#!/usr/bin/env python
"""
@package oft

OpenFlow test framework top level script

This script is the entry point for running OpenFlow tests
using the OFT framework.

The global configuration is passed around in a dictionary
generally called config.  The keys have the following
significance.

<pre>
    platform          : String identifying the target platform
    controller_host   : Host on which test controller is running (for sockets)
    controller_port   : Port on which test controller listens for switch cxn
    test_dir          : (TBD) Directory to search for test files (default .)
    test_spec         : (TBD) Specification of test(s) to run
    log_file          : Filename for test logging
    list              : Boolean:  List all tests and exit
    debug             : String giving debug level (info, warning, error...)
</pre>

See config_defaults below for the default values.

The following are stored in the config dictionary, but are not currently
configurable through the command line.

<pre>
    dbg_level         : logging module value of debug level
    port_map          : Map of dataplane OpenFlow port to OS interface names
</pre>

Each test may be assigned a priority by setting the "priority" property
in the class definition.  For now, the only use of this is to avoid
automatic inclusion of tests into the default list.  This is done by
setting the priority value less than 0.  Eventually we may add ordering
of test execution by test priority.

To add a test to the system, either: edit an existing test case file (like
basic.py) to add a test class which inherits from unittest.TestCase (directly
or indirectly); or add a new file which includes a function definition 
test_set_init(config).  Preferably the file is in the same directory as existing
tests, though you can specify the directory on the command line.  The file
should not be called "all" as that's reserved for the test-spec.

If you add a new file, the test_set_init function should record the port
map object from the configuration along with whatever other configuration 
information it may need.

TBD:  To add configuration to the system, first add an entry to config_default
below.  If you want this to be a command line parameter, edit config_setup
to add the option and default value to the parser.  Then edit config_get
to make sure the option value gets copied into the configuration 
structure (which then gets passed to everyone else).

By convention, oft attempts to import the contents of a file by the 
name of $platform.py into the local namespace.  

IMPORTANT: That file should define a function platform_config_update which
takes a configuration dictionary as an argument and updates it for the
current run.  In particular, it should set up config["port_map"] with
the proper map from OF port numbers to OF interface names.

You can add your own platform, say gp104, by adding a file gp104.py to the
platforms directory that defines the function platform_config_update and then
use the parameter --platform=gp104 on the command line. You can also use the
--platform-dir option to change which directory is searched.

The current model for test sets is basic.py.  The current convention is
that the test set should implement a function test_set_init which takes
an oft configuration dictionary and returns a unittest.TestSuite object.
Future test sets should do the same thing.

Default setup:

The default setup runs locally using veth pairs.  To exercise this, 
checkout and build an openflow userspace datapath.  Then start it on 
the local host:
<pre>
  sudo ~/openflow/regress/bin/veth_setup.pl 
  sudo ofdatapath -i veth0,veth2,veth4,veth6 punix:/tmp/ofd &
  sudo ofprotocol unix:/tmp/ofd tcp:127.0.0.1 --fail=closed --max-backoff=1 &

Next, run oft: 
  sudo ./oft --debug=info
</pre>

Examine oft.log if things don't work.

@todo Support per-component debug levels (esp controller vs dataplane)
@todo Allow specification of priority to override prio check

Current test case setup:
    Files in the tests direcoty that contain a function test_set_init are
considered test files.
    The function test_set_init examines the test_spec config variable
and generates a suite of tests.
    Support a command line option --test_mod so that all tests in that
module will be run.
    Support all to specify all tests from the module.

"""

import sys
from optparse import OptionParser
from subprocess import Popen,PIPE
import logging
import unittest
import time
import os
import imp
import random
import signal
import fnmatch

root_dir = os.path.dirname(os.path.realpath(__file__))

pydir = os.path.join(root_dir, 'src', 'python')
if os.path.exists(os.path.join(pydir, 'oftest')):
    # Running from source tree
    sys.path.insert(0, pydir)

try:
    import oftest.message
except:
    sys.exit("Missing OpenFlow message classes: please run \"make -C tools/munger\"")

import oftest.testutils
import oftest.ofutils

try:
    import scapy.all as scapy
except:
    try:
        import scapy as scapy
    except:
        sys.exit("Need to install scapy for packet parsing")

