# encoding: ascii-8bit

# Copyright 2024 OpenC3, Inc.
# All Rights Reserved.
#
# This program is free software; you can modify and/or redistribute it
# under the terms of the GNU Affero General Public License
# as published by the Free Software Foundation; version 3 with
# attribution addendums as found in the LICENSE.txt
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# This file may also be used under the terms of a commercial license
# if purchased from OpenC3, Inc.

require 'openc3/conversions/conversion'

module OpenC3
  class BitReverseConversion < Conversion
    def initialize(converted_type, converted_bit_size)
      super()
      @converted_type = converted_type.to_s.upcase.intern
      @converted_bit_size = converted_bit_size.to_i
      if @converted_type == :FLOAT
        raise "Float Bit Reverse Not Yet Supported"
      end
      @params = [@converted_type, @converted_bit_size]
    end

    # Perform the conversion on the value.
    #
    # @param value [Object] The value to convert
    # @param packet [Packet] The packet which contains the value. This can
    #   be useful to reach into the packet and use other values in the
    #   conversion.
    # @param buffer [String] The packet buffer
    # @return The converted value
    def call(value, _packet, _buffer)
      reversed = 0
      @converted_bit_size.times do
        reversed = (reversed << 1) | (value & 1)
        value >>= 1
      end
      return reversed & ((2 ** @converted_bit_size) - 1)
    end

    # @return [String] The conversion class
    def to_s
      "#{self.class.to_s.split('::')[-1]}.new(:#{@converted_type}, #{@converted_bit_size})"
    end

    # @param read_or_write [String] Either 'READ' or 'WRITE'
    # @return [String] Config fragment for this conversion
    def to_config(read_or_write)
      "    #{read_or_write}_CONVERSION #{self.class.name.class_name_to_filename} #{@converted_type} #{@converted_bit_size}\n"
    end
  end
end
