#
# Author:: Adam Jacob (<adam@opscode.com>)
# Copyright:: Copyright (c) 2008 Opscode, Inc.
# License:: Apache License, Version 2.0
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#     http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#

require 'chef/provider/package'
require 'chef/mixin/command'
require 'chef/resource/package'
require 'singleton'

class Chef
  class Provider
    class Package
      class Yum < Chef::Provider::Package

        class YumCache
          include Chef::Mixin::Command
          include Singleton

          def initialize
            load_data
          end

          def stale?
            interval = Chef::Config[:interval].to_f

            # run once mode
            if interval == 0
              return false
            elsif (Time.now - @updated_at) > interval
              return true
            end

            false
          end
            
          def refresh
            if @data.empty?
              reload
            elsif stale?
               reload
            end
          end

          def load_data
            @data = Hash.new
            error = String.new

            helper = ::File.join(::File.dirname(__FILE__), 'yum-dump.py')
            status = popen4("python #{helper}", :waitlast => true) do |pid, stdin, stdout, stderr|
              stdout.each do |line|
                line.chomp!
                name, type, epoch, version, release, arch = line.split(',')
                type_sym = type.to_sym
                if !@data.has_key?(name)
                  @data[name] = Hash.new
                end
                if !@data[name].has_key?(type_sym)
                  @data[name][type_sym] = Hash.new
                end
                @data[name][type_sym][arch] = { :epoch => epoch, :version => version,
                                                :release => release }
              end
              
              error = stderr.readlines
            end

            unless status.exitstatus == 0
              raise Chef::Exceptions::Package, "yum failed - #{status.inspect} - returns: #{error}"
            end

            @updated_at = Time.now
          end
          alias :reload :load_data

          def version(package_name, type, arch)
            if (x = @data[package_name])
              if (y = x[type])
                if arch
                  if (z = y[arch])
                    return "#{z[:version]}-#{z[:release]}"
                  end
                else
                  # no arch specified - take the first match
                  z = y.to_a[0][1]
                  return "#{z[:version]}-#{z[:release]}"
                end
              end
            end

            nil
          end

          def version_available?(package_name, desired_version, arch)
            if (package_data = @data[package_name])
              if (available_versions = package_data[:available])
                if arch
                  # arch gets passed like ".x86_64"
                  matching_versions = [ available_versions[arch.sub(/^./, '')]]
                else
                  matching_versions = available_versions.values
                end

                if matching_versions.nil?
                  if arch.empty?
                    arch_msg = ""
                  else
                    arch_msg = "with arch #{arch.sub(/^./, '')} "
                  end

                  raise ArgumentError, "#{package_name}: Found no available versions #{arch_msg}to match"
                end

                # Expect [ { :version => "ver", :release => "rel" }, { :version => "ver", :release => "rel" }, { :version => "ver", :release => "rel" } ] ???
                matching_versions.each do |ver|
                  Chef::Log.debug("#{package_name}: trying to match #{desired_version} to version #{ver[:version]} and release #{ver[:release]}")
                  if (desired_version == "#{ver[:version]}-#{ver[:release]}")
                    return true
                  end
                end
              end
            end

            nil
          end

          def installed_version(package_name, arch)
            version(package_name, :installed, arch)
          end

          def candidate_version(package_name, arch)
            version(package_name, :available, arch)
          end

          def flush
            @data.clear
          end
        end

        def initialize(new_resource, run_context)
          super
          @yum = YumCache.instance
        end

        def arch
          if @new_resource.respond_to?("arch")
            @new_resource.arch 
          else
            nil
          end
        end

        def yum_arch
          arch ? ".#{arch}" : nil
        end

        def load_current_resource
          @current_resource = Chef::Resource::Package.new(@new_resource.name)
          @current_resource.package_name(@new_resource.package_name)

          if @new_resource.source
            unless ::File.exists?(@new_resource.source)
              raise Chef::Exceptions::Package, "Package #{@new_resource.name} not found: #{@new_resource.source}"
            end

            Chef::Log.debug("Checking rpm status for  #{@new_resource.package_name}")
            status = popen4("rpm -qp --queryformat '%{NAME} %{VERSION}-%{RELEASE}\n' #{@new_resource.source}") do |pid, stdin, stdout, stderr|
              stdout.each do |line|
                case line
                when /([\w\d_.-]+)\s([\w\d_.-]+)/
                  @current_resource.package_name($1)
                  @new_resource.version($2)
                end
              end
            end
          end

          Chef::Log.debug("Checking yum info for #{@new_resource.package_name}#{yum_arch}")

          @yum.refresh

          installed_version = @yum.installed_version(@new_resource.package_name, arch)
          @candidate_version = @yum.candidate_version(@new_resource.package_name, arch)

          @current_resource.version(installed_version)
          if candidate_version
            @candidate_version = candidate_version
          else
            @candidate_version = installed_version
          end
          Chef::Log.debug("#{@current_resource.name}: Installed version: #{installed_version} Candidate version: #{candidate_version}")

          @current_resource
        end

        def install_package(name, version)
          if @new_resource.source 
            run_command_with_systems_locale(
              :command => "yum -d0 -e0 -y #{@new_resource.options} localinstall #{@new_resource.source}"
            )
          else
            # Work around yum not exiting with an error if a package doesn't exist for CHEF-2062
            if @yum.version_available?(name, version, yum_arch)
              run_command_with_systems_locale(
                :command => "yum -d0 -e0 -y #{@new_resource.options} install #{name}-#{version}#{yum_arch}"
              )
            else
              raise ArgumentError, "#{@new_resource.name}: Version #{version} of #{name} not found. Did you specify both version and release? (version-release, e.g. 1.84-10.fc6)"
            end
          end
          @yum.flush
        end

        def upgrade_package(name, version)
          # If we're not given a version, running update is the correct
          # option. If we are, then running install_package is right.
          unless version
            run_command_with_systems_locale(
              :command => "yum -d0 -e0 -y #{@new_resource.options} update #{name}#{yum_arch}"
            )   
            @yum.flush
          else
            install_package(name, version)
          end
        end

        def remove_package(name, version)
          if version
            run_command_with_systems_locale(
             :command => "yum -d0 -e0 -y #{@new_resource.options} remove #{name}-#{version}#{yum_arch}"
            )
          else
            run_command_with_systems_locale(
             :command => "yum -d0 -e0 -y #{@new_resource.options} remove #{name}#{yum_arch}"
            )
          end
            
          @yum.flush
        end

        def purge_package(name, version)
          remove_package(name, version)
        end

      end
    end
  end
end