#!/usr/bin/env ruby
# vim: set et ts=2 sw=2:
#
# Ruby ASPSMS -- aspsms.com short message service gateway library and client
# http://www.roe.ch/ASPSMS
#
# Copyright (C) 2005-2011, Daniel Roethlisberger <daniel@roe.ch>
# All rights reserved.
#
# Redistribution and use, with or without modification, are permitted
# provided that the following conditions are met:
# 1. Redistributions must retain the above copyright notice, this list of
#    conditions and the following disclaimer.
# 2. The name of the author may not be used to endorse or promote products
#    derived from this software without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
# $Id: aspsms.rb 80 2011-03-10 20:38:16Z roe $

# This is both a ruby library and a command line client for painfree,
# UNIX-style interaction with the aspsms.com short message gateways.
#
# Written to conform with the ASPSMS XML Interface Specs 1.91, 2007-12-05.
# -   Support for text SMS, show credits, and originator unlocking/testing.
# -   Conforms to ASPSMS failure safety recommendations.
# -   Delivery status notification is supported by the low-level library
#     but not exposed in the easy API nor the command line client.
#     The same is true for some other features such as blinking or flashing.
# -   Currently, a latin1 locale is assumed (this is a bug, patches welcome).
#
# Configuration is read from ~/.aspsms or [/usr/local]/etc/aspsms by default:
#   # ASPSMS configuration
#   # mandatory options:
#   userkey XYZXYZXYZXYZ
#   password y0UrPasSw0rD
#   # optional default originator:
#   originator +41XXXXXXXXX
#   # optional gateway override:
#   gateway othergateway:port
# Make sure to set sensible permissions (0600 is a good start).

require 'rexml/document'
require 'net/http'
require 'iconv'

class String
  def utf8
    Iconv::iconv('utf-8', 'latin1', self)[0] # XXX take charset from locale
  end
  def is_phone_number?
    self.match(/^\+[0-9]{2,20}$/)
  end
end

module ASPSMS
  REVISION = '$Revision: 80 $'.gsub(/^.*: (\d+) .*$/, '\1');
  FILES = [ "#{ENV['HOME']}/.aspsms", '/etc/aspsms', '/usr/local/etc/aspsms' ]

  # Handles configuration.
  # Currently, configuration is global (bound to this class).
  # There can be only a single configuration at a time, but individual
  # configuration items can be overridden on a per-object basis.
  # XXX Change to allow for multiple configurations.
  class Config
    @@password, @@userkey, @@originator, @@gateway = nil, nil, nil, nil
    def self.autoload
      FILES.each do |fn|
        begin
          self.load(fn)
          return
        rescue Errno::ENOENT
          # ignore if not found
        end
        raise "No configuration file found (#{FILES.join(' ')})"
      end
    end
    def self.load(fn)
      conf = {}
      File.open(fn).each do |line|
        line.chomp.scan(/^([a-zA-Z0-9]+)\s+(.+)$/) do |k,v|
          case k.downcase
          when 'password'
            conf[:password] = v
          when 'userkey'
            conf[:userkey] = v
          when 'sender' # backwards compat
            conf[:originator] = v
          when 'originator'
            conf[:originator] = v
          when 'gateway'
            conf[:gateway] = v
          end
        end
      end
      self.set(conf)
    end
    def self.set(conf)
      @@password   = conf[:password]   if conf.has_key?(:password)
      @@userkey    = conf[:userkey]    if conf.has_key?(:userkey)
      @@originator = conf[:originator] if conf.has_key?(:originator)
      @@gateway    = conf[:gateway]    if conf.has_key?(:gateway)

      raise "#{fn}: 'userkey' missing!" if @@userkey.nil?
      raise "#{fn}: 'password' missing!" if @@password.nil?
      if !@@gateway.nil? && !@@gateway.match(/^[a-zA-Z0-9\[\]:._-]+:[0-9]{1,5}$/)
        raise "#{fn}: 'gateway' not in format 'host:port'!"
      end
    end
    def self.userkey
      @@userkey
    end
    def self.password
      @@password
    end
    def self.originator
      @@originator.nil? ? 'aspsms' : @@originator
    end
    def self.gateways
      if @@gateway.nil?
        return [ 'xml1.aspsms.com:5061', 'xml2.aspsms.com:5061' ]
      else
        return [ @@gateway ]
      end
    end
    def self.useragent
      "ASPSMS::Gateway/#{REVISION} (http://www.roe.ch/ASPSMS)"
    end
  end

