#coding:utf-8

"""
ID:          issue-2454
ISSUE:       2454
TITLE:       I/O statistics for stored procedures are not accounted in monitoring tables
DESCRIPTION:
  We open TWO cursors within the same attachments and:
  1) make query to procedure inside cursor-1 (trivial count from table there);
  2) ask MON$ tables inside cur-2 with aquiring IO statistics (fetches) for cur-1 statement.
  Number of fetches should be not less then 202400 - see results for 2.1.x, 2.5.x and 3.0 below.
NOTES:
[17.12.2016]
  Value of fetches in 3.0.2 and 4.0.0 was significantly reduced (~ twice) since ~25-nov-2016
  See results for: 4.0.0.459 and 3.0.2.32641
  Possible reason:
  https://github.com/FirebirdSQL/firebird/commit/8d5b1ff46ed9f22be4a394b941961c522e063ed1
  https://github.com/FirebirdSQL/firebird/commit/dac882c97e2642e260abef475de75c490c5e4bc7
  "Introduced small per-relation cache of physical numbers of data pages.
  It allows to reduce number of pointer page fetches and improves performance."
[20.1.2022] pcisar
  The number of fetches depends on page size. Test will fail if page_size is not 4096 !!!
JIRA:        CORE-2017
FBTEST:      bugs.core_2017
"""

import pytest
from firebird.qa import *

init_script = """
    create table T (C integer);
    commit;

    set term ^ ;

    execute block
    as
    declare i int = 0;
    begin
      while (i < 100000) do
      begin
        insert into T values (:i);
        i = i + 1;
      end
    end ^
    commit ^

    create procedure sp_test
    returns (i bigint)
    as
    begin
     select count(*)
     from T
     into :i;
     suspend;
    end ^

    commit ^
"""

db = db_factory(page_size=4096, init=init_script)

act = python_act('db')

expected_stdout = """
IO statistics for procedure is OK
"""

sql_io = """
    select
       iif( i.mon$page_fetches > 104500, 'IO statistics for procedure is OK',
            'Strange low value for fetches: ' || i.mon$page_fetches
          ) as fetches_result
    from rdb$database r
        left join mon$statements m on
            m.mon$sql_text containing 'select * from sp_test'
            and m.mon$sql_text NOT containing 'mon$statements'
        left join  mon$io_stats i on
            m.mon$stat_id = i.mon$stat_id and i.mon$stat_group = 3
    ;
"""

@pytest.mark.version('>=3')
def test_1(act: Action, capsys):
    act.expected_stdout = expected_stdout
    with act.db.connect() as con:
        stt1 = con.cursor()
        stt2 = con.cursor()
        stt2.execute('select * from sp_test')
        stt2.fetchall()
        stt1.execute(sql_io)
        for row in stt1:
            print(row[0])
        act.stdout = capsys.readouterr().out
    assert act.clean_stdout == act.clean_expected_stdout