
  @candidates = nil
  @mandatories = nil
  @allLimits = nil
end

# File lib/taskjuggler/TaskScenario.rb, line 1561
def getAllocatedTime(startIdx, endIdx, resource = nil)
  return 0.0 if @milestone || startIdx >= endIdx ||
                (resource && !@assignedresources.include?(resource))

  @dCache.cached(self, :TaskScenarioAllocatedTime, startIdx, endIdx, resource) do
    allocatedTime = 0.0
    if @property.container?
      @property.kids.each do |task|
        allocatedTime += task.getAllocatedTime(@scenarioIdx,
                                               startIdx, endIdx, resource)
      end
    else
      if resource
        allocatedTime += resource.getAllocatedTime(@scenarioIdx,
                                                   startIdx, endIdx,
                                                   @property)
      else
        @assignedresources.each do |r|
          allocatedTime += r.getAllocatedTime(@scenarioIdx, startIdx, endIdx,
                                              @property)
        end
      end
    end
    allocatedTime
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1591
def getEffectiveWork(startIdx, endIdx, resource = nil)
  # Make sure we have the real Resource and not a proxy.
  resource = resource.ptn if resource
  return 0.0 if @milestone || startIdx >= endIdx ||
                (resource && !@assignedresources.include?(resource))

  @dCache.cached(self, :TaskScenarioEffectiveWork, startIdx, endIdx,
                 resource) do
    workLoad = 0.0
    if @property.container?
      @property.kids.each do |task|
        workLoad += task.getEffectiveWork(@scenarioIdx, startIdx, endIdx,
                                          resource)
      end
    else
      if resource
        workLoad += resource.getEffectiveWork(@scenarioIdx, startIdx,
                                              endIdx, @property)
      else
        @assignedresources.each do |r|
          workLoad += r.getEffectiveWork(@scenarioIdx, startIdx, endIdx,
                                         @property)
        end
      end
    end
    workLoad
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 183
def hasDependency?(depType, target, onEnd)
  a(depType).include?([target, onEnd])
end

# File lib/taskjuggler/TaskScenario.rb, line 1714
def hasResourceAllocated?(interval, resource)
  return false unless @assignedresources.include?(resource)

  if @property.leaf?
    return resource.allocated?(@scenarioIdx, interval, @property)
  else
    @property.kids.each do |t|
      return true if t.hasResourceAllocated?(@scenarioIdx, interval,
                                             resource)
    end
  end
  false
end

# File lib/taskjuggler/TaskScenario.rb, line 1656
def isDependencyOf(task, depth, list = [])
  return true if task == @property

  # If this task is already in the list of traversed task, we can ignore
  # it.
  return false if list.include?(@property)
  list << @property

  @startsuccs.each do |t, onEnd|
    unless onEnd
      # must be a start->start dependency
      return true if t.isDependencyOf(@scenarioIdx, task, depth, list)
    end
  end

  # For task to depend on this task, the start of task must be after the
  # end of this task.
  if task['start', @scenarioIdx] && @end
    return false if task['start', @scenarioIdx] < @end
  end

  # Check if any of the parent tasks is a dependency of _task_.
  t = @property.parent
  while t
    # If the parent is a dependency, than all childs are as well.
    return true if t.isDependencyOf(@scenarioIdx, task, depth, list)
    t = t.parent
  end

  return false if depth == 1

  @endsuccs.each do |ta, onEnd|
    unless onEnd
      # must be an end->start dependency
      return true if ta.isDependencyOf(@scenarioIdx, task, depth - 1, list)
    end
  end

  false
end

# File lib/taskjuggler/TaskScenario.rb, line 1699
def isFeatureOf(task)
  sources = @property.all
  destinations = task.all

  sources.each do |s|
    destinations.each do |d|
      return true if s.isDependencyOf(@scenarioIdx, d, 0)
    end
  end

  false
end

# File lib/taskjuggler/TaskScenario.rb, line 1229
def latestEnd
  # This is the date that we will return.
  endDate = nil
  @precedes.each do |dependency|
    potentialEndDate =
      dependency.task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
    return nil if potentialEndDate.nil?

    # Determine the end date of a 'length' gap.
    dateBeforeLengthGap = potentialEndDate
    gapLength = dependency.gapLength
    while gapLength > 0 && dateBeforeLengthGap > @project['start'] do
      if @project.isWorkingTime(dateBeforeLengthGap -
                                @project['scheduleGranularity'])
        gapLength -= 1
      end
      dateBeforeLengthGap -= @project['scheduleGranularity']
    end

