# -*- encoding: utf-8 -*-
#
# Author:: Fletcher Nichol (<fnichol@nichol.ca>)
#
# Copyright (C) 2015, Fletcher Nichol
#
# 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 "json"

module Kitchen

  module Provisioner

    module Chef

      # Internal object to manage common sandbox preparation for
      # Chef-related provisioners.
      #
      # @author Fletcher Nichol <fnichol@nichol.ca>
      # @api private
      class CommonSandbox

        include Logging

        # Constructs a new object, taking config, a sandbox path, and an
        # instance.
        #
        # @param config [Hash] configuration hash
        # @param sandbox_path [String] path to local sandbox directory
        # @param instance [Instance] an instance
        def initialize(config, sandbox_path, instance)
          @config = config
          @sandbox_path = sandbox_path
          @instance = instance
        end

        # Populate the sandbox.
        def populate
          prepare_json
          prepare_cache
          prepare_cookbooks
          prepare(:data)
          prepare(:data_bags)
          prepare(:environments)
          prepare(:nodes)
          prepare(:roles)
          prepare(:clients)
          prepare(
            :secret,
            :type => :file,
            :dest_name => "encrypted_data_bag_secret",
            :key_name => :encrypted_data_bag_secret_key_path
          )
        end

        private

        # @return [Hash] configuration hash
        # @api private
        attr_reader :config

        # @return [Instance] an instance
        # @api private
        attr_reader :instance

        # @return [String] path to local sandbox directory
        # @api private
        attr_reader :sandbox_path

        # Generates a list of all files in the cookbooks directory in the
        # sandbox path.
        #
        # @return [Array<String>] an array of absolute paths to files
        # @api private
        def all_files_in_cookbooks
          Dir.glob(File.join(tmpbooks_dir, "**/*"), File::FNM_DOTMATCH).
            select { |fn| File.file?(fn) && ! %w[. ..].include?(fn) }
        end

        # @return [String] an absolute path to a Policyfile, relative to the
        #   kitchen root
        # @api private
        def policyfile
          basename = config[:policyfile_path] || "Policyfile.rb"
          File.join(config[:kitchen_root], basename)
        end

        # @return [String] an absolute path to a Berksfile, relative to the
        #   kitchen root
        # @api private
        def berksfile
          File.join(config[:kitchen_root], "Berksfile")
        end

        # @return [String] an absolute path to a Cheffile, relative to the
        #   kitchen root
        # @api private
        def cheffile
          File.join(config[:kitchen_root], "Cheffile")
        end

        # @return [String] an absolute path to a cookbooks/ directory, relative
        #   to the kitchen root
        # @api private
        def cookbooks_dir
          File.join(config[:kitchen_root], "cookbooks")
        end

        # Copies a cookbooks/ directory into the sandbox path.
        #
        # @api private
        def cp_cookbooks
          info("Preparing cookbooks from project directory")
          debug("Using cookbooks from #{cookbooks_dir}")

          FileUtils.mkdir_p(tmpbooks_dir)
          FileUtils.cp_r(File.join(cookbooks_dir, "."), tmpbooks_dir)

          cp_site_cookbooks if File.directory?(site_cookbooks_dir)
          cp_this_cookbook if File.exist?(metadata_rb)
        end

        # Copies a site-cookbooks/ directory into the sandbox path.
        #
        # @api private
        def cp_site_cookbooks
          info("Preparing site-cookbooks from project directory")
          debug("Using cookbooks from #{site_cookbooks_dir}")

          FileUtils.mkdir_p(tmpsitebooks_dir)
          FileUtils.cp_r(File.join(site_cookbooks_dir, "."), tmpsitebooks_dir)
        end

        # Copies the current project, assumed to be a Chef cookbook into the
        # sandbox path.
        #
        # @api private
        def cp_this_cookbook
          info("Preparing current project directory as a cookbook")
          debug("Using metadata.rb from #{metadata_rb}")

          cb_name = MetadataChopper.extract(metadata_rb).first || raise(UserError,
            "The metadata.rb does not define the 'name' key." \
              " Please add: `name '<cookbook_name>'` to metadata.rb and retry")

          cb_path = File.join(tmpbooks_dir, cb_name)

          glob = Dir.glob("#{config[:kitchen_root]}/**")

          FileUtils.mkdir_p(cb_path)
          FileUtils.cp_r(glob, cb_path)
        end

        # Removes all non-cookbook files in the sandbox path.
        #
        # @api private
        def filter_only_cookbook_files
          info("Removing non-cookbook files before transfer")
          FileUtils.rm(all_files_in_cookbooks - only_cookbook_files)
          Dir.glob(File.join(tmpbooks_dir, "**/"), File::FNM_PATHNAME).
            reverse_each { |fn| FileUtils.rmdir(fn) if Dir.entries(fn).size == 2 }
        end

        # @return [Logger] the instance's logger or Test Kitchen's common
        #   logger otherwise
        # @api private
        def logger
          instance ? instance.logger : Kitchen.logger
        end

        # Creates a minimal, no-op cookbook in the sandbox path.
        #
        # @api private
        def make_fake_cookbook
          info("Berksfile, Cheffile, cookbooks/, or metadata.rb not found " \
            "so Chef will run with effectively no cookbooks. Is this intended?")
          name = File.basename(config[:kitchen_root])
          fake_cb = File.join(tmpbooks_dir, name)
          FileUtils.mkdir_p(fake_cb)
          File.open(File.join(fake_cb, "metadata.rb"), "wb") do |file|
            file.write(%{name "#{name}"\n})
          end
        end

