Handle SQLite date subtraction

lib/rails_ext/active_record_date_arithmetic.rb

@@ -0,0 +1,53 @@
+# frozen_string_literal: true
+
+# Adds database-agnostic date arithmetic methods to ActiveRecord adapters.
+# This allows code to perform date calculations without checking which database adapter is in use.
+#
+# Usage:
+#   connection.date_subtract("created_at", "3600")
+#   # MySQL/Trilogy: "DATE_SUB(created_at, INTERVAL 3600 SECOND)"
+#   # SQLite: "datetime(created_at, '-' || (3600) || ' seconds')"
+
+# Module for MySQL-based adapters (Trilogy, Mysql2, etc.)
+module MysqlDateArithmetic
+  # Generates SQL for subtracting seconds from a date/time column in MySQL.
+  #
+  # @param date_column [String] The date/time column or expression
+  # @param seconds_expression [String] SQL expression that evaluates to number of seconds
+  # @return [String] MySQL DATE_SUB expression
+  #
+  # Example:
+  #   date_subtract("last_active_at", "COALESCE(auto_postpone_period, 3600)")
+  #   # => "DATE_SUB(last_active_at, INTERVAL COALESCE(auto_postpone_period, 3600) SECOND)"
+  def date_subtract(date_column, seconds_expression)
+    "DATE_SUB(#{date_column}, INTERVAL #{seconds_expression} SECOND)"
+  end
+end
+
+# Module for SQLite adapter
+module SqliteDateArithmetic
+  # Generates SQL for subtracting seconds from a date/time column in SQLite.
+  #
+  # @param date_column [String] The date/time column or expression
+  # @param seconds_expression [String] SQL expression that evaluates to number of seconds
+  # @return [String] SQLite datetime expression
+  #
+  # Example:
+  #   date_subtract("last_active_at", "COALESCE(auto_postpone_period, 3600)")
+  #   # => "datetime(last_active_at, '-' || (COALESCE(auto_postpone_period, 3600)) || ' seconds')"
+  def date_subtract(date_column, seconds_expression)
+    "datetime(#{date_column}, '-' || (#{seconds_expression}) || ' seconds')"
+  end
+end
+
+ActiveSupport.on_load(:active_record) do
+  # Prepend MySQL date arithmetic to AbstractMysqlAdapter (covers Trilogy, Mysql2, etc.)
+  if defined?(ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter)
+    ActiveRecord::ConnectionAdapters::AbstractMysqlAdapter.prepend(MysqlDateArithmetic)
+  end
+
+  # Prepend SQLite date arithmetic to SQLite3Adapter
+  if defined?(ActiveRecord::ConnectionAdapters::SQLite3Adapter)
+    ActiveRecord::ConnectionAdapters::SQLite3Adapter.prepend(SqliteDateArithmetic)
+  end
+end