##@var Profile module
profile_mod = None

##@var DEBUG_LEVELS
# Map from strings to debugging levels
DEBUG_LEVELS = {
    'debug'              : logging.DEBUG,
    'verbose'            : logging.DEBUG,
    'info'               : logging.INFO,
    'warning'            : logging.WARNING,
    'warn'               : logging.WARNING,
    'error'              : logging.ERROR,
    'critical'           : logging.CRITICAL
}

_debug_default = "warning"
_debug_level_default = DEBUG_LEVELS[_debug_default]

##@var config_default
# The default configuration dictionary for OFT
config_default = {
    "param"              : None,
    "platform"           : "local",
    "platform_args"      : None,
    "controller_host"    : "0.0.0.0",
    "controller_port"    : 6633,
    "relax"              : False,
    "test_spec"          : "all",
    "log_file"           : "oft.log",
    "list"               : False,
    "list_test_names"    : False, 
    "debug"              : _debug_default,
    "dbg_level"          : _debug_level_default,
    "port_map"           : {},
    "test_params"        : "None",
    "profile"            : "default",
    "allow_user"         : False,
    "fail_skipped"       : False,
    "default_timeout"    : 2,
    "minsize"            : 0,
    "random_seed"        : None,
    "test_dir"           : os.path.join(root_dir, "tests"),
    "platform_dir"       : os.path.join(root_dir, "platforms"),
    "profile_dir"        : os.path.join(root_dir, "profiles"),
}

# Default test priority
TEST_PRIO_DEFAULT=100
TEST_PRIO_SKIP=-1

#@todo Set up a dict of config params so easier to manage:
# <param> <cmdline flags> <default value> <help> <optional parser>

# Map options to config structure
def config_get(opts):
    "Convert options class to OFT configuration dictionary"
    cfg = config_default.copy()
    for key in cfg.keys():
        cfg[key] = getattr(opts, key)

    # Special case checks
    if opts.debug not in DEBUG_LEVELS.keys():
        print "Warning:  Bad value specified for debug level; using default"
        opts.debug = _debug_default
    if opts.verbose:
        cfg["debug"] = "verbose"
    cfg["dbg_level"] = DEBUG_LEVELS[cfg["debug"]]

    return cfg

def config_setup(cfg_dflt):
    """
    Set up the configuration including parsing the arguments

    @param cfg_dflt The default configuration dictionary
    @return A pair (config, args) where config is an config
    object and args is any additional arguments from the command line
    """

    parser = OptionParser(version="%prog 0.1")

    #@todo parse port map as option?
    # Set up default values
    parser.set_defaults(**cfg_dflt)

    #@todo Add options via dictionary
    plat_help = """Set the platform type.  Valid values include:
        local:  User space virtual ethernet pair setup
        remote:  Remote embedded Broadcom based switch
        Create a new_plat.py file and use --platform=new_plat on the command line
        """
    parser.add_option("-a", "--platform-args", help="Custom arguments per platform.")
    parser.add_option("-P", "--platform", help=plat_help)
    parser.add_option("-H", "--host", dest="controller_host",
                      help="The IP/name of the test controller host")
    parser.add_option("-p", "--port", dest="controller_port",
                      type="int", help="Port number of the test controller")
    test_list_help = """Indicate tests to run.  Valid entries are "all" (the
        default) or a comma separated list of:
        module            Run all tests in the named module
        testcase          Run tests in all modules with the name testcase
        module.testcase   Run the specific test case
        """
    parser.add_option("-T", "--test-spec", "--test-list", help=test_list_help)
    parser.add_option("--log-file", 
                      help="Name of log file, empty string to log to console")
    parser.add_option("--debug",
                      help="Debug lvl: debug, info, warning, error, critical")
    parser.add_option("--port-count", type="int",
                      help="Number of ports to use (optional)")
    parser.add_option("--base-of-port", type="int",
                      help="Base OpenFlow port number (optional)")
    parser.add_option("--base-if-index", type="int",
                      help="Base interface index number (optional)")
    parser.add_option("--list-test-names", action='store_true',
                      help="List only test names.", default=False)
    parser.add_option("--list", action="store_true",
                      help="List all tests and exit")
    parser.add_option("--verbose", action="store_true",
                      help="Short cut for --debug=verbose")
    parser.add_option("--relax", action="store_true",
                      help="Relax packet match checks allowing other packets")
    parser.add_option("--param", type="int",
                      help="Parameter sent to test (for debugging)")
    parser.add_option("--profile", 
                      help="File listing tests to skip/run")
    parser.add_option("-t", "--test-params",
                      help="""Set test parameters: key=val;...
        NOTE:  key MUST be a valid Python identifier, egr_count not egr-count
        See --list""")
    parser.add_option("--allow-user", action="store_true",
                      help="Proceed even if oftest is not run as root")
    parser.add_option("--fail-skipped", action="store_true",
                      help="Return failure if any test was skipped")
    parser.add_option("--default-timeout", type="int",
                      help="Timeout in seconds for most operations")
    parser.add_option("--minsize", type="int", 
                      help="Minimum allowable packet size on the dataplane.", 
                      default=0)
    parser.add_option("--random-seed", type="int",
                      help="Random number generator seed",
                      default=None)
    parser.add_option("--test-dir", type="string",
                      help="Directory containing tests")
    parser.add_option("--platform-dir", type="string",
                      help="Directory containing platform modules")
    parser.add_option("--profile-dir", type="string",
                      help="Directory containing profile modules")

