#!/usr/bin/ruby -w

#
# cdntrans.rb v1.1 - 2007/01
#
# this script converts GPS coordinates between 3 different formats:
# - Degrees, Minutes, Seconds
# - Degrees, Minutes, Decimal
# - Degrees, Decimal
#
# I wrote because when geotagging pictures, each application uses its format
# for GPS data. I looked for the most widely used and wrote this conversion
# tool.
#
# Copyright (C) 2006 by Pedro Venda < pjvenda (at) pjvenda org >
#
# Distributed under the terms of the GNU Public License Agreement (GPLv2)
# http://www.fsf.org/licensing/licenses/gpl.html or
# http://www.fsf.org/licensing/licenses/gpl.txt
#
# Credit
# ======
#
# The following websites helped me write this application:
# http://jeeep.com/details/coord/
# http://life.csu.edu.au/geo/coord.html
# http://www.csgnetwork.com/gpscoordconv.html
#
# This one has a massive amount of GPS related information:
# http://www.colorado.edu/geography/gcraft/notes/gps/gps_f.html
#
# Usage
# =====
#
# this script receives its input from stdin and outputs it into stdout.
#
# input coordinates can be given in any of the output formats (the program
# detects which format was supplied). output is the same input data written
# in all supported formats.
#
# example: $ echo "38º 41' 29.69\" N, 9º 12' 57.27\" W" | ./cdntrans.rb
# DMS:      38 41' 29.69" N,  9 12' 57.27" W
# Min Dec:  38 41.494833, -9 12.954500
# Deg Dec:  38.69158056, -9.21590833
# $
# alternatively, the input can be given as a command line argument
# example: $ ./cdntrans.rb "38º 41' 29.69\" N, 9º 12' 57.27\" W"
# DMS:      38 41' 29.69" N,  9 12' 57.27" W
# Min Dec:  38 41.494833, -9 12.954500
# Deg Dec:  38.69158056, -9.21590833
# $
#
# as a funny (useful) side effect, google maps' links are correctly parsed:
# $ ./cdntrans.rb "http://maps.google.com/maps?f=q&hl=en&ie=UTF8&z=18&ll=38.691581,-9.215909&spn=0.003341,0.00736&t=h&om=1"
# DMS:      38 41' 29.69" N,  9 12' 57.27" W
# Min Dec:     38 41.494860,   -9 -12.954540
# Deg Dec:      38.69158100,     -9.21590900
# $
#
# finally it can be included as a class 'Coordinate' to instantiate objects
#
# Changelog
# =========
#
# v1.1 - 2007/01/28
# - added input flexibility: 38.69158100 S, -9.21590900 W is now accepted
# 	(although it may not make any sense)
# - added input flexibility: 40° 24.991 N 007° 31.861 W is now accepted
# - added input flexibility: N 40° 24.991 W 007° 31.861 is now accepted
# - added lower case directions (N-n, S-s, W-w, E-e) for mindec, degdec 
#	and dms coordinates
#
# v1.0 - 2006/12/31
# - initial (ruby) version. basically works as I needed
#

class Coordinate
	@@VERSION="1.1"
	# regular expressions to trap and identify input format
	@@dms_re=Regexp.new('(\d+)[\W\D]*\s+(\d+)\'\s+(\d+([.,]\d+)?)\"\s*([NnSs])[,\s]\s*(\d+)[\W\D]*\s+(\d+)\'\s+(\d+([.,]\d+)?)\"\s*([WwEe])(?# )')
	@@mindec_re=Regexp.new('([+-]?\d+)[\W\D]*\s*(\d+(\.\d+))\s*([NnSs]?)[\s,;]+([+-]?\d+)[\W\D]*\s*(\d+(\.\d+))\s*([WwEe]?)(?# )')
	# alternative for mindec input: directions (N,S,W,E) are given 
	# at the beginning of the coordinate string
	@@mindec_alt_re=Regexp.new('([NnSs]?)\s*([+-]?\d+)[\W\D]*\s*(\d+(\.\d+))[\s,;]+([WwEe]?)\s*([+-]?\d+)[\W\D]*\s*(\d+(\.\d+))(?# )')
	@@degdec_re=Regexp.new('([+-]?\d+(\.\d+)?)\s*([NnSs]?)[\s,;]+([+-]?\d+(\.\d+)?)\s*([WwEe]?)(?# )')
	@@degdec_alt_re=Regexp.new('([NnSs]?)\s*([+-]?\d+(\.\d+)?)[\s,;]+\s*([WwEe]?)\s*([+-]?\d+(\.\d+)?)(?# )')