        # @return [String] an absolute path to a metadata.rb, relative to the
        #   kitchen root
        # @api private
        def metadata_rb
          File.join(config[:kitchen_root], "metadata.rb")
        end

        # Generates a list of all typical cookbook files needed in a Chef run,
        # located in the cookbooks directory in the sandbox path.
        #
        # @return [Array<String>] an array of absolute paths to files
        # @api private
        def only_cookbook_files
          glob = File.join(tmpbooks_dir, "*", "{#{config[:cookbook_files_glob]}}")

          Dir.glob(glob, File::FNM_DOTMATCH).
            select { |fn| File.file?(fn) && ! %w[. ..].include?(fn) }
        end

        # Prepares a generic Chef component source directory or file for
        # inclusion in the sandbox path. These components might includes nodes,
        # roles, etc.
        #
        # @param component [Symbol,String] a component name such as `:node`
        # @param opts [Hash] optional configuration
        # @option opts [Symbol] :type whether the component is a directory or
        #   file (default: `:directory`)
        # @option opts [Symbol] :key_name the key name in the config hash from
        #   which to pull the source path (default: `"#{component}_path"`)
        # @option opts [String] :dest_name the destination file or directory
        #   basename in the sandbox path (default: `component.to_s`)
        # @api private
        def prepare(component, opts = {})
          opts = { :type => :directory }.merge(opts)
          key_name = opts.fetch(:key_name, "#{component}_path")
          src = config[key_name.to_sym]
          return if src.nil?

          info("Preparing #{component}")
          debug("Using #{component} from #{src}")

          dest = File.join(sandbox_path, opts.fetch(:dest_name, component.to_s))

          case opts[:type]
          when :directory
            FileUtils.mkdir_p(dest)
            FileUtils.cp_r(Dir.glob("#{src}/*"), dest)
          when :file
            FileUtils.mkdir_p(File.dirname(dest))
            FileUtils.cp_r(src, dest)
          end
        end

        # Prepares a cache directory for inclusion in the sandbox path.
        #
        # @api private
        def prepare_cache
          FileUtils.mkdir_p(File.join(sandbox_path, "cache"))
        end

        # Prepares Chef cookbooks for inclusion in the sandbox path.
        #
        # @api private
        # rubocop:disable Metrics/PerceivedComplexity, Metrics/CyclomaticComplexity
        def prepare_cookbooks
          if File.exist?(policyfile)
            resolve_with_policyfile
          elsif File.exist?(berksfile)
            resolve_with_berkshelf
          elsif File.exist?(cheffile)
            resolve_with_librarian
            cp_site_cookbooks if File.directory?(site_cookbooks_dir)
          elsif File.directory?(cookbooks_dir)
            cp_cookbooks
          elsif File.exist?(metadata_rb)
            cp_this_cookbook
          else
            make_fake_cookbook
          end

          filter_only_cookbook_files
        end

        # Prepares a Chef JSON file, sometimes called a dna.json or
        # first-boot.json, for inclusion in the sandbox path.
        #
        # @api private
        def prepare_json
          dna = if File.exist?(policyfile)
            update_dna_for_policyfile
          else
            config[:attributes].merge(:run_list => config[:run_list])
          end

          info("Preparing dna.json")
          debug("Creating dna.json from #{dna.inspect}")

          File.open(File.join(sandbox_path, "dna.json"), "wb") do |file|
            file.write(dna.to_json)
          end
        end

        def update_dna_for_policyfile
          if !config[:run_list].nil? && !config[:run_list].empty?
            warn("You must set your run_list in your policyfile instead of "\
                 "kitchen config. The run_list in your config will be ignored.")
            warn("Ignored run_list: #{config[:run_list].inspect}")
          end
          policylock = policyfile.gsub(/\.rb\Z/, ".lock.json")
          unless File.exist?(policylock)
            Kitchen.mutex.synchronize do
              Chef::Policyfile.new(policyfile, sandbox_path, logger).compile
            end
          end
          policy_name = JSON.parse(IO.read(policylock))["name"]
          policy_group = "local"
          config[:attributes].merge(:policy_name => policy_name, :policy_group => policy_group)
        end

        # Performs a Policyfile cookbook resolution inside a common mutex.
        #
        # @api private
        def resolve_with_policyfile
          Kitchen.mutex.synchronize do
            Chef::Policyfile.new(policyfile, sandbox_path, logger).resolve
          end
        end

        # Performs a Berkshelf cookbook resolution inside a common mutex.
        #
        # @api private
        def resolve_with_berkshelf
          Kitchen.mutex.synchronize do
            Chef::Berkshelf.new(berksfile, tmpbooks_dir, logger).resolve
          end
        end

        # Performs a Librarin-Chef cookbook resolution inside a common mutex.
        #
        # @api private
        def resolve_with_librarian
          Kitchen.mutex.synchronize do
            Chef::Librarian.new(cheffile, tmpbooks_dir, logger).resolve
          end
        end

        # @return [String] an absolute path to a site-cookbooks/ directory,
        #   relative to the kitchen root
        # @api private
        def site_cookbooks_dir
          File.join(config[:kitchen_root], "site-cookbooks")
        end

        # @return [String] an absolute path to a cookbooks/ directory in the
        #   sandbox path
        # @api private
        def tmpbooks_dir
          File.join(sandbox_path, "cookbooks")
        end

        # @return [String] an absolute path to a site cookbooks directory in the
        #   sandbox path
        # @api private
        def tmpsitebooks_dir
          File.join(sandbox_path, "cookbooks")
        end

      end
    end
  end
end