#!/usr/bin/env ruby

# A HTTP-based API server, which provides queries to determine the status of
# entities and the checks that are reported against them.
#
# There's a matching flapjack-diner gem at https://github.com/flpjck/flapjack-diner
# which consumes data from this API.

require 'time'

require 'rack/fiber_pool'
require 'sinatra/base'

require 'flapjack/rack_logger'
require 'flapjack/redis_pool'

require 'flapjack/gateways/api/rack/json_params_parser'

require 'flapjack/gateways/api/contact_methods'
require 'flapjack/gateways/api/entity_methods'

module Flapjack

  module Gateways

    class API < Sinatra::Base

      include Flapjack::Utility

      set :show_exceptions, false

      #rescue_exception = Proc.new { |env, exception|
      #  @logger.error exception.message
      #  @logger.error exception.backtrace.join("\n")
      #  [503, {}, {:errors => [exception.message]}.to_json]
      #}
      #use Rack::FiberPool, :size => 25, :rescue_exception => rescue_exception
      #
      # FIXME: not sure why the above isn't working, had to add a general
      # error handler later in this file
      use Rack::FiberPool, :size => 25

      use Rack::MethodOverride
      use Rack::JsonParamsParser

      class << self
        def start
          @redis = Flapjack::RedisPool.new(:config => @redis_config, :size => 1)

          @logger.info "starting api - class"

          if @config && @config['access_log']
            access_logger = Flapjack::AsyncLogger.new(@config['access_log'])
            use Flapjack::CommonLogger, access_logger
          end
        end
      end

      def redis
        self.class.instance_variable_get('@redis')
      end

      def logger
        self.class.instance_variable_get('@logger')
      end

      before do
        input = env['rack.input'].read
        input_short = input.gsub(/\n/, '').gsub(/\s+/, ' ')
        logger.info("#{request.request_method} #{request.path_info}#{request.query_string} #{input_short[0..80]}")
        logger.debug("#{request.request_method} #{request.path_info}#{request.query_string} #{input}")
        env['rack.input'].rewind
      end

      after do
        logger.debug("Returning #{response.status} for #{request.request_method} #{request.path_info}#{request.query_string}")
      end

      register Flapjack::Gateways::API::EntityMethods

      register Flapjack::Gateways::API::ContactMethods

      not_found do
        logger.debug("in not_found :-(")
        err(404, "not routable")
      end

      error Flapjack::Gateways::API::ContactNotFound do
        e = env['sinatra.error']
        err(403, "could not find contact '#{e.contact_id}'")
      end

      error Flapjack::Gateways::API::NotificationRuleNotFound do
        e = env['sinatra.error']
        err(403, "could not find notification rule '#{e.rule_id}'")
      end

      error Flapjack::Gateways::API::EntityNotFound do
        e = env['sinatra.error']
        err(403, "could not find entity '#{e.entity}'")
      end

      error Flapjack::Gateways::API::EntityCheckNotFound do
        e = env['sinatra.error']
        err(403, "could not find entity check '#{e.check}'")
      end

      error do
        e = env['sinatra.error']
        err(response.status, "#{e.class} - #{e.message}")
      end

      private

      def err(status, *msg)
        msg_str = msg.join(", ")
        logger.info "Error: #{msg_str}"
        [status, {}, {:errors => msg}.to_json]
      end

    end

  end

end