# Author:: Steven Danna (<steve@chef.io>)
# Copyright:: Copyright 2015-2016, Chef Software, 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/version"
class Chef
  class Knife
    class SubcommandLoader
      #
      # Load a subcommand from a pre-computed path
      # for the given command.
      #
      class HashedCommandLoader < Chef::Knife::SubcommandLoader
        KEY = "_autogenerated_command_paths"

        attr_accessor :manifest
        def initialize(chef_config_dir, plugin_manifest)
          super(chef_config_dir)
          @manifest = plugin_manifest
        end

        def guess_category(args)
          category_words = positional_arguments(args)
          category_words.map! { |w| w.split("-") }.flatten!
          find_longest_key(manifest[KEY]["plugins_by_category"], category_words, " ")
        end

        def list_commands(pref_category = nil)
          if pref_category || manifest[KEY]["plugins_by_category"].key?(pref_category)
            commands = { pref_category => manifest[KEY]["plugins_by_category"][pref_category] }
          else
            commands = manifest[KEY]["plugins_by_category"]
          end
          # If any of the specified plugins in the manifest dont have a valid path we will
          # eventually get an error and the user will need to rehash - instead, lets just
          # print out 1 error here telling them to rehash
          errors = {}
          commands.collect { |k, v| v }.flatten.each do |command|
            paths = manifest[KEY]["plugins_paths"][command]
            if paths && paths.is_a?(Array)
              # It is only an error if all the paths don't exist
              if paths.all? { |sc| !File.exists?(sc) }
                errors[command] = paths
              end
            end
          end
          if errors.empty?
            commands
          else
            Chef::Log.error "There are files specified in the manifest that are missing. Please rehash to update the subcommands cache. If you see this error after rehashing delete the cache at #{Chef::Knife::SubcommandLoader.plugin_manifest_path}"
            Chef::Log.error "Missing files:\n\t#{errors.values.flatten.join("\n\t")}"
            {}
          end
        end

        def subcommand_files
          manifest[KEY]["plugins_paths"].values.flatten
        end

        def load_command(args)
          paths = manifest[KEY]["plugins_paths"][subcommand_for_args(args)]
          if paths.nil? || paths.empty? || (! paths.is_a? Array)
            false
          else
            paths.each do |sc|
              if File.exists?(sc)
                Kernel.load sc
              else
                return false
              end
            end
            true
          end
        end

        def subcommand_for_args(args)
          if manifest[KEY]["plugins_paths"].key?(args)
            args
          else
            find_longest_key(manifest[KEY]["plugins_paths"], args, "_")
          end
        end
      end
    end
  end
end
