KeyDB

keydb.rb

module KeyDB
  class DB
    # Makes filename and version into attributes
    attr_reader :filename, :version
    # Global version variable
    $KEYDB_VERSION = "5.0.0"

    def initialize filename
      # Makes sure the filename ends in .db
      @filename = filename.split(".")
      @filename = "#{@filename[0]}.db"
      # Checks if file exists
      unless Dir.entries('.').detect {|f| f.match "#{@filename}"}
        @db_file = File.new(@filename, "w")
        @db_file.close
      end
    end

    def change_key keyname, value
      @db_file = File.open(@filename, "a")
      # Writes a changekey sequence
      @db_file.write(Marshal.dump("CK-***-#{keyname}-***-#{value}"))
      @db_file.write("\n")
      @db_file.close
    end

    def delete_key keyname
      @db_file = File.open(@filename, "a")
      # Writes a deletekey sequence
      @db_file.write(Marshal.dump("DK(---)#{keyname}"))
      @db_file.write("\n")
      @db_file.close
    end

    def to_s
      # Returns a string representation
      return "KeyDB-#{@filename}"
    end

    def keys
      # Creates a new array of keys to ignore
      to_ignore = Array.new
      File.open(@filename).each_line do |line|
        if Marshal.load(line).split("(---)")[1] != nil
          # Pushes deleted keys
          to_ignore.push(Marshal.load(line).split("(---)")[1])
        elsif Marshal.load(line).split("-***-")[1] != nil
          # Pushes changed keys
          to_ignore.push(Marshal.load(line).split("-***-")[1])
        end
      end
      puts to_ignore
      File.open(@filename).each_line do |line|
        line = Marshal.load(line)
        @keys_and_vals = line.split('///')
        # Checks if key is ignored
        if line.split("(---)").length == 2 or to_ignore.include? line.split("///")[0]
          print
        elsif to_ignore.include? line.split("-***-")[1] 
          print  
        else
          # Prints valid keys
          puts @keys_and_vals[0]
        end
      end
    end

    def delete_db
      # Deletes the database
      system("rm #{@filename}")
    end

    def wipe_db
      # Creates a new, clean database
      delete_db
      File.new(@filename, "w")
    end

    def method_missing(keyname, *value)
      # Converts the keyname (method) to a string
      keyname = keyname.to_s
      # Checks if it is an accessor method
      if keyname =~ /=/
        keyname.gsub!("=", "")
        value = value[0]
        # Validates the keyname
        if keyname =~ /\/\/\/|\(---\)|-\*\*\*-/
          raise "Invalid Keyname!"
          return
        end
        File.open(@filename, "r").each_line do |line|
          if Marshal.load(line).split("///")[0] == keyname
            # Checks key for uniqueness
            raise "Keynames must be unique"
            return
          end
        end
        @db_file = File.open(@filename, "a")
        # Writes key
        @db_file.write(Marshal.dump("#{keyname}///#{value}"))
        @db_file.write("\n")
        @db_file.close
      else
        File.open(@filename, "r").each_line do |line|
          # Checks if key has been deleted
          if Marshal.load(line).split("(---)")[1] == keyname
            return "Key has been deleted"
          # Checks for a changekey sequence
          elsif Marshal.load(line).split("-***-")[1] == keyname
            return Marshal.load(line).split("-***-")[2]
          end
        end
        File.open(@filename, "r").each_line do |line|
          line = Marshal.load(line)
          # Returns unchanged, undeleted keys
          if line.split("///")[0] == keyname
            return line.split("///")[1]
          end
        end
      end 
    end
  end
end