#!/usr/bin/ruby

require 'ip'
require 'pathname'
require 'cli'

options = CLI.new do
	description 'HTTP based image storage and thumbnailer'
	switch :no_bind, :description => "Do not bind to TCP socket - useful with -s fastcgi option"
	switch :no_logging, :description => "Disable logging"
	switch :debug, :description => "Enable debugging"
	switch :no_uri_encode, :description => "Disable output URI encoding"
	option :bind, :short => :b, :default => IP.new('127.0.0.1'), :cast => IP, :description => "HTTP server bind address - use 0.0.0.0 to bind to all interfaces"
	option :port, :short => :p, :default => 3000, :cast => Integer, :description => "HTTP server TCP port"
	option :server, :short => :s, :default => 'mongrel', :description => "Rack server handler like thin, mongrel, webrick, fastcgi etc."
	option :upload_retry_times, :default => 3, :cast => Integer, :description => "Number of times file upload will be retried in case of an error"
	option :upload_retry_delay, :default => 0.0, :cast => Float, :description => "Time to sleep between retries"
	argument :config, :cast => Pathname, :description => "Configuration file path"
end.parse!

require 'sinatra/base'
require 'httpthumbnailer-client'
require 'digest/sha2'

$LOAD_PATH.unshift(File.join(File.dirname(__FILE__), '..', 'lib'))
require 'httpimagestore/configuration'
require 'httpimagestore/image_path'
require 'httpimagestore/s3_service'

sinatra = Sinatra.new

unless options.no_bind
	sinatra.set :port, options.port
	sinatra.set :bind, options.bind.to_s
else
	sinatra.set :port, nil
	sinatra.set :bind, nil
end
sinatra.set :environment, 'production'
sinatra.set :server, options.server
sinatra.set :lock, true
sinatra.set :logging, (not options.no_logging)
sinatra.set :debug, options.debug
sinatra.set :uri_encode, (not options.no_uri_encode)
sinatra.set :upload_retry_times, options.upload_retry_times
sinatra.set :upload_retry_delay, options.upload_retry_delay

Configuration.from_file(options.config).put(sinatra)

class ThumbnailingError < RuntimeError
	def initialize(thumbnail_class, remote_error)
		@remote_error = remote_error
		super "Thumbnailing for class '#{thumbnail_class.name}' failed: #{remote_error.message}"
	end

	attr_reader :remote_error
end

sinatra.before do
	logger.level = Logger::DEBUG if settings.logging and settings.debug
	# singletons
	$s3 ||= S3Service.new(settings.s3_key_id, settings.s3_key_secret, settings.s3_bucket, :logger => logger, :upload_retry_times => settings.upload_retry_times, :upload_retry_delay => settings.upload_retry_delay)
	$thumbnailer ||= HTTPThumbnailerClient.new(settings.thumbnailer_url)
end

sinatra.helpers do
	def hatl_response(status, msg)
		headers "Content-Type" => "text/plain"
		body msg.gsub("\n", "\r\n") + "\r\n"
		halt status
	end

	def halt_exception(status, exception)
		hatl_response(status, "Error: #{exception.class.name}: #{exception}")
	end

	def digest(data)
		Digest::SHA2.new.update(data).to_s[0,16]
	end
end

sinatra.get '/' do
	"hello"
end

sinatra.put %r{/thumbnail/([^/]*)/?(.*)} do |thumbnail_classes, image_path|
	thumbnail_classes = thumbnail_classes.split(',').map{|thumbnail_class| settings.thumbnail_classes[thumbnail_class]}

	image = request.body.read
	image_hash = digest(image)

	unless image_path.empty?
		image_path = ImagePath::Custom.new(image_hash, image_path)
	else
		image_path = ImagePath::Auto.new(image_hash)
	end

	thumbnails = $thumbnailer.thumbnail(image) do
		thumbnail_classes.each do |thumbnail_class|
			thumbnail thumbnail_class.method, thumbnail_class.width, thumbnail_class.height, thumbnail_class.format, thumbnail_class.options
		end
	end

	# check for errors
	thumbnails.zip(thumbnail_classes).each do |thumbnail, thumbnail_class|
		raise ThumbnailingError.new(thumbnail_class, thumbnail) if thumbnail.kind_of? HTTPThumbnailerClient::ThumbnailingError
	end

	urls = []

	# store all images
	urls << $s3.put_image(image_path.original_image(thumbnails.input_mime_type), thumbnails.input_mime_type, image)

	thumbnails.zip(thumbnail_classes).each do |thumbnail, thumbnail_class|
		urls << $s3.put_image(image_path.thumbnail_image(thumbnail.mime_type, thumbnail_class.name), thumbnail.mime_type, thumbnail.data)
	end

	status 200
	headers "Content-Type" => "text/uri-list"

	body urls.map{|u| settings.uri_encode ? URI.encode(u) : u}.map{|u| u + "\r\n"}.join
end

sinatra.error HTTPThumbnailerClient::UnsupportedMediaTypeError do
	halt_exception(415, env['sinatra.error'])
end

sinatra.error HTTPThumbnailerClient::ImageTooLargeError do
	halt_exception(413, env['sinatra.error'])
end

# problem with singe thumbnail
sinatra.error ThumbnailingError do
	e = env['sinatra.error']
	case e.remote_error.type
	when "Thumbnailer::ImageTooLargeError"
		halt_exception(413, e)
	else
		halt_exception(500, e)
	end
end

sinatra.error Configuration::ThumbnailClassDoesNotExistError do
	halt_exception(404, env['sinatra.error'])
end

sinatra.error Sinatra::NotFound do
	hatl_response(404, "Resource '#{request.path_info}' not found")
end

sinatra.error do
	halt_exception(500, env['sinatra.error'])
end

sinatra.run!