# Shell class for a test, inherited by all individual tests
#
# Methods:
#       __init__        initialise
#       initialize      run once for each job
#       setup           run once for each new version of the test installed
#       run             run the test (wrapped by job.run_test())
#
# Data:
#       job             backreference to the job this test instance is part of
#       outputdir       eg. results/<job>/<testname.tag>
#       resultsdir      eg. results/<job>/<testname.tag>/results
#       profdir         eg. results/<job>/<testname.tag>/profiling
#       debugdir        eg. results/<job>/<testname.tag>/debug
#       bindir          eg. tests/<test>
#       src             eg. tests/<test>/src
#       tmpdir          eg. tmp/<tempname>_<testname.tag>

#pylint: disable-msg=C0111

import fcntl, json, os, re, sys, shutil, tempfile, time, traceback
import logging

from autotest_lib.client.common_lib import error
from autotest_lib.client.bin import utils


class base_test(object):
    preserve_srcdir = False
    network_destabilizing = False

    def __init__(self, job, bindir, outputdir):
        self.job = job
        self.pkgmgr = job.pkgmgr
        self.autodir = job.autodir
        self.outputdir = outputdir
        self.tagged_testname = os.path.basename(self.outputdir)
        self.resultsdir = os.path.join(self.outputdir, 'results')
        os.mkdir(self.resultsdir)
        self.profdir = os.path.join(self.outputdir, 'profiling')
        os.mkdir(self.profdir)
        self.debugdir = os.path.join(self.outputdir, 'debug')
        os.mkdir(self.debugdir)
        # TODO(ericli): figure out how autotest crash handler work with cros
        # Once this is re-enabled import getpass. crosbug.com/31232
        # crash handler, we should restore it in near term.
        # if getpass.getuser() == 'root':
        #     self.configure_crash_handler()
        # else:
        self.crash_handling_enabled = False
        self.bindir = bindir
        self.srcdir = os.path.join(self.bindir, 'src')
        self.tmpdir = tempfile.mkdtemp("_" + self.tagged_testname,
                                       dir=job.tmpdir)
        self._keyvals = []
        self._new_keyval = False
        self.failed_constraints = []
        self.iteration = 0
        self.before_iteration_hooks = []
        self.after_iteration_hooks = []


    def configure_crash_handler(self):
        pass


    def crash_handler_report(self):
        pass


    def assert_(self, expr, msg='Assertion failed.'):
        if not expr:
            raise error.TestError(msg)


    def write_test_keyval(self, attr_dict):
        utils.write_keyval(self.outputdir, attr_dict,
                           tap_report=self.job._tap)

    @staticmethod
    def _append_type_to_keys(dictionary, typename):
        new_dict = {}
        for key, value in dictionary.iteritems():
            new_key = "%s{%s}" % (key, typename)
            new_dict[new_key] = value
        return new_dict


    def output_perf_value(self, description, value, units,
                          higher_is_better=True):
        """
        Records a measured performance value in an output file.

        The output file will subsequently be parsed by the TKO parser to have
        the information inserted into the results database.

        @param description: A string describing the measured perf value. Must
                be maximum length 256, and may only contain letters, numbers,
                periods, dashes, and underscores.  For example:
                "page_load_time", "scrolling-frame-rate".
        @param value: A number representing the measured perf value, or a list
                of measured values if a test takes multiple measurements.
                Measured perf values can be either ints or floats.
        @param units: A string describing the units associated with the
                measured perf value. Must be maximum length 32, and may only
                contain letters, numbers, periods, dashes, and underscores.
                For example: "msec", "fps", "score", "runs_per_second".
        @param higher_is_better: A boolean indicating whether or not a "higher"
                measured perf value is considered to be better. If False, it is
                assumed that a "lower" measured value is considered to be
                better.

