#!/usr/bin/env ruby -w
# encoding: UTF-8
#
# = ChartView.rb -- PostRunner - Manage the data from your Garmin sport devices.
#
# Copyright (c) 2014 by Chris Schlaeger <cs@taskjuggler.org>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of version 2 of the GNU General Public License as
# published by the Free Software Foundation.
#

require 'postrunner/HRV_Analyzer'

module PostRunner

  class ChartView

    def initialize(activity, unit_system)
      @activity = activity
      @sport = activity.sport
      @unit_system = unit_system
      @empty_charts = {}
      @hrv_analyzer = HRV_Analyzer.new(activity)

      @charts = [
        {
          :id => 'pace',
          :label => 'Pace',
          :unit => select_unit('min/km'),
          :graph => :line_graph,
          :colors => '#0A7BEE',
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'speed',
          :label => 'Speed',
          :unit => select_unit('km/h'),
          :graph => :line_graph,
          :colors => '#0A7BEE',
          :show => @sport != 'running'
        },
        {
          :id => 'Power_18FB2CF01A4B430DAD66988C847421F4',
          :label => 'Power',
          :unit => select_unit('Watts'),
          :graph => :line_graph,
          :colors => '#FFAC2E',
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'altitude',
          :label => 'Altitude',
          :unit => select_unit('m'),
          :graph => :line_graph,
          :colors => '#5AAA44',
          :show => @activity.sub_sport != 'treadmill'
        },
        {
          :id => 'heart_rate',
          :label => 'Heart Rate',
          :unit => 'bpm',
          :graph => :line_graph,
          :colors => '#900000',
          :show => true
        },
        {
          :id => 'hrv',
          :label => 'Heart Rate Variability',
          :short_label => 'HRV',
          :unit => 'ms',
          :graph => :line_graph,
          :colors => '#900000',
          :show => @hrv_analyzer.has_hrv_data?
        },
        {
          :id => 'hrv_score',
          :label => 'rMSSD (30s Window)',
          :short_label => 'rMSSD',
          :graph => :line_graph,
          :colors => '#900000',
          :show => false
        },
        {
          :id => 'respiration_rate',
          :label => 'Respiration Rate',
          :unit => 'brpm',
          :graph => :line_graph,
          :colors => '#9cd6ef',
          :show => true
        },
        {
          :id => 'performance_condition',
          :label => 'Performance Condition',
          :graph => :line_graph,
          :colors => '#7CB7E7',
          :show => true
        },
        {
          :id => 'run_cadence',
          :label => 'Run Cadence',
          :unit => 'spm',
          :graph => :point_graph,
          :colors => [ [ '#EE3F2D', 151 ], [ '#F79666', 163 ],
                       [ '#A0D488', 174 ], [ '#96D7DE', 185 ],
                       [ '#A88BBB', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'stride_length',
          :label => 'Stride Length',
          :unit => select_unit('m'),
          :graph => :point_graph,
          :colors => [ ['#506DE1', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'vertical_oscillation',
          :label => 'Vertical Oscillation',
          :short_label => 'Vert. Osc.',
          :unit => select_unit('cm'),
          :graph => :point_graph,
          :colors => [ [ '#A88BBB', 67 ], [ '#96D7DE', 84 ],
                       [ '#A0D488', 101 ], [ '#F79666', 118 ],
                       [ '#EE3F2D', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'vertical_ratio',
          :label => 'Vertical Ratio',
          :unit => '%',
          :graph => :point_graph,
          :colors => [ [ '#CF45BD', 6.1 ], [ '#4FBEED', 7.4 ],
                       [ '#6AB03A', 8.6 ], [ '#EDA14F', 10.1 ],
                       [ '#FF5558', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'Form_Power_18FB2CF01A4B430DAD66988C847421F4',
          :label => 'Form Power',
          :unit => select_unit('Watts'),
          :graph => :line_graph,
          :colors => '#CBBB58',
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'Leg_Spring_Stiffness_18FB2CF01A4B430DAD66988C847421F4',
          :label => 'Leg Spring Stiffness',
          :unit => select_unit('kN/m'),
          :graph => :line_graph,
          :colors => '#358C88',
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'stance_time',
          :label => 'Ground Contact Time',
          :short_label => 'GCT',
          :unit => 'ms',
          :graph => :point_graph,
          :colors => [ [ '#A88BBB', 208 ], [ '#96D7DE', 241 ],
                       [ '#A0D488', 273 ], [ '#F79666', 305 ],
                       [ '#EE3F2D', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'gct_balance',
          :label => 'Ground Contact Time Balance',
          :short_label => 'GCT Balance',
          :unit => '%',
          :graph => :point_graph,
          :colors => [ [ '#FF5558', 47.8 ], [ '#EDA14F', 49.2 ],
                       [ '#6AB03A', 50.7 ], [ '#EDA14F', 52.2 ],
                       [ '#FF5558', nil ] ],
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'cadence',
          :label => 'Cadence',
          :unit => 'rpm',
          :graph => :line_graph,
          :colors => '#A88BBB',
          :show => @sport == 'cycling'
        },
        {
          :id => "Air_Power_18FB2CF01A4B430DAD66988C847421F4",
          :label => 'Air Power',
          :unit => select_unit('Watts'),
          :graph => :line_graph,
          :colors => '#919498',
          :show => @sport == 'running' || @sport == 'multisport'
        },
        {
          :id => 'temperature',
          :label => 'Temperature',
          :short_label => 'Temp.',
          :unit => 'C',
          :graph => :line_graph,
          :colors => '#444444',
          :show => true
        }
      ]
    end

