#!/usr/bin/env ruby

$VERSION = File.read(File.dirname(__FILE__) + '/../VERSION').chomp
$DEBUG = false
if $DEBUG
  require 'benchmark'
  require 'rubygems'
  require 'ruby-debug'
end
def log(*msgs)
  msgs.each do |msg|
    $stdout << msg
  end
  $stdout.flush
  true
end

require 'socket'
$options = {}

ENV['XDG_DATA_DIRS'] = (ENV['XDG_DATA_DIRS'].to_s.split(/:/) << '/opt/local/share').join(':')

require 'optparse'
optparse = OptionParser.new do |opts|
  opts.banner = "Usage: #{$0} [options]"

  $options[:port] = 80
  opts.on( '-p PORT', '--port PORT', "Run on PORT. Defaults to #{$options[:port]}" ) do |port|
    $options[:port] = port.to_i
  end

  # Gets the IP address for the default
  # $options[:address] = Socket.getaddrinfo(Socket.gethostname, nil, 'AF_INET')[0][2]
  $options[:address] = '0.0.0.0'
  opts.on( '-a ADDRESS', '--address ADDRESS', "Listen on ADDRESS ip. Defaults to [#{$options[:address]}]") do |address|
    $options[:address] = address
  end

  $options[:cache_size] = nil
  opts.on( '--cache-size SIZE', "Turn in-memory caching on and set the maximum cache size. Example: 500K, 10M, 1G") do |size|
    $options[:cache_size] = case size
    when /^\d+$/
      size.to_i
    when /^\d+kb?$/i
      size.to_i * 1024 # kilobytes
    when /^\d+mb?$/i
      size.to_i * 1024*1024 # megabytes
    when /^\d+gb?$/i
      size.to_i * 1024*1024*1000 # gigabytes
    else
      warn "Couldn't understand --cache-size #{size}!"
      exit
    end
  end

  $options[:https_domain] = $options[:address]
end

optparse.parse!

require 'socket'
require 'openssl'

class ::OpenSSL::SSL::SSLSocket
  alias :read_nonblock :readpartial
end

class EventMachineMini
  DEFAULT_SSL_OPTIONS = Hash.new do |h,k|
    case k
    when :SSLCertificate
      h[k] = OpenSSL::X509::Certificate.new(File.read(h[:SSLCertificateFile]))
    when :SSLPrivateKey
      h[k] = OpenSSL::PKey::RSA.new(File.read(h[:SSLPrivateKeyFile]))
    else
      nil
    end
  end

  DEFAULT_SSL_OPTIONS.merge!(
    :GenerateSSLCert      => false,
    :ServerSoftware       => "Ruby TCP Router OpenSSL/#{::OpenSSL::OPENSSL_VERSION.split[1]}",
    :SSLCertName          => [['CN', $options[:https_domain]]],
    :SSLCertComment       => "Generated by Ruby/OpenSSL",
    :SSLCertificateFile   => 'cert.pem',
    :SSLPrivateKeyFile    => 'key.pem',
    :SSLClientCA          => nil,
    :SSLExtraChainCert    => nil,
    :SSLCACertificateFile => 'cacert.pem',
    :SSLCACertificatePath => nil,
    :SSLCertificateStore  => nil,
    :SSLVerifyClient      => ::OpenSSL::SSL::VERIFY_PEER,
    :SSLVerifyDepth       => 1,
    :SSLVerifyCallback    => nil,   # custom verification
    :SSLTimeout           => nil,
    :SSLOptions           => nil,
    :SSLStartImmediately  => true
  )

  class << self
    def ssl_config(config=DEFAULT_SSL_OPTIONS)
      @ssl_config ||= config
    end
  end

  def running?
    Thread.current[:status] == :running
  end
  def stop!
    Thread.current[:status] = :stop
  end

  attr_reader :router
  def initialize(routes={})
    @router = {}
    # Set up the listening sockets
    (routes[:listen] || {}).each do |ip_port,instantiate_klass|
      ip, port = ip_port.split(/:/)
      socket = TCPServer.new(ip, port)
      socket.setsockopt(Socket::SOL_SOCKET, Socket::SO_REUSEADDR, 1)
      @router[socket] = instantiate_klass
      # puts "Listening on #{ip_port} for #{instantiate_klass.name} messages..."
    end
    # Set up the listening SSL sockets
    (routes[:ssl_listen] || {}).each do |ip_port,instantiate_klass|
      ip, port = ip_port.split(/:/)
      socket = TCPServer.new(ip, port)
      socket.setsockopt(Socket::SOL_SOCKET, Socket::SO_REUSEADDR, 1)

      ssl_socket = ::OpenSSL::SSL::SSLServer.new(socket, ssl_context)
      ssl_socket.start_immediately = self.class.ssl_config[:SSLStartImmediately]

