module ActiveRecord::ConnectionAdapters::PostgreSQL::DatabaseStatements

def affected_rows(result)
  affected_rows = result.cmd_tuples
  result.clear
  affected_rows
end

def begin_db_transaction # :nodoc:
  internal_execute("BEGIN", "TRANSACTION", allow_retry: true, materialize_transactions: false)
end

def begin_isolated_db_transaction(isolation) # :nodoc:
  internal_execute("BEGIN ISOLATION LEVEL #{transaction_isolation_levels.fetch(isolation)}", "TRANSACTION", allow_retry: true, materialize_transactions: false)
end

def build_explain_clause(options = [])
  return "EXPLAIN" if options.empty?
  "EXPLAIN (#{options.join(", ").upcase})"
end

def build_truncate_statements(table_names)
  ["TRUNCATE TABLE #{table_names.map(&method(:quote_table_name)).join(", ")}"]
end

def cancel_any_running_query
  return if @raw_connection.nil? || IDLE_TRANSACTION_STATUSES.include?(@raw_connection.transaction_status)
  @raw_connection.cancel
  @raw_connection.block
rescue PG::Error
end

def cast_result(result)
  if result.fields.empty?
    result.clear
    return ActiveRecord::Result.empty
  end
  types = {}
  fields = result.fields
  fields.each_with_index do |fname, i|
    ftype = result.ftype i
    fmod  = result.fmod i
    types[fname] = types[i] = get_oid_type(ftype, fmod, fname)
  end
  ar_result = ActiveRecord::Result.new(fields, result.values, types.freeze)
  result.clear
  ar_result
end

def commit_db_transaction # :nodoc:
  internal_execute("COMMIT", "TRANSACTION", allow_retry: false, materialize_transactions: true)
end

def exec_insert(sql, name = nil, binds = [], pk = nil, sequence_name = nil, returning: nil) # :nodoc:
  if use_insert_returning? || pk == false
    super
  else
    result = internal_exec_query(sql, name, binds)
    unless sequence_name
      table_ref = extract_table_ref_from_insert_sql(sql)
      if table_ref
        pk = primary_key(table_ref) if pk.nil?
        pk = suppress_composite_primary_key(pk)
        sequence_name = default_sequence_name(table_ref, pk)
      end
      return result unless sequence_name
    end
    last_insert_id_result(sequence_name)
  end
end

def exec_restart_db_transaction # :nodoc:
  cancel_any_running_query
  internal_execute("ROLLBACK AND CHAIN", "TRANSACTION", allow_retry: false, materialize_transactions: true)
end

def exec_rollback_db_transaction # :nodoc:
  cancel_any_running_query
  internal_execute("ROLLBACK", "TRANSACTION", allow_retry: false, materialize_transactions: true)
end

def execute(...) # :nodoc:
  super
ensure
  @notice_receiver_sql_warnings = []
end

def execute_batch(statements, name = nil, **kwargs)
  raw_execute(combine_multi_statements(statements), name, batch: true, **kwargs)
end

def explain(arel, binds = [], options = [])
  sql    = build_explain_clause(options) + " " + to_sql(arel, binds)
  result = internal_exec_query(sql, "EXPLAIN", binds)
  PostgreSQL::ExplainPrettyPrinter.new.pp(result)
end

def handle_warnings(sql)
  @notice_receiver_sql_warnings.each do |warning|
    next if warning_ignored?(warning)
    warning.sql = sql
    ActiveRecord.db_warnings_action.call(warning)
  end
end

def high_precision_current_timestamp
  HIGH_PRECISION_CURRENT_TIMESTAMP
end

def last_insert_id_result(sequence_name)
  internal_exec_query("SELECT currval(#{quote(sequence_name)})", "SQL")
end

def perform_query(raw_connection, sql, binds, type_casted_binds, prepare:, notification_payload:, batch: false)
  update_typemap_for_default_timezone
  result = if prepare
    begin
      stmt_key = prepare_statement(sql, binds, raw_connection)
      notification_payload[:statement_name] = stmt_key
      raw_connection.exec_prepared(stmt_key, type_casted_binds)
    rescue PG::FeatureNotSupported => error
      if is_cached_plan_failure?(error)
        # Nothing we can do if we are in a transaction because all commands
        # will raise InFailedSQLTransaction
        if in_transaction?
          raise PreparedStatementCacheExpired.new(error.message, connection_pool: @pool)
        else
          @lock.synchronize do
            # outside of transactions we can simply flush this query and retry
            @statements.delete sql_key(sql)
          end
          retry
        end
      end
      raise
    end
  elsif binds.nil? || binds.empty?
    raw_connection.async_exec(sql)
  else
    raw_connection.exec_params(sql, type_casted_binds)
  end
  verified!
  handle_warnings(result)
  notification_payload[:row_count] = result.count
  result
end

def query(sql, name = nil) # :nodoc:
  result = internal_execute(sql, name)
  result.map_types!(@type_map_for_results).values
end

def returning_column_values(result)
  result.rows.first
end

def set_constraints(deferred, *constraints)
  unless %i[deferred immediate].include?(deferred)
    raise ArgumentError, "deferred must be :deferred or :immediate"
  end
  constraints = if constraints.empty?
    "ALL"
  else
    constraints.map { |c| quote_table_name(c) }.join(", ")
  end
  execute("SET CONSTRAINTS #{constraints} #{deferred.to_s.upcase}")
end

def suppress_composite_primary_key(pk)
  pk unless pk.is_a?(Array)
end

def warning_ignored?(warning)
  ["WARNING", "ERROR", "FATAL", "PANIC"].exclude?(warning.level) || super
end

def write_query?(sql) # :nodoc:
  !READ_QUERY.match?(sql)
rescue ArgumentError # Invalid encoding
  !READ_QUERY.match?(sql.b)
end