#!/usr/bin/ruby

require 'cli'
options = CLI.new do
	description 'HTTP based image storage and thumbnailer'
	option :bind, :short => :b, :default => 'localhost', :description => "HTTP server bind address"
	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."
	argument :config, :cast => Pathname, :description => "Configuration file path"
end.parse!

require 'sinatra/base'
require 'pathname'
require 's3'
require 'httpthumbnailer-client'
require 'digest/sha2'

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

sinatra = Sinatra.new

sinatra.set :port, options.port
sinatra.set :bind, options.bind
sinatra.set :environment, 'production'
sinatra.set :server, options.server
sinatra.set :lock, true
sinatra.set :logging, true

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

class S3Put
	def initialize(key_id, key_secret, bucket, options = {})
		@options = options
		@logger = (options[:logger] or Logger.new('/dev/null'))

		@s3 = S3::Service.new(:access_key_id => key_id, :secret_access_key => key_secret)

		@logger.info "Getting bucket: #{bucket}"
		@bucket = @s3.buckets.find(bucket) or fail "no buckte '#{bucket}' found"
	end

	def put_image(image_path, content_type, data)
		@logger.info "Putting image in bucket '#{@bucket.name}': #{image_path}"

		file = @bucket.objects.build(image_path)
		file.content_type = content_type
		file.content = data
		file.save

		"http://#{@bucket.name}.s3.amazonaws.com/#{image_path}"
	end
end

sinatra.before do
	# singletons
	$s3 ||= S3Put.new(settings.s3_key_id, settings.s3_key_secret, settings.s3_bucket, :logger => logger)
	$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

	class BadRequestError < RuntimeError
	end

	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
end

sinatra.get '/' do
	"hello"
end

sinatra.put %r{/thumbnail/([^/]*)/(.*)} do |classes, image_path|
	raise BadRequestError, "Path is empty" if image_path.empty?
	image_path = Pathname.new(image_path)

	classes = classes.split(',').map{|tc| settings.thumbnail_classes[tc]}
	image = request.body.read
	image_hash = digest(image)

	thumbs = $thumbnailer.thumbnail(image) do
		classes.each do |tc|
			thumbnail tc.method, tc.width, tc.height, tc.format, tc.options
		end
	end

	# check for errors
	thumbs.zip(classes).each do |thumb, thumbnail_class|
		raise ThumbnailingError.new(thumbnail_class, thumb) if thumb.kind_of? HTTPThumbnailerClient::ThumbnailingError
	end

	urls = []

	# store all images
	urls << $s3.put_image(image_path.original_image(image_hash).to_s, response.headers['Content-Type'], image)

	thumbs.zip(classes).each do |thumb, thumbnail_class|
		urls << $s3.put_image(image_path.thumbnail_image(image_hash, thumbnail_class.name).to_s, thumb.mime_type, thumb.data)
	end

	status 200
	headers "Content-Type" => "text/uri-list"
	body urls.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 BadRequestError do
	halt_exception(400, env['sinatra.error'])
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!