      @router[ssl_socket] = instantiate_klass
      # puts "Listening on #{ip_port} (SSL) for #{instantiate_klass.name} messages..."
    end
    # Set up the connect sockets
    (routes[:connect] || {}).each do |ip_port,args|
      args = [args] unless args.is_a?(Array); instantiate_klass = args.shift
      ip, port = ip_port.split(/:/)
      socket = TCPSocket.new(ip, port)
      clients[socket] = instantiate_klass.new(self,socket,*args)
      # puts "Connecting to #{ip_port} for #{instantiate_klass.name} messages..."
    end
  end

  def run
    Thread.current[:status] = :running
    # trap("INT") { stop! } # This will end the event loop within 0.5 seconds when you hit Ctrl+C
    loop do
      # log "tick #{Thread.current[:status]}\n" if $DEBUG

      # Clean up any closed clients
      clients.each_key do |sock|
        if sock.closed?
          conn = clients.delete(sock)
          conn.upon_unbind if conn.respond_to?(:upon_unbind)
          if conn.respond_to?(:key)
            connections_by_key.delete(conn.key) rescue nil
          end
        end
      end
      
      if !running?
        unless listen_sockets.empty?
          # puts "Closing all listening ports."
          shutdown_listeners!
        end
        if client_sockets.empty?
          # It's the next time around after we closed all the client connections.
          break
        else
          # puts "Closing all client connections."
          close_all_clients!
        end
      end

      # puts "Listening to #{listen_sockets.length} sockets: #{listen_sockets.inspect}"
      begin
        event = select(listen_sockets + client_sockets,nil,nil,0.5)
      rescue IOError
        next
      end
      if event.nil? # nil would be a timeout, we'd do nothing and start loop over. Of course here we really have no timeout...
        @router.values.each { |klass|
          klass.tick if klass.respond_to?(:tick)
        }
      else
        event[0].each do |sock| # Iterate through all sockets that have pending activity
          # puts "Event on socket #{sock.inspect}"
          if listen_sockets.include?(sock) # Received a new connection to a listening socket
            sock = accept_client(sock)
            clients[sock].upon_new_connection if clients[sock].respond_to?(:upon_new_connection)
          else # Activity on a client-connected socket
            if sock.eof? # Socket's been closed by the client
              log "Connection #{clients[sock].to_s} was closed by the client.\n"
              sock.close
              clients[sock].upon_unbind if clients[sock].respond_to?(:upon_unbind)
              client = clients[sock]
              clients.delete(sock)
            else # Data in from the client
              catch :stop_reading do
                # puts "Reading data from socket #{sock.inspect} / #{clients[sock].inspect}"
                begin
                  if sock.respond_to?(:read_nonblock)
                    # puts "read_nonblock"
                    10.times {
                      data = sock.read_nonblock(4096)
                      clients[sock].receive_data(data)
                    }
                  else
                    # puts "sysread"
                    data = sock.sysread(4096)
                    clients[sock].receive_data(data)
                  end
                rescue Errno::EAGAIN, Errno::EWOULDBLOCK, EOFError => e
                  # no-op. This will likely happen after every request, but that's expected. It ensures that we're done with the request's data.
                rescue Errno::ECONNRESET, Errno::ECONNABORTED, Errno::ECONNREFUSED, IOError => e
                  log "Closed Err: #{e.inspect}\n"
                  sock.close
                  clients[sock].upon_unbind if clients[sock].respond_to?(:upon_unbind)
                end
              end
            end
          end
        end
      end
    end
  end

