#  Phusion Passenger - https://www.phusionpassenger.com/
#  Copyright (c) 2010-2014 Phusion Holding B.V.
#
#  "Passenger", "Phusion Passenger" and "Union Station" are registered
#  trademarks of Phusion Holding B.V.
#
#  Permission is hereby granted, free of charge, to any person obtaining a copy
#  of this software and associated documentation files (the "Software"), to deal
#  in the Software without restriction, including without limitation the rights
#  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
#  copies of the Software, and to permit persons to whom the Software is
#  furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included in
#  all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
#  THE SOFTWARE.

PhusionPassenger.require_passenger_lib 'constants'

module PhusionPassenger

  class NativeSupportLoader
    def self.supported?
      return !defined?(RUBY_ENGINE) || RUBY_ENGINE == "ruby" || RUBY_ENGINE == "rbx"
    end

    def try_load
      if defined?(NativeSupport)
        return true
      else
        load_from_native_support_output_dir ||
        load_from_buildout_dir ||
        load_from_load_path ||
        load_from_home_dir
      end
    end

    def start
      if ENV['PASSENGER_USE_RUBY_NATIVE_SUPPORT'] == '0'
        STDERR.puts " [#{library_name}] will not be used (PASSENGER_USE_RUBY_NATIVE_SUPPORT=0)"
        STDERR.puts "  --> Passenger will still operate normally."
        return false
      elsif try_load
        return true
      elsif compile_and_load || download_binary_and_load
        STDERR.puts " [#{library_name}] successfully loaded."
        return true
      else
        STDERR.puts " [#{library_name}] will not be used (can't compile or download) "
        STDERR.puts "  --> Passenger will still operate normally."
        return false
      end
    end

  private
    def archdir
      @archdir ||= begin
        PhusionPassenger.require_passenger_lib 'platform_info/binary_compatibility'
        PlatformInfo.ruby_extension_binary_compatibility_id
      end
    end

    def libext
      @libext ||= begin
        PhusionPassenger.require_passenger_lib 'platform_info/operating_system'
        PlatformInfo.library_extension
      end
    end

    def library_name
      return "passenger_native_support.#{libext}"
    end

    def extconf_rb
      File.join(PhusionPassenger.ruby_extension_source_dir, "extconf.rb")
    end

    def load_from_native_support_output_dir
      # Quick workaround for people suffering from
      # https://code.google.com/p/phusion-passenger/issues/detail?id=865
      output_dir = ENV['PASSENGER_NATIVE_SUPPORT_OUTPUT_DIR']
      if output_dir && !output_dir.empty?
        begin
          return load_native_extension("#{output_dir}/#{VERSION_STRING}/#{archdir}/#{library_name}")
        rescue LoadError
          return false
        end
      else
        return false
      end
    end

    def load_from_buildout_dir
      if PhusionPassenger.build_system_dir
        begin
          return load_native_extension("#{PhusionPassenger.build_system_dir}/buildout/ruby/#{archdir}/#{library_name}")
        rescue LoadError
          return false
        end
      else
        return false
      end
    end

    def load_from_load_path
      return load_native_extension('passenger_native_support')
    rescue LoadError
      return false
    end

    def load_from_home_dir
      begin
        return load_native_extension("#{PhusionPassenger.home_dir}/#{USER_NAMESPACE_DIRNAME}/native_support/#{VERSION_STRING}/#{archdir}/#{library_name}")
      rescue LoadError
        return false
      end
    end

    def download_binary_and_load
      if !PhusionPassenger.installed_from_release_package?
        STDERR.puts " [#{library_name}] not downloading because passenger wasn't installed from a release package"
        return
      end
      if ENV['PASSENGER_DOWNLOAD_NATIVE_SUPPORT_BINARY'] == '0'
        STDERR.puts " [#{library_name}] not downloading because PASSENGER_DOWNLOAD_NATIVE_SUPPORT_BINARY=0"
        return
      end

      STDERR.puts " [#{library_name}] finding downloads for the current Ruby interpreter..."
      STDERR.puts "     (set PASSENGER_DOWNLOAD_NATIVE_SUPPORT_BINARY=0 to disable)"

      require 'logger'
      PhusionPassenger.require_passenger_lib 'platform_info/ruby'
      PhusionPassenger.require_passenger_lib 'utils/tmpio'
      PhusionPassenger.require_passenger_lib 'utils/download'
      PhusionPassenger.require_passenger_lib 'utils/shellwords'

      PhusionPassenger::Utils.mktmpdir("passenger-native-support-") do |dir|
        Dir.chdir(dir) do
          basename = "rubyext-#{archdir}.tar.gz"
          if !download(basename, dir, :total_timeout => 30)
            return false
          end

          s_basename = Shellwords.escape(basename)
          sh "tar xzf #{s_basename}"
          sh "rm -f #{s_basename}"
          STDERR.puts "     Checking whether downloaded binary is usable..."

