# python lib modules

import os

import sys

import shutil

import pproc as subprocess

import errno

# WAF modules

import Options

import Utils

import Task

# local modules

import wutils

def dev_null():

    if sys.platform == 'win32':

        return open("NUL:", "w")

    else:

        return open("/dev/null", "w")

def _find_tests(testdir):

    """Return a list of test modules in the test directory

    Arguments:

    testdir -- the directory to look in for tests

    """

    names = os.listdir(testdir)

    tests = []

    for name in names:

        if name[:5] == "test-" and name[-3:] == ".py":

            testname = name[:-3]

            tests.append(testname)

    tests.sort()

    return tests

def diff(dir1, dir2, verbose):

    import filecmp

    comp = filecmp.dircmp(dir1, dir2)

    differ = (comp.left_only or comp.right_only or comp.diff_files)

    if differ:

        # ok, stupid binary comparison reports differences, but maybe

        # only text files differ, in which case we should compare

        # again while ignoring newline differences between

        # windows/mac/unix.

        if not comp.left_only and not comp.right_only:

            for diff_fname in comp.diff_files:

                if not (diff_fname.endswith(".tr") or diff_fname.endswith(".mob")):

                    # doesn't look like a text file; it has to differ

                    break

                diff_file1 = open(os.path.join(dir1, diff_fname), "rtU").readlines()

                diff_file2 = open(os.path.join(dir2, diff_fname), "rtU").readlines()

                if diff_file1 != diff_file2:

                    break

                #else:

                #    print ">>>>>>>> %s file does not really differ!" % (diff_fname)

            else:

                differ = False

    if differ:

        if verbose:

            comp.report()

            import difflib

            for diff_fname in comp.diff_files:

                if not (diff_fname.endswith(".tr") or diff_fname.endswith(".mob")):

                    print "The different file %r does not sound like a text file, not compared." % (diff_fname,)

                diff_file1 = open(os.path.join(dir1, diff_fname), "rt").readlines()

                diff_file2 = open(os.path.join(dir2, diff_fname), "rt").readlines()

                diff = difflib.unified_diff(diff_file1, diff_file2)

                count = 0

                print "Differences in file %r" % (diff_fname,)

                for line in diff:

                    print line

                    count += 1

                    if count > 100:

                        break

        return 1

    else:

        return 0

class regression_test_task(Task.TaskBase):

    after = 'cc cxx cc_link cxx_link'

    color = 'BLUE'

    def __init__(self, bld, env, test_name, test_scripts_dir, build_traces_dir, reference_traces):

        self.bld = bld

        self.generator = self

        self.env = env

        super(regression_test_task, self).__init__(generator=self, env=env)

        self.test_name = test_name

        assert self.test_name.startswith('test-')

        short_name = self.test_name[len('test-'):]

        self.test_scripts_dir = test_scripts_dir

        self.build_traces_dir = build_traces_dir

        self.reference_traces_dir = reference_traces

        sys.path.insert(0, self.test_scripts_dir)

        try:

            mod = __import__(self.test_name, globals(), locals(), [])

        finally:

            sys.path.remove(self.test_scripts_dir)

        self.mod = mod

        if hasattr(mod, 'may_run'):

            reason_cannot_run = mod.may_run(self.env, Options.options)

        else:

            reason_cannot_run = None

        if not reason_cannot_run:

            pyscript = getattr(mod, "pyscript", None)

            if pyscript:

                Options.options.compile_targets += ',ns3module,pybindgen-command'

            else:

                program = getattr(mod, "program", short_name)

                Options.options.compile_targets += ',' + program

    def __str__(self):

        return 'regression-test (%s)\n' % self.test_name

    def runnable_status(self):

        return Task.RUN_ME

    def run(self):

        """Run a single test"""

        assert self.test_name.startswith('test-')

        short_name = self.test_name[len('test-'):]

        mod = self.mod

        trace_dir_name = getattr(mod, "trace_dir_name", None)

        if trace_dir_name is None:

            trace_dir_name = "%s.ref" % short_name

        trace_output_path = os.path.join(self.build_traces_dir, trace_dir_name)

        reference_traces_path = os.path.join(self.reference_traces_dir, trace_dir_name)

        if hasattr(mod, 'get_arguments'):

            arguments = mod.get_arguments(self.env, '..')

        else:

            arguments = getattr(mod, "arguments", [])

        pyscript = getattr(mod, "pyscript", None)

        if pyscript:

            is_pyscript = True

            program = pyscript

        else:

            is_pyscript = False

            program = getattr(mod, "program", short_name)

        if hasattr(mod, 'may_run'):

            reason_cannot_run = mod.may_run(self.env, Options.options)

        else:

            reason_cannot_run = None

        if reason_cannot_run:

            print "SKIP %s (%s)" % (self.test_name, reason_cannot_run)

            self.result = None

            return 0

        if Options.options.regression_generate:

