module AdventureRL
  module Helpers
    module Error
      PADDING = '  '
      STACK_TRACE_SIZE    = 20
      STACK_TRACE_PADDING = 1

      def self.error *messages
        message = messages.join ?\n
        message.gsub! /^/, PADDING
        stack_trace_lines = caller[STACK_TRACE_PADDING ... (STACK_TRACE_SIZE + STACK_TRACE_PADDING)].map do |line|
          next "#{PADDING}#{line}"
        end .reverse
        abort([
          "#{DIR[:entry].to_s} Error:",
          message,
          "#{PADDING}Exiting.",
          "Stack traceback (most recent call last):",
          stack_trace_lines
        ].flatten.join(?\n))
      end

      def self.error_no_file file
        filepath = file
        filepath = file.to_path  if (file.is_a? Pathname)
        error "File does not exist, or is a directory:", "  '#{filepath}'"
      end

      def self.error_no_directory directory
        dirpath = directory
        dirpath = directory.to_path  if (directory.is_a? Pathname)
        error "Directory does not exist, or is a file:", "  '#{dirpath}'"
      end

      def self.file_exists? file
        return false  unless (file)
        return File.file? file
      end

      def self.directory_exists? directory
        return false  unless (directory)
        return File.directory? directory
      end

      private

        def error *messages
          AdventureRL::Helpers::Error.error *messages
        end

        def error_no_file file
          AdventureRL::Helpers::Error.error_no_file file
        end

        def error_no_directory directory
          AdventureRL::Helpers::Error.error_no_directory directory
        end

        def file_exists? file
          return AdventureRL::Helpers::Error.file_exists? file
        end

        def directory_exists? directory
          return AdventureRL::Helpers::Error.directory_exists? directory
        end
    end
  end
end