Track UChicago local bus system using defined 'stops'

tranloc.rb

# TODO html/jquery for getting all the points on the route

require 'yaml'
require 'json'
require 'open-uri'
require 'redis'

ROUTE = 1000299
ERROR = 0.0001  #This is radial wiggle room for arriving buses, in lat/lng

def get_data(route)  
  vehicles_url = "http://api.transloc.com/1.0/vehicles.json?agencies=100"
  vehicles_data = open("http://api.transloc.com/1.0/vehicles.json?agencies=100").read
  data = JSON.parse(vehicles_data)["data"]["100"]
  proper_route = data.collect { |x| x["route_id"] == "#{ROUTE}" ? x : nil}.compact[0]
end

class Stop
  attr_accessor :name, :latitude, :longitude

  def initialize args
    args.each do |k, v|
      instance_variable_set("@#{k}", v) unless v.nil?
    end
  end
  
  def arrived?
    vehicle_data = get_data ROUTE
    (vehicle_data["location"]["lat"] - self.latitude).abs < ERROR and (vehicle_data["location"]["lng"] - self.longitude).abs < ERROR 
  end
  
end

# Load em up, stopify, collect
stops = YAML::load(File.open('central.yml')).collect {|s| Stop.new(s) }

# And a redis server for the data
redis = Redis.new

stop_number = 0
# wait for the bus to reach the initial stop
puts "Waiting to begin the magical journey (ie for the bus to reach a stop)"
while !stops[stop_number].arrived?
  sleep 1
end

while true
  start_route_time = Time.now
  until stops[stop_number+1].arrived?
    puts "... Been traveling for #{(Time.now - start_route_time).to_i} seconds"
    sleep 1
  end
  route_time = Time.now - start_route_time
  puts "Bus made it to the next stop"
  unless stop_number == 0
    redis.set "#{stop_number}", JSON.parse(redis.get "#{stop_number}") << route_time
  else redis.set "#{stop_number}", [route_time].to_json
  end
  stop_number = (stop_number + 1)%stops.count
end

This and all my other work on transloc api has been moved here https://github.com/paulkaplan/Transloc