import os

import sys

import Params

import shutil

import pproc as subprocess

import urllib

import wutils

#

# The directory in which the tarball of the reference traces lives.  This is

# used if Mercurial is not on the system.

#

REGRESSION_TRACES_URL = "http://www.nsnam.org/releases/"

#

# The path to the Mercurial repository used to find the reference traces if

# we find "hg" on the system.  We expect that the repository will be named

# identically to refDirName below

#

REGRESSION_TRACES_REPO = "http://code.nsnam.org/"

#

# Name of the local directory where the regression code lives.

#

REGRESSION_DIR = "regression"

#

# The last part of the path name to use to find the regression traces.  The

# path will be APPNAME + '-' + VERSION + REGRESSION_SUFFIX, e.g.,

# ns-3-dev-ref-traces

#

REGRESSION_SUFFIX = "-ref-traces"

def dev_null():

    if sys.platform == 'win32':

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

    else:

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

### Regression testing

class Regression(object):

    def __init__(self, testdir):

        self.testdir = testdir

        self.env = Params.g_build.env_of_name('default')

    def run_test(self, verbose, generate, refDirName, testName, arguments=[], pyscript=None, refTestName=None):

        """

        @param verbose: enable verbose execution

        @param generate: generate new traces instead of comparing with the reference

        @param refDirName: name of the base directory containing reference traces

        @param testName: name of the test

        @arguments: list of extra parameters to pass to the program to be tested

        @pyscript: if not None, the test is written in Python and this

        parameter contains the path to the python script, relative to

        the project root dir

        @param refTestName: if not None, this is the name of the directory under refDirName

        that contains the reference traces. Otherwise "refDirname/testName + .ref" is used.

        """

        if not isinstance(arguments, list):

            raise TypeError

        if refTestName is None:

            refTestDirName = os.path.join(refDirName, (testName + ".ref"))

        else:

            refTestDirName = os.path.join(refDirName, refTestName)

        if not os.path.exists(refDirName):

            print"No reference trace repository"

            return 1

        if generate:

            if not os.path.exists(refTestDirName):

                print "creating new " + refTestDirName

                os.mkdir(refTestDirName)

            if pyscript is None:

                Params.g_options.cwd_launch = refTestDirName

                tmpl = "%s"

                for arg in arguments:

                    tmpl = tmpl + " " + arg

                wutils.run_program(testName, tmpl)

            else:

                argv = [self.env['PYTHON'], os.path.join('..', '..', '..', *os.path.split(pyscript))] + arguments

                before = os.getcwd()

                os.chdir(refTestDirName)

                try:

                    wutils.run_argv(argv)

                finally:

                    os.chdir(before)

            print "Remember to commit " + refTestDirName

            return 0

        else:

            if not os.path.exists(refTestDirName):

                print "Cannot locate reference traces in " + refTestDirName

                return 1

            if refTestName is None:

                traceDirName = testName + ".ref"

            else:

                traceDirName = refTestName

            traceDirName = os.path.join ('traces', traceDirName)

            try:

                shutil.rmtree(traceDirName)

            except OSError:

                pass

            os.mkdir(traceDirName)

            #os.system("./waf --cwd regression/traces --run " +

            #  testName + " > /dev/null 2>&1")

            if pyscript is None:

                Params.g_options.cwd_launch = traceDirName

                wutils.run_program(testName, command_template=wutils.get_command_template(*arguments))

            else:

                argv = [self.env['PYTHON'], os.path.join('..', '..', '..', *os.path.split(pyscript))] + arguments

                before = os.getcwd()

                os.chdir(traceDirName)

                try:

                    wutils.run_argv(argv)

                finally:

                    os.chdir(before)

            if verbose:

                #diffCmd = "diff traces " + refTestDirName + " | head"

                diffCmd = subprocess.Popen([self.env['DIFF'], traceDirName, refTestDirName],

                                           stdout=subprocess.PIPE)

                headCmd = subprocess.Popen("head", stdin=diffCmd.stdout)

                rc2 = headCmd.wait()

                diffCmd.stdout.close()

                rc1 = diffCmd.wait()

                rc = rc1 or rc2

            else:

                rc = subprocess.Popen([self.env['DIFF'], traceDirName, refTestDirName], stdout=dev_null()).wait()

            if rc:

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

                print "Traces differ in test: test-" + testName

                print "Reference traces in directory: regression/" + refTestDirName

                print "Traces in directory: traces"

                print "Rerun regression test as: " + \

                    "\"./waf --regression --regression-tests=test-" + testName + "\""

                print "Then do \"diff -u regression/" + refTestDirName + " regression/" + traceDirName +\

                    "\" for details"

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

            return rc

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 run_regression():

    """Execute regression tests."""

    testdir = "tests"

    if not os.path.exists(testdir):

        print "Tests directory does not exist"

        sys.exit(3)

    sys.path.append(testdir)

    sys.modules['tracediff'] = Regression(testdir)

    if Params.g_options.regression_tests:

        tests = Params.g_options.regression_tests.split(',')

    else:

        tests = _find_tests(testdir)

    print "========== Running Regression Tests =========="

    dir_name = wutils.APPNAME + '-' + wutils.VERSION + REGRESSION_SUFFIX

    env = Params.g_build.env_of_name('default')

    if env['MERCURIAL']:

        print "Synchronizing reference traces using Mercurial."

        if not os.path.exists(dir_name):

            print "Cloning " + REGRESSION_TRACES_REPO + dir_name + " from repo."

            argv = ["hg", "clone", REGRESSION_TRACES_REPO + dir_name, dir_name]

            rv = subprocess.Popen(argv).wait()

        else:

            _dir = os.getcwd()

            os.chdir(dir_name)

            try:

                print "Pulling " + REGRESSION_TRACES_REPO + dir_name + " from repo."

                result = subprocess.Popen(["hg", "-q", "pull", REGRESSION_TRACES_REPO + dir_name]).wait()

                if not result:

                    result = subprocess.Popen(["hg", "-q", "update"]).wait()

            finally:

                os.chdir("..")

            if result:

                Params.fatal("Synchronizing reference traces using Mercurial failed.")

    else:

        if not os.path.exists(dir_name):

            traceball = dir_name + wutils.TRACEBALL_SUFFIX

            print "Retrieving " + traceball + " from web."

            urllib.urlretrieve(REGRESSION_TRACES_URL + traceball, traceball)

            os.system("tar -xjf %s -C .." % (traceball))

            print "Done."

    if not os.path.exists(dir_name):

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

        return 3

    bad = []

    for test in tests:

        try:

            result = _run_regression_test(test)

            if result == 0:

                if Params.g_options.regression_generate:

                    print "GENERATE " + test

                else:

                    print "PASS " + test

            else:

                bad.append(test)

                print "FAIL " + test

        except NotImplementedError:

                print "SKIP " + test            

    return len(bad) > 0

def _run_regression_test(test):

    """Run a single test.

    Arguments:

    test -- the name of the test

    """

    if os.path.exists("traces"):

        files = os.listdir("traces")

        for file in files:

            if file == '.' or file == '..':

                continue

            shutil.rmtree(os.path.join("traces", file), ignore_errors=True)

    else:

        os.mkdir("traces")

    dir_name = wutils.APPNAME + '-' + wutils.VERSION + REGRESSION_SUFFIX

    mod = __import__(test, globals(), locals(), [])

    return mod.run(verbose=(Params.g_options.verbose > 0),

                   generate=Params.g_options.regression_generate,

                   refDirName=dir_name)