  # Represents a request of specific types.
  # Handles construction of the request XML document.
  class Request
    class Abstract
      include REXML
      attr_accessor :userkey, :password
      def initialize
        @userkey = ASPSMS::Config.userkey
        @password = ASPSMS::Config.password
      end
      def to_s
        doc = Document.new
        doc << REXML::XMLDecl.new('1.0', 'ISO-8859-1')
        root = Element.new('aspsms')
        root.elements.add(Element.new('Userkey').add_text(userkey.utf8))
        root.elements.add(Element.new('Password').add_text(password.utf8))
        each_element do |element|
          root.elements.add(element)
        end
        root.elements.add(Element.new('Action').
                          add_text(self.class.name.gsub(/^.*::/, '')))
        doc << root
        doc.to_s
      end
    end
    class SendTextSMS < Abstract
      attr_accessor :originator, :recipients, :text, :flashing, :blinking,
                    :tx_refs, :url_buffered, :url_nondelivery, :url_delivery
      def initialize
        super
        @originator = ASPSMS::Config.originator
        @recipients = []
        @text = ''
        @flashing = false
        @blinking = false
        @tx_refs = []
        @url_buffered = ''
        @url_delivery = ''
        @url_nondelivery = ''
      end
      def each_element
        yield REXML::Element.new('Originator').add_text(originator.utf8)
        @recipients = [ @recipients ] unless @recipients.kind_of?(Array)
        txr = @tx_refs.dup
        recipients.each do |recipient|
          rcpt = REXML::Element.new('Recipient')
          rcpt.elements.add(Element.new('PhoneNumber').add_text(recipient.utf8))
          rcpt.elements.add(Element.new('TransRefNumber').
                            add_text(txr.shift)) unless txr.empty?
          yield rcpt
        end
        yield REXML::Element.new('MessageData').add_text(text.utf8)
        yield REXML::Element.new('UsedCredits').add_text('1')
        yield REXML::Element.new('FlashingSMS').add_text('1') if flashing
        yield REXML::Element.new('BlinkingSMS').add_text('1') if blinking
        yield REXML::Element.new('URLBufferedMessageNotification').
            add_text(url_buffered.utf8) unless url_buffered.empty?
        yield REXML::Element.new('URLDeliveryNotification').
            add_text(url_delivery.utf8) unless url_delivery.empty?
        yield REXML::Element.new('URLNonDeliveryNotification').
            add_text(url_nondelivery.utf8) unless url_nondelivery.empty?
      end
    end
    class SendOriginatorUnlockCode < Abstract
      attr_accessor :originator
      def initialize
        super
        @originator = ASPSMS::Config.originator
      end
      def each_element
        yield REXML::Element.new('Originator').add_text(originator.utf8)
      end
    end
    class UnlockOriginator < Abstract
      attr_accessor :originator, :code
      def initialize
        super
        @originator = ASPSMS::Config.originator
        @code = ''
      end
      def each_element
        yield REXML::Element.new('Originator').add_text(originator.utf8)
        yield REXML::Element.new('OriginatorUnlockCode').add_text(code.utf8)
      end
    end
    class CheckOriginatorAuthorization < Abstract
      attr_accessor :originator
      def initialize
        super
        @originator = ASPSMS::Config.originator
      end
      def each_element
        yield REXML::Element.new('Originator').add_text(originator.utf8)
      end
    end
    class ShowCredits < Abstract
      def each_element
        # no additional elements
      end
    end
  end

  # Represents a response to a request of any type.
  # Handles parsing of the response XML document and
  # provides easy access to data fields therein.
  class Response
    def self.parse(xmlstr)
      args = {}
      doc = REXML::Document.new(xmlstr)
      doc.root.each_element('*') do |element|
        args[element.name] = element.text.chomp
      end
      raise "'ErrorCode' missing!" if args['ErrorCode'].nil?
      raise "'ErrorDescription' missing!" if args['ErrorDescription'].nil?
      Response.new(args)
    end
    def initialize(args)
      @args = args
    end
    def success?
      @args['ErrorCode'] == '1' or authorized?
    end
    def authorized?
      @args['ErrorCode'] == '31' # Originator Already Authorized
    end
    def errno
      @args['ErrorCode']
    end
    def errdesc
      @args['ErrorDescription']
    end
    def credits
      @args['Credits']
    end
    def credits_used
      @args['CreditsUsed']
    end
    def to_s
      "#{@args['ErrorCode']}: #{@args['ErrorDescription']} #{@args.inspect}"
    end
  end

