# amazon.rb: Making link with image to Amazon using Amazon ECS.
#
# see document: #{@lang}/amazon.rb
#
# Copyright (C) 2005-2007 TADA Tadashi <sho@spc.gr.jp>
# You can redistribute it and/or modify it under GPL2 or any later version.
#

require 'net/http'
require 'uri'
require 'timeout'
require 'rexml/document'

# do not change these variables
@amazon_subscription_id = '1CVA98NEF1G753PFESR2'
@amazon_require_version = '2011-08-01'

@amazon_url_hash = {
  'ca' => 'http://www.amazon.ca/exec/obidos/ASIN',
  'cn' => 'http://www.amazon.cn/exec/obidos/ASIN',
  'de' => 'http://www.amazon.de/exec/obidos/ASIN',
  'es' => 'http://www.amazon.es/exec/obidos/ASIN',
  'fr' => 'http://www.amazon.fr/exec/obidos/ASIN',
  'it' => 'http://www.amazon.it/exec/obidos/ASIN',
  'jp' => 'http://www.amazon.co.jp/exec/obidos/ASIN',
  'uk' => 'http://www.amazon.co.uk/exec/obidos/ASIN',
  'us' => 'http://www.amazon.com/exec/obidos/ASIN',
}

@amazon_ecs_url_hash = {
  'ca' => 'http://rpaproxy.tdiary.org/rpaproxy/ca/',
  'cn' => 'http://rpaproxy.tdiary.org/rpaproxy/cn/',
  'de' => 'http://rpaproxy.tdiary.org/rpaproxy/de/',
  'es' => 'http://rpaproxy.tdiary.org/rpaproxy/es/',
  'fr' => 'http://rpaproxy.tdiary.org/rpaproxy/fr/',
  'it' => 'http://rpaproxy.tdiary.org/rpaproxy/it/',
  'jp' => 'http://rpaproxy.tdiary.org/rpaproxy/jp/',
  'uk' => 'http://rpaproxy.tdiary.org/rpaproxy/uk/',
  'us' => 'http://rpaproxy.tdiary.org/rpaproxy/us/',
}

enable_js( 'amazon.js' )

if @conf['amazon.bitly'] and @conf['bitly.login'] and @conf['bitly.key'] then
	enable_js( 'amazon_bitly.js' )
	add_js_setting( '$tDiary.plugin.bitly' )
	add_js_setting( '$tDiary.plugin.bitly.login', "'#{@conf['bitly.login']}'" )
	add_js_setting( '$tDiary.plugin.bitly.apiKey', "'#{@conf['bitly.key']}'" )
end

class AmazonRedirectError < StandardError; end

class AmazonItem
	def initialize(xml, parser = :rexml)
		@parser = parser
		if parser == :oga
			@doc = Oga.parse_xml(xml)
			@item = @doc.xpath('*/*/Item')[0]
		else
			@doc = REXML::Document::new( REXML::Source::new( xml ) ).root
			@item = @doc.elements.to_a( '*/Item' )[0]
		end
	end

	def nodes(path)
		if @parser == :oga
			if @item
				@item.xpath(path)
			else
				@doc.xpath(path)
			end
		else
			if @item
				@item.elements.to_a(path)
			else
				@doc.elements.to_a(path)
			end
		end
	end

	def has_item?
		!@item.nil?
	end
end

def amazon_fetch( url, limit = 10 )
	raise ArgumentError, 'HTTP redirect too deep' if limit == 0

	px_host, px_port = (@conf['proxy'] || '').split( /:/ )
	px_port = 80 if px_host and !px_port
	res = Net::HTTP::Proxy( px_host, px_port ).get_response( URI::parse( url ) )
	case res
	when Net::HTTPSuccess
		res.body
	when Net::HTTPRedirection, Net::HTTPFound
		amazon_fetch( res['location'], limit - 1 )
	when Net::HTTPForbidden, Net::HTTPServiceUnavailable
		raise AmazonRedirectError.new( limit.to_s )
	else
		raise ArgumentError, res.error!
	end
end

def amazon_call_ecs( asin, id_type, country )
	@conf["amazon.aid.#{@amazon_default_country}"] = @conf['amazon.aid'] unless @conf['amazon.aid'].to_s.empty?
	aid = @conf["amazon.aid.#{country}"] || ''

	url = (@conf['amazon.endpoints'] || @amazon_ecs_url_hash)[country].dup
	url << "?Service=AWSECommerceService"
	url << "&SubscriptionId=#{@amazon_subscription_id}"
	url << "&AssociateTag=#{aid}" unless aid.empty?
	url << "&Operation=ItemLookup"
	url << "&ItemId=#{asin}"
	url << "&IdType=#{id_type}"
	url << "&SearchIndex=Books" if id_type == 'ISBN'
	url << "&SearchIndex=All"   if id_type == 'EAN'
	url << "&ResponseGroup=Medium"
	url << "&Version=#{@amazon_require_version}"

