#!/usr/bin/python

# ex:ts=4:sw=4:sts=4:et
# -*- tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*-
#
# Copyright (C) 2015 Alexandru Damian for Intel Corp.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# This program 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.


# This is the main test execution controller. It is designed to be run
# manually from the command line, or to be called from a different program
# that schedules test execution.
#
# Execute   runner.py -h   for help.


from __future__ import print_function
import sys, os
import unittest, importlib
import logging, pprint, json
import re
from shellutils import ShellCmdException, mkdirhier, run_shell_cmd

import config

# we also log to a file, in addition to console, because our output is important
__log_file_name__ = os.path.join(os.path.dirname(__file__), "log/tts_%d.log" % config.OWN_PID)
mkdirhier(os.path.dirname(__log_file_name__))
__log_file__ = open(__log_file_name__, "w")
__file_handler__ = logging.StreamHandler(__log_file__)
__file_handler__.setFormatter(logging.Formatter("%(asctime)s %(levelname)s: %(message)s"))

config.logger.addHandler(__file_handler__)

# set up log directory
try:
    if not os.path.exists(config.LOGDIR):
        os.mkdir(config.LOGDIR)
    else:
        if not os.path.isdir(config.LOGDIR):
            raise Exception("Expected log dir '%s' is not actually a directory." % config.LOGDIR)
except OSError as exc:
    raise exc

# creates the under-test-branch as a separate directory
def set_up_test_branch(settings, branch_name):
    testdir = "%s/%s.%d" % (settings['workdir'], config.TEST_DIR_NAME, config.OWN_PID)

    # creates the host dir
    if os.path.exists(testdir):
        raise Exception("Test dir '%s'is already there, aborting" % testdir)

    # may raise OSError, is to be handled by the caller
    os.makedirs(testdir)


    # copies over the .git from the localclone
    run_shell_cmd("cp -a '%s'/.git '%s'" % (settings['localclone'], testdir))

    # add the remote if it doesn't exist
    crt_remotes = run_shell_cmd("git remote -v", cwd=testdir)
    remotes = [word for line in crt_remotes.split("\n") for word in line.split()]
    if not config.CONTRIB_REPO in remotes:
        remote_name = "tts_contrib"
        run_shell_cmd("git remote add %s %s" % (remote_name, config.CONTRIB_REPO), cwd=testdir)
    else:
        remote_name = remotes[remotes.index(config.CONTRIB_REPO) - 1]

    # do the fetch
    run_shell_cmd("git fetch %s -p" % remote_name, cwd=testdir)

    # do the checkout
    run_shell_cmd("git checkout origin/master && git branch -D %s; git checkout %s/%s -b %s && git reset --hard" % (branch_name, remote_name, branch_name, branch_name), cwd=testdir)

    return testdir


def __search_for_tests():
    # we find all classes that can run, and run them
    tests = []
    for _, _, files_list in os.walk(os.path.dirname(os.path.abspath(__file__))):
        for module_file in [f[:-3] for f in files_list if f.endswith(".py") and not f.startswith("__init__")]:
            config.logger.debug("Inspecting module %s", module_file)
            current_module = importlib.import_module(module_file)
            crtclass_names = vars(current_module)
            for name in crtclass_names:
                tested_value = crtclass_names[name]
                if isinstance(tested_value, type(unittest.TestCase)) and issubclass(tested_value, unittest.TestCase):
                    tests.append((module_file, name))
        break
    return tests


# boilerplate to self discover tests and run them
def execute_tests(dir_under_test, testname):

    if testname is not None and "." in testname:
        tests = []
        tests.append(tuple(testname.split(".", 2)))
    else:
        tests = __search_for_tests()

    # let's move to the directory under test
    crt_dir = os.getcwd()
    os.chdir(dir_under_test)

    # execute each module
    # pylint: disable=broad-except
    # we disable the broad-except because we want to actually catch all possible exceptions
    try:
        # sorting the tests by the numeric order in the class name
        tests = sorted(tests, key=lambda x: int(re.search(r"[0-9]+", x[1]).group(0)))
        config.logger.debug("Discovered test clases: %s", pprint.pformat(tests))
        unittest.installHandler()
        suite = unittest.TestSuite()
        loader = unittest.TestLoader()
        result = unittest.TestResult()
        result.failfast = True
        for module_file, test_name in tests:
            suite.addTest(loader.loadTestsFromName("%s.%s" % (module_file, test_name)))
        config.logger.info("Running %d test(s)", suite.countTestCases())
        suite.run(result)

        for error in result.errors:
            config.logger.error("Exception on test: %s\n%s", error[0],
                                "\n".join(["-- %s" % x for x in error[1].split("\n")]))

        for failure in result.failures:
            config.logger.error("Failed test: %s:\n%s\n", failure[0],
                                "\n".join(["--  %s" % x for x in failure[1].split("\n")]))

        config.logger.info("Test results: %d ran, %d errors, %d failures", result.testsRun, len(result.errors), len(result.failures))

    except Exception as exc:
        import traceback
        config.logger.error("Exception while running test. Tracedump: \n%s", traceback.format_exc(exc))
    finally:
        os.chdir(crt_dir)
    return len(result.failures)

# verify that we had a branch-under-test name as parameter
def validate_args():
    from optparse import OptionParser
    parser = OptionParser(usage="usage: %prog [options] branch_under_test")

    parser.add_option("-t", "--test-dir", dest="testdir", default=None, help="Use specified directory to run tests, inhibits the checkout.")
    parser.add_option("-s", "--single", dest="singletest", default=None, help="Run only the specified test")

    (options, args) = parser.parse_args()
    if len(args) < 1:
        raise Exception("Please specify the branch to run on. Use option '-h' when in doubt.")
    return (options, args)


# load the configuration options
def read_settings():
    if not os.path.exists(config.SETTINGS_FILE) or not os.path.isfile(config.SETTINGS_FILE):
        raise Exception("Config file '%s' cannot be openend" % config.SETTINGS_FILE)
    return json.loads(open(config.SETTINGS_FILE, "r").read())


# cleanup !
def clean_up(testdir):
    run_shell_cmd("rm -rf -- '%s'" % testdir)

def dump_info(settings, options, args):
    """ detailed information about current run configuration, for debugging purposes.
    """
    config.logger.debug("Settings:\n%s\nOptions:\n%s\nArguments:\n%s\n", settings, options, args)

def main():
    (options, args) = validate_args()

    settings = read_settings()
    need_cleanup = False

    # dump debug info
    dump_info(settings, options, args)

    testdir = None
    no_failures = 1
    try:
        if options.testdir is not None and os.path.exists(options.testdir):
            testdir = os.path.abspath(options.testdir)
            config.logger.info("No checkout, using %s", testdir)
        else:
            need_cleanup = True
            testdir = set_up_test_branch(settings, args[0]) # we expect a branch name as first argument

        config.TESTDIR = testdir    # we let tests know where to run

        # ensure that the test dir only contains no *.pyc leftovers
        run_shell_cmd("find '%s' -type f -name *.pyc -exec rm {} \\;" % testdir)

        no_failures = execute_tests(testdir, options.singletest)

    except ShellCmdException as exc:
        import traceback
        config.logger.error("Error while setting up testing. Traceback: \n%s", traceback.format_exc(exc))
    finally:
        if need_cleanup and testdir is not None:
            clean_up(testdir)

    sys.exit(no_failures)

if __name__ == "__main__":
    main()