#
# Ronin - A Ruby platform for exploit development and security research.
#
# Copyright (c) 2006-2009 Hal Brodigan (postmodern.mod3 at gmail.com)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
#

require 'ronin/platform/exceptions/overlay_not_found'
require 'ronin/platform/overlay_cache'
require 'ronin/platform/object_cache'
require 'ronin/platform/extension_cache'

require 'uri'

module Ronin
  module Platform
    #
    # Load the overlay cache.
    #
    # @param [String] path
    #   The optional path to the overlay cache file.
    #
    # @return [OverlayCache]
    #   The newly loaded overlay cache.
    #
    # @example
    #   Overlay.load_overlays
    #   # => #<Ronin::Platform::OverlayCache: ...>
    #
    # @example
    #   Overlay.load_overlays('/custom/overlays/cache.yaml')
    #   # => #<Ronin::Platform::OverlayCache: ...>
    #
    def Platform.load_overlays(path=OverlayCache::CACHE_FILE)
      @@ronin_overlay_cache = OverlayCache.new(path)
    end

    #
    # @return [OverlayCache]
    #   The current overlay cache. If no overlay cache is present, the
    #   default overlay will be loaded.
    #
    def Platform.overlays
      @@ronin_overlay_cache ||= OverlayCache.new
    end

    #
    # Adds a new overlay to the overlay cache.
    #
    # @param [Hash] options
    #   Additional options.
    #
    # @option options [String] :path
    #   A pre-existing path to the overlay.
    #
    # @option options [Symbol] :media
    #   The media type of the overlay, may be either +:git+, +:hg+,
    #   +:svn+ or +:rsync+.
    #
    # @option options [String, URI::HTTP, URI::HTTPS] uri
    #   The URI of the overlay.
    #
    # @yield [overlay]
    #   If a block is given, it will be passed the overlay after it has
    #   been added to the cache.
    #
    # @yieldparam [Overlay] overlay
    #   The newly added overlay.
    #
    # @return [Overlay]
    #   The newly added overlay.
    #
    # @raise [ArgumentError]
    #   The +:path+ option was not specified.
    #
    # @raise [OverlayNotFound]
    #   The +:path+ option did not represent a valid directory.
    #
    def Platform.add(options={},&block)
      path = options[:path]

      unless path
        raise(ArgumentError,":path must be passed to Platform.add",caller)
      end

      path = path.to_s

      unless File.directory?(path)
        raise(OverlayNotFound,"overlay #{path.dump} cannot be found",caller)
      end

      media = options[:media]
      uri = options[:uri]

      overlay = Overlay.new(path,media,uri)

      Platform.overlays.add(overlay) do |overlay|
        ObjectCache.cache(overlay.objects_dir)
      end

      block.call(overlay) if block
      return overlay
    end

    #
    # Installs an overlay into the OverlayCache::CACHE_DIR and adds it
    # to the overlay cache.
    #
    # @param [Hash] options
    #   Additional options.
    #
    # @option options [String, URI::HTTP, URI::HTTPS] :uri
    #   The URI to the overlay.
    #
    # @option options [Symbol] :media
    #   The media type of the overlay, may be either +:git+, +:hg+,
    #   +:svn+ or +:rsync+.
    #
    # @yield [overlay]
    #   If a block is given, it will be passed the overlay, after it has
    #   been installed.
    #
    # @yieldparam [Overlay] overlay
    #   The newly installed overlay.
    #
    # @return [Overlay]
    #   The newly installed overlay.
    #
    # @raise [ArgumentError]
    #   The +:uri+ option must be specified.
    #
    def Platform.install(options={},&block)
      unless options[:uri]
        raise(ArgumentError,":uri must be passed to Platform.install",caller)
      end

      uri = options[:uri].to_s
      host = (URI(uri).host || 'localhost')
      host_dir = File.join(OverlayCache::CACHE_DIR,host)
      options = options.merge(:into => host_dir)

      Repertoire.checkout(options) do |repo|
        return Platform.add(
          :path => repo.path,
          :media => repo.media_name,
          :uri => uri,
          &block
        )
      end
    end

    #
    # Updates all previously installed overlays within the overlay cache.
    #
    # @yield []
    #   If a block is given, it will be called after all overlays have been
    #   updated within the cache.
    #
    def Platform.update(&block)
      Platform.overlays.update do |overlay|
        ObjectCache.mirror(overlay.objects_dir)
      end

      block.call if block
      return nil
    end

    #
    # Removes an overlay from the overlay cache, but leaves the contents
    # of the overlay intact.
    #
    # @param [String] name
    #   The name of the overlay to remove.
    #
    # @yield [overlay]
    #   If a block is given, it will be passed the overlay after it has
    #   been removed.
    #
    # @yieldparam [Overlay] overlay
    #   The removed overlay.
    #
    # @raise [OverlayNotFound]
    #   The overlay with the specified _name_ could not be found in the
    #   overlay cache.
    #
    def Platform.remove(name,&block)
      Platform.overlays.remove(name,&block)
      return nil
    end

    #
    # Uninstalls an overlay from the overlay cache, and deletes the
    # contents of the overlay.
    #
    # @param [String] name
    #   The name of the overlay to uninstall.
    #
    # @yield []
    #   If a block is given, it will be called after the overlay has been
    #   uninstalled.
    #
    # @raise [OverlayNotFound]
    #   The overlay with the specified _name_ could not be found in the
    #   overlay cache.
    #
    def Platform.uninstall(name,&block)
      Platform.overlays.uninstall(name) do |overlay|
        ObjectCache.clean(overlay.objects_dir)
      end

      block.call() if block
      return nil
    end

    #
    # @return [Array]
    #   The names of all extensions within the overlays in the overlay
    #   cache.
    #
    def Platform.extension_names
      Platform.overlays.extensions
    end

    #
    # Searches for the extension with the specified _name_, in all
    # overlays within the overlay cache.
    #
    # @param [String] name
    #   The name of the extension to search for.
    #
    # @return [Boolean]
    #   Specifies whether the overlay cache contains the extension with
    #   the matching _name_.
    #
    def Platform.has_extension?(name)
      Platform.overlays.has_extension?(name)
    end

    #
    # The extension cache.
    #
    # @return [ExtensionCache]
    #   The extension cache of all currently loaded extensions.
    #
    # @example
    #   Platform.extensions['shellcode']
    #   # => #<Ronin::Platform::Extension: ...>
    #
    def Platform.extensions
      @@ronin_extension_cache ||= ExtensionCache.new
    end

    #
    # Loads an extension into the extension cache, if it has yet to be
    # loaded.
    #
    # @param [String] name
    #   The name of the desired extension.
    #
    # @yield [ext]
    #   If a block is given, it will be passed the extension with the
    #   matching _name_.
    #
    # @yieldparam [Extension] ext
    #   The desired extension.
    #
    # @return [Extension]
    #   The desired extension.
    #
    # @raise [ExtensionNotFound]
    #   The extension with the specified _name_ could not be found in any
    #   of the overlays or in the extension cache.
    #
    def Platform.extension(name,&block)
      ext = Platform.extensions[name]

      block.call(ext) if block
      return ext
    end

    #
    # Reloads the overlay cache and the extension cache.
    #
    # @return [Boolean]
    #   Specifies whether the reload was successful or not.
    #
    def Platform.reload!
      Platform.overlays.reload! && Platform.extensions.reload!
    end
  end
end