    def to_html(doc)
      doc.unique(:chartview_style) {
        doc.head {
          doc.style(style)
        }
      }
      doc.script(java_script)
      @charts.each do |chart|
        label = chart[:label] + (chart[:unit] ? " (#{chart[:unit]})" : '')
        chart_div(doc, chart[:id], label) if chart[:show]
      end
    end

    private

    def select_unit(metric_unit)
      case @unit_system
      when :metric
        metric_unit
      when :statute
        { 'min/km' => 'min/mi', 'km/h' => 'mph',
          'mm' => 'in', 'cm' => 'in', 'm' => 'ft',
          'bpm' => 'bpm', 'rpm' => 'rpm', 'spm' => 'spm', '%' => '%',
          'ms' => 'ms' }[metric_unit]
      else
        Log.fatal "Unknown unit system #{@unit_system}"
      end
    end

    def style
      <<EOT
.chart-container {
	box-sizing: border-box;
	width: 600px;
	height: 200px;
	padding: 10px 15px 15px 15px;
	margin: 15px auto 15px auto;
	border: 1px solid #ddd;
	background: #fff;
	background: linear-gradient(#f6f6f6 0, #fff 50px);
	background: -o-linear-gradient(#f6f6f6 0, #fff 50px);
	background: -ms-linear-gradient(#f6f6f6 0, #fff 50px);
	background: -moz-linear-gradient(#f6f6f6 0, #fff 50px);
	background: -webkit-linear-gradient(#f6f6f6 0, #fff 50px);
	box-shadow: 0 3px 10px rgba(0,0,0,0.15);
	-o-box-shadow: 0 3px 10px rgba(0,0,0,0.1);
	-ms-box-shadow: 0 3px 10px rgba(0,0,0,0.1);
	-moz-box-shadow: 0 3px 10px rgba(0,0,0,0.1);
	-webkit-box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}
.chart-placeholder {
	width: 580px;
	height: 200px;
	font-size: 14px;
	line-height: 1.2em;
}
EOT
    end

    def java_script
      s = "$(document).ready(function() {\n"

      s << tooltip_div
      @charts.each do |chart|
        s << send(chart[:graph], chart) if chart[:show]
      end

      s << "\n});\n"

      s
    end

    def tooltip_div
      <<"EOT"
        function timeToHMS(usecs) {
           var secs = parseInt(usecs / 1000.0);
           var s = secs % 60;
           var mins = parseInt(secs / 60);
           var m = mins % 60;
           var h = parseInt(mins / 60);
           s = (s < 10) ? "0" + s : s;
           if (h == 0) {
             return ("" + m + ":" + s);
           } else {
             m = (m < 10) ? "0" + m : m;
             return ("" + h + ":" + m + ":" + s);
           }
        };
        $("<div id='tooltip'></div>").css({
                position: "absolute",
                display: "none",
                border: "1px solid #888",
                padding: "2px",
                "background-color": "#EEE",
                opacity: 0.90,
                "font-size": "8pt"
        }).appendTo("body");
EOT
    end

    def line_graph(chart)
      s = "var #{chart[:id]}_data = [\n"

