require 'csv'

module Redmine
  class CsvBaseService
    API_LOCATION = 'https://redmine.renuo.ch'.freeze

    def initialize(token)
      @token = token
    end

    def get
      http_response = http_request(generate_url)
      encoded_body = http_response.body.force_encoding('ISO-8859-1').encode('UTF-8')
      csv = parse_csv(encoded_body)
      parse_results(csv)
    end

    private

    def generate_url
      URI("#{API_LOCATION}/time_entries/report.csv?#{query}&key=#{@token}")
    end

    def http_request(url)
      req = Net::HTTP::Get.new(url)
      Net::HTTP.start(url.hostname, url.port, use_ssl: true) do |http|
        http.request(req)
      end
    end

    def query
      # to be implemented in concrete service
    end

    def parse_results(_csv)
      # to be implemented in concrete service
    end

    def parse_csv(body)
      separated_csv_entries = CSV.parse(body, col_sep: ',')
      keys = separated_csv_entries.shift[1..-2]
      entries = separated_csv_entries.shift[1..-2]
      Hash[keys.zip(entries)]
    rescue CSV::MalformedCSVError
      raise_bad_data_error
    end

    def raise_bad_data_error
      error = 'Malformed CSV, please use comma delimiters (Redmine language setting?)'
      Rails.logger.error error
      raise Redmine::BadData, error
    end
  end
end