    # Determine the end date of a 'duration' gap.
    if dateBeforeLengthGap < potentialEndDate - dependency.gapDuration
      potentialEndDate = dateBeforeLengthGap
    else
      potentialEndDate -= dependency.gapDuration
    end

    endDate = potentialEndDate if endDate.nil? || endDate > potentialEndDate
  end

  # If any of the parent tasks has an explicit end date, the task must end
  # at or before this date.
  task = @property
  while (task = task.parent) do
    if task['end', @scenarioIdx] &&
       (endDate.nil? || task['end', @scenarioIdx] < endDate)
      endDate = task['end', @scenarioIdx]
      break
    end
  end

  # When the computed end date is before the already determined start date
  # of the task, the end dependencies were too weak. This happens when
  # task A precedes B and they are specified this way:
  # task A: | --> D-
  # task B: -D <-- |
  if @start && (endDate.nil? || endDate < @start)
    error('impossible_end_dep',
          "Task #{@property.fullId} has end date dependencies " +
          "that conflict with the start date #{@start}.")
  end

  endDate
end

# File lib/taskjuggler/TaskScenario.rb, line 56
def markAsScheduled
  return if @scheduled
  @scheduled = true

  Log.msg do
    if @milestone
      typename = 'Milestone'
    elsif @property.leaf?
      typename = 'Task'
    else
      typename = 'Container'
    end
    "#{typename} #{@property.fullId} has been scheduled."
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 434
def postScheduleCheck
  @errors = 0
  @property.children.each do |task|
    @errors += 1 unless task.postScheduleCheck(@scenarioIdx)
  end

  # There is no point to check the parent if the child(s) have errors.
  return false if @errors > 0

  # Same for runaway tasks. They have already been reported.
  if @isRunAway
    error('sched_runaway', "Some tasks did not fit into the project time " +
          "frame.")
  end

  # Make sure the task is marked complete
  unless @scheduled
    error('not_scheduled',
          "Task #{@property.fullId} has not been marked as scheduled.")
  end

  # If the task has a follower or predecessor that is a runaway this task
  # is also incomplete.
  (@startsuccs + @endsuccs).each do |task, onEnd|
    return false if task.isRunAway(@scenarioIdx)
  end
  (@startpreds + @endpreds).each do |task, onEnd|
    return false if task.isRunAway(@scenarioIdx)
  end

  # Check if the start time is ok
  if @start.nil?
    error('task_start_undef',
          "Task #{@property.fullId} has undefined start time")
  end
  if @start < @project['start'] || @start > @project['end']
    error('task_start_range',
          "The start time (#{@start}) of task #{@property.fullId} " +
          "is outside the project interval (#{@project['start']} - " +
          "#{@project['end']})")
  end
  if !@minstart.nil? && @start < @minstart
    warning('minstart',
           "The start time (#{@start}) of task #{@property.fullId} " +
           "is too early. Must be after #{@minstart}.")
  end
  if !@maxstart.nil? && @start > @maxstart
    warning('maxstart',
           "The start time (#{@start}) of task #{@property.fullId} " +
           "is too late. Must be before #{@maxstart}.")
  end
  # Check if the end time is ok
  error('task_end_undef',
        "Task #{@property.fullId} has undefined end time") if @end.nil?
  if @end < @project['start'] || @end > @project['end']
    error('task_end_range',
          "The end time (#{@end}) of task #{@property.fullId} " +
          "is outside the project interval (#{@project['start']} - " +
          "#{@project['end']})")
  end
  if !@minend.nil? && @end < @minend
    warning('minend',
            "The end time (#{@end}) of task #{@property.fullId} " +
            "is too early. Must be after #{@minend}.")
  end
  if !@maxend.nil? && @end > @maxend
    warning('maxend',
            "The end time (#{@end}) of task #{@property.fullId} " +
            "is too late. Must be before #{@maxend}.")
  end
  # Make sure the start is before the end
  if @start > @end
    error('start_after_end',
          "The start time (#{@start}) of task #{@property.fullId} " +
          "is after the end time (#{@end}).")
  end


  # Check that tasks fits into parent task.
  unless (parent = @property.parent).nil? ||
          parent['start', @scenarioIdx].nil? ||
          parent['end', @scenarioIdx].nil?
    if @start < parent['start', @scenarioIdx]
      error('task_start_in_parent',
            "The start date (#{@start}) of task #{@property.fullId} " +
            "is before the start date (#{parent['start', @scenarioIdx]}) " +
            "of the enclosing task.")
    end
    if @end > parent['end', @scenarioIdx]
      error('task_end_in_parent',
            "The end date (#{@end}) of task #{@property.fullId} " +
            "is after the end date (#{parent['end', @scenarioIdx]}) " +
            "of the enclosing task.")
    end
  end

