#!/usr/bin/env ruby

require 'pp'
require 'yaml'

require 'rubygems'
require 'bundler/setup'
require 'nokogiri'
require 'open-uri'

config_path = ARGV.shift
config_fh = File.open config_path
config_yml = YAML.load config_fh
pp config_yml

class Page
	attr_reader :url


	def initialize url, config
		puts "page %s" % url
		@url = url
		@config = config
		@prev = nil
		@next = nil
		@first = nil
		@last = nil

		@doc = Nokogiri::HTML(open(url))
	end

	def first
		return @first unless @first.nil?
		first_url = @doc.xpath @config['first_xpath']
		#puts "first %s" % first_url.text
		url = _make_url @url, first_url.text
		@first = Page.new url, @config
		return @first
	end

	def last
		return @last unless @last.nil?
		last_url = @doc.xpath @config['last_xpath']
		#puts "last %s" % last_url.text
		url = _make_url @url, last_url.text
		@last = Page.new url, @config
		return @last
	end

	def next
		return @next unless @next.nil?
		next_url = @doc.xpath @config['next_xpath']
		#puts "next %s" % next_url.text
		url = _make_url @url, next_url.text
		@next = Page.new url, @config
		return @next
	end

	def prev
		return @prev unless @prev.nil?
		prev_url = @doc.xpath @config['prev_xpath']
		#puts "prev %s" % prev_url.text
		url = _make_url @url, prev_url.text
		@prev = Page.new url, @config
		return @prev
	end

	def image
		return @image unless @image.nil?
		image_url = @doc.xpath @config['image_xpath']
		url = _make_url @url, image_url.text
		#pp url
		url
		#@prev = Page.new @prev, @config
		# get image
	end

	def _make_url current_str, next_str
		current_url = URI.parse(current_str)
		case next_str 
		when /^\// then
			# semi-absolute
			next_url = current_url
			next_url.path = URI.parse(next_str).path
		when /^https?/ then
			# absolute
			next_url = URI.parse(next_str)
		else
			# relative
			next_url = current_url
			next_url.path += URI.parse(next_str).path
		end
		#pp "make_url %s" % next_url.to_s
		return next_url.to_s
	end
end

page = Page.new config_yml['base_url'],config_yml
page = page.first

while not page.nil? do 
	puts "PAGE %s" % page.url
	puts "  image = %s" % page.image.inspect
	page = page.next
	sleep config_yml['sleep']
end