	# object and class variables accessible by the outsude
	attr_reader :dms, :mindec, :degdec
	attr_reader :dms_re, :mindec_re, :degdec_re

	def initialize(input='')
		# initialize all data	
		@dms={ :lat => { :deg => 0, 
						 :min => 0, 
						 :sec => 0,
						 :ref => '' }, 
			   :lon => { :deg => 0, 
			   			 :min => 0, 
						 :sec => 0,
						 :ref => '' } 
			 }
		@mindec={ :lat => { :deg => 0, 
							:frac => 0 }, 
				  :lon => { :deg => 0, 
				  			:frac => 0 } 
				}
		@degdec={ :lat => 0, 
		          :lon => 0 
				}
		@parsed=false
		# identify, parse and convert input data through all supported formats
		parse_str(input)
	end

	# print coordinate data in all supported formats
	def to_s
		if @parsed 
			"DMS:".ljust(10)\
				+(sprintf("%2d",@dms[:lat][:deg])+" "\
				+sprintf("%2d",@dms[:lat][:min])+"' "\
				+sprintf("%2.2f",@dms[:lat][:sec])+"\" "\
				+@dms[:lat][:ref].to_s.upcase).rjust(14)+", "\
				+(sprintf("%2d",@dms[:lon][:deg])+" "\
				+sprintf("%2d",@dms[:lon][:min])+"' "\
				+sprintf("%2.2f",@dms[:lon][:sec])+"\" "\
				+@dms[:lon][:ref].to_s.upcase).rjust(14)+"\n"\
			+"Min Dec:".ljust(10)\
				+(sprintf("%2d",@mindec[:lat][:deg])+" "\
				+sprintf("%2.6f",@mindec[:lat][:frac])).rjust(15)+", "\
				+(sprintf("%2d",@mindec[:lon][:deg])+" "\
				+sprintf("%2.6f",@mindec[:lon][:frac])).rjust(15)+"\n"\
			+"Deg Dec:".ljust(10)\
				+sprintf("%2.8f",@degdec[:lat]).rjust(15)+", "\
				+sprintf("%2.8f",@degdec[:lon]).rjust(15)+"\n"
		else
			"unable to parse input string\n\n"
		end
	end

	def parse_str(input_str)
		#puts "  input string: "+input_str+"\n"
		if res=@@dms_re.match(input_str)
			#puts "    input string matches dms format"

			# fill in @dms variable
			@dms[:lat][:deg]=res[1].to_i
			@dms[:lat][:min]=res[2].to_i
			@dms[:lat][:sec]=res[3].to_f
			@dms[:lat][:ref]=res[5].to_s
			@dms[:lon][:deg]=res[6].to_i
			@dms[:lon][:min]=res[7].to_i
			@dms[:lon][:sec]=res[8].to_f
			@dms[:lon][:ref]=res[10].to_s

			# fill in @mindec and @degdec variables
			dms_to_mindec
			dms_to_degdec
			@parsed=true
		elsif res=@@mindec_re.match(input_str)
			#puts "    input string matches mindec format"

			# fill in @mindec variable
			@mindec[:lat][:deg]=res[1].to_f
			@mindec[:lat][:frac]=res[2].to_f
			if res[4].to_s.upcase=="S"
				@mindec[:lat][:deg]*=-1
			end
			@mindec[:lon][:deg]=res[5].to_f
			@mindec[:lon][:frac]=res[6].to_f
			if res[8].to_s.upcase=="W"
				@mindec[:lon][:deg]*=-1
			end
			# fill in @dms and @degdec variables
			mindec_to_dms
			mindec_to_degdec
			@parsed=true
		elsif res=@@mindec_alt_re.match(input_str)
			#puts "    input string matches alternative mindec format"

			# fill in @mindec variable
			@mindec[:lat][:deg]=res[2].to_f
			@mindec[:lat][:frac]=res[3].to_f
			if res[1].to_s.upcase=="S"
				@mindec[:lat][:deg]*=-1
			end
			@mindec[:lon][:deg]=res[6].to_f
			@mindec[:lon][:frac]=res[7].to_f
			if res[5].to_s.upcase=="W"
				@mindec[:lon][:deg]*=-1
			end
			# fill in @dms and @degdec variables
			mindec_to_dms
			mindec_to_degdec
			@parsed=true
		elsif res=@@degdec_alt_re.match(input_str)
			#puts "    input string matches degdec format"

			# fill in @degdec variable
			@degdec[:lat]=res[2].to_f
			if res[1].to_s.upcase=="S"
				@degdec[:lat]*=-1
			end
			@degdec[:lon]=res[5].to_f
			if res[4].to_s.upcase=="W"
				@degdec[:lon]*=-1
			end

			# fill in @dms and @mindec variables
			degdec_to_dms
			degdec_to_mindec
			@parsed=true
		elsif res=@@degdec_re.match(input_str)
			#puts "    input string matches degdec format"