  # Check that all preceding tasks start/end before this task.
  @depends.each do |dependency|
    task = dependency.task
    limit = task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
    next if limit.nil?
    if @start < limit ||
       (dependency.gapDuration > 0 &&
        limit + dependency.gapDuration > @start) ||
       (dependency.gapLength > 0 &&
        calcLength(limit, @start) < dependency.gapLength)
      error('task_pred_before',
            "Task #{@property.fullId} (#{@start}) must start " +
            (dependency.gapDuration > 0 ?
              "#{dependency.gapDuration / (60 * 60 * 24)} days " :
              (dependency.gapLength > 0 ?
                "#{@project.slotsToDays(dependency.gapLength)} " +
                "working days " : '')) +
            "after " +
            "#{dependency.onEnd ? 'end' : 'start'} (#{limit}) of task " +
            "#{task.fullId}. This condition could not be met.")
    end
  end

  # Check that all following tasks end before this task
  @precedes.each do |dependency|
    task = dependency.task
    limit = task[dependency.onEnd ? 'end' : 'start', @scenarioIdx]
    next if limit.nil?
    if limit < @end ||
       (dependency.gapDuration > 0 &&
        limit - dependency.gapDuration < @end) ||
       (dependency.gapLength > 0 &&
        calcLength(@end, limit) < dependency.gapLength)
      error('task_succ_after',
            "Task #{@property.fullId} (#{@end}) must end " +
            (dependency.gapDuration > 0 ?
               "#{dependency.gapDuration / (60 * 60 * 24)} days " :
               (dependency.gapLength > 0 ?
                 "#{@project.slotsToDays(dependency.gapLength)} " +
                 "working days " : '')) +
            "before " +
            "#{dependency.onEnd ? 'end' : 'start'} (#{limit}) of task " +
            "#{task.fullId}. This condition could not be met.")
    end
  end

  if @milestone && @start != @end
    error('milestone_times_equal',
          "Milestone #{@property.fullId} must have identical start and " +
          "end date.")
  end

  if @property.leaf? && @effort == 0 && !@milestone && !@allocate.empty? &&
     @assignedresources.empty?
    # The user used an 'allocate' for the task, but did not specify any
    # 'effort'. Actual allocations will only happen when resources are
    # available by chance. If there are no assigned resources, we generate
    # a warning as this is probably not what the user intended.
    warning('allocate_no_assigned',
            "Task #{@property.id} has resource allocation requested, but " +
            "did not get any resources assigned. Either use 'effort' " +
            "to ensure allocations or use a higher 'priority'.")
  end

  thieves = []
  @competitors.each do |t|
    thieves << t if t['priority', @scenarioIdx] < @priority
  end
  unless thieves.empty?
    warning('priority_inversion',
            "Due to a mix of ALAP and ASAP scheduled tasks or a " +
            "dependency on a lower priority tasks the following " +
            "task#{thieves.length > 1 ? 's' : ''} stole resources from " +
            "#{@property.fullId} despite having a lower priority:")
    thieves.each do |t|
      info('priority_inversion_info', "Task #{t.fullId}", t.sourceFileInfo)
    end
  end

  @errors == 0
end

# File lib/taskjuggler/TaskScenario.rb, line 209
def preScheduleCheck
  # Accounts can have sub accounts added after being used in a chargetset.
  # So we need to re-test here.
  @chargeset.each do |chargeset|
    chargeset.each do |account, share|
      unless account.leaf?
        error('account_no_leaf',
            "Chargesets may not include group account #{account.fullId}.")
      end
    end
  end

  @responsible.map! do |resourceId|
    # 'resource' is still just an ID and needs to be converted into a
    # Resource.
    if (resource = @project.resource(resourceId)).nil?
      error('resource_id_expected', "#{resourceId} is not a defined " +
            'resource.', @sourceFileInfo)
    end
    resource
  end
  @responsible.uniq!

  # Leaf tasks can be turned into containers after bookings have been added.
  # We need to check for this.
  unless @property.leaf? || @booking.empty?
    error('container_booking',
          "Container task #{@property.fullId} may not have bookings.")
  end

  # Milestones may not have bookings.
  if @milestone && !@booking.empty?
    error('milestone_booking',
          "Milestone #{@property.fullId} may not have bookings.")
  end

  # All 'scheduled' tasks must have a fixed start and end date.
  if @scheduled && (@start.nil? || @end.nil?)
    error('not_scheduled',
          "Task #{@property.fullId} is marked as scheduled but does not " +
          'have a fixed start and end date.')
  end

  # If an effort has been specified resources must be allocated as well.
  if @effort > 0 && @allocate.empty?
    error('effort_no_allocations',
          "Task #{@property.fullId} has an effort but no resource " +
          "allocations.")
  end

  durationSpecs = 0
  durationSpecs += 1 if @effort > 0
  durationSpecs += 1 if @length > 0
  durationSpecs += 1 if @duration > 0
  durationSpecs += 1 if @milestone

