# copyright 2003-2011 LOGILAB S.A. (Paris, FRANCE), all rights reserved.
# contact http://www.logilab.fr/ -- mailto:contact@logilab.fr
#
# This file is part of CubicWeb.
#
# CubicWeb is free software: you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation, either version 2.1 of the License, or (at your option)
# any later version.
#
# CubicWeb is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License along
# with CubicWeb.  If not, see <http://www.gnu.org/licenses/>.
""" Usage: %s [OPTIONS] <instance id> <queries file>

Stress test a CubicWeb repository

OPTIONS:
  -h / --help
     Display this help message and exit.

  -u / --user <user>
     Connect as <user> instead of being prompted to give it.
  -p / --password <password>
     Automatically give <password> for authentication instead of being prompted
     to give it.

  -n / --nb-times <num>
     Repeat queries <num> times.
  -t / --nb-threads <num>
     Execute queries in <num> parallel threads.
  -P / --profile <prof_file>
     dumps profile results (hotshot) in <prof_file>
  -o / --report-output <filename>
     Write profiler report into <filename> rather than on stdout

Copyright (c) 2003-2011 LOGILAB S.A. (Paris, FRANCE), license is LGPL v2.
http://www.logilab.fr/ -- mailto:contact@logilab.fr
"""
from __future__ import print_function

import os
import sys
import threading
import getopt
import traceback
from getpass import getpass
from os.path import basename
from time import clock

from logilab.common.fileutils import lines
from logilab.common.ureports import Table, TextWriter
from cubicweb.server.repository import Repository

TB_LOCK = threading.Lock()

class QueryExecutor:
    def __init__(self, session, times, queries, reporter = None):
        self._session = session
        self._times = times
        self._queries = queries
        self._reporter = reporter

    def run(self):
        with self._session.new_cnx() as cnx:
            times = self._times
            while times:
                for index, query in enumerate(self._queries):
                    start = clock()
                    try:
                        cnx.execute(query)
                    except Exception:
                        TB_LOCK.acquire()
                        traceback.print_exc()
                        TB_LOCK.release()
                        return
                    if self._reporter is not None:
                        self._reporter.add_proftime(clock() - start, index)
                times -= 1

def usage(status=0):
    """print usage string and exit"""
    print(__doc__ % basename(sys.argv[0]))
    sys.exit(status)


class ProfileReporter:
    """a profile reporter gathers all profile informations from several
    threads and can write a report that summarizes all profile informations
    """
    profiler_lock = threading.Lock()

    def __init__(self, queries):
        self._queries = tuple(queries)
        self._profile_results = [(0., 0)] * len(self._queries)
        # self._table_report = Table(3, rheaders = True)
        len_max = max([len(query) for query in self._queries]) + 5
        self._query_fmt = '%%%ds' % len_max

    def add_proftime(self, elapsed_time, query_index):
        """add a new time measure for query"""
        ProfileReporter.profiler_lock.acquire()
        cumul_time, times = self._profile_results[query_index]
        cumul_time += elapsed_time
        times += 1.
        self._profile_results[query_index] = (cumul_time, times)
        ProfileReporter.profiler_lock.release()

    def dump_report(self, output = sys.stdout):
        """dump report in 'output'"""
        table_elems = ['RQL Query', 'Times', 'Avg Time']
        total_time = 0.
        for query, (cumul_time, times) in zip(self._queries, self._profile_results):
            avg_time = cumul_time / float(times)
            table_elems += [str(query), '%f' % times, '%f' % avg_time ]
            total_time += cumul_time
        table_elems.append('Total time :')
        table_elems.append(str(total_time))
        table_elems.append(' ')
        table_layout = Table(3, rheaders = True, children = table_elems)
        TextWriter().format(table_layout, output)
        # output.write('\n'.join(tmp_output))


def run(args):
    """run the command line tool"""
    try:
        opts, args = getopt.getopt(args, 'hn:t:u:p:P:o:', ['help', 'user=', 'password=',
                                                           'nb-times=', 'nb-threads=',
                                                           'profile', 'report-output=',])
    except Exception as ex:
        print(ex)
        usage(1)
    repeat = 100
    threads = 1
    user = os.environ.get('USER', os.environ.get('LOGNAME'))
    password = None
    report_output = sys.stdout
    prof_file = None
    for opt, val in opts:
        if opt in ('-h', '--help'):
            usage()
        if opt in ('-u', '--user'):
            user = val
        elif opt in ('-p', '--password'):
            password = val
        elif opt in ('-n', '--nb-times'):
            repeat = int(val)
        elif opt in ('-t', '--nb-threads'):
            threads = int(val)
        elif opt in ('-P', '--profile'):
            prof_file = val
        elif opt in ('-o', '--report-output'):
            report_output = open(val, 'w')
    if len(args) != 2:
        usage(1)
    queries =  [query for query in lines(args[1]) if not query.startswith('#')]
    if user is None:
        user = raw_input('login: ')
    if password is None:
        password = getpass('password: ')
    from cubicweb.cwconfig import instance_configuration
    config = instance_configuration(args[0])
    # get local access to the repository
    print("Creating repo", prof_file)
    repo = Repository(config, prof_file)
    session = repo.new_session(user, password=password)
    reporter = ProfileReporter(queries)
    if threads > 1:
        executors = []
        while threads:
            qe = QueryExecutor(session, repeat, queries, reporter = reporter)
            executors.append(qe)
            thread = threading.Thread(target=qe.run)
            qe.thread = thread
            thread.start()
            threads -= 1
        for qe in executors:
            qe.thread.join()
##         for qe in executors:
##             print qe.thread, repeat - qe._times, 'times'
    else:
        QueryExecutor(session, repeat, queries, reporter = reporter).run()
    reporter.dump_report(report_output)


if __name__ == '__main__':
    run(sys.argv[1:])