require 'puppet/util/filetype'
Puppet::Type.type(:a2mod).provide(:gentoo, :parent => Puppet::Provider) do
  desc "Manage Apache 2 modules on Gentoo"

  confine :operatingsystem => :gentoo
  defaultfor :operatingsystem => :gentoo

  attr_accessor :property_hash

  def create
    @property_hash[:ensure] = :present
  end

  def exists?
    (!(@property_hash[:ensure].nil?) and @property_hash[:ensure] == :present)
  end

  def destroy
    @property_hash[:ensure] = :absent
  end

  def flush
    self.class.flush
  end

  class << self
    attr_reader :conf_file
  end

  def self.clear
    @mod_resources = []
    @modules       = []
    @other_args    = ""
  end

  def self.initvars
    @conf_file     = "/etc/conf.d/apache2"
    @filetype      = Puppet::Util::FileType.filetype(:flat).new(conf_file)
    @mod_resources = []
    @modules       = []
    @other_args    = ""
  end

  self.initvars

  # Retrieve an array of all existing modules
  def self.modules
    if @modules.length <= 0
      # Locate the APACHE_OPTS variable
      records = filetype.read.split(/\n/)
      apache2_opts = records.grep(/^\s*APACHE2_OPTS=/).first

      # Extract all defines
      while apache2_opts.sub!(/-D\s+(\w+)/, '')
        @modules << $1.downcase
      end

      # Hang on to any remaining options.
      if apache2_opts.match(/APACHE2_OPTS="(.+)"/)
        @other_args = $1.strip
      end

      @modules.sort!.uniq!
    end

    @modules
  end

  def self.prefetch(resources={})
    # Match resources with existing providers
    instances.each do |provider|
      if resource = resources[provider.name]
        resource.provider = provider
      end
    end

    # Store all resources using this provider for flushing
    resources.each do |name, resource|
      @mod_resources << resource
    end
  end

  def self.instances
    modules.map {|mod| new(:name => mod, :provider => :gentoo, :ensure => :present)}
  end

  def self.flush

    mod_list       = modules
    mods_to_remove = @mod_resources.select {|mod| mod.should(:ensure) == :absent}.map {|mod| mod[:name]}
    mods_to_add    = @mod_resources.select {|mod| mod.should(:ensure) == :present}.map {|mod| mod[:name]}

    mod_list -= mods_to_remove
    mod_list += mods_to_add
    mod_list.sort!.uniq!

    if modules != mod_list
      opts = @other_args + " "
      opts << mod_list.map {|mod| "-D #{mod.upcase}"}.join(" ")
      opts.strip!
      opts.gsub!(/\s+/, ' ')

      apache2_opts = %Q{APACHE2_OPTS="#{opts}"}
      Puppet.debug("Writing back \"#{apache2_opts}\" to #{conf_file}")

      records = filetype.read.split(/\n/)

      opts_index = records.find_index {|i| i.match(/^\s*APACHE2_OPTS/)}
      records[opts_index] = apache2_opts

      filetype.backup
      filetype.write(records.join("\n"))
      @modules = mod_list
    end
  end
end