class Inspec::WaiverFileReader

def self.fetch_waivers_by_profile(profile_id, files)
  read_waivers_from_file(profile_id, files) if @waivers_data.nil? || @waivers_data[profile_id].nil?
  @waivers_data[profile_id]
end

def self.read_waivers_from_file(profile_id, files)
  @waivers_data ||= {}
  output = {}
  files.each do |file_path|
    file_extension = File.extname(file_path)
    data = nil
    if [".yaml", ".yml"].include? file_extension
      data = Secrets::YAML.resolve(file_path)
      data = data.inputs unless data.nil?
      validate_json_yaml(data)
    elsif file_extension == ".csv"
      data = Waivers::CSVFileReader.resolve(file_path)
      headers = Waivers::CSVFileReader.headers
      validate_headers(headers)
    elsif file_extension == ".json"
      data = Waivers::JSONFileReader.resolve(file_path)
      validate_json_yaml(data)
    end
    output.merge!(data) if !data.nil? && data.is_a?(Hash)
    if data.nil?
      raise Inspec::Exceptions::WaiversFileNotReadable,
          "Cannot find parser for waivers file '#{file_path}'. " \
          "Check to make sure file has the appropriate extension."
    end
  end
  @waivers_data[profile_id] = output
end

def self.validate_headers(headers, json_yaml = false)
  required_fields = json_yaml ? %w{justification} : %w{control_id justification}
  all_fields = %w{control_id justification expiration_date run}
  Inspec::Log.warn "Missing column headers: #{(required_fields - headers)}" unless (required_fields - headers).empty?
  Inspec::Log.warn "Invalid column header: Column can't be nil" if headers.include? nil
  Inspec::Log.warn "Extra column headers: #{(headers - all_fields)}" unless (headers - all_fields).empty?
end

def self.validate_json_yaml(data)
  headers = []
  data.each_value do |value|
    headers.push value.keys
  end
  validate_headers(headers.flatten.uniq, true)
end