Module: Bakong::Khqr::Controllers::DecodeValidation

Defined in:
lib/bakong/khqr/controllers/decode_validation.rb

Overview

Walks a candidate KHQR string TLV-by-TLV, instantiating each tag’s validator class. Used by ‘verify` after the CRC check passes.

Class Method Summary collapse

Class Method Details

.call(khqr_string) ⇒ Object 



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# File 'lib/bakong/khqr/controllers/decode_validation.rb', line 18

def call(khqr_string)
  all_fields = KHQR_TAG.map { |el| el[:tag] }
  subtag_set = KHQR_TAG.select { |el| el[:sub] }.map { |el| el[:tag] }
  required_fields = KHQR_TAG.select { |el| el[:required] }.map { |el| el[:tag] }
  sub_tag_input = KHQR_SUBTAG[:input]
  sub_tag_compare = KHQR_SUBTAG[:compare]

  tags = []
  merchant_type = "individual"
  last_tag = ""
  remainder = khqr_string

  until remainder.nil? || remainder.empty?
    slice = Helpers::CutString.call(remainder)
    tag = slice[:tag]
    value = slice[:value]
    remainder = slice[:remainder]

    break if tag == last_tag

    if tag == "30"
      merchant_type = "merchant"
      tag = "29"
    end

    if all_fields.include?(tag)
      tags << { tag: tag, value: value }
      required_fields.delete(tag)
    end

    last_tag = tag
  end

  if tags.any? { |t| t[:tag] == "01" && t[:value] == "12" }
    raise Error.from(ERROR_CODES[:INVALID_DYNAMIC_KHQR]) unless tags.any? { |t| t[:tag] == "54" }
    raise Error.from(ERROR_CODES[:EXPIRATION_TIMESTAMP_REQUIRED]) unless tags.any? { |t| t[:tag] == "99" }
  end

  if tags.any? { |t| t[:tag] == "54" } && tags.none? { |t| t[:tag] == "99" }
    raise Error.from(ERROR_CODES[:EXPIRATION_TIMESTAMP_REQUIRED])
  end

  unless required_fields.empty?
    required_tag = required_fields.first
    missing_instance = KHQR_TAG.find { |el| el[:tag] == required_tag }[:instance]
    missing_instance.new(required_tag, nil) # raises with the proper error
  end

  decode_value = { merchant_type: merchant_type }
  sub_tag_input.each { |el| decode_value.merge!(el[:data]) }

  poi = nil
  tags.each do |khqr_tag|
    tag = khqr_tag[:tag]
    schema = KHQR_TAG.find { |el| el[:tag] == tag }
    value = khqr_tag[:value]
    input_value = value
    poi = value if tag == EMV[:POINT_OF_INITIATION_METHOD]

    if subtag_set.include?(tag)
      input_data_template = sub_tag_input.find { |el| el[:tag] == tag }[:data]
      input_data = deep_dup(input_data_template)

      while value && !value.empty?
        cut = Helpers::CutString.call(value)
        sub_tag = cut[:tag]
        sub_value = cut[:value]
        value = cut[:remainder]

        name_subtag = sub_tag_compare
                      .select { |el| el[:tag] == tag }
                      .find { |el| el[:sub_tag] == sub_tag }

        next unless name_subtag

        input_data[name_subtag[:name]] = sub_value
        input_value = input_data
      end

      decode_value.merge!(input_value) if input_value.is_a?(Hash)

      if tag == EMV[:TIMESTAMP_TAG]
        schema[:instance].new(tag, input_value, poi)
      else
        schema[:instance].new(tag, input_value)
      end
    else
      instance = schema[:instance].new(tag, input_value)
      decode_value[schema[:type]] = instance.value
    end
  end

  decode_value
end

.deep_dup(hash) ⇒ Object 



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# File 'lib/bakong/khqr/controllers/decode_validation.rb', line 113

def deep_dup(hash)
  hash.each_with_object({}) { |(k, v), acc| acc[k] = v.is_a?(Hash) ? deep_dup(v) : v }
end