        """
        if len(description) > 256:
            raise ValueError('The description must be at most 256 characters.')
        if len(units) > 32:
            raise ValueError('The units must be at most 32 characters.')
        string_regex = re.compile(r'^[-\.\w]+$')
        if (not string_regex.search(description) or
            not string_regex.search(units)):
            raise ValueError('Invalid description or units string. May only '
                             'contain letters, numbers, periods, dashes, and '
                             'underscores.')

        entry = {
            'description': description,
            'value': value,
            'units': units,
            'higher_is_better': higher_is_better,
        }

        output_path = os.path.join(self.resultsdir, 'perf_measurements')
        with open(output_path, 'a') as fp:
            fp.write(json.dumps(entry, sort_keys=True) + '\n')


    def write_perf_keyval(self, perf_dict):
        self.write_iteration_keyval({}, perf_dict,
                                    tap_report=self.job._tap)


    def write_attr_keyval(self, attr_dict):
        self.write_iteration_keyval(attr_dict, {},
                                    tap_report=self.job._tap)


    def write_iteration_keyval(self, attr_dict, perf_dict, tap_report=None):
        # append the dictionaries before they have the {perf} and {attr} added
        self._keyvals.append({'attr':attr_dict, 'perf':perf_dict})
        self._new_keyval = True

        if attr_dict:
            attr_dict = self._append_type_to_keys(attr_dict, "attr")
            utils.write_keyval(self.resultsdir, attr_dict, type_tag="attr",
                               tap_report=tap_report)

        if perf_dict:
            perf_dict = self._append_type_to_keys(perf_dict, "perf")
            utils.write_keyval(self.resultsdir, perf_dict, type_tag="perf",
                               tap_report=tap_report)

        keyval_path = os.path.join(self.resultsdir, "keyval")
        print >> open(keyval_path, "a"), ""


    def analyze_perf_constraints(self, constraints):
        if not self._new_keyval:
            return

        # create a dict from the keyvals suitable as an environment for eval
        keyval_env = self._keyvals[-1]['perf'].copy()
        keyval_env['__builtins__'] = None
        self._new_keyval = False
        failures = []

        # evaluate each constraint using the current keyvals
        for constraint in constraints:
            logging.info('___________________ constraint = %s', constraint)
            logging.info('___________________ keyvals = %s', keyval_env)

            try:
                if not eval(constraint, keyval_env):
                    failures.append('%s: constraint was not met' % constraint)
            except:
                failures.append('could not evaluate constraint: %s'
                                % constraint)

        # keep track of the errors for each iteration
        self.failed_constraints.append(failures)


    def process_failed_constraints(self):
        msg = ''
        for i, failures in enumerate(self.failed_constraints):
            if failures:
                msg += 'iteration %d:%s  ' % (i, ','.join(failures))

        if msg:
            raise error.TestFail(msg)


    def register_before_iteration_hook(self, iteration_hook):
        """
        This is how we expect test writers to register a before_iteration_hook.
        This adds the method to the list of hooks which are executed
        before each iteration.

        @param iteration_hook: Method to run before each iteration. A valid
                               hook accepts a single argument which is the
                               test object.
        """
        self.before_iteration_hooks.append(iteration_hook)


    def register_after_iteration_hook(self, iteration_hook):
        """
        This is how we expect test writers to register an after_iteration_hook.
        This adds the method to the list of hooks which are executed
        after each iteration.

        @param iteration_hook: Method to run after each iteration. A valid
                               hook accepts a single argument which is the
                               test object.
        """
        self.after_iteration_hooks.append(iteration_hook)


    def initialize(self):
        pass


    def setup(self):
        pass


    def warmup(self, *args, **dargs):
        pass


    def drop_caches_between_iterations(self):
        if self.job.drop_caches_between_iterations:
            utils.drop_caches()


    def _call_run_once_with_retry(self, constraints, profile_only,
                                  postprocess_profiled_run, args, dargs):
        """Thin wrapper around _call_run_once that retries unsuccessful tests.

        If the job object's attribute test_retry is > 0 retry any tests that
        ran unsuccessfully X times.
        *Note this does not competely re-initialize the test, it only
            re-executes code once all the initial job set up (packages,
            sysinfo, etc) is complete.
        """
        if self.job.test_retry != 0:
            logging.info('Test will be retried a maximum of %d times',
                         self.job.test_retry)

        max_runs = self.job.test_retry
        for retry_run in xrange(0, max_runs+1):
            try:
                self._call_run_once(constraints, profile_only,
                                    postprocess_profiled_run, args, dargs)
                break
            except error.TestFailRetry as err:
                if retry_run == max_runs:
                    raise
                self.job.record('INFO', None, None, 'Run %s failed with %s' % (
                        retry_run, err))
        if retry_run > 0:
            self.write_test_keyval({'test_retries_before_success': retry_run})


