kf8a/alpkem

# frozen_string_literal: true

# Helper class to parse files for Run data
module Parsers
  # Parses incoming data files
  class FileParser
    attr_accessor :load_errors, :plot_errors, :measurements, :plot,
                  :sample, :sample_type_id, :sample_date

    def initialize(date, id)
      self.sample_date = date
      self.sample_type_id = id
      self.plot_errors = ""
      self.load_errors = ""
      self.measurements = []
      @no3_analyte = Analyte.find_by(name: "NO3")
      @nh4_analyte = Analyte.find_by(name: "NH4")
      @nitrogen_analyte = Analyte.find_by(name: "N")
      @carbon_analyte = Analyte.find_by(name: "C")
    end

    # subclasses need to implement this
    def process_line(_line)
      raise NotImplementedError
    end

    # this takes a file object not a string
    def parse_file(file)
      if file && !file.instance_of?(String)
        parse_contents(file)
      elsif file.instance_of?(String)
        data = File.read(file)
        parse_contents(data)
      else
        self.load_errors = "No file was selected to upload."
      end
    end

    def parse_contents(file)
      file_contents = StringIO.new(file)

      require_data(file_contents)
      require_sample_type_id
      require_sample_date
      parse_data(file_contents) if load_errors.blank?
    end

    # subclasses should override this if they need to specifiy
    # different line parsers for the sample type
    def parse_data(data)
      data.each { |line| process_line(line) }
      return unless measurements.blank?

      self.load_errors += "No data was able to be loaded from this file."
    end

    def find_plot(plot_to_find)
      self.plot = Plot.find_by(name: plot_to_find)
      self.plot_errors += "There is no plot named #{plot_to_find}" unless plot.present?
    end

    def find_or_create_sample
      find_sample(sample_date, sample_type_id) unless sample_already_found?
      sample ? unapprove_sample : create_sample(sample_date, sample_type_id, plot)
    end

    def find_sample(sample_date, sample_type_id)
      self.sample = plot.samples.find_by(sample_date: sample_date, sample_type_id: sample_type_id)
    end

    def create_sample(sample_date, sample_type_id, plot)
      self.sample = Sample.create(sample_date: sample_date,
                                  plot: plot,
                                  sample_type_id: sample_type_id)
    end

    private

    def require_sample_type_id
      self.load_errors += "No Sample Type selected." unless sample_type_id
    end

    def require_sample_date
      self.load_errors += "No Sample Date selected." unless sample_date
    end

    def require_data(data)
      # false positive stringio does not have an empty method
      self.load_errors += "Data file is empty."      if data.length == 0
    end

    def cn_plot_name_ok?
      !@plot_name.blank? &&
        !@plot_name.include?("Standard") &&
        !@plot_name.include?("Blindstd")
    end

    def process_cn_sample
      format_sample_date if sample_date.instance_of?(String)
      find_or_create_sample
      create_measurement(@percent_n, @nitrogen_analyte) unless @percent_n.blank?
      create_measurement(@percent_c, @carbon_analyte) unless @percent_c.blank?
    end

    def format_sample_date
      self.sample_date = Date.strptime(sample_date, "%m/%d/%Y")
    end

    def unapprove_sample
      sample.unapprove # New data makes sample unapproved
    end

    def sample_already_found?
      sample && right_plot? && right_date?
    end

    def right_plot?
      sample.plot == plot
    end

    def right_date?
      sample.sample_date == sample_date
    end

    def process_nhno_sample(nh4_amount, no3_amount)
      find_or_create_sample
      create_measurement(nh4_amount, @nh4_analyte) unless nh4_amount.blank?
      create_measurement(no3_amount, @no3_analyte) unless no3_amount.blank?
    end

    def create_measurement(amount, analyte)
      measurement = Measurement.new(analyte: analyte, amount: amount)
      sample.measurements  << measurement
      measurements         << measurement
    end
  end
end