          File.open("test.rb", "w") do |f|
            f.puts(%Q{
              require File.expand_path('passenger_native_support')
              f = File.open("test.txt", "w")
              PhusionPassenger::NativeSupport.writev(f.fileno, ["hello", "\n"])
            })
          end

          if sh_nonfatal("#{PlatformInfo.ruby_command} -I. test.rb") &&
             File.exist?("test.txt") &&
             File.read("test.txt") == "hello\n"
            STDERR.puts "     Binary is usable."
            File.unlink("test.rb")
            File.unlink("test.txt")
            result = try_directories(installation_target_dirs) do |target_dir|
              files = Dir["#{dir}/*"]
              STDERR.puts "     Installing " + files.map{ |n| File.basename(n) }.join(' ')
              FileUtils.cp(files, target_dir)
              load_result = load_native_extension("#{target_dir}/#{library_name}")
              [load_result, false]
            end
            return result
          else
            STDERR.puts "     Binary is not usable."
            return false
          end
        end
      end
    end

    def compile_and_load
      if ENV['PASSENGER_COMPILE_NATIVE_SUPPORT_BINARY'] == '0'
        STDERR.puts " [#{library_name}] not compiling because PASSENGER_COMPILE_NATIVE_SUPPORT_BINARY=0"
        return false
      end

      if PhusionPassenger.custom_packaged? && !File.exist?(PhusionPassenger.ruby_extension_source_dir)
        PhusionPassenger.require_passenger_lib 'constants'
        STDERR.puts " [#{library_name}] not found for current Ruby interpreter."
        case PhusionPassenger.packaging_method
        when 'deb'
          STDERR.puts "     This library provides various optimized routines that make"
          STDERR.puts "     #{PhusionPassenger::PROGRAM_NAME} faster. Please run 'sudo apt-get install #{PhusionPassenger::DEB_DEV_PACKAGE}'"
          STDERR.puts "     so that #{PhusionPassenger::PROGRAM_NAME} can compile one on the next run."
        when 'rpm'
          STDERR.puts "     This library provides various optimized routines that make"
          STDERR.puts "     #{PhusionPassenger::PROGRAM_NAME} faster. Please run 'sudo yum install #{PhusionPassenger::RPM_DEV_PACKAGE}-#{PhusionPassenger::VERSION_STRING}'"
          STDERR.puts "     so that #{PhusionPassenger::PROGRAM_NAME} can compile one on the next run."
        else
          STDERR.puts "     #{PhusionPassenger::PROGRAM_NAME} can compile one, but an extra package must be installed"
          STDERR.puts "     first. Please ask your packager or operating system vendor for instructions."
        end
        return false
      end

      STDERR.puts " [#{library_name}] trying to compile for the current user (#{current_user_name_or_id}) and Ruby interpreter..."
      STDERR.puts "     (set PASSENGER_COMPILE_NATIVE_SUPPORT_BINARY=0 to disable)"

      require 'fileutils'
      PhusionPassenger.require_passenger_lib 'utils/shellwords'
      PhusionPassenger.require_passenger_lib 'platform_info/ruby'

      target_dir = compile(installation_target_dirs)
      if target_dir
        return load_native_extension("#{target_dir}/#{library_name}")
      else
        return false
      end
    end

    # Name of the user under which we are executing, or the id as fallback
    # N.B. loader_shared_helpers.rb has the same method 
    def current_user_name_or_id
      require 'etc' if !defined?(Etc)
      begin
        user = Etc.getpwuid(Process.uid)
      rescue ArgumentError
        user = nil
      end
      if user
        return user.name
      else
        return "##{Process.uid}"
      end
    end

    def installation_target_dirs
      target_dirs = []
      if (output_dir = ENV['PASSENGER_NATIVE_SUPPORT_OUTPUT_DIR']) && !output_dir.empty?
        target_dirs << "#{output_dir}/#{VERSION_STRING}/#{archdir}"
      end
      if PhusionPassenger.build_system_dir
        target_dirs << "#{PhusionPassenger.build_system_dir}/buildout/ruby/#{archdir}"
      end
      target_dirs << "#{PhusionPassenger.home_dir}/#{USER_NAMESPACE_DIRNAME}/native_support/#{VERSION_STRING}/#{archdir}"
      return target_dirs
    end

    def download(name, output_dir, options = {})
      logger = Logger.new(STDERR)
      logger.level = Logger::WARN
      logger.formatter = proc do |severity, datetime, progname, msg|
        msg.gsub(/^/, "     ") + "\n"
      end
      sites = PhusionPassenger.binaries_sites
      sites.each_with_index do |site, i|
        if real_download(site, name, output_dir, logger, options)
          logger.warn "Download OK!" if i > 0
          return true
        elsif i != sites.size - 1
          logger.warn "Trying next mirror..."
        end
      end
      return false
    end

