begin
  require 'json'
rescue LoadError
  p "Flotilla will not work without the 'json' gem"
end

module ActionView
  module Helpers
    module ScriptaculousHelper
      
      # Insert a flot chart into the page.  <tt>placeholder</tt> should be the 
      # name of the div that will hold the chart, <tt>collections</tt> is a hash 
      # of legends (as strings) and datasets with options as hashes, <tt>options</tt>
      # contains graph-wide options.
      # 
      # Example usage:
      #   
      #  chart("graph_div", { 
      #   "January" => { :collection => @january, :x => :day, :y => :sales, :options => { :lines => {:show =>true}} }, 
      #   "February" => { :collection => @february, :x => :day, :y => :sales, :options => { :points => {:show =>true} } },
      #   :grid => { :backgroundColor => "#fffaff" })
      # 
      # Options:
      #   :js_includes - includes flot library inline
      #   :js_tags - wraps resulting javascript in javascript tags if true.  Defaults to true.
      #   :placeholder_tag - appends a placeholder div for graph
      #   :placeholder_size - specifys the size of the placeholder div
      def chart(placeholder, series, options = {}, html_options = {})
        html_options.reverse_merge!({ :js_includes => true, :js_tags => true, :placeholder_tag => true, :placeholder_size => "800x300", :pie_hover => false, :pie_hover_absolute => false })
        width, height = html_options[:placeholder_size].split("x") if html_options[:placeholder_size].respond_to?(:split)
        additional_js = get_additional_js(placeholder, html_options)
        
        data, x_is_date, y_is_date = series_to_json(series)
        if x_is_date
          options[:xaxis] ||= {}
          options[:xaxis].merge!({ :mode => 'time' })
        end
        if y_is_date
          options[:yaxis] ||= {}
          options[:yaxis].merge!({ :mode => 'time' })
        end

        if html_options[:js_includes]
          chart_js = <<-EOF
          <script type="text/javascript">
            (function () {
              if (typeof(jQuery) == 'undefined') {
                alert("Please include jQuery to view flot");
              } else {
                if (typeof(jQuery.plot) == 'undefined') {
                  $('##{placeholder}').html("<span class='flot-error'>Please include jQuery.plot to view flot</span>");
                } else {
                  var plot = jQuery.plot($('##{placeholder}'), #{data}, #{options.to_json});
                  #{additional_js}
                }
              }
            })();
          </script>
          EOF
        else
          chart_js = <<-EOF
          (function () {
            if (typeof(jQuery) == 'undefined') {
              alert("Please include jQuery to view flot");
            } else {
              if (typeof(jQuery.plot) == 'undefined') {
                $('##{placeholder}').html("<span class='flot-error'>Please include jQuery.plot to view flot</span>");
              } else {
                var plot = jQuery.plot($('##{placeholder}'), #{data}, #{options.to_json});
                #{additional_js}
              }
            }
          })();
          EOF
        end        
        
        html_options[:js_tags] ? javascript_tag(chart_js) : chart_js
        output = html_options[:placeholder_tag] ? content_tag(:div, nil, :id => placeholder, :style => "width:#{width}px;height:#{height}px;", :class => "chart") + chart_js : chart_js
        output.html_safe
      end

      private
      def series_to_json(series)
        data_sets = []
        x_is_date, y_is_date = false, false
        series.each do |name, values|
          set, data = {}, []
          set[:label] = name
          first = values[:collection].first
          logger.warn "Collection is: #{values[:collection].inspect}"
          if first #&& !values[:collection].is_a?(Array)
            if first.is_a?(Hash)
              x_is_date = first[values[:x]].acts_like?(:date) || first[values[:x]].acts_like?(:time)
              y_is_date = first[values[:y]].acts_like?(:date) || first[values[:y]].acts_like?(:time)
            else
              x_is_date = first.send(values[:x]).acts_like?(:date) || first.send(values[:x]).acts_like?(:time)
              y_is_date = first.send(values[:y]).acts_like?(:date) || first.send(values[:y]).acts_like?(:time)
            end
          end
          values[:collection].each do |object|
            if values[:collection].is_a?(Hash) || object.is_a?(Hash)
              x_value, y_value = object[values[:x]], object[values[:y]]
              #logger.warn "A: Object is: #{object}, x,y: #{[x_value, y_value]} from #{[values[:x], values[:y]]}"
            else
              x_value, y_value = object.send(values[:x]), object.send(values[:y])
              #logger.warn "B: Object is: #{object}, x,y: #{[x_value, y_value]}"
            end
            x = x_is_date ? x_value.to_time.to_i * 1000 : x_value.to_f
            y = y_is_date ? y_value.to_time.to_i * 1000 : y_value.to_f
            #logger.warn "Tally x,y: #{[x, y]}"
            data << [x,y]
          end
          set[:data] = data
          values[:options].each {|option, parameters| set[option] = parameters } if values[:options]
          data_sets << set
        end
        return data_sets.to_json, x_is_date, y_is_date
      end

      def get_additional_js(placeholder, options)
        res = ""
        if options[:pie_hover]
          res << <<-EOF
             function showTooltip(x, y, contents) {
                $('<div id="tooltip">' + contents + '</div>').css( {
                    position: 'absolute',
                    //display: 'none',
                    top: y + 5,
                    left: x + 5,
                    border: '1px solid #fdd',
                    padding: '2px',
                    'background-color': '#fee',
                    opacity: 0.80
                }).appendTo("body");//.fadeIn(200);
            }
         
            var previousPoint = null;
            $('##{placeholder}').bind('mouseout', function() {
              plot.unhighlight();
              $("#tooltip").remove();
              $(this).data('previous-post', -1);
            });
            
            $('##{placeholder}').bind('plothover', function(event, pos, item) {
              if (item) {
                if ($(this).data('previous-post') != item.seriesIndex) {
                  plot.unhighlight();
                  plot.highlight(item.series, item.datapoint);
                  $(this).data('previous-post', item.seriesIndex);
                }
                $("#tooltip").remove();
                #{ options[:line_hover_absolute] ? "y = 'on ' + (new Date(item.datapoint[0])).toDateString() + ': ' + item.datapoint[1] + ' #{options[:item_title] || ''}'" : !options[:pie_hover_absolute] ? "y = item.datapoint[0].toFixed(0) + '%';" : "y = item.datapoint[1][0][1] + ' #{options[:item_title] || ''}'" } 
                showTooltip(pos.pageX, pos.pageY, item.series.label + " " + y);
              } else {
                //console.log('unhighlight (3)');
                plot.unhighlight();
                $("#tooltip").remove();
                previousPost = $(this).data('previous-post', -1);
              }
            });
          EOF
        end
        
        res
      end
    end
  end
end