    def _call_run_once(self, constraints, profile_only,
                       postprocess_profiled_run, args, dargs):
        self.drop_caches_between_iterations()
        # execute iteration hooks
        for hook in self.before_iteration_hooks:
            hook(self)

        try:
            if profile_only:
                if not self.job.profilers.present():
                    self.job.record('WARN', None, None,
                                    'No profilers have been added but '
                                    'profile_only is set - nothing '
                                    'will be run')
                self.run_once_profiling(postprocess_profiled_run,
                                        *args, **dargs)
            else:
                self.before_run_once()
                self.run_once(*args, **dargs)
                self.after_run_once()

            self.postprocess_iteration()
            self.analyze_perf_constraints(constraints)
        finally:
            for hook in self.after_iteration_hooks:
                hook(self)


    def execute(self, iterations=None, test_length=None, profile_only=None,
                _get_time=time.time, postprocess_profiled_run=None,
                constraints=(), *args, **dargs):
        """
        This is the basic execute method for the tests inherited from base_test.
        If you want to implement a benchmark test, it's better to implement
        the run_once function, to cope with the profiling infrastructure. For
        other tests, you can just override the default implementation.

        @param test_length: The minimum test length in seconds. We'll run the
            run_once function for a number of times large enough to cover the
            minimum test length.

        @param iterations: A number of iterations that we'll run the run_once
            function. This parameter is incompatible with test_length and will
            be silently ignored if you specify both.

        @param profile_only: If true run X iterations with profilers enabled.
            If false run X iterations and one with profiling if profiles are
            enabled. If None, default to the value of job.default_profile_only.

        @param _get_time: [time.time] Used for unit test time injection.

        @param postprocess_profiled_run: Run the postprocessing for the
            profiled run.
        """

        # For our special class of tests, the benchmarks, we don't want
        # profilers to run during the test iterations. Let's reserve only
        # the last iteration for profiling, if needed. So let's stop
        # all profilers if they are present and active.
        profilers = self.job.profilers
        if profilers.active():
            profilers.stop(self)
        if profile_only is None:
            profile_only = self.job.default_profile_only
        # If the user called this test in an odd way (specified both iterations
        # and test_length), let's warn them.
        if iterations and test_length:
            logging.debug('Iterations parameter ignored (timed execution)')
        if test_length:
            test_start = _get_time()
            time_elapsed = 0
            timed_counter = 0
            logging.debug('Test started. Specified %d s as the minimum test '
                          'length', test_length)
            while time_elapsed < test_length:
                timed_counter = timed_counter + 1
                if time_elapsed == 0:
                    logging.debug('Executing iteration %d', timed_counter)
                elif time_elapsed > 0:
                    logging.debug('Executing iteration %d, time_elapsed %d s',
                                  timed_counter, time_elapsed)
                self._call_run_once_with_retry(constraints, profile_only,
                                               postprocess_profiled_run, args,
                                               dargs)
                test_iteration_finish = _get_time()
                time_elapsed = test_iteration_finish - test_start
            logging.debug('Test finished after %d iterations, '
                          'time elapsed: %d s', timed_counter, time_elapsed)
        else:
            if iterations is None:
                iterations = 1
            if iterations > 1:
                logging.debug('Test started. Specified %d iterations',
                              iterations)
            for self.iteration in xrange(1, iterations + 1):
                if iterations > 1:
                    logging.debug('Executing iteration %d of %d',
                                  self.iteration, iterations)
                self._call_run_once_with_retry(constraints, profile_only,
                                               postprocess_profiled_run, args,
                                               dargs)

        if not profile_only:
            self.iteration += 1
            self.run_once_profiling(postprocess_profiled_run, *args, **dargs)

        # Do any postprocessing, normally extracting performance keyvals, etc
        self.postprocess()
        self.process_failed_constraints()


    def run_once_profiling(self, postprocess_profiled_run, *args, **dargs):
        profilers = self.job.profilers
        # Do a profiling run if necessary
        if profilers.present():
            self.drop_caches_between_iterations()
            profilers.before_start(self)

            self.before_run_once()
            profilers.start(self)
            logging.debug('Profilers present. Profiling run started')

            try:
                self.run_once(*args, **dargs)