  def clients
    @clients ||= {}
  end

  def connections_by_key
    @connections_by_key ||= {}
  end

  def close_all_clients!
    # puts "Closing #{client_sockets.length} client connections..."
    client_sockets.each { |socket| socket.close rescue nil }
  end
  def shutdown_listeners!
    # puts "Shutting down #{listen_sockets.length} listeners..."
    listen_sockets.each { |socket| socket.close rescue nil }
  end

  private
    def listen_sockets
      @router.keys.select {|socket| !socket.closed? }
    end

    def accept_client(source_socket)
      client_socket = source_socket.accept
      connection = @router[source_socket].new(self,client_socket)
      clients[client_socket] = connection
    end

    def client_sockets
      @clients.keys
    end

    def ssl_context
      unless @ssl_context
        @ssl_context = OpenSSL::SSL::SSLContext.new
        @ssl_context.client_ca         = self.class.ssl_config[:SSLClientCA]
        @ssl_context.ca_file           = self.class.ssl_config[:SSLCACertificateFile]
        @ssl_context.ca_path           = self.class.ssl_config[:SSLCACertificatePath]
        @ssl_context.extra_chain_cert  = self.class.ssl_config[:SSLExtraChainCert]
        @ssl_context.cert_store        = self.class.ssl_config[:SSLCertificateStore]
        @ssl_context.verify_mode       = self.class.ssl_config[:SSLVerifyClient]
        @ssl_context.verify_depth      = self.class.ssl_config[:SSLVerifyDepth]
        @ssl_context.verify_callback   = self.class.ssl_config[:SSLVerifyCallback]
        @ssl_context.timeout           = self.class.ssl_config[:SSLTimeout]
        @ssl_context.options           = self.class.ssl_config[:SSLOptions]
        if self.class.ssl_config[:GenerateSSLCert]
          puts "Generating SSL Certificate..."
          @ssl_context.key = OpenSSL::PKey::RSA.generate(4096)
          ca = OpenSSL::X509::Name.parse("/C=US/ST=Michigan/O=BehindLogic/CN=behindlogic.com/emailAddress=cert@desktopconnect.com")
          cert = OpenSSL::X509::Certificate.new
          cert.version = 2
          cert.serial = 1
          cert.subject = ca
          cert.issuer = ca
          cert.public_key = @ssl_context.key.public_key
          cert.not_before = Time.now
          cert.not_after = Time.now + 3600 # this http session should last no longer than 1 hour
          @ssl_context.cert = cert
        else
          @ssl_context.cert              = self.class.ssl_config[:SSLCertificate]
          @ssl_context.key               = self.class.ssl_config[:SSLPrivateKey]
        end
      end
      @ssl_context
    end
end

require 'base64'

module EventParsers

  # Implement this by including it in a class and call receive_data on every read event.
  # Callbacks available:
  #   upon_new_request(request)       # after first HTTP line
  #   receive_header(request, header) # after each header is received
  #   upon_headers_finished(request)  # after all headers are received
  #   process_request(request)        # after the full request is received
  module Http11Parser
    module BasicAuth
      ::UnparsableBasicAuth = Class.new(RuntimeError)

      class << self
        def parse(basic_auth_string)
          # Do the special decoding here
          if basic_auth_string =~ /^Basic (.*)$/
            auth_string = $1
            auth_plain = Base64.decode64(auth_string)
            return auth_plain.split(/:/,2)
          else
            warn "Bad Auth string!"
            raise UnparsableBasicAuth
          end
        end
      end

      def initialize(username, password)
        @username = username
        @password = password
      end

      def to_s
        # Do the special encoding here
      end
    end

    class HeaderAndEntityStateStore
      attr_accessor :state, :delimiter, :linebuffer, :textbuffer, :entity_size, :entity_pos, :bogus_lines

      def initialize(state, delimiter)
        @state = state
        @delimiter = delimiter
        reset!
      end

      def reset!
        @linebuffer = []
        @textbuffer = []
        @entity_size = nil
        @entity_pos = 0
        @bogus_lines = 0
      end

      def entity?
        !entity_size.nil? && entity_size > 0
      end

  	  def bogus_line!(ln=nil)
        log "bogus line:\n#{ln}\n" if ln && $DEBUG
        @bogus_lines += 1
      end
    end
    
    class Request
      attr_accessor :connection, :method, :http_version, :resource_uri, :query_params, :headers, :entity, :response
      def ready!
        @ready = true
      end
      def ready?
        !!@ready
      end

      def initialize(request_params={})
        @http_version = request_params[:http_version] if request_params.has_key? :http_version
        @resource_uri = request_params[:resource_uri] if request_params.has_key? :resource_uri
        @headers      = request_params[:headers] if request_params.has_key? :headers
        @entity       = request_params[:entity] if request_params.has_key? :entity