	limit = 10
	begin
		Timeout.timeout( limit ) do
			amazon_fetch( url )
		end
	rescue AmazonRedirectError
		limit = $!.message.to_i
		retry
	rescue ArgumentError, SystemCallError, Net::HTTPExceptions
		@logger.error "amazon.rb: #{$!.message} by #{asin}"
	end
end

def amazon_author( item )
	begin
		author = []
		%w(Author Creator Artist).each do |elem|
			item.nodes( "*/#{elem}" ).each do |a|
				author << a.text
			end
		end
		@conf.to_native( author.uniq.join( '/' ), 'utf-8' )
	rescue
		'-'
	end
end

def amazon_title( item )
	@conf.to_native( item.nodes( '*/Title' )[0].text, 'utf-8' )
end

def amazon_image( item )
	image = {}
	begin
		size = case @conf['amazon.imgsize']
		when 0; 'Large'
		when 2; 'Small'
		else;   'Medium'
		end
		if item.nodes("#{size}Image")[0]
			node_prefix = "#{size}Image"
		elsif item.nodes("ImageSets/ImageSet/#{size}Image")[0]
			node_prefix = "ImageSets/ImageSet/#{size}Image"
		end
		image[:src] = item.nodes("#{node_prefix}/URL")[0].text
		image[:src].gsub!(/http:\/\/ecx\.images-amazon\.com/, 'https://images-na.ssl-images-amazon.com')
		image[:height] = item.nodes("#{node_prefix}/Height")[0].text
		image[:width] = item.nodes("#{node_prefix}/Width")[0].text
	rescue
		base = @conf['amazon.default_image_base'] || 'https://tdiary.github.io/tdiary-theme/plugin/amazon/'
		case @conf['amazon.imgsize']
		when 0
			image[:src] = "#{base}large.png"
			image[:height] = 500
			image[:width] = 380
		when 2
			image[:src] = "#{base}small.png"
			image[:height] = 75
			image[:width] = 57
		else
			image[:src] = "#{base}medium.png"
			image[:height] = 160
			image[:width] = 122
		end
	end
	image
end

def amazon_url( item )
	item.nodes( 'DetailPageURL' )[0].text
end

def amazon_label( item )
	begin
		@conf.to_native( item.nodes( '*/Label' )[0].text, 'utf-8' )
	rescue
		'-'
	end
end

def amazon_price( item )
	begin
		@conf.to_native( item.nodes( '*/LowestNewPrice/FormattedPrice' )[0].text, 'utf-8' )
	rescue
		begin
			@conf.to_native( item.nodes( '*/ListPrice/FormattedPrice' )[0].text, 'utf-8' )
		rescue
			'(no price)'
		end
	end
end

def amazon_detail_html( item )
	author = amazon_author( item )
	title = amazon_title( item )

	size_orig = @conf['amazon.imgsize']
	@conf['amazon.imgsize'] = 2
	image = amazon_image( item )
	@conf['amazon.imgsize'] = size_orig

	url = amazon_url( item )
	<<-HTML
	<a class="amazon-detail" href="#{url}"><span class="amazon-detail">
		<img class="amazon-detail left" src="#{h image[:src]}"
		height="#{h image[:height]}" width="#{h image[:width]}"
		alt="">
		<span class="amazon-detail-desc">
			<span class="amazon-title">#{h title}</span><br>
			<span class="amazon-author">#{h author}</span><br>
			<span class="amazon-label">#{h amazon_label( item )}</span><br>
			<span class="amazon-price">#{h amazon_price( item )}</span>
		</span>
	</span></a>
	HTML
end

def amazon_to_html( item, with_image = true, label = nil, pos = 'amazon' )
	with_image = false if @mode == 'categoryview'

	author = amazon_author( item )
	author = "(#{author})" unless author.empty?

	label ||= %Q|#{amazon_title( item )}#{author}|
	alt = ''
	if with_image and @conf['amazon.hidename'] || pos != 'amazon' then
		label, alt = alt, label
	end

	if with_image
		image = amazon_image( item )
		unless image[:src] then
			img = ''
		else
			size = %Q|height="#{h image[:height]}" width="#{h image[:width]}"|
			img = <<-HTML
			<img class="#{h pos}" src="#{h image[:src]}"
			#{size} alt="#{h alt}">
			HTML
			img.gsub!( /\t/, '' )
		end
	end

	url = amazon_url( item )
	%Q|<a href="#{h url}">#{img}#{h label}</a>|
end

def amazon_get( asin, with_image = true, label = nil, pos = 'amazon' )
	asin = asin.to_s.strip # delete white spaces
	asin.sub!(/\A([a-z]+):/, '')
	country = $1 || @conf['amazon.default_country'] || @amazon_default_country
	digit = asin.gsub( /[^\d]/, '' )
	if digit.length == 13 then # ISBN-13
		asin = digit
		id_type = /^97[89]/ =~ digit ? 'ISBN' : 'EAN'
	else
		id_type = 'ASIN'
	end

