module Eco
  module API
    module Common
      module Session
        class FileManager

          include Eco::Data::Files

          attr_reader :dir, :dir_path
          attr_accessor :timestamp_pattern

          def initialize(init = {}, enviro: nil)
            @enviro = enviro
            init = @enviro.config if @enviro && init.empty?
            @timestamp_pattern = init.files.timestamp_pattern || DEFAULT_TIMESTAMP_PATTERN
            self.dir_path = init.files.working_directory || Dir.pwd
          end

          def dir_path=(value)
            begin
              @dir = Eco::Data::Files::Directory.new(value)
              @dir_path = @dir.create
            rescue
              logger.error("could not create or make any sense of directory '#{value}'")
            end
          end

          def logger
            @enviro&.logger || ::Logger.new(IO::NULL)
          end

          #####    FILE   #####
          def file(filename, should_exist: false)
            dir.file(filename, should_exist: should_exit)
          end

          def newest(filename)
            dir.newest_file(file: filename)
          end

          def file_content(filename)
            file = dir.file(filename, should_exist: true)
            if !file
              logger.error("Can't read from file '#{filename}' because it does not exist.")
              return nil
            end
            logger.debug("Reading from file '#{file}'")
            File.read(file)
          end

          def load_json(filename)
            content = file_content(filename)
            return content && JSON.parse(content)
          end

          def touch(filename, modifier = :no_stamp, mode: :string)
            save("", filename, modifier, mode: mode)
          end

          def save(content, filename, modifier = :no_stamp, mode: :string)
            file = dir.file(filename)
            file = FileManager.timestamp_file(file) if modifier == :timestamp
            mode = (mode == :binary) ? 'wb' : 'w'

            FileManager.create_directory(FileManager.file_fullpath(file))

            logger.debug("Writting to file '#{file}'")
            File.open(file, mode) { |fd| fd << content }
            return file
          end

          def save_json(data, filename, modifier = :no_stamp)
            return save(data.to_json, filename, modifier)
          end

          # if the file does not exist, it creates it
          def append(content, filename, mode: :string)
            file = dir.file(filename)
            mode = (mode == :binary) ? 'ab' : 'a'

            logger.debug("Appending to file '#{file}'")
            File.open(file, mode) { |fd| fd << content + "\n" } # '\n' won't add line
            return file
          end

        end
      end
    end
  end
end