require 'time'

require 'nukumi2/entry'

class FileBackend
  class Parser
    def self.parse(io)
      entry = Nukumi2::Entry.new

      fields = {}

      while line = io.gets
        line.chomp!
        break  if line.empty?

        if line =~ /^(\w\S+?):\s*(.*)/
          field = $1.downcase
          fields[field] = $2
        elsif field
          fields[field] << " " << line.lstrip
        end
      end
      
      fields.each { |field, value|
        case field
        when "category"
          entry.categories.concat value.split.map { |c| c.strip }
        when "date"
          entry.time = Time.parse value
        when "subject"
          entry.title = value
        else
          if entry.respond_to? field + "="
            entry.send field + "=", value
          else
            entry.fields[field] = value
          end
        end
      }

      entry.content = io.read

      entry
    end
  end

  def self.load(file)
    file = file.backend_data  if file.kind_of? Nukumi2::Entry

    File.open(file) { |handle|
      entry = Parser.parse handle
      entry.change_time = handle.mtime
      entry.backend = self
      entry.backend_data = File.expand_path(file)
      entry
    }
  end

  def self.outdated?(entry)
    File.mtime(entry.backend_data) != entry.change_time
  end

  def initialize(dir)
    @dir = File.expand_path dir
  end

  def get
    Dir[File.join(@dir, "**/*")].map { |file|
      if File.file? file and File.readable? file
        if file =~ /~$/         # Backup file?
          nil
        else
          self.class.load file
        end
      end
    }.compact.uniq
  end
end