# plot.rb: the style of a plot object.
# copyright (c) 2009 by Vincent Fourmond
  
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
  
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details (in the COPYING file).

require 'ctioga2/utils'
require 'ctioga2/log'

require 'ctioga2/graphics/coordinates'

# This module contains all the classes used by ctioga
module CTioga2

  Version::register_svn_info('$Revision: 94 $', '$Date: 2009-06-25 23:37:13 +0200 (Thu, 25 Jun 2009) $')

  module Graphics

    module Styles

      # The style of a Elements::Subplot object.
      #
      # TODO: it should hold
      # * labels
      # * axes and edges (in a *clean* way !)
      # * ticks
      # * background (uniform fill + watermark if applicable + possibly
      #   a picture .?)
      class PlotStyle

        include Tioga::FigureConstants

        # The various sides of the plot. A hash location -> AxisStyle.
        attr_accessor :axes

        # The default location of the X axis (well, mainly, the X label)
        attr_accessor :xaxis_location

        # The default location of the Y axis (well, mainly, the Y label)
        attr_accessor :yaxis_location

        # The title of the plot
        attr_accessor :title

        # A margin to be left around the data points
        attr_accessor :plot_margin

        # Coordinate tranforms
        attr_accessor :transforms

        # Style of the background of the plot
        attr_accessor :background

        # Scale of the lines of the plot. The plot is wrapped in a
        # t.rescale_lines call.
        attr_accessor :lines_scale

        # Scale of the text of the plot. The plot is wrapped in a
        # t.rescale_text call.
        attr_accessor :text_scale

        # A padding around the box when automatic spacing is in auto
        # mode. A Dimension.
        attr_accessor :padding

        def initialize
          # Default style for the plots.
          @axes = {}
          @axes[:left] = AxisStyle.new(:left, 
                                       AXIS_WITH_TICKS_AND_NUMERIC_LABELS,
                                       '$y$')
          @axes[:bottom] = AxisStyle.new(:bottom, 
                                         AXIS_WITH_TICKS_AND_NUMERIC_LABELS,
                                         '$x$')

          @axes[:right] = AxisStyle.new(:right, AXIS_WITH_TICKS_ONLY)
          @axes[:top] = AxisStyle.new(:top, AXIS_WITH_TICKS_ONLY)

          @xaxis_location = :bottom
          @yaxis_location = :left

          @title = TextLabel.new
          @title.loc = :top

          @plot_margin = nil

          @transforms = CoordinateTransforms.new

          @background = BackgroundStyle.new

          # A padding of 4bp ? Why ?? Why not ?
          @padding = Types::Dimension.new(:bp, 4)
        end

        # Whether to use log scale for the given axis.
        #
        # Now the question is: how should that affect user-defined
        # axes ? It should not.
        def set_log_scale(which, val)
          case which
          when :x
            @axes[:top].log = val
            @axes[:bottom].log = val
            @transforms.x_log = val
          when :y
            @axes[:left].log = val
            @axes[:right].log = val
            @transforms.y_log = val
          else
            raise "Unknown axis: #{which.inspect}"
          end
        end

        # Returns the AxisStyle corresponding to the named
        # axis. _name_ can be:
        # * one of the named elements of axes (ie, by default: top,
        #   left, right, bottom). All names are stripped from spaces
        #   around, and downcased (see #clean_axis_name).
        # * x(axis)?/y(axis)?, which returns the default object for the
        #   given location
        def get_axis_style(name)
          if name =~ /^\s*([xy])(?:axis)?\s*$/i
            return @axes[self.send("#{$1.downcase}axis_location")]
          else
            style = @axes[clean_axis_name(name)]
            if ! style
              raise "Unkown named axis: '#{name}'"
            else
              return style
            end
          end 
        end

