# JBoss, Home of Professional Open Source
# Copyright 2009, Red Hat Middleware LLC, and individual contributors
# by the @authors tag. See the copyright.txt in the distribution for a
# full listing of individual contributors.
#
# This is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as
# published by the Free Software Foundation; either version 2.1 of
# the License, or (at your option) any later version.
#
# This software is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with this software; if not, write to the Free
# Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
# 02110-1301 USA, or see the FSF site: http://www.fsf.org.

require 'guestfs'
require 'logger'

module BoxGrinder
  class SilencerProxy
    def initialize( o, destination )
      @o            = o
      @destination  = destination
    end

    def method_missing( m, *args, &block )
      begin
        redirect_streams( @destination ) do
          @o.send(m, *args, &block)
        end
      rescue
        raise
      end
    end

    def redirect_streams( destination )
      old_stdout_stream = STDOUT.dup
      old_stderr_stream = STDERR.dup

      STDOUT.reopen( destination )
      STDERR.reopen( destination )

      STDOUT.sync = true
      STDERR.sync = true

      yield
    ensure
      STDOUT.reopen( old_stdout_stream )
      STDERR.reopen( old_stderr_stream )
    end
  end
end

module Guestfs
  class Guestfs
    alias_method :sh_original, :sh

    def sh( command )
      begin
        output = sh_original( command )
        puts output
      rescue => e
        puts "Error occurred while executing above command. Appliance may not work properly."
      end

      output
    end

    def redirect( destination )
      BoxGrinder::SilencerProxy.new( self, destination )
    end
  end
end

module BoxGrinder
  class GuestFSHelper
    def initialize( raw_disk, options = {} )
      @raw_disk = raw_disk
      @log      = options[:log] || Logger.new(STDOUT)

      @partitions = {}
    end

    attr_reader :guestfs

    def customize
      read_pipe, write_pipe = IO.pipe

      fork do
        read_pipe.each do |o|
          if o.chomp.strip.eql?("<EOF>")
            exit
          else
            @log.trace "GFS: #{o.chomp.strip}"
          end
        end
      end

      helper = execute( write_pipe )

      yield @guestfs, helper

      clean_close

      write_pipe.puts "<EOF>"

      Process.wait
    end

    def execute( pipe = nil )
      @log.debug "Preparing guestfs..."

      @guestfs = pipe.nil? ? Guestfs::create : Guestfs::create.redirect( pipe )

      # TODO remove this, https://bugzilla.redhat.com/show_bug.cgi?id=502058
      @guestfs.set_append( "noapic" )

      @guestfs.set_verbose(1)
      @guestfs.set_trace(1)

      # workaround for latest qemu
      # It'll only work if qemu-stable package is installed. It is installed by default on meta-appliance
      # TODO wait for stable qemu and remove this
      # Looks like in F13 (qemu-img-0.12.3-8.fc13.i686) this is fixed
      qemu_wrapper = "/usr/share/qemu-stable/bin/qemu.wrapper"

      if File.exists?( qemu_wrapper )
        @guestfs.set_qemu( qemu_wrapper )
      end

      @log.trace "Adding drive '#{@raw_disk}'..."
      @guestfs.add_drive( @raw_disk )
      @log.trace "Drive added."

      @log.debug "Launching guestfs..."
      @guestfs.launch

      case @guestfs.list_partitions.size
        when 0
          mount_partition( @guestfs.list_devices.first, '/' )
        when 1
          mount_partition( @guestfs.list_partitions.first, '/' )
        else
          mount_partitions
      end

      @log.trace "Guestfs launched."

      self
    end

    def clean_close
      @log.trace "Closing guestfs..."

      @guestfs.sync
      @guestfs.umount_all
      @guestfs.close

      @log.trace "Guestfs closed."
    end

    def mount_partition( part, mount_point )
      @log.trace "Mounting #{part} partition to #{mount_point}..."
      @guestfs.mount_options( "", part, mount_point )
      @log.trace "Partition mounted."
    end

    # TODO this is shitty, I know... https://bugzilla.redhat.com/show_bug.cgi?id=507188
    def rebuild_rpm_database
      @log.debug "Cleaning RPM database..."
      @guestfs.sh( "rm -f /var/lib/rpm/__db.*" )
      @guestfs.sh( "rpm --rebuilddb" )
      @log.debug "Cleaning RPM database finished."
    end

    def mount_partitions
      root_partition = nil

      @guestfs.list_partitions.each do |partition|
        mount_partition( partition, '/' )
        if @guestfs.exists( '/sbin/e2label' ) != 0
          root_partition = partition
          break
        end
        @guestfs.umount( partition )
      end

      raise "No root partition found for '#{File.basename( @raw_disk )}' disk!" if root_partition.nil?

      @guestfs.list_partitions.each do |partition|
        next if partition == root_partition
        mount_partition( partition, @guestfs.sh( "/sbin/e2label #{partition}" ).chomp.strip )
      end
    end
  end
end