require 'yajl'
require 'sinatra/base'
require 'sinatra/synchrony'
#require 'sinatra/reloader' if ENV['RACK_ENV'] == 'development'

%w[connection_pool graph params version].each { |file| require "batsd-dash/#{file}" }

module BatsdDash
  class App < Sinatra::Base
    #configure(:development) { register Sinatra::Reloader }

    configure do
      register Sinatra::Synchrony
      helpers ParamsHelper, GraphHelper, ConnectionHelpers

      set :haml, :format => :html5

      EM::Synchrony.next_tick { ConnectionPool::initialize_connection_pool }
    end

    helpers do
      def render_error(msg)
        render_json 400, error: msg
      end

      def render_json(code = 200, json)
        halt code, String === json ? json : Yajl::Encoder.encode(json)
      end
    end

    get "/" do
      haml :root
    end

    get "/version", :provides => :json do
      render_json version: BatsdDash::VERSION
    end

    get "/available", :provides => :json do
      connection_pool.async_available_list.callback do |json|
        render_json json
      end
    end

    # this route renders the template (with codes for the graph)
    get "/graph", :provides => :html do
      haml :view
    end

    # actual data API route
    get "/data", :provides => :json do
      statistics = parse_statistics
      range = parse_time_range

      return render_error('Invalid time range') unless range
      return render_error('Invalid metrics') if statistics.empty?

			results = []
			options = {
				range: range.dup.map { |n| n * 1000 },
				zero_fill: !params[:no_zero_fill]
			}

      statistics.each do |datatype, metrics|
        metrics.each do |metric|
          statistic = "#{datatype}:#{metric}"
          deferrable = connection_pool.async_values(statistic, range)

          deferrable.errback { |e| return render_error(e.message) }
          deferrable.callback do |json|
            options[:interval] ||= json['interval']

            points = json[statistic] || []
            values = values_for_graph(points, options)

            results << { key: metric, type: datatype[0..-2], values: values }
          end
        end
      end

      cache_control :no_cache, :no_store
      render_json range: options[:range], interval: options[:interval], results: results
    end
  end
end