    def real_download(site, name, output_dir, logger, options)
      url = "#{site[:url]}/#{VERSION_STRING}/#{name}"
      filename = "#{output_dir}/#{name}"
      real_options = options.merge(
        :cacert => site[:cacert],
        :use_cache => true,
        :logger => logger
      )
      return PhusionPassenger::Utils::Download.download(url, filename, real_options)
    end

    def log(message, options = {})
      if logger = options[:logger]
        logger.puts(message)
      else
        STDERR.puts "     #{message}"
      end
    end

    def mkdir(dir, options = {})
      begin
        log("# mkdir -p #{dir}", options)
        FileUtils.mkdir_p(dir)
      rescue Errno::EEXIST
      end
    end

    def sh(command_string)
      if !sh_nonfatal(command_string)
        raise "Could not compile #{library_name} (\"#{command_string}\" failed)"
      end
    end

    def sh_nonfatal(command_string, options = {})
      log("# #{command_string}", options)
      if logger = options[:logger]
        s_logpath = Shellwords.escape(logger.path)
        return system("(#{command_string}) >>#{s_logpath} 2>&1")
      else
        Utils.mktmpdir("passenger-native-support-") do |tmpdir|
          s_tmpdir = Shellwords.escape(tmpdir)
          result = system("(#{command_string}) >#{s_tmpdir}/log 2>&1")
          system("cat #{s_tmpdir}/log | sed 's/^/     /' >&2")
          return result
        end
      end
    end

    def compile(target_dirs)
      logger = Utils::TmpIO.new('passenger_native_support',
        :mode   => File::WRONLY | File::APPEND,
        :binary => false,
        :suffix => ".log",
        :unlink_immediately => false)
      options = { :logger => logger }
      begin
        result = try_directories(target_dirs, options) do |target_dir|
          make_result = nil
          # Perform the actual compilation in a temporary directory to avoid
          # problems with multiple processes trying to concurrently compile.
          # https://github.com/phusion/passenger/issues/1570
          PhusionPassenger::Utils.mktmpdir("passenger-native-support-") do |tmpdir|
            Dir.chdir(tmpdir) do
              make_result =
                sh_nonfatal("#{PlatformInfo.ruby_command} #{Shellwords.escape extconf_rb}",
                  options) &&
                sh_nonfatal("make", options)
              if make_result
                begin
                  FileUtils.cp_r(".", target_dir)
                rescue SystemCallError => e
                  log("Error: #{e}")
                  make_result = false
                end
              end
            end
          end
          if make_result
            log "Compilation successful. The logs are here:"
            log logger.path
            [target_dir, false]
          else
            [nil, false]
          end
        end
        if !result
          log "Warning: compilation didn't succeed. To learn why, read this file:"
          log logger.path
        end
        return result
      end
    ensure
      logger.close if logger
    end

    def try_directories(dirs, options = {})
      result = nil
      log("# current user is: #{current_user_name_or_id}", options)
      dirs.each_with_index do |dir, i|
        begin
          mkdir(dir, options)
          File.open("#{dir}/.permission_test", "w").close
          File.unlink("#{dir}/.permission_test")
          log("# cd #{dir}", options)
          Dir.chdir(dir) do
            result, should_retry = yield(dir)
            return result if !should_retry
          end
        rescue Errno::EACCES
          # If we encountered a permission error, then try
          # the next target directory. If we get a permission
          # error on the last one too then propagate the
          # exception.
          if i == dirs.size - 1
            log("Encountered permission error, " +
              "but no more directories to try. Giving up.",
              options)
            log("-------------------------------", options)
            return nil
          else
            log("Encountered permission error, " +
              "trying a different directory...",
              options)
            log("-------------------------------", options)
          end
        rescue Errno::ENOTDIR
          # This can occur when locations.ini set build_system_dir
          # to an invalid path. Just ignore this error.
          if i == dirs.size - 1
            log("Not a valid directory, " +
              "but no more directories to try. Giving up.",
              options)
            log("-------------------------------", options)
            return nil
          else
            log("Not a valid directory. Trying a different one...",
              options)
            log("-------------------------------", options)
          end
        end
      end
    end

    def load_native_extension(name_or_filename)
      # If passenger_native_support.so exited because it detected that it was compiled
      # for a different Ruby version, then subsequent require("passenger_native_support")
      # calls will do nothing. So we remove passenger_native_support from $LOADED_FEATURES
      # to force it to be loaded.
      $LOADED_FEATURES.reject! { |fn| File.basename(fn) == library_name }
      begin
        require(name_or_filename)
        return defined?(PhusionPassenger::NativeSupport)
      rescue LoadError => e
        if e.to_s =~ /dlopen/
          # Print dlopen failures. We're not interested in any other
          # kinds of failures, such as file-not-found.
          puts e.to_s.gsub(/^/, "     ")
        end
        return false
      end
    end
  end

end # module PhusionPassenger

if PhusionPassenger::NativeSupportLoader.supported?
  PhusionPassenger::NativeSupportLoader.new.start
end