  # The rest of this function performs a number of plausibility tests with
  # regards to task start and end critiria. To explain the various cases,
  # the following symbols are used:
  #
  # |: fixed start or end date
  # -: no fixed start or end date
  # M: Milestone
  # D: start or end dependency
  # x->: ASAP task with duration criteria
  # <-x: ALAP task with duration criteria
  # -->: ASAP task without duration criteria
  # <--: ALAP task without duration criteria

  if @property.container?
    if durationSpecs > 0
      error('container_duration',
            "Container task #{@property.fullId} may not have a duration " +
            "or be marked as milestones.")
    end
  elsif @milestone
    if durationSpecs > 1
      error('milestone_duration',
            "Milestone task #{@property.fullId} may not have a duration.")
    end
    # Milestones can have the following cases:
    #
    #   |  M -   ok     |D M -   ok     - M -   err1   -D M -   ok
    #   |  M |   err2   |D M |   err2   - M |   ok     -D M |   ok
    #   |  M -D  ok     |D M -D  ok     - M -D  ok     -D M -D  ok
    #   |  M |D  err2   |D M |D  err2   - M |D  ok     -D M |D  ok

    # err1: no start and end
    # already handled by 'start_undetermed' or 'end_undetermed'

    # err2: differnt start and end dates
    if @start && @end && @start != @end
      error('milestone_start_end',
            "Start (#{@start}) and end (#{@end}) dates of " +
            "milestone task #{@property.fullId} must be identical.")
    end
  else
    #   Error table for non-container, non-milestone tasks:
    #   AMP: Automatic milestone promotion for underspecified tasks when
    #        no bookings or allocations are present.
    #   AMPi: Automatic milestone promotion when no bookings or
    #   allocations are present. When no bookings but allocations are
    #   present the task inherits start and end date.
    #   Ref. implicitXref()|
    #   inhS: Inherit start date from parent task or project
    #   inhE: Inherit end date from parent task or project
    #
    #   | x-> -   ok     |D x-> -   ok     - x-> -   inhS   -D x-> -   ok
    #   | x-> |   err1   |D x-> |   err1   - x-> |   inhS   -D x-> |   err1
    #   | x-> -D  ok     |D x-> -D  ok     - x-> -D  inhS   -D x-> -D  ok
    #   | x-> |D  err1   |D x-> |D  err1   - x-> |D  inhS   -D x-> |D  err1
    #   | --> -   AMP    |D --> -   AMP    - --> -   AMPi   -D --> -   AMP
    #   | --> |   ok     |D --> |   ok     - --> |   inhS   -D --> |   ok
    #   | --> -D  ok     |D --> -D  ok     - --> -D  inhS   -D --> -D  ok
    #   | --> |D  ok     |D --> |D  ok     - --> |D  inhS   -D --> |D  ok
    #   | <-x -   inhE   |D <-x -   inhE   - <-x -   inhE   -D <-x -   inhE
    #   | <-x |   err1   |D <-x |   err1   - <-x |   ok     -D <-x |   ok
    #   | <-x -D  err1   |D <-x -D  err1   - <-x -D  ok     -D <-x -D  ok
    #   | <-x |D  err1   |D <-x |D  err1   - <-x |D  ok     -D <-x |D  ok
    #   | <-- -   inhE   |D <-- -   inhE   - <-- -   AMP    -D <-- -   inhE
    #   | <-- |   ok     |D <-- |   ok     - <-- |   AMP    -D <-- |   ok
    #   | <-- -D  ok     |D <-- -D  ok     - <-- -D  AMP    -D <-- -D  ok
    #   | <-- |D  ok     |D <-- |D  ok     - <-- |D  AMP    -D <-- |D  ok

    # These cases are normally autopromoted to milestones or inherit their
    # start or end dates. But this only works for tasks that have no
    # allocations or bookings.
    #   -  --> -
    #   |  --> -
    #   |D --> -
    #   -D --> -
    #   -  <-- -
    #   -  <-- |
    #   -  <-- -D
    #   -  <-- |D
    if durationSpecs == 0 &&
       ((@forward && @end.nil? && !hasDependencies(true)) ||
        (!@forward && @start.nil? && !hasDependencies(false)))
      error('task_underspecified',
            "Task #{@property.fullId} has too few specifations to be " +
            "scheduled.")
    end

    #   err1: Overspecified (12 cases)
    #   |  x-> |
    #   |  <-x |
    #   |  x-> |D
    #   |  <-x |D
    #   |D x-> |
    #   |D <-x |
    #   |D <-x |D
    #   |D x-> |D
    #   -D x-> |
    #   -D x-> |D
    #   |D <-x -D
    #   |  <-x -D
    if durationSpecs > 1
      error('multiple_durations',
            "Tasks may only have either a duration, length or effort or " +
            "be a milestone.")
    end
    startSpeced = @property.provided('start', @scenarioIdx)
    endSpeced = @property.provided('end', @scenarioIdx)
    if ((startSpeced && endSpeced) ||
        (hasDependencies(false) && @forward && endSpeced) ||
        (hasDependencies(true) && !@forward && startSpeced)) &&
       durationSpecs > 0 && !@property.provided('scheduled', @scenarioIdx)
      error('task_overspecified',
            "Task #{@property.fullId} has a start, an end and a " +
            'duration specification.')
    end
  end

  if !@booking.empty? && !@forward && !@scheduled
    error('alap_booking',
          'A task scheduled in ALAP mode may only have bookings if it ' +
          'has been marked as fully scheduled. Keep in mind that ' +
          'certain attributes like \'end\' or \'precedes\' automatically ' +
          'switch the task to ALAP mode.')
  end