  # Handles network communication with the ASPSMS gateways.
  class Gateway
    attr_reader :host, :port
    def self.send(req)
      ASPSMS::Config.gateways.each do |spec|
        begin
          resp = Gateway.new(spec).send(req)
          return resp
        rescue
          # continue with next gateway in list
          # XXX collect exception objects and add to raise below
        end
      end
      raise 'Failed to send request to gateways!'
    end
    def initialize(gw)
      if gw.match(/^(.*):([0-9]{1,5})$/)
        @host, @port = $1, $2
      end
      @http = Net::HTTP.new(host, port)
    end
    def send(req)
      headers = { 'User-Agent' => ASPSMS::Config.useragent,
                  'Content-Type' => 'text/xml' }
      resp = @http.post('/xmlsvr.asp', req.to_s, headers)
      ASPSMS::Response.parse(resp.body)
    end
  end

  # Easy straightforward API class; for most use cases,
  # this should be all that is needed.
  class Easy
    def initialize(conf = nil)
      if conf.kind_of?(Hash)
        ASPSMS::Config.set(conf)
      elsif conf.kind_of?(String)
        ASPSMS::Config.load(conf)
      else
        ASPSMS::Config.autoload
      end
    end
    def show_credits
      request = ASPSMS::Request::ShowCredits.new
      response = ASPSMS::Gateway.send(request)
      raise 'Error status from server!' unless response.success?
      response.credits
    end
    def send_text_sms(text, recipients, opts = {})
      request = ASPSMS::Request::SendTextSMS.new
      request.text       = text
      request.recipients = recipients
      request.originator = opts[:originator] if opts.has_key?(:originator)
      request.flashing   = opts[:flashing]   if opts.has_key?(:flashing)
      request.blinking   = opts[:blinking]   if opts.has_key?(:blinking)
      response = ASPSMS::Gateway.send(request)
      raise 'Error status from server!' unless response.success?
      response.credits_used
    end
    def send_originator_unlock_code(opts = {})
      request = ASPSMS::Request::SendOriginatorUnlockCode.new
      request.originator = opts[:originator] if opts.has_key?(:originator)
      response = ASPSMS::Gateway.send(request)
      raise 'Error status from server!' unless response.success?
      response
    end
    def unlock_originator(code, opts = {})
      request = ASPSMS::Request::UnlockOriginator.new
      request.code       = code
      request.originator = opts[:originator] if opts.has_key?(:originator)
      response = ASPSMS::Gateway.send(request)
      raise 'Error status from server!' unless response.success?
      response
    end
    def check_originator_authorization(opts = {})
      request = ASPSMS::Request::CheckOriginatorAuthorization.new
      request.originator = opts[:originator] if opts.has_key?(:originator)
      response = ASPSMS::Gateway.send(request)
      raise 'Error status from server!' unless response.success?
      response
    end
  end
end

if $0 == __FILE__
  require 'getoptlong'

  $bn = File.basename($0)
  def usage
    puts <<EOF
Usage:
  #{$bn} [-M] [-v] [-c file] [-o orig] [-t [n]] [-f] [-b] rcpt [...]
  #{$bn}  -C  [-v] [-c file]
  #{$bn}  -O  [-v] [-c file] [-o orig]
  #{$bn}  -U  [-v] [-c file] [-o orig] [-u code]
Actions:
  -M    send text message read from stdin (implied if recipients are given)
  -C    retrieve credit balance
  -O    check originator authorization
  -U    send originator unlock code; unlock if used with -u
Parameters:
  -o    specify originator (phone number or up to 11 characters)
  -t    truncate message to n bytes, or 160 if used without argument
  -f/-b flashing/blinking text SMS
  -u    specify unlock code
  -c    specify config file (default: ~/.aspsms, [/usr/local]/etc/aspsms)
  -v    verbose
  -h/-V show help/version and exit
Recipient phone number format: international format, e.g. +41XXXXXXXXX
EOF
  end