                # Priority to the run_once() argument over the attribute.
                postprocess_attribute = getattr(self,
                                                'postprocess_profiled_run',
                                                False)

                if (postprocess_profiled_run or
                    (postprocess_profiled_run is None and
                     postprocess_attribute)):
                    self.postprocess_iteration()

            finally:
                profilers.stop(self)
                profilers.report(self)

            self.after_run_once()


    def postprocess(self):
        pass


    def postprocess_iteration(self):
        pass


    def cleanup(self):
        pass


    def before_run_once(self):
        """
        Override in tests that need it, will be called before any run_once()
        call including the profiling run (when it's called before starting
        the profilers).
        """
        pass


    def after_run_once(self):
        """
        Called after every run_once (including from a profiled run when it's
        called after stopping the profilers).
        """
        pass


    def _exec(self, args, dargs):
        self.job.logging.tee_redirect_debug_dir(self.debugdir,
                                                log_name=self.tagged_testname)
        try:
            if self.network_destabilizing:
                self.job.disable_warnings("NETWORK")

            # write out the test attributes into a keyval
            dargs   = dargs.copy()
            run_cleanup = dargs.pop('run_cleanup', self.job.run_test_cleanup)
            keyvals = dargs.pop('test_attributes', {}).copy()
            keyvals['version'] = self.version
            for i, arg in enumerate(args):
                keyvals['param-%d' % i] = repr(arg)
            for name, arg in dargs.iteritems():
                keyvals['param-%s' % name] = repr(arg)
            self.write_test_keyval(keyvals)

            _validate_args(args, dargs, self.initialize, self.setup,
                           self.execute, self.cleanup)

            try:
                # Initialize:
                _cherry_pick_call(self.initialize, *args, **dargs)

                lockfile = open(os.path.join(self.job.tmpdir, '.testlock'), 'w')
                try:
                    fcntl.flock(lockfile, fcntl.LOCK_EX)
                    # Setup: (compile and install the test, if needed)
                    p_args, p_dargs = _cherry_pick_args(self.setup,args,dargs)
                    utils.update_version(self.srcdir, self.preserve_srcdir,
                                         self.version, self.setup,
                                         *p_args, **p_dargs)
                finally:
                    fcntl.flock(lockfile, fcntl.LOCK_UN)
                    lockfile.close()

                # Execute:
                os.chdir(self.outputdir)

                # call self.warmup cherry picking the arguments it accepts and
                # translate exceptions if needed
                _call_test_function(_cherry_pick_call, self.warmup,
                                    *args, **dargs)

                if hasattr(self, 'run_once'):
                    p_args, p_dargs = _cherry_pick_args(self.run_once,
                                                        args, dargs)
                    # pull in any non-* and non-** args from self.execute
                    for param in _get_nonstar_args(self.execute):
                        if param in dargs:
                            p_dargs[param] = dargs[param]
                else:
                    p_args, p_dargs = _cherry_pick_args(self.execute,
                                                        args, dargs)

                _call_test_function(self.execute, *p_args, **p_dargs)
            except Exception:
                # Save the exception while we run our cleanup() before
                # reraising it.
                exc_info = sys.exc_info()
                try:
                    try:
                        if run_cleanup:
                            _cherry_pick_call(self.cleanup, *args, **dargs)
                    except Exception:
                        logging.error('Ignoring exception during cleanup() phase:')
                        traceback.print_exc()
                        logging.error('Now raising the earlier %s error',
                                      exc_info[0])
                    self.crash_handler_report()
                finally:
                    self.job.logging.restore()
                    try:
                        raise exc_info[0], exc_info[1], exc_info[2]
                    finally:
                        # http://docs.python.org/library/sys.html#sys.exc_info
                        # Be nice and prevent a circular reference.
                        del exc_info
            else:
                try:
                    if run_cleanup:
                        _cherry_pick_call(self.cleanup, *args, **dargs)
                    self.crash_handler_report()
                finally:
                    self.job.logging.restore()
        except error.AutotestError:
            if self.network_destabilizing:
                self.job.enable_warnings("NETWORK")
            # Pass already-categorized errors on up.
            raise
        except Exception, e:
            if self.network_destabilizing:
                self.job.enable_warnings("NETWORK")
            # Anything else is an ERROR in our own code, not execute().
            raise error.UnhandledTestError(e)
        else:
            if self.network_destabilizing:
                self.job.enable_warnings("NETWORK")


    def runsubtest(self, url, *args, **dargs):
        """
        Execute another autotest test from inside the current test's scope.