  @startsuccs.each do |task, onEnd|
    unless task['forward', @scenarioIdx]
      task.data[@scenarioIdx].error(
        'onstart_wrong_direction',
        'Tasks with on-start dependencies must be ASAP scheduled')
    end
  end
  @endpreds.each do |task, onEnd|
    if task['forward', @scenarioIdx]
      task.data[@scenarioIdx].error(
        'onend_wrong_direction',
        'Tasks with on-end dependencies must be ALAP scheduled')
    end
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 74
def prepareScheduling
  @property['startpreds', @scenarioIdx] = []
  @property['startsuccs', @scenarioIdx] = []
  @property['endpreds', @scenarioIdx] = []
  @property['endsuccs', @scenarioIdx] = []

  @isRunAway = false

  # And as global scoreboard index
  @currentSlotIdx = nil
  # The 'done' variables count scheduled values in number of time slots.
  @doneDuration = 0
  @doneLength = 0
  # Due to the 'efficiency' factor the effort slots must be a float.
  @doneEffort = 0.0

  @nowIdx = @project.dateToIdx(@project['now'])

  @startIsDetermed = nil
  @endIsDetermed = nil

  # To avoid multiple calls to propagateDate() we use these flags to know
  # when we've done it already.
  @startPropagated = false
  @endPropagated = false

  @durationType =
    if @effort > 0
      @hasDurationSpec = true
      :effortTask
    elsif @length > 0
      @hasDurationSpec = true
      :lengthTask
    elsif @duration > 0
      @hasDurationSpec = true
      :durationTask
    else
      # If the task is set as milestone it has a duration spec.
      @hasDurationSpec = @milestone
      :startEndTask
    end

  markAsMilestone

  # For start-end-tasks without allocation, we don't have to do
  # anything but to set the 'scheduled' flag.
  if @durationType == :startEndTask && @start && @end && @allocate.empty?
    markAsScheduled
  end

  # Collect the limits of this task and all parent tasks into a single
  # Array.
  @allLimits = []
  task = @property
  # Reset the counters of all limits of this task.
  task['limits', @scenarioIdx].reset if task['limits', @scenarioIdx]
  until task.nil?
    if task['limits', @scenarioIdx]
      @allLimits << task['limits', @scenarioIdx]
    end
    task = task.parent
  end

  @contendedResources = Hash.new { |hash, key| hash[key] = Hash.new(0) }

  # Collect the mandatory allocations.
  @mandatories = []
  @allocate.each do |allocation|
    @mandatories << allocation if allocation.mandatory
    allocation.lockedResource = nil
  end

  bookBookings

  if @durationType == :startEndTask
    @startIdx = @project.dateToIdx(@start) if @start
    @endIdx = @project.dateToIdx(@end) if @end
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 979
def propagateDate(date, atEnd, ignoreEffort = false)
  logTag = "propagateDate_#{@property.id}_#{atEnd ? 'end' : 'start'}"
  Log.enter(logTag, "Propagating #{atEnd ? 'end' : 'start'} date " +
                    "to task #{@property.id}")
  thisEnd = atEnd ? 'end' : 'start'
  otherEnd = atEnd ? 'start' : 'end'
  #puts "Propagating #{thisEnd} date #{date} to #{@property.fullId} " +
  #     "#{ignoreEffort ? "ignoring effort" : "" }"

  # These flags are just used to avoid duplicate calls of this function
  # during propagateInitialValues().
  if atEnd
    @endPropagated = true
  else
    @startPropagated = true
  end

  # For leaf tasks, propagate start may set the date. Container task dates
  # are only set in scheduleContainer().
  if @property.leaf?
    # If we already have a date, we will only shrink the task period with
    # the new date.
    if (setDate = instance_variable_get('@' + thisEnd)) &&
       atEnd ? date > setDate : date < setDate
      Log.msg { "Preserving #{thisEnd} date of #{typename} " +
                "#{@property.fullId}: #{setDate}" }
      return
    end

    instance_variable_set(('@' + thisEnd).intern, date)
    typename = 'Task'
    if @durationType == :startEndTask
      instance_variable_set(('@' + thisEnd + 'Idx').intern,
                            @project.dateToIdx(date))
      if @milestone
        typename = 'Milestone'
      end
    end
    Log.msg { "Update #{typename} #{@property.fullId}: #{period_to_s}" }
  end

  if @milestone
    # Start and end date of a milestone are identical.
    markAsScheduled
    if a(otherEnd).nil?
      propagateDate(a(thisEnd), !atEnd)
    end
  elsif !@scheduled && @start && @end &&
        !(@length == 0 && @duration == 0 && @effort == 0 &&
          !@allocate.empty?)
    markAsScheduled
  end

