# Copyright (c) 2016, Intel Corporation.
#
# This program is free software; you can redistribute it and/or modify it
# under the terms and conditions of the GNU General Public License,
# version 2, as published by the Free Software Foundation.
#
# This program is distributed in the hope 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.
#
"""Build performance test base classes and functionality"""
import glob
import logging
import os
import re
import shutil
import socket
import tempfile
import time
import traceback
import unittest
from datetime import datetime, timedelta

from oeqa.utils.commands import runCmd, get_bb_vars
from oeqa.utils.git import GitError, GitRepo

# Get logger for this module
log = logging.getLogger('build-perf')


class KernelDropCaches(object):
    """Container of the functions for dropping kernel caches"""
    sudo_passwd = None

    @classmethod
    def check(cls):
        """Check permssions for dropping kernel caches"""
        from getpass import getpass
        from locale import getdefaultlocale
        cmd = ['sudo', '-k', '-n', 'tee', '/proc/sys/vm/drop_caches']
        ret = runCmd(cmd, ignore_status=True, data=b'0')
        if ret.output.startswith('sudo:'):
            pass_str = getpass(
                "\nThe script requires sudo access to drop caches between "
                "builds (echo 3 > /proc/sys/vm/drop_caches).\n"
                "Please enter your sudo password: ")
            cls.sudo_passwd = bytes(pass_str, getdefaultlocale()[1])

    @classmethod
    def drop(cls):
        """Drop kernel caches"""
        cmd = ['sudo', '-k']
        if cls.sudo_passwd:
            cmd.append('-S')
            input_data = cls.sudo_passwd + b'\n'
        else:
            cmd.append('-n')
            input_data = b''
        cmd += ['tee', '/proc/sys/vm/drop_caches']
        input_data += b'3'
        runCmd(cmd, data=input_data)


def time_cmd(cmd, **kwargs):
    """TIme a command"""
    with tempfile.NamedTemporaryFile(mode='w+') as tmpf:
        timecmd = ['/usr/bin/time', '-v', '-o', tmpf.name]
        if isinstance(cmd, str):
            timecmd = ' '.join(timecmd) + ' '
        timecmd += cmd
        # TODO: 'ignore_status' could/should be removed when globalres.log is
        # deprecated. The function would just raise an exception, instead
        ret = runCmd(timecmd, ignore_status=True, **kwargs)
        timedata = tmpf.file.read()
    return ret, timedata


class BuildPerfTestResult(unittest.TextTestResult):
    """Runner class for executing the individual tests"""
    # List of test cases to run
    test_run_queue = []

    def __init__(self, out_dir, *args, **kwargs):
        super(BuildPerfTestResult, self).__init__(*args, **kwargs)

        self.out_dir = out_dir
        # Get Git parameters
        try:
            self.repo = GitRepo('.')
        except GitError:
            self.repo = None
        self.git_revision, self.git_branch = self.get_git_revision()
        self.hostname = socket.gethostname()
        self.start_time = self.elapsed_time = None
        self.successes = []
        log.info("Using Git branch:revision %s:%s", self.git_branch,
                 self.git_revision)

    def get_git_revision(self):
        """Get git branch and revision under testing"""
        rev = os.getenv('OE_BUILDPERFTEST_GIT_REVISION')
        branch = os.getenv('OE_BUILDPERFTEST_GIT_BRANCH')
        if not self.repo and (not rev or not branch):
            log.info("The current working directory doesn't seem to be a Git "
                     "repository clone. You can specify branch and revision "
                     "used in test results with OE_BUILDPERFTEST_GIT_REVISION "
                     "and OE_BUILDPERFTEST_GIT_BRANCH environment variables")
        else:
            if not rev:
                rev = self.repo.run_cmd(['rev-parse', 'HEAD'])
            if not branch:
                try:
                    # Strip 11 chars, i.e. 'refs/heads' from the beginning
                    branch = self.repo.run_cmd(['symbolic-ref', 'HEAD'])[11:]
                except GitError:
                    log.debug('Currently on detached HEAD')
                    branch = None
        return str(rev), str(branch)