	begin
		cache = "#{@cache_path}/amazon"
		Dir::mkdir( cache ) unless File::directory?( cache )
		begin
			xml = File::read( "#{cache}/#{country}#{asin}.xml" )
			if xml.chomp == 'true' # ignore dirty cache
				raise Errno::ENOENT
			end
		rescue Errno::ENOENT
			xml = amazon_call_ecs( asin, id_type, country )
			File::open( "#{cache}/#{country}#{asin}.xml", 'wb' ) {|f| f.write( xml )}
		end
		parser = defined?(Oga) ? :oga : :rexml
		item = AmazonItem.new(xml, parser)
		if pos == 'detail' then
			amazon_detail_html( item )
		else
			amazon_to_html( item, with_image, label, pos )
		end
	rescue Timeout::Error
		@logger.error "amazon.rb: Amazon API Timeouted."
		message = asin
		if @mode == 'preview' then
			message << %Q|<span class="message">(Amazon API Timeouted))</span>|
		end
		message
	rescue NoMethodError
		message = label || asin
		if @mode == 'preview' then
			if item.has_item? then
				message << %Q|<span class="message">(#{h $!}\n#{h $@.join( ' / ' )})</span>|
			else
				m = item.nodes( 'Items/Request/Errors/Error/Message' )[0].text
				message << %Q|<span class="message">(#{h @conf.to_native( m, 'utf-8' )})</span>|
			end
		end
		message
	end
end

add_conf_proc( 'amazon', @amazon_label_conf ) do
	amazon_conf_proc
end

def amazon_conf_proc
	if @mode == 'saveconf' then
		@conf['amazon.imgsize'] = @cgi.params['amazon.imgsize'][0].to_i
		@conf['amazon.hidename'] = (@cgi.params['amazon.hidename'][0] == 'true')
		@conf['amazon.bitly'] = (@cgi.params['amazon.bitly'][0] == 'true')
		@conf['amazon.nodefault'] = (@cgi.params['amazon.nodefault'][0] == 'true')
		if @cgi.params['amazon.clearcache'][0] == 'true' then
			Dir["#{@cache_path}/amazon/*"].each do |cache|
				File::delete( cache )
			end
		end
		unless @conf['amazon.hideconf'] then
			@conf['amazon.aid'] = @cgi.params['amazon.aid'][0]
		end
	end

	result = ''

	result << <<-HTML
		<h3>#{@amazon_label_imgsize}</h3>
		<p><select name="amazon.imgsize">
			<option value="0"#{" selected" if @conf['amazon.imgsize'] == 0}>#{@amazon_label_large}</option>
			<option value="1"#{" selected" if @conf['amazon.imgsize'] == 1}>#{@amazon_label_regular}</option>
			<option value="2"#{" selected" if @conf['amazon.imgsize'] == 2}>#{@amazon_label_small}</option>
		</select></p>
		<h3>#{@amazon_label_title}</h3>
		<p><select name="amazon.hidename">
			<option value="true"#{" selected" if @conf['amazon.hidename']}>#{@amazon_label_hide}</option>
			<option value="false"#{" selected" unless @conf['amazon.hidename']}>#{@amazon_label_show}</option>
		</select></p>
	HTML

	if @options['bitly.login'] and @options['bitly.key'] then
		result << <<-HTML
			<h3>#{@amazon_label_bitly}</h3>
			<p><select name="amazon.bitly">
				<option value="true"#{" selected" if @conf['amazon.bitly']}>#{@amazon_label_bitly_enabled}</option>
				<option value="false"#{" selected" unless @conf['amazon.bitly']}>#{@amazon_label_bitly_disabled}</option>
			</select></p>
		HTML
	end

	result << <<-HTML
		<h3>#{@amazon_label_notfound}</h3>
		<p><select name="amazon.nodefault">
			<option value="true"#{" selected" if @conf['amazon.nodefault']}>#{@amazon_label_usetitle}</option>
			<option value="false"#{" selected" unless @conf['amazon.nodefault']}>#{@amazon_label_usedefault}</option>
		</select></p>
		<h3>#{@amazon_label_clearcache}</h3>
		<p><label for="amazon.clearcache"><input type="checkbox" id="amazon.clearcache" name="amazon.clearcache" value="true">#{@amazon_label_clearcache_desc}</label></p>
	HTML

	unless @conf['amazon.hideconf'] then
		result << <<-HTML
			<h3>#{@amazon_label_aid}</h3>
			<p>#{@amazon_label_aid_desc}</p>
			<p><input name="amazon.aid" value="#{h( @conf['amazon.aid'] ) if @conf['amazon.aid']}"></p>
		HTML
	end
	result
end

def isbn_detail( asin )
	amazon_get( asin, true, nil, 'detail' )
end

def isbn_image( asin, label = nil )
	amazon_get( asin, true, label )
end

def isbn_image_left( asin, label = nil )
	amazon_get( asin, true, label, 'left' )
end

def isbn_image_right( asin, label = nil )
	amazon_get( asin, true, label, 'right' )
end

def isbn( asin, label = nil )
	amazon_get( asin, false, label )
end

# for compatibility
alias isbnImgLeft isbn_image_left
alias isbnImgRight isbn_image_right
alias isbnImg isbn_image
alias amazon isbn_image

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