  # Propagate date to all dependent tasks. Don't do this for start
  # successors or end predecessors if this task is effort based. In this
  # case, the date might still change to align with the first/last
  # allocation. In these cases, bookResource() has to propagate the final
  # date.
  if atEnd
    if ignoreEffort || @effort == 0
      @endpreds.each do |task, onEnd|
        propagateDateToDep(task, onEnd)
      end
    end
    @endsuccs.each do |task, onEnd|
      propagateDateToDep(task, onEnd)
    end
  else
    if ignoreEffort || @effort == 0
      @startsuccs.each do |task, onEnd|
        propagateDateToDep(task, onEnd)
      end
    end
    @startpreds.each do |task, onEnd|
      propagateDateToDep(task, onEnd)
    end
  end

  # Propagate date to sub tasks which have only an implicit
  # dependency on the parent task and no other criteria for this end of
  # the task.
  @property.children.each do |task|
    if task.canInheritDate?(@scenarioIdx, atEnd)
      task.propagateDate(@scenarioIdx, date, atEnd)
    end
  end

  # The date propagation might have completed the date set of the enclosing
  # containter task. If so, we can schedule it as well.
  @property.parents.each do |parent|
    parent.scheduleContainer(@scenarioIdx)
  end
  Log.exit(logTag, "Finished propagation of " +
                   "#{atEnd ? 'end' : 'start'} date " +
                   "to task #{@property.id}")
end

# File lib/taskjuggler/TaskScenario.rb, line 187
def propagateInitialValues
  unless @startPropagated
    if @start
      propagateDate(@start, false, true)
    elsif @property.parent.nil? &&
          @property.canInheritDate?(@scenarioIdx, false)
      propagateDate(@project['start'], false, true)
    end
  end

  unless @endPropagated
    if @end
      propagateDate(@end, true, true)
    elsif @property.parent.nil? &&
          @property.canInheritDate?(@scenarioIdx, true)
      propagateDate(@project['end'], true, true)
    end
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1289
def query_activetasks(query)
  count = activeTasks(query)

  query.sortable = query.numerical = count
  # For the string output, we only use integer numbers.
  query.string = "#{count.to_i}"
end

# File lib/taskjuggler/TaskScenario.rb, line 1297
def query_closedtasks(query)
  count = closedTasks(query)

  query.sortable = query.numerical = count
  # For the string output, we only use integer numbers.
  query.string = "#{count.to_i}"
end

# File lib/taskjuggler/TaskScenario.rb, line 1305
def query_competitorcount(query)
  query.sortable = query.numerical = @competitors.length
  query.string = "#{@competitors.length}"
end

# File lib/taskjuggler/TaskScenario.rb, line 1310
def query_complete(query)
  # If we haven't calculated the value yet, calculate it first.
  unless @complete
    calcCompletion
  end

  query.sortable = query.numerical = @complete
  # For the string output, we only use integer numbers.
  query.string = "#{@complete.to_i}%"
end

# File lib/taskjuggler/TaskScenario.rb, line 1324
def query_cost(query)
  if query.costAccount
    query.sortable = query.numerical = cost =
      turnover(query.startIdx, query.endIdx, query.costAccount,
               query.scopeProperty)
    query.string = query.currencyFormat.format(cost)
  else
    query.string = 'No \'balance\' defined!'
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1337
def query_duration(query)
  query.sortable = query.numerical = duration =
    (@end - @start) / (60 * 60 * 24)
  query.string = query.scaleDuration(duration)
end

# File lib/taskjuggler/TaskScenario.rb, line 1375
def query_effort(query)
  query.sortable = query.numerical = work =
    getEffectiveWork(query.startIdx, query.endIdx, query.scopeProperty)
  query.string = query.scaleLoad(work)
end

# File lib/taskjuggler/TaskScenario.rb, line 1346
def query_effortdone(query)
  if @effortdone
    effort = @project.convertToDailyLoad(@effortdone *
                                         @project['scheduleGranularity'])
  else
    # For this query, we always override the query period.
    effort = getEffectiveWork(@project.dateToIdx(@project['start'], false),
                              @project.dateToIdx(@project['now']),
                              query.scopeProperty)
  end
  query.sortable = query.numerical = effort
  query.string = query.scaleLoad(effort)
end