        @param test: Parent test.
        @param url: Url of new test.
        @param tag: Tag added to test name.
        @param args: Args for subtest.
        @param dargs: Dictionary with args for subtest.
        @iterations: Number of subtest iterations.
        @profile_only: If true execute one profiled run.
        """
        dargs["profile_only"] = dargs.get("profile_only", False)
        test_basepath = self.outputdir[len(self.job.resultdir + "/"):]
        return self.job.run_test(url, master_testpath=test_basepath,
                                 *args, **dargs)


def _get_nonstar_args(func):
    """Extract all the (normal) function parameter names.

    Given a function, returns a tuple of parameter names, specifically
    excluding the * and ** parameters, if the function accepts them.

    @param func: A callable that we want to chose arguments for.

    @return: A tuple of parameters accepted by the function.
    """
    return func.func_code.co_varnames[:func.func_code.co_argcount]


def _cherry_pick_args(func, args, dargs):
    """Sanitize positional and keyword arguments before calling a function.

    Given a callable (func), an argument tuple and a dictionary of keyword
    arguments, pick only those arguments which the function is prepared to
    accept and return a new argument tuple and keyword argument dictionary.

    Args:
      func: A callable that we want to choose arguments for.
      args: A tuple of positional arguments to consider passing to func.
      dargs: A dictionary of keyword arguments to consider passing to func.
    Returns:
      A tuple of: (args tuple, keyword arguments dictionary)
    """
    # Cherry pick args:
    if func.func_code.co_flags & 0x04:
        # func accepts *args, so return the entire args.
        p_args = args
    else:
        p_args = ()

    # Cherry pick dargs:
    if func.func_code.co_flags & 0x08:
        # func accepts **dargs, so return the entire dargs.
        p_dargs = dargs
    else:
        # Only return the keyword arguments that func accepts.
        p_dargs = {}
        for param in _get_nonstar_args(func):
            if param in dargs:
                p_dargs[param] = dargs[param]

    return p_args, p_dargs


def _cherry_pick_call(func, *args, **dargs):
    """Cherry picks arguments from args/dargs based on what "func" accepts
    and calls the function with the picked arguments."""
    p_args, p_dargs = _cherry_pick_args(func, args, dargs)
    return func(*p_args, **p_dargs)


def _validate_args(args, dargs, *funcs):
    """Verify that arguments are appropriate for at least one callable.

    Given a list of callables as additional parameters, verify that
    the proposed keyword arguments in dargs will each be accepted by at least
    one of the callables.

    NOTE: args is currently not supported and must be empty.

    Args:
      args: A tuple of proposed positional arguments.
      dargs: A dictionary of proposed keyword arguments.
      *funcs: Callables to be searched for acceptance of args and dargs.
    Raises:
      error.AutotestError: if an arg won't be accepted by any of *funcs.
    """
    all_co_flags = 0
    all_varnames = ()
    for func in funcs:
        all_co_flags |= func.func_code.co_flags
        all_varnames += func.func_code.co_varnames[:func.func_code.co_argcount]

    # Check if given args belongs to at least one of the methods below.
    if len(args) > 0:
        # Current implementation doesn't allow the use of args.
        raise error.TestError('Unnamed arguments not accepted. Please '
                              'call job.run_test with named args only')

    # Check if given dargs belongs to at least one of the methods below.
    if len(dargs) > 0:
        if not all_co_flags & 0x08:
            # no func accepts *dargs, so:
            for param in dargs:
                if not param in all_varnames:
                    raise error.AutotestError('Unknown parameter: %s' % param)


def _installtest(job, url):
    (group, name) = job.pkgmgr.get_package_name(url, 'test')

    # Bail if the test is already installed
    group_dir = os.path.join(job.testdir, "download", group)
    if os.path.exists(os.path.join(group_dir, name)):
        return (group, name)

