Maybe/app/models/entry_search.rb

class EntrySearch
  include ActiveModel::Model
  include ActiveModel::Attributes

  attribute :search, :string
  attribute :amount, :string
  attribute :amount_operator, :string
  attribute :types, :string
  attribute :accounts, array: true
  attribute :account_ids, array: true
  attribute :start_date, :string
  attribute :end_date, :string

  class << self
    def apply_search_filter(scope, search)
      return scope if search.blank?

      query = scope
      query = query.where("entries.name ILIKE :search",
        search: "%#{ActiveRecord::Base.sanitize_sql_like(search)}%"
      )
      query
    end

    def apply_date_filters(scope, start_date, end_date)
      return scope if start_date.blank? && end_date.blank?

      query = scope
      query = query.where("entries.date >= ?", start_date) if start_date.present?
      query = query.where("entries.date <= ?", end_date) if end_date.present?
      query
    end

    def apply_amount_filter(scope, amount, amount_operator)
      return scope if amount.blank? || amount_operator.blank?

      query = scope

      case amount_operator
      when "equal"
        query = query.where("ABS(ABS(entries.amount) - ?) <= 0.01", amount.to_f.abs)
      when "less"
        query = query.where("ABS(entries.amount) < ?", amount.to_f.abs)
      when "greater"
        query = query.where("ABS(entries.amount) > ?", amount.to_f.abs)
      end

      query
    end

    def apply_accounts_filter(scope, accounts, account_ids)
      return scope if accounts.blank? && account_ids.blank?

      query = scope
      query = query.where(accounts: { name: accounts }) if accounts.present?
      query = query.where(accounts: { id: account_ids }) if account_ids.present?
      query
    end
  end

  def build_query(scope)
    query = scope.joins(:account)
    query = self.class.apply_search_filter(query, search)
    query = self.class.apply_date_filters(query, start_date, end_date)
    query = self.class.apply_amount_filter(query, amount, amount_operator)
    query = self.class.apply_accounts_filter(query, accounts, account_ids)
    query
  end
end