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.working_directory || Dir.pwd
          end

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

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

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

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

          def file_content(filename, mode: nil)
            file = dir.file(filename, should_exist: true)

            unless file
              logger.error("Can't read from file '#{filename}' because it does not exist.")
              return nil
            end

            logger.debug("Reading from file '#{file}'")
            mode ? File.read(file, mode: mode) : File.read(file)
          end

          def load_json(filename)
            file = dir.file(filename, should_exist: true)

            unless file
              logger.error("Can't read from file '#{filename}' because it does not exist.")
              return nil
            end

            fd = File.open(file)
            JSON.load fd # rubocop:disable Security/JSONLoad
          rescue JSON::ParserError => e
            pp "Parsing error on file #{file}"
            raise e
          ensure
            fd&.close
          end

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

          def save_json(data, filename, modifier = :no_stamp)
            return save(data.to_json, filename, modifier) unless data.is_a?(Array)

            file = filename_for(filename, modifier)
            FileManager.create_directory(
              FileManager.file_fullpath(file)
            )

            logger.debug("Writting to file '#{file}'")

            mode = mode == :binary ? 'wb' : 'w'

            File.open(file, mode) do |fd|
              first = true

              fd << '['
              data.each do |elem|
                fd << "," unless first
                first = false

                fd << elem.to_json
              end
              fd << ']'
            end

            file
          end

          def save(content, filename, modifier = :no_stamp, mode: :string)
            file = filename_for(filename, modifier)
            FileManager.create_directory(
              FileManager.file_fullpath(file)
            )

            logger.debug("Writting to file '#{file}'")

            mode = mode == :binary ? 'wb' : 'w'
            File.open(file, mode) { |fd| fd << content }
            file
          end

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

            logger.debug("Appending to file '#{file}'")

            mode = mode == :binary ? 'ab' : 'a'
            File.open(file, mode) { |fd| fd << "#{content}\n" }
            file
          end

          def filename_for(filename, modifier = :no_stamp)
            file = dir.file(filename)
            file = FileManager.timestamp_file(file) if modifier == :timestamp
            file
          end
        end
      end
    end
  end
end