    def addSuccess(self, test):
        """Record results from successful tests"""
        super(BuildPerfTestResult, self).addSuccess(test)
        self.successes.append((test, None))

    def startTest(self, test):
        """Pre-test hook"""
        test.out_dir = self.out_dir
        log.info("Executing test %s: %s", test.name, test.shortDescription())
        self.stream.write(datetime.now().strftime("[%Y-%m-%d %H:%M:%S] "))
        super(BuildPerfTestResult, self).startTest(test)

    def startTestRun(self):
        """Pre-run hook"""
        self.start_time = datetime.utcnow()

    def stopTestRun(self):
        """Pre-run hook"""
        self.elapsed_time = datetime.utcnow() - self.start_time

    def all_results(self):
        result_map = {'SUCCESS': self.successes,
                      'FAIL': self.failures,
                      'ERROR': self.errors,
                      'EXP_FAIL': self.expectedFailures,
                      'UNEXP_SUCCESS': self.unexpectedSuccesses}
        for status, tests in result_map.items():
            for test in tests:
                yield (status, test)


    def update_globalres_file(self, filename):
        """Write results to globalres csv file"""
        # Map test names to time and size columns in globalres
        # The tuples represent index and length of times and sizes
        # respectively
        gr_map = {'test1': ((0, 1), (8, 1)),
                  'test12': ((1, 1), (None, None)),
                  'test13': ((2, 1), (9, 1)),
                  'test2': ((3, 1), (None, None)),
                  'test3': ((4, 3), (None, None)),
                  'test4': ((7, 1), (10, 2))}

        if self.repo:
            git_tag_rev = self.repo.run_cmd(['describe', self.git_revision])
        else:
            git_tag_rev = self.git_revision

        values = ['0'] * 12
        for status, test in self.all_results():
            if status not in ['SUCCESS', 'FAILURE', 'EXP_SUCCESS']:
                continue
            (t_ind, t_len), (s_ind, s_len) = gr_map[test.name]
            if t_ind is not None:
                values[t_ind:t_ind + t_len] = test.times
            if s_ind is not None:
                values[s_ind:s_ind + s_len] = test.sizes

        log.debug("Writing globalres log to %s", filename)
        with open(filename, 'a') as fobj:
            fobj.write('{},{}:{},{},'.format(self.hostname,
                                             self.git_branch,
                                             self.git_revision,
                                             git_tag_rev))
            fobj.write(','.join(values) + '\n')


class BuildPerfTestCase(unittest.TestCase):
    """Base class for build performance tests"""
    SYSRES = 'sysres'
    DISKUSAGE = 'diskusage'

    def __init__(self, *args, **kwargs):
        super(BuildPerfTestCase, self).__init__(*args, **kwargs)
        self.name = self._testMethodName
        self.out_dir = None
        self.start_time = None
        self.elapsed_time = None
        self.measurements = []
        self.bb_vars = get_bb_vars()
        # TODO: remove 'times' and 'sizes' arrays when globalres support is
        # removed
        self.times = []
        self.sizes = []

    def run(self, *args, **kwargs):
        """Run test"""
        self.start_time = datetime.now()
        super(BuildPerfTestCase, self).run(*args, **kwargs)
        self.elapsed_time = datetime.now() - self.start_time

    def log_cmd_output(self, cmd):
        """Run a command and log it's output"""
        cmd_log = os.path.join(self.out_dir, 'commands.log')
        with open(cmd_log, 'a') as fobj:
            runCmd(cmd, stdout=fobj)

    def measure_cmd_resources(self, cmd, name, legend):
        """Measure system resource usage of a command"""
        def str_time_to_timedelta(strtime):
            """Convert time strig from the time utility to timedelta"""
            split = strtime.split(':')
            hours = int(split[0]) if len(split) > 2 else 0
            mins = int(split[-2])
            try:
                secs, frac = split[-1].split('.')
            except:
                secs = split[-1]
                frac = '0'
            secs = int(secs)
            microsecs = int(float('0.' + frac) * pow(10, 6))
            return timedelta(0, hours*3600 + mins*60 + secs, microsecs)