      data_set = []
      start_time = @activity.fit_activity.sessions[0].start_time.to_i
      min_value = nil
      if chart[:id] == 'hrv_score'
        window_time = 120
        0.upto(@hrv_analyzer.total_duration.to_i - window_time) do |t|
          if (hrv_score = @hrv_analyzer.rmssd(t, window_time)) >= 0.0
            min_value = hrv_score if min_value.nil? || min_value > hrv_score
            data_set << [ (t * 1000).to_i, hrv_score ]
          else
            data_set << [ (t * 1000).to_i, nil ]
          end
        end
      elsif chart[:id] == 'hrv'
        @hrv_analyzer.hrv.each_with_index do |dt, i|
          if dt
            data_set << [ (@hrv_analyzer.timestamps[i] * 1000).to_i, dt * 1000 ]
          else
            data_set << [ (@hrv_analyzer.timestamps[i] * 1000).to_i, nil ]
          end
        end
        min_value = 0
      else
        last_value = nil
        last_timestamp = nil
        @activity.fit_activity.records.each do |r|
          if last_timestamp && (r.timestamp - last_timestamp) > 10.0
            # We have a gap in the values that is longer than 5 seconds. We'll
            # finish the line and start a new one later.
            data_set << [ (last_timestamp - start_time + 1).to_i * 1000, nil ]
          end
          value = r.get_as(chart[:id], chart[:unit] || '')
          if value.nil? && chart[:id] == 'speed'
            # If speed field doesn't exist the value might be in the
            # enhanced_speed field.
            value = r.get_as('enhanced_speed', chart[:unit] || '')
          end
          if value.nil? && chart[:id] == 'altitude'
            # If altitude field doesn't exist the value might be in the
            # enhanced_elevation field.
            value = r.get_as('enhanced_elevation', chart[:unit] || '')
          end
          if value
            if chart[:id] == 'pace'
              # Slow speeds lead to very large pace values that make the graph
              # hard to read. We cap the pace at 20.0 min/km to keep it
              # readable.
              if value > (@unit_system == :metric ? 20.0 : 36.0 )
                value = nil
              else
                value = (value * 3600.0 * 1000).to_i
              end
              min_value = 0.0
            else
              min_value = value if (min_value.nil? || min_value > value)
            end
          end
          if value
            data_set << [ (r.timestamp - start_time).to_i * 1000, value ]
          end
          last_value = value
          last_timestamp = r.timestamp
        end
      end

      # We don't want to plot charts with all nil values.
      unless data_set.find { |v| v[1] != nil }
        @empty_charts[chart[:id]] = true
        return ''
      end
      s << data_set.map do |set|
        "[ #{set[0]}, #{set[1] ? set[1] : 'null'} ]"
      end.join(', ')
      s << "];\n"

      s << lap_marks(start_time)

      chart_id = "#{chart[:id]}_chart"
      s << <<"EOT"
	  	var plot = $.plot(\"##{chart_id}\",
             [ { data: #{chart[:id]}_data,
                 #{chart[:colors] ? "color: \"#{chart[:colors]}\"," : ''}
                 lines: { show: true#{chart[:id] == 'pace' ? '' :
                                      ', fill: true'} } } ],
             { xaxis: { mode: "time", min: 0.0 },
               grid: { markings: lap_marks, hoverable: true }
EOT
      if chart[:id] == 'pace'
        s << ", yaxis: { mode: \"time\",\n" +
             "           transform: function (v) { return -v; },\n" +
             "           inverseTransform: function (v) { return -v; } }"
      else
        # Set the minimum slightly below the lowest found value.
        if min_value > 0.0 && !chart[:min_y]
          s << ", yaxis: { min: #{0.9 * min_value} }"
        end
      end
      if chart[:min_y]
        s << ", yaxis: { #{chart[:min_y] ? "min: #{chart[:min_y]}" : '' } " +
                        "#{chart[:min_y] && chart[:max_y] ? ', ' : ''}" +
                        "#{chart[:max_y] ? "max: #{chart[:max_y]}" : '' } }"
      end
      s << "});\n"
      s << lap_mark_labels(chart_id, start_time)
      s << hover_function(chart_id, chart[:short_label] || chart[:label],
                          select_unit(chart[:unit] || '')) + "\n"
    end

    def point_graph(chart)
      # We need to split the y-values into separate data sets for each
      # color. The max value for each color determines which set a data point
      # ends up in.
      # Initialize the data sets. The key for data_sets is the corresponding
      # index in colors.
      data_sets = {}
      chart[:colors].each.with_index { |cp, i| data_sets[i] = [] }

      # Now we can split the y-values into the sets.
      start_time = @activity.fit_activity.sessions[0].start_time.to_i
      @activity.fit_activity.records.each do |r|
        # Undefined values will be discarded.
        next unless (value = r.send(chart[:id]))

        # Find the right set by looking at the maximum allowed values for each
        # color.
        chart[:colors].each.with_index do |col_max_value, i|
          col, range_max_value = col_max_value
          if range_max_value.nil? || value < range_max_value
            # A range_max_value of nil means all values allowed. The value is
            # in the allowed range for this set, so add the value as x/y pair
            # to the set.
            x_val = (r.timestamp.to_i - start_time) * 1000
            data_sets[i] << [ x_val, r.get_as(chart[:id], chart[:unit] || '') ]
            # Abort the color loop since we've found the right set already.
            break
          end
        end
      end

