#!/usr/bin/env ruby
 
require File.expand_path('../../lib/gpx', __FILE__)
require 'optparse'


def str_to_int_or_time(str)
  if str =~ /\A\d{10}\Z/
    return Time.at(str.to_i)
  elsif str =~ /\A\d+\Z/
    return str.to_i
  else
    return DateTime.strptime(str, '%Y%m%d-%H:%M:%S').to_time
  end
end


options = {}
OptionParser.new do |opts|
  opts.banner = "Usage: smooth [options]"

  opts.on("-i", "--input-file FILE", "Input file to read gpx data from (if omitted, data will be read from stdin)") do |v|
    options[:infile] = v
  end
  opts.on("-o", "--output-file FILE", "Output file to write smoothed gpx data to (if omitted, data will be written to stdout)") do |v|
    options[:outfile] = v
  end
  opts.on("-s", "--start-time [YYYYMMDD-HH:MM:SS|EPOCH|OFFSET]", "Start smoothing from time or offset specified (if omitted start from the start of the file)") do |v|
    options[:start] = v
  end
  opts.on("-e", "--end-time [YYYYMMDD-HH:MM:SS|EPOCH|OFFSET]", "Finish smoothing from time or offset specified (if omitted finish at the end of the file)") do |v|
    options[:end] = v
  end
end.parse!


if options[:infile]
  input = File.open(options[:infile])
else
  input = $stdin
end

options[:start] = str_to_int_or_time(options[:start]) if options[:start]
options[:end] = str_to_int_or_time(options[:end]) if options[:end]

gpx =  GPX::GPXFile.new(:gpx_data => input)
$stderr.puts "read track with distance #{gpx.distance}"

#1419062980
gpx.tracks.each do |track|
  track.segments.each do |segment|
    segment.smooth_location_by_average({:end => options[:end], :start => options[:start]})
  end
end
gpx.recalculate_distance
$stderr.puts "smoothed distance #{gpx.distance}"

if options[:outfile]
  gpx.write(options[:outfile], false)
else
  puts gpx.to_s(false)
end