        # Returns a BaseTextStyle or similar for the given
        # location. The location is of the form:
        #   axis_name(_(ticks?|label))
        # or
        #   title
        #
        # If neither label nor ticks is specified in the first form,
        # ticks are implied.
        def get_label_style(location)
          if location =~ /^\s*title\s*$/
            return @title
          end
          location =~ /^\s*(.*?)(?:_(ticks?|label))?\s*$/i
          which = $2
          axis = get_axis_style($1)
          if which =~ /label/
            return axis.axis_label
          else
            return axis.tick_label_style
          end
        end

        # Sets the style of the given label. Sets the text as well, if
        # _text_ is not _nil_
        def set_label_style(which, hash, text = nil)
          style = get_label_style(which)
          hash = hash.merge({'text' => text}) unless text.nil?
          if hash.key?('text') and ! style.is_a?(TextLabel)
            CTioga2::Log::warn("Text property of label #{which} was set, but this has no meaning: tick labels can't be set this way. Did you mean to use \"#{which}_label\"" + " instead ?")
          end
          style.set_from_hash(hash)
        end


        # Draws all axes for the plot.
        def draw_all_axes(t)
          for which, axis in @axes
            axis.draw_axis(t)
          end
          # We draw the title last
          title.draw(t, 'title')
        end

        # Draws all axes background lines for the plot.
        def draw_all_background_lines(t)
          for which, axis in @axes
            axis.draw_background_lines(t)
          end
        end

        # Sets up the FigureMaker object for the plot. To be called
        # just after the outermost context call for the concerned
        # plot.
        def setup_figure_maker(t)
          if @lines_scale
            t.rescale_lines(@lines_scale)
          end
          if @text_scale
            t.rescale_text(@text_scale)
          end
        end


        # Returns a deep copy of _self_, with all references stripped.
        def deep_copy
          return Marshal.load(Marshal.dump(self))
        end

        # Returns the PlotStyle object of the current plot
        def self.current_plot_style(plotmaker)
          return plotmaker.root_object.current_plot.style
        end

        # Estimate the margins of the plot whose style this object
        # controls. These margins are used when the plot margins are
        # in automatic mode.
        #
        # Returns a Types::MarginsBox
        def estimate_margins(t)
          margins = [:left, :right, :top, :bottom].map do |side|
            ext = @axes[side].extension(t,self)
            if side == @title.loc
              ext2 = @title.label_extension(t, 'title', side) * 
                (@text_scale || 1)
              if ext < ext2
                ext = ext2
              end
            end
            Types::Dimension.new(:dy, ext)
          end

          # TODO: add the plot title !
          box = Types::MarginsBox.new(*margins)
          if @padding
            for dim in box.margins
              dim.replace_if_bigger(t, @padding)
            end
          end
          return box
        end

        protected

        # Takes a string and returns a Symbol suitable for use with
        # the #axes hash (lower case without spaces).
        def clean_axis_name(name)
          if name.is_a?(::Symbol) # Argh ! Tioga redefined Symbol !
            return name
          end
          name =~ /^\s*(.*?)\s*$/
          return $1.downcase.to_sym
        end

      end

      AxisGroup = CmdGroup.new('axes-labels',
                               "Axes and labels", "Axes and labels", 40)


      
      AxisTypeCommands = []
      [:left, :right, :top, :bottom].each do |loc|
        AxisTypeCommands << 
          Cmd.new("#{loc}",nil,"--#{loc}", 
                  [
                   CmdArg.new('axis-decoration'),
                  ], PartialAxisStyle) do |plotmaker, dec, opts|
          style = AxisStyle.current_axis_style(plotmaker, loc)
          style.decoration = dec

          style.set_from_hash(opts)
        end
        AxisTypeCommands.last.
          describe("Sets the type of the #{loc} axis", 
                   <<"EOH", AxisGroup)
Sets the type of the #{loc} axis.
EOH
      end