        @headers ||= {}
        @entity ||= ''
      end

      def inspect
        "HTTP Request:\n\t#{@method} #{@resource_uri} HTTP/#{@http_version}\n\t#{@headers.map {|k,v| "#{k}: #{v}"}.join("\n\t")}\n\n\t#{@entity.to_s.gsub(/\n/,"\n\t")}"
      end

      def has_entity?
        @entity != ''
      end

      def basic_auth
        BasicAuth.parse(@headers['authorization']) if @headers['authorization']
      end

      def params
        query_params
      end
    end

    def self.included(base)
      base.extend ClassMethods
    end
    module ClassMethods
      def request_klass(klass=nil)
        @request_klass ||= (klass || Request)
      end
    end

    attr_reader :socket

    def request_backlog
      @request_backlog ||= []
    end

    def current_request
      request_backlog.first
    end
    def parsing_request
      request_backlog.last
    end

    HttpResponseRE = /\AHTTP\/(1.[01]) ([\d]{3})/i
    HttpRequestRE = /^(GET|POST|PUT|DELETE) (\/.*) HTTP\/([\d\.]+)[\r\n]?$/i
    BlankLineRE = /^[\n\r]+$/

		def receive_data(data)
			return unless (data and data.size > 0)

      @last_activity = Time.now

      case parser.state
      when :init
  			if ix = data.index("\n")
  				parser.linebuffer << data[0...ix+1]
  				ln = parser.linebuffer.join
  				     parser.linebuffer.clear
          log "[#{parser.state}]: #{ln}" if $DEBUG
          if ln =~ HttpRequestRE
            request_backlog << self.class.request_klass.new
            parsing_request.connection = self
            method, resource_uri, http_version = parse_init_line(ln)
            parsing_request.method = method
            parsing_request.resource_uri = resource_uri
            parsing_request.query_params = parse_query_string(resource_uri.index('?') ? resource_uri[(resource_uri.index('?')+1)..-1] : '')
            parsing_request.http_version = http_version
            upon_new_request(parsing_request) if respond_to?(:upon_new_request)
            parser.state = :headers
          else
    			  parser.bogus_line!(ln)
          end
  				receive_data(data[(ix+1)..-1])
        else
          parser.linebuffer << data
        end
      when :headers
  			if ix = data.index("\n")
  				parser.linebuffer << data[0...ix+1]
  				ln = parser.linebuffer.join
  				     parser.linebuffer.clear
          # If it's a blank line, move to content state
          if ln =~ BlankLineRE
            upon_headers_finished(parsing_request) if respond_to?(:upon_headers_finished)
            if parser.entity?
              # evaluate_headers(parsing_request.headers)
              parser.state = :entity
            else
              receive_full_request
            end
          else
            header = parse_header_line(ln)
            log "\t[#{parser.state}]: #{header.inspect}\n" if $DEBUG
            receive_header(parsing_request, header.to_a[0]) if respond_to?(:receive_header)
            parsing_request.headers.merge!(header)
          end
  				receive_data(data[(ix+1)..-1])
  			else
  				parser.linebuffer << data
  			end
			when :entity
				if parser.entity_size
					chars_yet_needed = parser.entity_size - parser.entity_pos
					taking_this_many = [chars_yet_needed, data.size].sort.first
					parser.textbuffer << data[0...taking_this_many]
 					leftover_data = data[taking_this_many..-1]
					parser.entity_pos += taking_this_many
					if parser.entity_pos >= parser.entity_size
						entity_data = parser.textbuffer.join
						              parser.textbuffer.clear
						parsing_request.entity << entity_data
            log "[#{parser.state}]: #{entity_data}\n" if $DEBUG
            receive_full_request
					end
					receive_data(leftover_data)
				else
				  raise "TODO!"
          # receive_binary_data data
				end
        
		  else
        # Probably shouldn't ever be here?
        raise "Shouldn't be here!"
			end