# File lib/taskjuggler/TaskScenario.rb, line 1363
def query_effortleft(query)
  # For this query, we always override the query period.
  query.sortable = query.numerical = effort =
    getEffectiveWork(@project.dateToIdx(@project['now']),
                     @project.dateToIdx(@project['end'], false),
                     query.scopeProperty)
  query.string = query.scaleLoad(effort)
end

# File lib/taskjuggler/TaskScenario.rb, line 1381
def query_followers(query)
  list = []

  # First gather the task that depend on the start of this task.
  @startsuccs.each do |task, onEnd|
    if onEnd
      date = task['end', query.scenarioIdx].to_s(query.timeFormat)
      dep = "[->]"
    else
      date = task['start', query.scenarioIdx].to_s(query.timeFormat)
      dep = "[->["
    end
    list << generateDepencyListItem(query, task, dep, date)
  end
  # Than add the tasks that depend on the end of this task.
  @endsuccs.each do |task, onEnd|
    if onEnd
      date = task['end', query.scenarioIdx].to_s(query.timeFormat)
      dep = "]->]"
    else
      date = task['start', query.scenarioIdx].to_s(query.timeFormat)
      dep = "]->["
    end
    list << generateDepencyListItem(query, task, dep, date)
  end

  query.assignList(list)
end

# File lib/taskjuggler/TaskScenario.rb, line 1410
def query_gauge(query)
  # If we haven't calculated the schedule status yet, calculate it first.
  calcGauge unless @gauge

  query.string = @gauge
end

# File lib/taskjuggler/TaskScenario.rb, line 1420
def query_headcount(query)
  headcount = 0
  assignedResources(Interval.new(query.start, query.end)).each do |res|
    headcount += res['efficiency', @scenarioIdx].round
  end

  query.sortable = query.numerical = headcount
  query.string = query.numberFormat.format(headcount)
end

# File lib/taskjuggler/TaskScenario.rb, line 1430
def query_inputs(query)
  inputList = PropertyList.new(@project.tasks, false)
  inputs(inputList, true)
  inputList.delete(@property)
  inputList.setSorting([['start', true, @scenarioIdx],
                        ['seqno', true, -1 ]])
  inputList.sort!

  query.assignList(generateTaskList(inputList, query))
end

# File lib/taskjuggler/TaskScenario.rb, line 1441
def query_maxend(query)
  queryDateLimit(query, @maxend)
end

# File lib/taskjuggler/TaskScenario.rb, line 1445
def query_maxstart(query)
  queryDateLimit(query, @maxstart)
end

# File lib/taskjuggler/TaskScenario.rb, line 1449
def query_minend(query)
  queryDateLimit(query, @minend)
end

# File lib/taskjuggler/TaskScenario.rb, line 1453
def query_minstart(query)
  queryDateLimit(query, @minstart)
end

# File lib/taskjuggler/TaskScenario.rb, line 1457
def query_opentasks(query)
  count = openTasks(query)

  query.sortable = query.numerical = count
  # For the string output, we only use integer numbers.
  query.string = "#{count.to_i}"
end

# File lib/taskjuggler/TaskScenario.rb, line 1465
def query_precursors(query)
  list = []

  # First gather the task that depend on the start of this task.
  @startpreds.each do |task, onEnd|
    if onEnd
      date = task['end', query.scenarioIdx].to_s(query.timeFormat)
      dep = "]->["
    else
      date = task['start', query.scenarioIdx].to_s(query.timeFormat)
      dep = "[->["
    end
    list << generateDepencyListItem(query, task, dep, date)
  end
  # Than add the tasks that depend on the end of this task.
  @endpreds.each do |task, onEnd|
    if onEnd
      date = task['end', query.scenarioIdx].to_s(query.timeFormat)
      dep = "]->]"
    else
      date = task['start', query.scenarioIdx].to_s(query.timeFormat)
      dep = "[->]"
    end
    list << generateDepencyListItem(query, task, dep, date)
  end

  query.assignList(list)
end

# File lib/taskjuggler/TaskScenario.rb, line 1496
def query_resources(query)
  list = []
  iv = TimeInterval.new(query.start, query.end)
  assignedResources(iv).each do |resource|
    if resource.allocated?(@scenarioIdx, iv, @property)
      if query.listItem
        rti = RichText.new(query.listItem, RTFHandlers.create(@project)).
          generateIntermediateFormat
        unless rti
          error('bad_resource_ts_query',
                "Syntax error in query statement for task attribute " +
                "'resources'.")
        end
        q = query.dup
        q.property = resource
        q.scopeProperty = @property
        rti.setQuery(q)
        list << "<nowiki>#{rti.to_s}</nowiki>"
      else
        list << "<nowiki>#{resource.name} (#{resource.fullId})</nowiki>"
      end
    end
  end
  query.assignList(list)
end