            # clean the target dir

            try:

                shutil.rmtree(reference_traces_path)

            except OSError, ex:

                if ex.errno not in [errno.ENOENT]:

                    raise

            os.makedirs(reference_traces_path)

            result = self.run_reference_generate(reference_traces_path, program, arguments, is_pyscript)

            if result == 0:

                print "GENERATE " + self.test_name

            else:

                print "GENERATE FAIL " + self.test_name

        else:

            # clean the target dir

            try:

                shutil.rmtree(trace_output_path)

            except OSError, ex:

                if ex.errno not in [errno.ENOENT]:

                    raise

            os.makedirs(trace_output_path)

            # run it

            #print "self.run_reference_test:(%r, %r, %r, %r, %r)" \

            #    % (reference_traces_path, trace_output_path, program, arguments, is_pyscript)

            result = self.run_reference_test(reference_traces_path, trace_output_path, program, arguments, is_pyscript)

            if result == 0:

                print "PASS " + self.test_name

            else:

                print "FAIL " + self.test_name

        self.result = result

        return 0

    def run_reference_test(self, reference_traces_path, trace_output_path, program, arguments, is_pyscript):

        if not os.path.exists(reference_traces_path):

            print "Cannot locate reference traces in " + reference_traces_path

            return 1

        if is_pyscript:

            script = os.path.abspath(os.path.join('..', *os.path.split(program)))

            argv = [self.env['PYTHON'], script] + arguments

            try:

                wutils.run_argv(argv, self.env, cwd=trace_output_path, force_no_valgrind=True)

            except Utils.WafError, ex:

                print >> sys.stderr, ex

                return 1

        else:

            try:

                wutils.run_program(program, self.env,

                                   command_template=wutils.get_command_template(self.env, arguments),

                                   cwd=trace_output_path)

            except Utils.WafError, ex:

                print >> sys.stderr, ex

                return 1

        rc = diff(trace_output_path, reference_traces_path, Options.options.verbose)

        if rc:

            print "----------"

            print "Traces differ in test: ", self.test_name

            print "Reference traces in directory: " + reference_traces_path

            print "Traces in directory: " + trace_output_path

            print "Run the following command for details:"

            print "\tdiff -u %s %s" % (reference_traces_path, trace_output_path)

            if not Options.options.verbose:

                print "Or re-run regression testing with option -v"

            print "----------"

        return rc

    def run_reference_generate(self, trace_output_path, program, arguments, is_pyscript):

        if is_pyscript:

            script = os.path.abspath(os.path.join('..', *os.path.split(program)))

            argv = [self.env['PYTHON'], script] + arguments

            try:

                retval = wutils.run_argv(argv, self.env, cwd=trace_output_path, force_no_valgrind=True)

            except Utils.WafError, ex:

                print >> sys.stderr, ex

                return 1

        else:

            try:

                retval = wutils.run_program(program, self.env,

                                            command_template=wutils.get_command_template(self.env, arguments),

                                            cwd=trace_output_path)

            except Utils.WafError, ex:

                print >> sys.stderr, ex

                return 1

        return retval

class regression_test_collector_task(Task.TaskBase):

    after = 'regression_test_task'

    color = 'BLUE'

    def __init__(self, bld, test_tasks):

        self.bld = bld

        super(regression_test_collector_task, self).__init__(generator=self)

        self.test_tasks = test_tasks

    def __str__(self):

        return 'regression-test-collector\n'

    def runnable_status(self):

        return Task.RUN_ME

    def run(self):

        failed_tests = [test for test in self.test_tasks if test.result is not None and test.result != 0]

        skipped_tests = [test for test in self.test_tasks if test.result is None]

        print "Regression testing summary:"

        if skipped_tests:

            print "SKIP: %i of %i tests have been skipped (%s)" % (

                len(skipped_tests), len(self.test_tasks),

                ', '.join([test.test_name for test in skipped_tests]))

        if failed_tests:

            print "FAIL: %i of %i tests have failed (%s)" % (

                len(failed_tests), len(self.test_tasks),

                ', '.join([test.test_name for test in failed_tests]))

            return 1

        else:

            print "PASS: %i of %i tests passed" % (len(self.test_tasks) - len(skipped_tests),

                                                   len(self.test_tasks))

            return 0

def run_regression(bld, reference_traces):

    """Execute regression tests.  Called with cwd set to the 'regression' subdir of ns-3.

    @param reference_traces: reference traces directory.

    """

    testdir = os.path.join("regression", "tests")

    if not os.path.exists(testdir):

        print "Tests directory does not exist"

        sys.exit(3)

    if Options.options.regression_tests:

        tests = Options.options.regression_tests.split(',')

    else:

        tests = _find_tests(testdir)

    if not os.path.exists(reference_traces):

        print "Reference traces directory (%s) does not exist" % reference_traces

        return 3

    test_scripts_dir = bld.path.find_dir('regression/tests').abspath()

    build_traces_dir = bld.path.find_or_declare('regression/traces').abspath(bld.env)

    tasks = []

    for test in tests:

        task = regression_test_task(bld, bld.env, test, test_scripts_dir, build_traces_dir, reference_traces)

        #bld.task_manager.add_task(task)

        tasks.append(task)

    regression_test_collector_task(bld, tasks)