#!/usr/bin/env ruby
require 'nokogiri'
require 'open-uri'

# our actual weather API interface code.  Simple, eh?
def getweather(somelocation)
  $doc = Nokogiri::XML(open("http://api.wunderground.com/auto/wui/geo/ForecastXML/index.xml?query=#{somelocation}"))
end

# configure a default location
# this can be a zipcode, airport code, city name + state...whatever Wunderground...
# ...will accept.  Don't worry about spaces at this point.
$defaultlocation = '48104'

# init 'location' as a blank global var (don't touch this)
$location = ""

# if we're being called with no args, set the location to our default location
if ARGV.first.nil?
  $location = $defaultlocation
# otherwise, parse the args, encode them as URI-safe, and add a '+' to the end of each one
else
  ARGV.each { |a| $location << URI::encode(a) << '+' }
# as a hackey fix to the last +, just use chop! to strip it.
  $location.chop!
end

# try to get the forecast
getweather($location)

# handle cases where the args supplied are valid, but Wunderground doesn't return forecast info
# first, look to see if there are any child nodes under simpleforecast
if $doc.xpath('/forecast/simpleforecast').children.to_s.chomp.empty?
  puts "Wunderground API didn't like location #{$location} , retrying with #{$defaultlocation}.", "\n"
  # set location back to the default location and re-try getting the weather.
  # TODO: account for cases where the default location is also invalid / returns no forecast info
  $location = $defaultlocation
  getweather($location)
end

# use xpath to parse the XML and operate on each item.  Should be pretty self-explanatory; we're not doing anything fancy here.
# we're really only using '.each' on this first block to shorten the xpath needed for each item.
$doc.xpath('/forecast/moon_phase').each {
  |node|
  moon = node.xpath('percentIlluminated').text
  timehour = node.xpath('current_time/hour').text
  timeminute = node.xpath('current_time/minute').text
  sunsethour = node.xpath('sunset/hour').text
  sunsetminute = node.xpath('sunset/minute').text
  sunrisehour = node.xpath('sunrise/hour').text
  sunriseminute = node.xpath('sunrise/minute').text
  puts "\n", "Location: #{$location}", "Sunrise: #{sunrisehour}:#{sunriseminute}"
  puts "Sunset: #{sunsethour}:#{sunsetminute}", "Moon visible: #{moon}%", "\n"
}

$doc.xpath('/forecast/txt_forecast').each {
    |node|
    currentconditions = node.xpath('forecastday/fcttext').first.text
    periodtitle = node.xpath('forecastday/title').first.text
    time = node.xpath('date').text
    puts "Current conditions for [the] #{periodtitle} as of #{time}: #{currentconditions}", "\n", "Forecast:", "\n"
}

#puts "Current conditions: #{$doc.xpath('/forecast/txt_forecast/forecastday/fcttext').text}", "\n", "Forecast:", "\n"
$doc.xpath('/forecast/simpleforecast/forecastday').each { 
  |node| 
  nodeid = node.xpath('period').text
  date = node.xpath('date/pretty').text
  dayname = node.xpath('date/weekday').text
  conditions = node.xpath('conditions').text
  high = node.xpath('high/fahrenheit').text
  low = node.xpath('low/fahrenheit').text
  pop = node.xpath('pop').text
  puts "#{dayname} - #{conditions} - #{low}F to #{high}F - #{pop}% chance of rain"
# we could also do this, but the above is *much* more readable
# puts dayname << ' - ' << conditions << ' - ' << low << 'F to ' << high << 'F - ' << pop << '% chance of rain'
}