    # If the group directory is missing create it and add
    # an empty  __init__.py so that sub-directories are
    # considered for import.
    if not os.path.exists(group_dir):
        os.makedirs(group_dir)
        f = file(os.path.join(group_dir, '__init__.py'), 'w+')
        f.close()

    logging.debug("%s: installing test url=%s", name, url)
    tarball = os.path.basename(url)
    tarball_path = os.path.join(group_dir, tarball)
    test_dir = os.path.join(group_dir, name)
    job.pkgmgr.fetch_pkg(tarball, tarball_path,
                         repo_url = os.path.dirname(url))

    # Create the directory for the test
    if not os.path.exists(test_dir):
        os.mkdir(os.path.join(group_dir, name))

    job.pkgmgr.untar_pkg(tarball_path, test_dir)

    os.remove(tarball_path)

    # For this 'sub-object' to be importable via the name
    # 'group.name' we need to provide an __init__.py,
    # so link the main entry point to this.
    os.symlink(name + '.py', os.path.join(group_dir, name,
                            '__init__.py'))

    # The test is now installed.
    return (group, name)


def _call_test_function(func, *args, **dargs):
    """Calls a test function and translates exceptions so that errors
    inside test code are considered test failures."""
    try:
        return func(*args, **dargs)
    except error.AutotestError:
        raise
    except Exception, e:
        # Other exceptions must be treated as a FAIL when
        # raised during the test functions
        raise error.UnhandledTestFail(e)


def runtest(job, url, tag, args, dargs,
            local_namespace={}, global_namespace={},
            before_test_hook=None, after_test_hook=None,
            before_iteration_hook=None, after_iteration_hook=None):
    local_namespace = local_namespace.copy()
    global_namespace = global_namespace.copy()
    # if this is not a plain test name then download and install the
    # specified test
    if url.endswith('.tar.bz2'):
        (testgroup, testname) = _installtest(job, url)
        bindir = os.path.join(job.testdir, 'download', testgroup, testname)
        importdir = os.path.join(job.testdir, 'download')
        site_bindir = None
        modulename = '%s.%s' % (re.sub('/', '.', testgroup), testname)
        classname = '%s.%s' % (modulename, testname)
        path = testname
    else:
        # If the test is local, it may be under either testdir or site_testdir.
        # Tests in site_testdir override tests defined in testdir
        testname = path = url
        testgroup = ''
        path = re.sub(':', '/', testname)
        modulename = os.path.basename(path)
        classname = '%s.%s' % (modulename, modulename)

        # Try installing the test package
        # The job object may be either a server side job or a client side job.
        # 'install_pkg' method will be present only if it's a client side job.
        if hasattr(job, 'install_pkg'):
            try:
                bindir = os.path.join(job.testdir, testname)
                job.install_pkg(testname, 'test', bindir)
            except error.PackageInstallError, e:
                # continue as a fall back mechanism and see if the test code
                # already exists on the machine
                pass

        bindir = testdir = None
        for dir in [job.testdir, getattr(job, 'site_testdir', None)]:
            if dir is not None and os.path.exists(os.path.join(dir, path)):
                testdir = dir
                importdir = bindir = os.path.join(dir, path)
        if not bindir:
            raise error.TestError(testname + ': test does not exist')

    subdir = os.path.join(dargs.pop('master_testpath', ""), testname)
    outputdir = os.path.join(job.resultdir, subdir)
    if tag:
        outputdir += '.' + tag

    local_namespace['job'] = job
    local_namespace['bindir'] = bindir
    local_namespace['outputdir'] = outputdir

    sys.path.insert(0, importdir)
    try:
        exec ('import %s' % modulename, local_namespace, global_namespace)
        exec ("mytest = %s(job, bindir, outputdir)" % classname,
              local_namespace, global_namespace)
    finally:
        sys.path.pop(0)

    pwd = os.getcwd()
    os.chdir(outputdir)

    try:
        mytest = global_namespace['mytest']
        if before_test_hook:
            before_test_hook(mytest)

        # we use the register iteration hooks methods to register the passed
        # in hooks
        if before_iteration_hook:
            mytest.register_before_iteration_hook(before_iteration_hook)
        if after_iteration_hook:
            mytest.register_after_iteration_hook(after_iteration_hook)
        mytest._exec(args, dargs)
    finally:
        os.chdir(pwd)
        if after_test_hook:
            after_test_hook(mytest)
        shutil.rmtree(mytest.tmpdir, ignore_errors=True)