# frozen_string_literal: true

require "csv"

class EnrollmentLoader
  def self.load_data(filepath:)
    enrollments = []
    CSV.parse(File.read(filepath), headers: true) do |row|
      row = EnrollmentRowValues.new(row:)
      next unless row.school.present? && row.academic_year.present?

      enrollments << create_enrollment_entry(row:)
    end

    # It's possible that instead of updating all columns on duplicate key, we could just update the student columns and leave total_teachers alone. Right now enrollment data loads before staffing data so it works correctly.
    Respondent.import enrollments, batch_size: 1000,
                                   on_duplicate_key_update: %i[pk k one two three four five six seven eight nine ten eleven twelve total_students]
  end

  private

  def self.create_enrollment_entry(row:)
    respondent = Respondent.find_or_initialize_by(school: row.school, academic_year: row.academic_year)
    respondent.pk = row.pk
    respondent.k = row.k
    respondent.one = row.one
    respondent.two = row.two
    respondent.three = row.three
    respondent.four = row.four
    respondent.five = row.five
    respondent.six = row.six
    respondent.seven = row.seven
    respondent.eight = row.eight
    respondent.nine = row.nine
    respondent.ten = row.ten
    respondent.eleven = row.eleven
    respondent.twelve = row.twelve
    respondent.total_students = row.total_students
    respondent
  end

  def self.clone_previous_year_data
    years = AcademicYear.order(:range).last(2)
    previous_year = years.first
    current_year = years.last
    respondents = []
    School.all.each do |school|
      Respondent.where(school:, academic_year: previous_year).each do |respondent|
        current_respondent = Respondent.find_or_initialize_by(school:, academic_year: current_year)
        current_respondent.pk = respondent.pk
        current_respondent.k = respondent.k
        current_respondent.one = respondent.one
        current_respondent.two = respondent.two
        current_respondent.three = respondent.three
        current_respondent.four = respondent.four
        current_respondent.five = respondent.five
        current_respondent.six = respondent.six
        current_respondent.seven = respondent.seven
        current_respondent.eight = respondent.eight
        current_respondent.nine = respondent.nine
        current_respondent.ten = respondent.ten
        current_respondent.eleven = respondent.eleven
        current_respondent.twelve = respondent.twelve
        current_respondent.total_students = respondent.total_students
        respondents << current_respondent
      end
    end
    Respondent.import respondents, batch_size: 1000, on_duplicate_key_update: [:total_teachers]
  end

  private_class_method :create_enrollment_entry
end

class EnrollmentRowValues
  attr_reader :row

  def initialize(row:)
    @row = row
  end

  def school
    @school ||= begin
      dese_id = row["DESE ID"].try(:strip).to_i
      School.find_by_dese_id(dese_id)
    end
  end

  def academic_year
    @academic_year ||= begin
      year = row["Academic Year"]
      AcademicYear.find_by_range(year)
    end
  end

  def pk
    row["PK"] || row["pk"]
  end

  def k
    row["K"] || row["k"]
  end

  def one
    row["1"]
  end

  def two
    row["2"]
  end

  def three
    row["3"]
  end

  def four
    row["4"]
  end

  def five
    row["5"]
  end

  def six
    row["6"]
  end

  def seven
    row["7"]
  end

  def eight
    row["8"]
  end

  def nine
    row["9"]
  end

  def ten
    row["10"]
  end

  def eleven
    row["11"]
  end

  def twelve
    row["12"]
  end

  def total_students
    row["Total"].delete(",").to_i
  end
end