      # TODO: Exception if number of parser.bogus_lines is higher than threshold
    end

    def process_request(request)
      warn "STUB - overwrite process_request in a subclass of Http11Parser to process this #{request.inspect}"
    end

    def send_response!(http_response)
      log "Sending Response: #{http_response.inspect}\n" if $DEBUG
      socket.write(http_response)
      request_backlog.shift
      # Process the next request IF it is already waiting.
      process_request(current_request) if current_request && current_request.ready?
    end

    private
      def parse_init_line(ln)
        method, resource_uri, http_version = ln.match(HttpRequestRE).to_a[1..-1]
        # TODO: Exception if the request is improper!
        [method, resource_uri, http_version]
      end

      def parse_query_string(qstring)
        params = (CGI.parse(qstring) || {}) rescue {}
        params.inject({}) do |h,(k,v)|
          h[k.to_sym] = (v.is_a?(Array) && v.length == 1) ? v[0] : v
          h
        end
      end

      def parse_header_line(ln)
        ln.chomp!
        if ln =~ /:/
    			name,value = ln.split(/:\s*/,2)
          if name.downcase == 'content-length'
            parser.entity_size = Integer(value.gsub(/\D/,''))
            # TODO: Exception if content-length specified is too big
          end
    			{name.downcase => value}
  			else
  			  parser.bogus_line!(ln)
  			  {}
        end
      end

      def receive_full_request
        parsing_request.ready!
        parser.state = :init
        # Process this request now that we're ready -- IF any previous requests are already responded to.
        # Otherwise, this request will be waiting, and when the previous one(s) are responded to, this one
        # will be triggered next.
        process_request(parsing_request) if parsing_request == current_request
        log "Processed request. Prepared for next request.\n\n" if $DEBUG
        parser.reset!
      end

      def parser
        @parser ||= HeaderAndEntityStateStore.new(:init, "\n")
      end
  end
end

require 'iconv'
require 'rubygems'
module Renderers
  autoload :Markdown, 'httphere/markdown'
  autoload :Textile,  'httphere/textile'
end
require 'UniversalDetector'
require 'shared-mime-info'
class File
  def size
    File.size(path)
  end
end

class FileServer < EventParsers::Http11Parser::Request
  class << self
    attr_accessor :cache
    def cached?(filename)
      # Serve from cache if it's in the cache and if the file hasn't changed.
      if cache
        # Delete from cache if the file's been modified since last cache.
        cache.delete(filename) if cache.has_key?(filename) && File.mtime(filename) > cache[filename][0][:mtime]
        cache.has_key?(filename)
      end
    end
    def from_cache(filename)
      cache[filename][0][:last_accessed_at] = Time.now
      puts "From cache: #{filename} / #{cache[filename][0][:size]}"
      [cache[filename][1], cache[filename][0][:content_type]]
    end
    def cache?(filename,response_body)
      # Obviously, don't cache if it's bigger than the cache max size
      cache && File.exists?(filename) && response_body.size < cache.max_size
    end
    def cache!(filename,content_type,response_body)
      if cache?(filename,response_body)
        puts "Caching #{filename} / #{response_body.size}"
        cache[filename] = [
          {
            :last_accessed_at => Time.now,
            :mtime => File.mtime(filename),
            :size => response_body.size,
            :content_type => content_type
          },
          response_body
        ]
      end
    end
  end

  # This is where the routing is processed.
  def process
    # Get the filename desired
    filename, query = resource_uri.split('?',2)
    @filename = filename.sub(/^\//,'')
    # Default to any file named index.*
    @filename = Dir["index.*"].first if filename.to_s == '' && Dir["index.*"].length > 0
    file_extension = (filename.match(/\.([^\.]+)$/) || [])[1]

    if File.exists?(@filename) && !File.directory?(@filename)

      # Read from cache if possible
      file_handle = FileServer.cached?(@filename) ? :from_cache : :from_disk
      if file_handle == :from_disk
        if $DEBUG
          Benchmark.bm do |x|
            x.report("Getting MIME type") do
              @content_type = MIME.check(@filename).type
            end
          end
        else
          @content_type = MIME.check(@filename).type
        end

        file_handle = File.open(@filename)