  actions = []
  truncate = -1
  code = nil
  cf = nil
  verbose = false
  opts = {}
  GetoptLong.new(
    [ "-M", GetoptLong::NO_ARGUMENT ],
    [ "-C", GetoptLong::NO_ARGUMENT ],
    [ "-O", GetoptLong::NO_ARGUMENT ],
    [ "-U", GetoptLong::NO_ARGUMENT ],
    [ "-o", GetoptLong::REQUIRED_ARGUMENT ],
    [ "-t", GetoptLong::OPTIONAL_ARGUMENT ],
    [ "-f", GetoptLong::NO_ARGUMENT ],
    [ "-b", GetoptLong::NO_ARGUMENT ],
    [ "-u", GetoptLong::REQUIRED_ARGUMENT ],
    [ "-c", GetoptLong::REQUIRED_ARGUMENT ],
    [ "-v", GetoptLong::NO_ARGUMENT ],
    [ "-h", GetoptLong::NO_ARGUMENT ],
    [ "-V", GetoptLong::NO_ARGUMENT ]
  ).each do |opt, arg|
    case opt
    when '-h'
      usage
      exit 0
    when '-V'
      puts "#{$bn}: Ruby ASPSMS r#{ASPSMS::REVISION}"
      puts "Copyright (C) 2005-2011, Daniel Roethlisberger <daniel@roe.ch>"
      puts "http://www.roe.ch/ASPSMS"
      exit 0
    when '-M'
      actions << :textsms
    when '-C'
      actions << :credits
    when '-O'
      actions << :auth
    when '-U'
      actions << :unlock
    when '-o'
      opts[:originator] = arg
    when '-t'
      unless arg.empty? || arg.to_i > 0
        STDERR.puts 'Usage error! (-t takes a non-negative integer argument)'
        exit 1
      end
      truncate = arg.empty? ? 160 : arg.to_i
    when '-f'
      opts[:flashing] = true
    when '-b'
      opts[:blinking] = true
    when '-u'
      code = arg
    when '-c'
      cf = arg
    when '-v'
      verbose = true
    end
  end
  actions << :textsms unless ARGV.empty? || actions.include?(:textsms)

  if actions.length > 1
    STDERR.puts 'Usage error! (only one of -M, -C, -O and -U allowed)'
    exit 1
  end
  if actions[0] != :textsms && (truncate > 0 ||
                                opts.has_key?(:flashing) ||
                                opts.has_key?(:blinking))
    STDERR.puts 'Usage error! (-t, -f and -b only allowed with -M)'
    exit 1
  end
  if actions[0] != :unlock && !code.nil?
    STDERR.puts 'Usage error! (-c only allowed with -U)'
    exit 1
  end
  if actions.include?(:credits) && opts.has_key?(:originator)
    STDERR.puts 'Usage error! (-o not allowed with -C)'
    exit 1
  end

  aspsms = ASPSMS::Easy.new(cf)
  actions.each do |action|
    case action
    when :credits
      credits = aspsms.show_credits
      print credits
      puts verbose ? ' credits' : ''
      exit credits.to_i > 0 ? 0 : 1
    when :auth
      res = aspsms.check_originator_authorization(opts) rescue nil
      # XXX improve exception mechanism to disambiguate failures from noauth
      puts res.nil? ? 'not authorized' : 'authorized' if verbose
      exit res.nil? ? 1 : 0
    when :unlock
      if code.nil?
        res = aspsms.send_originator_unlock_code(opts)
        puts 'sent unlock code' if verbose
      else
        res = aspsms.unlock_originator(code, opts)
        puts 'unlocked originator' if verbose
      end
      exit 0
    when :textsms
      rcpt = ARGV.dup
      rcpt.each do |rcpt|
        unless rcpt.is_phone_number?
          STDERR.puts 'Syntax error! (%s not a phone number)' % rcpt
          exit 1
        end
      end
      text = STDIN.read.gsub(/\s+/, ' ').gsub(/^\s+|\s+$/, '')
      text = text[0..(truncate - 1)] if truncate > 0
      credits_used = aspsms.send_text_sms(text, rcpt, opts)
      puts "message delivered (#{credits_used} credits used)" if verbose
      exit 0
    end
  end
  usage
  exit 1
end