      AxisStyleCommand = 
          Cmd.new("axis-style",nil,"--axis-style", 
                  [
                   CmdArg.new('axis'),
                  ], FullAxisStyle) do |plotmaker, which, opts|
        style = AxisStyle.current_axis_style(plotmaker, which)
        style.set_from_hash(opts)
      end
      AxisStyleCommand.
        describe("Sets the style of the given axis", 
                 <<"EOH", AxisGroup)
This command can be used to set various aspects of the style of the 
given axis, through its various options:
 * decoration
EOH

      BackgroundLinesCommands = 
        Cmd.new('background-lines', nil, '--background-lines',
                [
                 CmdArg.new('axis'), 
                 CmdArg.new('color-or-false')
                ],{
                  'style' => CmdArg.new('line-style'),
                  'width' => CmdArg.new('float')
                }) do |plotmaker, which, color, options|
        axis = AxisStyle.current_axis_style(plotmaker, which)
        if color
          style = {'color' => color}
          style.merge!(options)
          if axis.background_lines
            axis.background_lines.set_from_hash(style)
          else
            axis.background_lines = StrokeStyle.from_hash(style)
          end
        else
          axis.background_lines = false
        end
      end
      
      BackgroundLinesCommands.
        describe("Sets the color of the background lines", 
                 <<"EOH", AxisGroup)
Sets the color of the background lines for the given axis.
EOH


      XAxisLabelCommand = 
        Cmd.new('xlabel', '-x', '--xlabel', [ CmdArg.new('text') ],
                FullTextStyleOptions) do |plotmaker, label, options|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style('x_label', options, label)
      end

      XAxisLabelCommand.describe("Sets the X label of the plot", 
                                 <<"EOH", AxisGroup)
Sets the X label of the current plot.
EOH

      NoXAxisLabelCommand = 
        Cmd.new('no-xlabel', nil, '--no-xlabel', []) do |plotmaker|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style('x_label', {}, false)
      end

      NoXAxisLabelCommand.describe("Disables X label for the plot", 
                                   <<"EOH", AxisGroup)
Disables the X label for the current plot.
EOH


      YAxisLabelCommand = 
        Cmd.new('ylabel', '-y', '--ylabel', [ CmdArg.new('text') ],
                FullTextStyleOptions) do |plotmaker, label, options|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style('y_label', options, label)
      end

      YAxisLabelCommand.describe("Sets the Y label of the plot", 
                                 <<"EOH", AxisGroup)
Sets the Y label of the current plot.
EOH

      NoYAxisLabelCommand = 
        Cmd.new('no-ylabel', nil, '--no-ylabel', []) do |plotmaker|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style('y_label', {}, false)
      end

      NoYAxisLabelCommand.describe("Disables Y label for the plot", 
                                   <<"EOH", AxisGroup)
Disables the Y label for the current plot.
EOH

      TitleLabelCommand = 
        Cmd.new('title', '-t', '--title', [ CmdArg.new('text') ],
                FullTextStyleOptions) do |plotmaker, label, options|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style('title', options, label)
      end

      TitleLabelCommand.describe("Sets the title of the plot", 
                                 <<"EOH", AxisGroup)
Sets the title of the current plot.
EOH

      LabelStyleCommand = 
        Cmd.new('label-style', nil, '--label-style',
                [ CmdArg.new('label') ], # Here: change the label too... 
                FullTextLabelOptions) do |plotmaker, which, options|
        PlotStyle.current_plot_style(plotmaker).
          set_label_style(which, options)
      end
      
      LabelStyleCommand.describe("Sets the style of the given label", 
                                 <<"EOH", AxisGroup)
Sets the style of the given label (see the type {type: label} for more
information).

The option text permits to also set the text of the label (does not
work for ticks). 

For tick labels, setting the color option also sets the color for the
lines of the corresponding axis. If you don't want that, you can 
override the color using the /stroke_color option of 
{command: axis-style}. This will only work with Tioga version 1.11 or 
greater.
EOH

    end
  end
end