require "digest/md5"
require "securerandom"
require "set"

require "log4r"

require "vagrant/util/counter"

require_relative "base"

module VagrantPlugins
  module Chef
    module Provisioner
      # This class implements provisioning via chef-zero.
      class ChefZero < Base
        extend Vagrant::Util::Counter
        include Vagrant::Util::Counter
        include Vagrant::Action::Builtin::MixinSyncedFolders

        attr_reader :environments_folders
        attr_reader :cookbook_folders
        attr_reader :role_folders
        attr_reader :data_bags_folders

        def initialize(machine, config)
          super
          @logger = Log4r::Logger.new("vagrant::provisioners::chef_zero")
          @shared_folders = []
        end

        def configure(root_config)
          @cookbook_folders  = expanded_folders(@config.cookbooks_path, "cookbooks")
          @role_folders      = expanded_folders(@config.roles_path, "roles")
          @data_bags_folders = expanded_folders(@config.data_bags_path, "data_bags")
          @environments_folders = expanded_folders(@config.environments_path, "environments")

          existing = synced_folders(@machine, cached: true)
          share_folders(root_config, "csc", @cookbook_folders, existing)
          share_folders(root_config, "csr", @role_folders, existing)
          share_folders(root_config, "csdb", @data_bags_folders, existing)
          share_folders(root_config, "cse", @environments_folders, existing)
        end

        def provision(mode = :client)
          install_chef
          # Verify that the proper shared folders exist.
          check = []
          @shared_folders.each do |type, local_path, remote_path|
            # We only care about checking folders that have a local path, meaning
            # they were shared from the local machine, rather than assumed to
            # exist on the VM.
            check << remote_path if local_path
          end

          chown_provisioning_folder
          verify_shared_folders(check)
          verify_binary(chef_binary_path("chef-client"))
          upload_encrypted_data_bag_secret
          setup_json
          setup_zero_config
          run_chef(mode)
          delete_encrypted_data_bag_secret
        end

        # Converts paths to a list of properly expanded paths with types.
        def expanded_folders(paths, appended_folder=nil)
          # Convert the path to an array if it is a string or just a single
          # path element which contains the folder location (:host or :vm)
          paths = [paths] if paths.is_a?(String) || paths.first.is_a?(Symbol)

          results = []
          paths.each do |type, path|
            # Create the local/remote path based on whether this is a host
            # or VM path.
            local_path = nil
            remote_path = nil
            if type == :host
              # Get the expanded path that the host path points to
              local_path = File.expand_path(path, @machine.env.root_path)

              if File.exist?(local_path)
                # Path exists on the host, setup the remote path. We use
                # the MD5 of the local path so that it is predictable.
                key         = Digest::MD5.hexdigest(local_path)
                remote_path = "#{@config.provisioning_path}/#{key}"
              else
                @machine.ui.warn(I18n.t("vagrant.provisioners.chef.cookbook_folder_not_found_warning",
                                       path: local_path.to_s))
                next
              end
            else
              # Path already exists on the virtual machine. Expand it
              # relative to where we're provisioning.
              remote_path = File.expand_path(path, @config.provisioning_path)

              # Remove drive letter if running on a windows host. This is a bit
              # of a hack but is the most portable way I can think of at the moment
              # to achieve this. Otherwise, Vagrant attempts to share at some crazy
              # path like /home/vagrant/c:/foo/bar
              remote_path = remote_path.gsub(/^[a-zA-Z]:/, "")
            end

            # If we have specified a folder name to append then append it
            remote_path += "/#{appended_folder}" if appended_folder

            # Append the result
            results << [type, local_path, remote_path]
          end

          results
        end

        # Shares the given folders with the given prefix. The folders should
        # be of the structure resulting from the `expanded_folders` function.
        def share_folders(root_config, prefix, folders, existing=nil)
          existing_set = Set.new
          (existing || []).each do |_, fs|
            fs.each do |id, data|
              existing_set.add(data[:guestpath])
            end
          end

          folders.each do |type, local_path, remote_path|
            next if type != :host

            # If this folder already exists, then we don't share it, it means
            # it was already put down on disk.
            if existing_set.include?(remote_path)
              @logger.debug("Not sharing #{local_path}, exists as #{remote_path}")
              next
            end

            opts = {}
            opts[:id] = "v-#{prefix}-#{self.class.get_and_update_counter(:shared_folder)}"
            opts[:type] = @config.synced_folder_type if @config.synced_folder_type

            root_config.vm.synced_folder(local_path, remote_path, opts)
          end

          @shared_folders += folders
        end

        def setup_zero_config
          setup_config("provisioners/chef_zero/zero", "client.rb", {
            local_mode: true,
            enable_reporting: false,
            cookbooks_path: guest_paths(@cookbook_folders),
            roles_path: guest_paths(@role_folders),
            data_bags_path: guest_paths(@data_bags_folders).first,
            environments_path: guest_paths(@environments_folders).first,
          })
        end

        def run_chef(mode)
          if @config.run_list && @config.run_list.empty?
            @machine.ui.warn(I18n.t("vagrant.chef_run_list_empty"))
          end

          if @machine.guest.capability?(:wait_for_reboot)
            @machine.guest.capability(:wait_for_reboot)
          end

          command = build_command(:client)

          @config.attempts.times do |attempt|
            if attempt == 0
              @machine.ui.info I18n.t("vagrant.provisioners.chef.running_#{mode}")
            else
              @machine.ui.info I18n.t("vagrant.provisioners.chef.running_#{mode}_again")
            end

            opts = { error_check: false, elevated: true }
            exit_status = @machine.communicate.sudo(command, opts) do |type, data|
              # Output the data with the proper color based on the stream.
              color = type == :stdout ? :green : :red

              data = data.chomp
              next if data.empty?

              @machine.ui.info(data, color: color)
            end

            # There is no need to run Chef again if it converges
            return if exit_status == 0
          end

          # If we reached this point then Chef never converged! Error.
          raise ChefError, :no_convergence
        end

        def verify_shared_folders(folders)
          folders.each do |folder|
            @logger.debug("Checking for shared folder: #{folder}")
            if !@machine.communicate.test("test -d #{folder}", sudo: true)
              raise ChefError, :missing_shared_folders
            end
          end
        end

        protected

        # Extracts only the remote paths from a list of folders
        def guest_paths(folders)
          folders.map { |parts| parts[2] }
        end
      end
    end
  end
end