module GitStats
  module StatsView
    module Charts
      class Chart
        def method_missing(name, *args, &block)
          @chart.send(name, *args, &block)
        end

        def respond_to_missing?(name, include_private = false)
          @chart.respond_to?(name, include_private)
        end

        def initialize
          @chart = LazyHighCharts::HighChart.new('graph')
          yield self if block_given?
        end

        def simple_column_chart(params)
          column_chart(params)
          series(name: params[:title], data: params[:data_y])
        end

        def multiple_column_chart(params)
          column_chart(params)
          params[:data_y].each do |s|
            series(name: s[:name], data: s[:data])
          end
        end

        def column_hash_chart(params)
          simple_column_chart(params.merge(
                                data_x: params[:data].keys,
                                data_y: params[:data].values
                              ))
        end

        def date_chart(params)
          common_options(params)
          series(date_series({name: params[:title], data: params[:data]}))
        end

        def multi_date_chart(params)
          common_options(params)
          default_legend
          params[:data].each do |s|
            series(date_series(s))
          end
        end

        def date_column_chart(params)
          common_options(params)
          series(date_series({name: params[:title], data: params[:data]}, aggregated: false).merge(
                   {
                     type: 'column',
                     dataGrouping: {units: [['day', [1]], ['week', [1]]], forced: true}
                   }
                 ))
        end

        def default_legend
          legend(
            enabled: true,
            layout: 'vertical',
            backgroundColor: '#FFFFFF',
            align: 'left',
            verticalAlign: 'top',
            x: 100,
            y: 70,
            floating: true,
            shadow: true
          )
        end

        def no_legend
          legend(
            enabled: false
          )
        end

        def type(type)
          @chart.chart!(type: type)
        end

        def x_categories(categories)
          @chart.xAxis!(categories: categories)
        end

        def x_text(text)
          @chart.xAxis!(title: {text: text})
        end

        def y_text(text)
          @chart.yAxis!(title: {text: text})
        end

        def title(title)
          @chart.title!(text: title)
        end

        private

        def common_options(params)
          no_legend
          title ''
          y_text params[:y_text]
          x_text params[:x_text]
        end

        def date_series(params, aggregated: true)
          {
            name: params[:name],
            type: 'spline',
            data: (params[:data]).to_h.fill_empty_days!(aggregated: aggregated)
                                 .map { |date, value| [date.to_datetime.to_i * 1000, value] }.sort_by { |d| d[0] }
          }
        end

        def column_chart(params)
          common_options(params)
          type 'column'
          x_categories params[:data_x]
        end
      end
    end
  end
end