module CSVImportable

# File app/models/concerns/csv_importable.rb, line 233
def self.model_name
  ActiveModel::Name.new(
    self,
    nil,
    [@import_type.camelize, @record_type.singularize.camelize].sort.join
  )
end

# File app/models/concerns/csv_importable.rb, line 212
def count_columns
  %i[
    new_record_count
    changed_record_count
    exact_duplicate_record_count
  ].freeze
end

# File app/models/concerns/csv_importable.rb, line 120
def csv
  csv_data
end

# File app/models/concerns/csv_importable.rb, line 100
def csv=(source)
  if persisted?
    raise "Cannot change the CSV file for an existing import. " \
            "Create a new import instead."
  end

  if source.is_a?(ActionDispatch::Http::UploadedFile)
    # CSV files exported from Excel may have a BOM.
    # https://en.wikipedia.org/wiki/Byte_order_mark
    # e.g. if you create a new class import from scratch in Excel on Mac v16,
    # save the file as CSV, and upload it.
    self.csv_data = source.to_io.tap(&:set_encoding_by_bom).read
    self.csv_filename = source&.original_filename
    self.rows_count = csv_data_object&.count
  else
    raise ArgumentError, "Expected an uploaded file, got #{source}"
  end
end

# File app/models/concerns/csv_importable.rb, line 124
def csv_data_object
  @csv_data_object ||= Import::CSVData.new(csv_data)
end

# File app/models/concerns/csv_importable.rb, line 175
def csv_has_records
  return unless csv_data

  csv_has_no_records =
    csv_data_object.empty? ||
      (csv_data_object.count == 1 && csv_data_object.has_instruction_row?)
  errors.add(:csv, :empty) if csv_has_no_records
end

# File app/models/concerns/csv_importable.rb, line 167
def csv_is_not_too_large
  return unless csv_data

  if rows_count > MAX_CSV_ROWS
    errors.add(:csv, :too_many_rows, count: MAX_CSV_ROWS)
  end
end

# File app/models/concerns/csv_importable.rb, line 163
def csv_is_valid
  errors.add(:csv, :invalid) unless csv_data_object.well_formed?
end

# File app/models/concerns/csv_importable.rb, line 128
def csv_removed?
  csv_removed_at != nil
end

# File app/models/concerns/csv_importable.rb, line 220
def ensure_processed_with_count_statistics
  if processed? && count_columns.any? { |column| send(column).nil? }
    raise "Count statistics must be set for a processed import."
  end
end

# File app/models/concerns/csv_importable.rb, line 226
def join_table_class(import_type, record_type)
  Class.new(ApplicationRecord) do
    @import_type = import_type.to_s.pluralize
    @record_type = record_type.to_s

    self.table_name = [@import_type, @record_type.pluralize].sort.join("_")

    def self.model_name
      ActiveModel::Name.new(
        self,
        nil,
        [@import_type.camelize, @record_type.singularize.camelize].sort.join
      )
    end
  end
end

# File app/models/concerns/csv_importable.rb, line 243
def link_records_by_type(type, records)
  import_type = self.class.name.underscore
  type = type.to_s

  join_table_class(import_type, type).import(
    ["#{type.singularize}_id", "#{import_type}_id"],
    records.map(&:id).product([id]).uniq,
    on_duplicate_key_ignore: true
  )
end

# File app/models/concerns/csv_importable.rb, line 153
def load_serialized_errors!(limit: nil)
  return if serialized_errors.blank?

  serialized_errors
    .then { limit ? it.first(limit) : it }
    .each do |attribute, messages|
      messages.each { errors.add(attribute, _1) }
    end
end

# File app/models/concerns/csv_importable.rb, line 132
def parse_rows!
  return if invalid?

  self.rows = csv_data_object.records.map { |row_data| parse_row(row_data) }

  if invalid?
    self.serialized_errors = errors.to_hash
    self.status = :rows_are_invalid
    save!(validate: false)
  end
end

# File app/models/concerns/csv_importable.rb, line 144
def processed?
  processed_at != nil
end

# File app/models/concerns/csv_importable.rb, line 148
def remove!
  return if csv_removed?
  update!(csv_data: nil, csv_removed_at: Time.zone.now)
end

# File app/models/concerns/csv_importable.rb, line 184
def rows_are_valid
  return unless rows

  rows.each(&:validate)

  check_rows_are_unique

  row_offset = csv_data_object.has_instruction_row? ? 3 : 2

  rows.each.with_index do |row, index|
    next if row.errors.empty?

    # The first row is the header and the index is 0-based, so we add two
    # to match what the user sees in the spreadsheet

    formatted_errors =
      row.errors.map do |error|
        if error.attribute == :base
          error.message
        else
          "<code>#{error.attribute}</code>: #{error.message}"
        end
      end

    errors.add("row_#{index + row_offset}".to_sym, formatted_errors)
  end
end