lib/kisyo/location.rb in kisyo-0.0.4 vs lib/kisyo/location.rb in kisyo-0.1.0

@@ -1,7 +1,30 @@
+require 'csv'
+
 module Kisyo
   class Location
     attr_reader :prefecture_id, :block_id
+
+    def self.dms_to_degrees(d, m, s = 0)
+      d + m / 60.0 + s / 3600.0
+    end
+
+    def self.nearest(lat, lng)
+      CSV.open(File.dirname(__FILE__) + '/../blocks.csv') do |csv|
+        distances =
+          csv.map do |row|
+            la = dms_to_degrees(row[5].to_f, row[6].to_f)
+            ln = dms_to_degrees(row[7].to_f, row[8].to_f)
+
+            [Math.sqrt((lat - la)**2 + (lng - ln)**2), row]
+          end
+
+        distance = distances.min_by { |(dist, _)| dist }
+        row = distance[1]
+
+        new(row[3], row[4])
+      end
+    end
 
     def initialize(prefecture_id, block_id)
       @prefecture_id = prefecture_id
       @block_id = block_id
     end