        cmd_str = cmd if isinstance(cmd, str) else ' '.join(cmd)
        log.info("Timing command: %s", cmd_str)
        cmd_log = os.path.join(self.out_dir, 'commands.log')
        with open(cmd_log, 'a') as fobj:
            ret, timedata = time_cmd(cmd, stdout=fobj)
        if ret.status:
            log.error("Time will be reported as 0. Command failed: %s",
                      ret.status)
            etime = timedelta(0)
            self._failed = True
        else:
            match = re.search(r'.*wall clock.*: (?P<etime>.*)\n', timedata)
            etime = str_time_to_timedelta(match.group('etime'))

        measurement = {'type': self.SYSRES,
                       'name': name,
                       'legend': legend}
        measurement['values'] = {'elapsed_time': etime}
        self.measurements.append(measurement)
        e_sec = etime.total_seconds()
        nlogs = len(glob.glob(self.out_dir + '/results.log*'))
        results_log = os.path.join(self.out_dir,
                                   'results.log.{}'.format(nlogs + 1))
        with open(results_log, 'w') as fobj:
            fobj.write(timedata)
        # Append to 'times' array for globalres log
        self.times.append('{:d}:{:02d}:{:.2f}'.format(int(e_sec / 3600),
                                                      int((e_sec % 3600) / 60),
                                                       e_sec % 60))

    def measure_disk_usage(self, path, name, legend):
        """Estimate disk usage of a file or directory"""
        # TODO: 'ignore_status' could/should be removed when globalres.log is
        # deprecated. The function would just raise an exception, instead
        ret = runCmd(['du', '-s', path], ignore_status=True)
        if ret.status:
            log.error("du failed, disk usage will be reported as 0")
            size = 0
            self._failed = True
        else:
            size = int(ret.output.split()[0])
            log.debug("Size of %s path is %s", path, size)
        measurement = {'type': self.DISKUSAGE,
                       'name': name,
                       'legend': legend}
        measurement['values'] = {'size': size}
        self.measurements.append(measurement)
        # Append to 'sizes' array for globalres log
        self.sizes.append(str(size))

    def save_buildstats(self):
        """Save buildstats"""
        shutil.move(self.bb_vars['BUILDSTATS_BASE'],
                    os.path.join(self.out_dir, 'buildstats-' + self.name))

    @staticmethod
    def force_rm(path):
        """Equivalent of 'rm -rf'"""
        if os.path.isfile(path) or os.path.islink(path):
            os.unlink(path)
        elif os.path.isdir(path):
            shutil.rmtree(path)

    def rm_tmp(self):
        """Cleanup temporary/intermediate files and directories"""
        log.debug("Removing temporary and cache files")
        for name in ['bitbake.lock', 'conf/sanity_info',
                     self.bb_vars['TMPDIR']]:
            self.force_rm(name)

    def rm_sstate(self):
        """Remove sstate directory"""
        log.debug("Removing sstate-cache")
        self.force_rm(self.bb_vars['SSTATE_DIR'])

    def rm_cache(self):
        """Drop bitbake caches"""
        self.force_rm(self.bb_vars['PERSISTENT_DIR'])

    @staticmethod
    def sync():
        """Sync and drop kernel caches"""
        log.debug("Syncing and dropping kernel caches""")
        KernelDropCaches.drop()
        os.sync()
        # Wait a bit for all the dirty blocks to be written onto disk
        time.sleep(3)


class BuildPerfTestLoader(unittest.TestLoader):
    """Test loader for build performance tests"""
    sortTestMethodsUsing = None


class BuildPerfTestRunner(unittest.TextTestRunner):
    """Test loader for build performance tests"""
    sortTestMethodsUsing = None

    def __init__(self, out_dir, *args, **kwargs):
        super(BuildPerfTestRunner, self).__init__(*args, **kwargs)
        self.out_dir = out_dir

    def _makeResult(self):
       return BuildPerfTestResult(self.out_dir, self.stream, self.descriptions,
                                  self.verbosity)