# File lib/taskjuggler/TaskScenario.rb, line 1525
def query_revenue(query)
  if query.revenueAccount
    query.sortable = query.numerical = revenue =
      turnover(query.startIdx, query.endIdx, query.revenueAccount,
               query.scopeProperty)
    query.string = query.currencyFormat.format(revenue)
  else
    query.string = 'No \'balance\' defined!'
  end
end

# File lib/taskjuggler/TaskScenario.rb, line 1536
def query_scheduling(query)
  query.string = @forward ? 'ASAP' : 'ASAP' if @property.leaf?
end

# File lib/taskjuggler/TaskScenario.rb, line 1540
def query_status(query)
  # If we haven't calculated the completion yet, calculate it first.
  calcStatus if @status.empty?

  query.string = @status
end

# File lib/taskjuggler/TaskScenario.rb, line 1547
def query_targets(query)
  targetList = PropertyList.new(@project.tasks, false)
  targets(targetList, true)
  targetList.delete(@property)
  targetList.setSorting([['start', true, @scenarioIdx],
                         ['seqno', true, -1 ]])
  targetList.sort!

  query.assignList(generateTaskList(targetList, query))
end

# File lib/taskjuggler/TaskScenario.rb, line 910
def readyForScheduling?
  # If the tasks has already been scheduled, we still call it 'ready' so
  # it will be removed from the todo list.
  return true if @scheduled

  return false if @isRunAway

  if @forward
    return true if @start && (@hasDurationSpec || @end)
  else
    return true if @end && (@hasDurationSpec || @start)
  end

  false
end

# File lib/taskjuggler/TaskScenario.rb, line 612
def resetLoopFlags
  @deadEndFlags = Array.new(4, false)
end

# File lib/taskjuggler/TaskScenario.rb, line 930
def schedule
  # Check if the task has already been scheduled e. g. by propagateDate().
  return true if @scheduled

  logTag = "schedule_#{@property.id}"
  Log.enter(logTag, "Scheduling task #{@property.id}")
  # Compute the date of the next slot this task wants to have scheduled.
  # This must either be the first slot ever or it must be directly
  # adjecent to the previous slot. If this task has not yet been scheduled
  # at all, @currentSlotIdx is still nil. Otherwise it contains the index
  # of the last scheduled slot.
  if @forward
    # On first call, the @currentSlotIdx is not set yet. We set it to the
    # start slot index or the 'now' slot if we are in projection mode and
    # the tasks has allocations.
    if @currentSlotIdx.nil?
      @currentSlotIdx = @project.dateToIdx(
        @projectionmode && (@project['now'] > @start) && !@allocate.empty? ?
        @project['now'] : @start)
    end
  else
    # On first call, the @currentSlotIdx is not set yet. We set it to the
    # slot index of the slot before the end slot.
    if @currentSlotIdx.nil?
      @currentSlotIdx = @project.dateToIdx(@end) - 1
    end
  end

  # Schedule all time slots from slot in the scheduling direction until
  # the task is completed or a problem has been found.
  # The task may not excede the project interval.
  lowerLimit = @project.dateToIdx(@project['start'])
  upperLimit = @project.dateToIdx(@project['end'])
  delta = @forward ? 1 : -1
  while scheduleSlot
    @currentSlotIdx += delta
    if @currentSlotIdx < lowerLimit || upperLimit < @currentSlotIdx
      markAsRunaway
      Log.exit(logTag, "Scheduling of task #{@property.id} failed")
      return false
    end
  end

  Log.exit(logTag, "Scheduling of task #{@property.id} completed")
  true
end

# File lib/taskjuggler/TaskScenario.rb, line 1125
def scheduleContainer
  return if @scheduled || !@property.container?

  nStart = nil
  nEnd = nil

  @property.kids.each do |task|
    # Abort if a child has not yet been scheduled. Since we haven't done
    # the consistency check yet, we can't rely on start and end being set
    # if 'scheduled' is set.
    return if (!task['scheduled', @scenarioIdx] ||
               task['start', @scenarioIdx].nil? ||
               task['end', @scenarioIdx].nil?)

    if nStart.nil? || task['start', @scenarioIdx] < nStart
      nStart = task['start', @scenarioIdx]
    end
    if nEnd.nil? || task['end', @scenarioIdx] > nEnd
      nEnd = task['end', @scenarioIdx]
    end
  end

  startSet = endSet = false
  # Propagate the dates to other dependent tasks.
  if @start.nil? || @start > nStart
    @start = nStart
    startSet = true
  end
  if @end.nil? || @end < nEnd
    @end = nEnd
    endSet = true
  end
  unless @start && @end
    raise "Start (#{@start}) and end (#{@end}) must be set"
  end
  Log.msg { "Container task #{@property.fullId} completed: #{period_to_s}" }
  markAsScheduled

  # If we have modified the start or end date, we need to communicate this
  # new date to surrounding tasks.
  propagateDate(nStart, false) if startSet
  propagateDate(nEnd, true) if endSet
end