        # If .markdown, render as Markdown
        if file_extension == 'markdown'
          file_handle = Renderers::Markdown.render_content(file_handle.read)
          @content_type = 'text/html'
        end

        # If .textile, render as Textile
        if file_extension == 'textile'
          file_handle = Renderers::Textile.render_content(file_handle.read)
          @content_type = 'text/html'
        end
      end

      # Send Response
      respond!('200 Ok', @content_type, file_handle)
    else
      respond!('404 Not Found', 'text/plain', "Could not find file: '#{resource_uri}'")
    end
  end

  def respond!(status, content_type, body)
    respond(status, content_type, body)
    connection.halt!
  end
  def respond(status, content_type, body)
    if body == :from_cache
      body, content_type = FileServer.from_cache(@filename)
    else
      body = StringIO.new(body.to_s) if !body.is_a?(IO) && body.respond_to?(:to_s)
      
      # Convert to UTF-8 if possible
      chardet = UniversalDetector::chardet(body.read(512)); body.rewind # Detect charset only from the first 512 bytes
      if chardet['confidence'] > 0.7 && ['utf-8', 'ascii'].include?(chardet['encoding'])
        if $DEBUG
          Benchmark.bm do |x|
            x.report("Converting from #{chardet['encoding']} to UTF-8") do
              charset = chardet['encoding']
              body = StringIO.new(Iconv.conv('utf-8', charset, body.read))
            end
          end
        else
          charset = chardet['encoding']
          body = StringIO.new(Iconv.conv('utf-8', charset, body.read))
        end
      else # no conversion
        puts "No charset conversion necessary." if $DEBUG
      end

      # Write to cache if we should
      FileServer.cache!(@filename, content_type, body)
    end

    body_length = body.size
    body.rewind

    # Send the response!
    connection.send_response! "HTTP/1.1 #{status}\r\nServer: HTTP-Here, version #{$VERSION}\r\nContent-Type: #{content_type}\r\nContent-Length: #{body_length+2}\r\n\r\n#{body.read}\r\n"
    span = (Time.now - connection.time).to_f
    puts (status =~ /200/ ?
      "Served #{resource_uri} (#{content_type})" :
      "404 #{resource_uri}"
    ) + " at #{1 / span} requests/second" unless status =~ /404/ && resource_uri == '/favicon.ico'
  end
end

# Requires that a module includes this and defines an initialize method that defines @options
class Http11Server
  include EventParsers::Http11Parser
  request_klass FileServer

  attr_reader :time
  def initialize(server,socket)
    @socket = socket
    @time = Time.now
  end

  # These just pass the call to the request to handle itself
  def upon_new_request(request)
    request.upon_new_request if request.respond_to?(:upon_new_request)
  end
  def upon_headers_finished(request)
    request.upon_headers_finished if request.respond_to?(:upon_headers_finished)
  end
  def process_request(request)
    request.process
  end

  def halt!
    socket.close
    throw :stop_reading
  end

  def upon_unbind
    # puts "Client #{@socket} disconnected."
  end
end

# EventMachineMini.ssl_config[:GenerateSSLCert] = true

class Cache
  def initialize(config={})
    @config = config
    @cache = {}
  end
  def max_size
    @config[:max_size]
  end
  def [](key)
    @cache[key]
  end
  def []=(key,value)
    @cache[key] = value
  end
  def has_key?(key)
    @cache.has_key?(key)
  end
  def delete(key)
    @cache.delete(key)
  end
  def bytes
    @cache.values.inject(0) {|s,v| s+v[0][:size]}
  end
end

# Turn Caching on if asked for
if $options[:cache_size]
  FileServer.cache = Cache.new(:max_size => $options[:cache_size])
  puts "Caching files in memory, using up to #{$options[:cache_size]} bytes."
end

puts "HTTP Here v#{$VERSION} : listening on #{$options[:address]}:#{$options[:port]}..."
begin
  $server = EventMachineMini.new( :listen => {"#{$options[:address]}:#{$options[:port]}" => Http11Server} )
rescue Errno::EACCES
  puts "\tLooks like you don't have permission to use that port!"
  exit
end

Kernel.trap(:INT) { $server.stop! }
$server.run

puts " HTTP Here Finished\n"
exit