    # Might need this if other parsers want command line
    # parser.allow_interspersed_args = False
    (options, args) = parser.parse_args()

    config = config_get(options)

    return (config, args)

def load_profile(config):
    """
    Import a profile from the profiles library
    """

    global profile_mod
    logging.info("Importing profile: %s" % config["profile"])
    try:
        profile_mod = imp.load_module(config["profile"], *imp.find_module(config["profile"], [config["profile_dir"]]))
        if not "skip_test_list" in dir(profile_mod):
            die("Profile did not define skip_test_list")
    except:
        logging.info("Could not import profile: %s.py" % config["profile"])
        print "Failed to import profile: %s" % config["profile"]
        raise

def logging_setup(config):
    """
    Set up logging based on config
    """
    _format = "%(asctime)s  %(name)-10s: %(levelname)-8s: %(message)s"
    _datefmt = "%H:%M:%S"
    logging.basicConfig(filename=config["log_file"],
                        level=config["dbg_level"],
                        format=_format, datefmt=_datefmt)

def load_test_modules(config):
    """
    Load tests from the test_dir directory.

    Test cases are subclasses of unittest.TestCase

    @param config The oft configuration dictionary
    @returns A dictionary from test module names to tuples of
    (module, dictionary from test names to test classes).
    """

    result = {}

    for root, dirs, filenames in os.walk(config["test_dir"]):
        # Iterate over each python file
        for filename in fnmatch.filter(filenames, '[!.]*.py'):
            modname = os.path.splitext(os.path.basename(filename))[0]

            try:
                if sys.modules.has_key(modname):
                    mod = sys.modules[modname]
                else:
                    mod = imp.load_module(modname, *imp.find_module(modname, [root]))
            except:
                logging.warning("Could not import file " + filename)
                raise

            # Find all testcases defined in the module
            tests = dict((k, v) for (k, v) in mod.__dict__.items() if type(v) == type and
                                                                      issubclass(v, unittest.TestCase))
            if tests:
                result[modname] = (mod, tests)

    return result

def prune_tests(test_spec, test_modules):
    """
    Return tests matching a given test-spec.
    @param test_spec A test-spec string.
    @param test_modules Same format as the output of load_test_modules.
    @returns Same format as the output of load_test_modules.
    """
    result = {}
    for (spec_modname, spec_testname) in parse_test_spec(test_spec):
        matched = False
        for (modname, (mod, tests)) in test_modules.items():
            if (spec_modname == None or spec_modname == modname):
                for (testname, test) in tests.items():
                    if (spec_testname == None or spec_testname == testname):
                            result.setdefault(modname, (mod, {}))
                            result[modname][1][testname] = test
                            matched = True
        if not matched:
            if spec_modname and spec_testname:
                el = "%s.%s" % (spec_modname, spec_testname)
            else:
                el = spec_modname or spec_testname or "all"
            die("test-spec element %s did not match any tests" % el)
    return result

def parse_test_spec(test_spec):
    """
    The input string is split on commas and each element is parsed
    individually into a module name and test name. Either may be None
    for a wildcard. The case of the first letter resolves ambiguity
    of whether a word is a test or module name. The special string
    "all" results in both fields wildcarded.