			# fill in @degdec variable
			@degdec[:lat]=res[1].to_f
			if res[3].to_s.upcase=="S"
				@degdec[:lat]*=-1
			end
			@degdec[:lon]=res[4].to_f
			if res[6].to_s.upcase=="W"
				@degdec[:lon]*=-1
			end

			# fill in @dms and @mindec variables
			degdec_to_dms
			degdec_to_mindec
			@parsed=true
		else
			return "input string doesn't match any known format...\n\n"
		end
	end

	# conversion from dms to degdec
	def dms_to_degdec
		@degdec[:lat]=@dms[:lat][:deg]\
					  +((@dms[:lat][:min]*1.0)/60)\
					  +((@dms[:lat][:sec]*1.0)/3600)
		if @dms[:lat][:ref].upcase=='S'
			@degdec[:lat]*=-1
		end
		@degdec[:lon]=@dms[:lon][:deg]\
					  +((@dms[:lon][:min]*1.0)/60)\
					  +((@dms[:lon][:sec]*1.0)/3600)
		if @dms[:lon][:ref].upcase=='W'
			@degdec[:lon]*=-1
		end
	end
	# conversion from degdec to dms
	def degdec_to_dms
		@dms[:lat][:deg]=@degdec[:lat].abs.truncate
		@dms[:lat][:min]=((@degdec[:lat].abs-@dms[:lat][:deg])*60).truncate
		@dms[:lat][:sec]=((((@degdec[:lat].abs-@dms[:lat][:deg])*60)-@dms[:lat][:min]))*60
		if @degdec[:lat] < 0
			@dms[:lat][:ref]="S"
		else
			@dms[:lat][:ref]="N"
		end
		@dms[:lon][:deg]=@degdec[:lon].abs.truncate
		@dms[:lon][:min]=((@degdec[:lon].abs-@dms[:lon][:deg])*60).truncate
		@dms[:lon][:sec]=((((@degdec[:lon].abs-@dms[:lon][:deg])*60)-@dms[:lon][:min]))*60
		if @degdec[:lon] < 0
			@dms[:lon][:ref]="W"
		else
			@dms[:lon][:ref]="E"
		end
	end

	# conversion from dms to mindec
	def dms_to_mindec
		@mindec[:lat][:deg]=@dms[:lat][:deg]
		@mindec[:lat][:frac]=@dms[:lat][:min]+((@dms[:lat][:sec]*1.0)/60)
		if @dms[:lat][:ref].upcase=='S'
			@mindec[:lat][:deg]*=-1
		end
		@mindec[:lon][:deg]=@dms[:lon][:deg]
		@mindec[:lon][:frac]=@dms[:lon][:min]+((@dms[:lon][:sec]*1.0)/60)
		if @dms[:lon][:ref].upcase=='W'
			@mindec[:lon][:deg]*=-1
		end
	end
	# conversion from mindec to dms
	def mindec_to_dms
		@dms[:lat][:deg]=@mindec[:lat][:deg].abs
		@dms[:lat][:min]=@mindec[:lat][:frac].abs.truncate
		@dms[:lat][:sec]=(@mindec[:lat][:frac].abs-@dms[:lat][:min])*60
		if @mindec[:lat][:deg] < 0
			@dms[:lat][:ref]="S"
		else
			@dms[:lat][:ref]="N"
		end

		@dms[:lon][:deg]=@mindec[:lon][:deg].abs
		@dms[:lon][:min]=@mindec[:lon][:frac].abs.truncate
		@dms[:lon][:sec]=(@mindec[:lon][:frac].abs-@dms[:lon][:min])*60
		if @mindec[:lon][:deg] < 0
			@dms[:lon][:ref]="W"
		else
			@dms[:lon][:ref]="E"
		end
	end

	# conversion from mindec to degdec
	def mindec_to_degdec
		@degdec[:lat]=@mindec[:lat][:deg].abs
		@degdec[:lat]+=@mindec[:lat][:frac]/60
		if @mindec[:lat][:deg] < 0
			@degdec[:lat]*=-1
		end
		@degdec[:lon]=@mindec[:lon][:deg].abs
		@degdec[:lon]+=@mindec[:lon][:frac]/60
		if @mindec[:lon][:deg] < 0
			@degdec[:lon]*=-1
		end
	end
	# conversion from degdec to mindec
	def degdec_to_mindec
		@mindec[:lat][:deg]=@degdec[:lat].truncate
		@mindec[:lat][:frac]=(@degdec[:lat]-@degdec[:lat].truncate)*60
		@mindec[:lon][:deg]=@degdec[:lon].truncate
		@mindec[:lon][:frac]=(@degdec[:lon]-@degdec[:lon].truncate)*60
	end

end

# see if we were called directly:
if __FILE__ == $0
    if ARGV.length == 0
		# accept input from stdin
        puts c=Coordinate.new(gets)
    else
		# accept input from command line
        puts c=Coordinate.new(ARGV[0].to_s)
    end
end