      # We don't want to plot charts with all nil values.
      if data_sets.values.flatten.empty?
        @empty_charts[chart[:id]] = true
        return ''
      end

      # Now generate the JS variable definitions for each set.
      s = ''
      data_sets.each do |index, ds|
        s << "var #{chart[:id]}_data_#{index} = [\n"
        s << ds.map { |dp| "[ #{dp[0]}, #{dp[1]} ]" }.join(', ')
        s << " ];\n"
      end

      s << lap_marks(start_time)

      chart_id = "#{chart[:id]}_chart"
      s << "var plot = $.plot(\"##{chart_id}\", [\n"
      s << data_sets.map do |index, ds|
             "{ data: #{chart[:id]}_data_#{index},\n" +
             "  color: \"#{chart[:colors][index][0]}\",\n" +
             "  points: { show: true, " +
             "            fillColor: \"#{chart[:colors][index][0]}\", " +
             "            fill: true, radius: 2 } }"
           end.join(', ')
      s << "], { xaxis: { mode: \"time\", min: 0.0 }, " +
           (chart[:id] == 'gct_balance' ? gct_balance_yaxis(data_sets) : '') +
           "     grid: { markings: lap_marks, hoverable: true } });\n"
      s << lap_mark_labels(chart_id, start_time)
      s << hover_function(chart_id, chart[:short_label] || chart[:label],
                          select_unit(chart[:unit] || ''))

      s
    end

    def chart_div(doc, field, title)
      # Don't plot frame for graph without data.
      return if @empty_charts[field]

      ViewFrame.new("#{field}_chart", title, 600, nil, true) {
        doc.div({ 'id' => "#{field}_chart", 'class' => 'chart-placeholder'})
      }.to_html(doc)
    end

    def hover_function(chart_id, y_label, y_unit)
      <<"EOT"
        $("##{chart_id}").bind("plothover", function (event, pos, item) {
         if (item) {
           var x = timeToHMS(item.datapoint[0]);
           var y = #{y_label == 'Pace' ? 'timeToHMS(item.datapoint[1] / 60)' :
                                         'item.datapoint[1].toFixed(0)'};
           $("#tooltip").html("<b>#{y_label}:</b> " + y + " #{y_unit}<br/>" +
                              "<b>Time:</b> " + x + " h:m:s")
             .css({top: item.pageY-20, left: item.pageX+15})
             .fadeIn(200);
         } else {
           $("#tooltip").hide();
         }
       });
EOT
    end

    def lap_marks(start_time)
      # Use vertical lines to mark the end of each lap.
      s = "var lap_marks = [\n"
      s += @activity.fit_activity.laps.map do |lap|
        x = ((lap.timestamp.to_i - start_time) * 1000).to_i
        "\n  { color: \"#666\", lineWidth: 1, " +
        "xaxis: { from: #{x} , to: #{x} } }"
      end.join(",\n")
      s + "];\n"
    end

    def lap_mark_labels(chart_id, start_time)
      # Mark the vertical lap marks with the number of the lap right to the
      # left at the top end of the line.
      s = ''
      @activity.fit_activity.laps[0..-2].each do |lap|
        x = ((lap.timestamp.to_i - start_time) * 1000).to_i
        s += "$(\"##{chart_id}\").append(" +
             "\"<div style='position:absolute;" +
             "left:\" + (plot.pointOffset({x: #{x}, y: 0}).left - 18) + \"px;" +
             "top:7px;width:16px;" +
             "text-align:right;" +
             "color:#666;font-size:smaller'>" +
             "#{lap.message_index + 1}</div>\");\n"
      end
      s
    end

    def gct_balance_yaxis(data_set)
      # Decompose hash of array with x/y touples into a flat array of just y
      # values.
      yvalues = data_set.values.flatten(1).map { |touple| touple[1] }
      # Find the largest and smallest value and round it up and down to the
      # next Fixnum.
      max = yvalues.max.ceil
      min = yvalues.min.floor
      # Ensure that the range 49 - 51 is always included.
      max = 51.0 if max < 51.0
      min = 49.0 if min > 49.0
      # The graph is large to fit 6 ticks quite nicely.
      tick_step = ((max - min) / 6.0).ceil
      # Generate an Array with the tick values
      tick_values = (0..5).to_a.map { |i| min + i * tick_step }
      # Remove values that are larger than max
      tick_values.delete_if { |v| v > max }
      # Generate an Array of tick/label touples
      ticks = []
      tick_labels = tick_values.each do |value|
        label = if value < 50
                  "#{100 - value}%R"
                elsif value > 50
                  "#{value}%L"
                else
                  '50/50'
                end
        ticks << [ value, label ]
      end
      # Convert the tick/label Array into a Flot yaxis definition.
      "yaxis: { ticks: #{ticks.inspect} }, "
    end

  end

end