class GoogleMapTimeline

# File lib/google_timeline/google_map_timeline.rb, line 6
def initialize(file_path, home_coordinate, google_api_key)
  self.file_path = file_path
  self.home_coordinate = home_coordinate
  self.google_api_key = google_api_key
end

# File lib/google_timeline/google_map_timeline.rb, line 12
def get_timeline_url(args)
  #initialize flags
  location_str_max_length = 1800
  overall_distance_flag = false
  transport_mode_flag = false
  places_flag = false
  if (args.empty?)==false
    overall_distance_flag = !args.select{|a| a.is_a?(Hash) and a[:distance]==true}.first.nil?
    transport_mode_flag = !args.select{|a| a.is_a?(Hash) and a[:transport_mode]==true}.first.nil?
    places_flag = !args.select{|a| a.is_a?(Hash) and a[:places]==true}.first.nil?
  end
  
  op_hash = {}
  url=default_map
  coordinates = []
  value = self.file_path
  key = Date.parse(value.split("/").last.split(".").first.gsub("history-", "")) rescue nil
  op_hash[:date] = key
  
  if key.nil? == false and File.exists?(value)
    kml = File.read(value)
    doc = Nokogiri::XML(kml)
    coordinates = doc.search('coordinates').map{|c| c.content.split(" ")}.flatten.map{|co| co.split(",")[0..1].reverse.map{|co1| co1.to_f}} rescue []
    if coordinates.is_a?(Array) 
      location_str = polylines_encoding(coordinates)

      if location_str.length > location_str_max_length
        coordinates_dup = coordinates.dup
        while location_str.length > location_str_max_length do
          coordinates_dup = coordinates_dup.values_at(* coordinates_dup.each_index.select {|i| i.even?})
          location_str = polylines_encoding(coordinates_dup)
        end
      end
      url = location_url(location_str)  
    end

  end
  op_hash[:url] = url
  #overall distance
  if overall_distance_flag
    distance = {:value => overall_distance(coordinates), :unit=>"meter"}
    op_hash[:distance] = distance
  end
  #Transport Mode and places
  
  
  if (transport_mode_flag or places_flag)
    transport_mode_hash, places_array = transport_mode_and_places(doc, transport_mode_flag, places_flag)
    op_hash[:transport_mode] = transport_mode_hash if transport_mode_flag
    op_hash[:places] = places_array if places_flag
  end
  return op_hash
end

# File lib/google_timeline/google_map_timeline.rb, line 75
def default_map
  location_url(polylines_encoding(self.home_coordinate))
end

# File lib/google_timeline/google_map_timeline.rb, line 94
def distance(loc1, loc2)
  rad_per_deg = Math::PI/180  # PI / 180
  rkm = 6371                  # Earth radius in kilometers
  rm = rkm * 1000             # Radius in meters

  dlat_rad = (loc2[0]-loc1[0]) * rad_per_deg  # Delta, converted to rad
  dlon_rad = (loc2[1]-loc1[1]) * rad_per_deg

  lat1_rad, lon1_rad = loc1.map {|i| i * rad_per_deg }
  lat2_rad, lon2_rad = loc2.map {|i| i * rad_per_deg }

  a = Math.sin(dlat_rad/2)**2 + Math.cos(lat1_rad) * Math.cos(lat2_rad) * Math.sin(dlon_rad/2)**2
  c = 2 * Math::atan2(Math::sqrt(a), Math::sqrt(1-a))

  rm * c # Delta in meters
end

# File lib/google_timeline/google_map_timeline.rb, line 67
def location_url(location_str)
  "http://maps.googleapis.com/maps/api/staticmap?scale=2&path=enc:#{location_str}&size=600x600&sensor=false&key=#{self.google_api_key}"
end

# File lib/google_timeline/google_map_timeline.rb, line 79
def overall_distance(coordinates)
  total_distance = 0
  for i in 0..(coordinates.count - 1)
    coo = coordinates[i]
    if i==0
      loc1 = coo
    else
      loc2 = coo
      total_distance += distance(loc1,loc2)
      loc1 = loc2
    end
  end
  return total_distance
end

# File lib/google_timeline/google_map_timeline.rb, line 71
def polylines_encoding(str)
  Polylines::Encoder.encode_points(str).gsub("\\", '%5c')
end

# File lib/google_timeline/google_map_timeline.rb, line 111
def transport_mode_and_places(doc, transport_mode_flag, places_flag)
  transport_mode_hash = {} 
  places_array = []    
  if transport_mode_flag
    doc.search('Placemark').select{|dc| dc.children.map(&:name).include?("LineString")}.map{|dc| dc.children.select{|d| d.name=="ExtendedData"}[0].children.map{|d| d.children[0]}.flatten[1..2].map{|d| d.children[0].text}}.each do |tm|
      transport_mode_hash[tm[0]] = transport_mode_hash[tm[0]].to_i + tm[1].to_i 
    end
  end
  places_array = (doc.search('Placemark').select{|dc| dc.children.map(&:name).include?("Point")}.map{|dc| dc.children.select{|d| d.name=="name"}[0].children[0].text} rescue []) if places_flag
  return transport_mode_hash, places_array
end