    Examples:
      basic.Echo -> ("basic", "Echo")
      basic -> ("basic", None)
      Echo -> (None, "Echo")
      all -> (None, None)
    """
    results = []
    for ts_entry in test_spec.split(","):
        parts = ts_entry.split(".")
        if len(parts) == 1:
            if ts_entry == "all":
                results.append((None, None))
            elif ts_entry[0].isupper():
                results.append((None, ts_entry))
            else:
                results.append((ts_entry, None))
        elif len(parts) == 2:
            results.append((parts[0], parts[1]))
        else:
            die("Bad test spec: " + ts_entry)
    return results

def die(msg, exit_val=1):
    print msg
    logging.critical(msg)
    sys.exit(exit_val)

def _space_to(n, str):
    """
    Generate a string of spaces to achieve width n given string str
    If length of str >= n, return one space
    """
    spaces = n - len(str)
    if spaces > 0:
        return " " * spaces
    return " "

def test_prio_get(test):
    """
    Return the priority of a test

    If test is in "skip list" from profile, return the skip value

    If the priority property is set in the class, return
    that value.  Otherwise return 100 (default)
    """
    if test.__name__ in profile_mod.skip_test_list:
        logging.info("Skipping test %s due to profile" % test.__name__)
        return TEST_PRIO_SKIP
    return getattr(test, "priority", TEST_PRIO_DEFAULT)

#
# Main script
#

# Get configuration, set up logging, import platform from file
(config, args) = config_setup(config_default)

logging_setup(config)
logging.info("++++++++ " + time.asctime() + " ++++++++")

# Allow tests to import each other
sys.path.append(config["test_dir"])

test_modules = prune_tests(config["test_spec"], load_test_modules(config))
oft_config = config

load_profile(config)

# Check if test list is requested; display and exit if so
if config["list"]:
    mod_count = 0
    test_count = 0
    print "\nTest List:"
    for (modname, (mod, tests)) in test_modules.items():
        mod_count += 1
        desc = mod.__doc__.strip()
        desc = desc.split('\n')[0]
        start_str = "  Module " + mod.__name__ + ": "
        print start_str + _space_to(22, start_str) + desc
        for (testname, test) in tests.items():
            try:
                desc = test.__doc__.strip()
                desc = desc.split('\n')[0]
            except:
                desc = "No description"
            if test_prio_get(test) < 0:
                start_str = "  * " + testname + ":"
            else:
                start_str = "    " + testname + ":"
            if len(start_str) > 22:
                desc = "\n" + _space_to(22, "") + desc
            print start_str + _space_to(22, start_str) + desc
            test_count += 1
        print
    print "%d modules shown with a total of %d tests" % \
        (mod_count, test_count)
    print
    print "Tests preceded by * are not run by default"
    print "Tests marked (TP1) after name take --test-params including:"
    print "    'vid=N;strip_vlan=bool;add_vlan=bool'"
    print "Note that --profile may override which tests are run"
    sys.exit(0)

# Check if test list is requested; display and exit if so
if config["list_test_names"]:
    for (modname, (mod, tests)) in test_modules.items():
        for (testname, test) in tests.items():
            if test_prio_get(test) >= 0:
                print "%s.%s" % (modname, testname)
    sys.exit(0)

# Generate the test suite
#@todo Decide if multiple suites are ever needed
suite = unittest.TestSuite()

for (modname, (mod, tests)) in test_modules.items():
    for (testname, test) in tests.items():
        if test_prio_get(test) >= 0:
            logging.info("Adding test " + modname + "." + testname)
            suite.addTest(test())

# Load the platform module
platform_name = config["platform"]
logging.info("Importing platform: " + platform_name)
platform_mod = None
try:
    platform_mod = imp.load_module(platform_name, *imp.find_module(platform_name, [config["platform_dir"], config["test_dir"]]))
except:
    logging.warn("Failed to import " + platform_name + " platform module")
    raise

try:
    platform_mod.platform_config_update(config)
except:
    logging.warn("Could not run platform host configuration")
    raise

if not config["port_map"]:
    die("Interface port map was not defined by the platform. Exiting.")

logging.debug("Configuration: " + str(config))
logging.info("OF port map: " + str(config["port_map"]))

# Init the test sets
for (modname, (mod, tests)) in test_modules.items():
    try:
        mod.test_set_init(config)
    except:
        logging.warning("Could not run test_set_init for " + modname)
        raise

if config["dbg_level"] == logging.CRITICAL:
    _verb = 0
elif config["dbg_level"] >= logging.WARNING:
    _verb = 1
else:
    _verb = 2

oftest.ofutils.default_timeout = config["default_timeout"]
oftest.testutils.MINSIZE = config['minsize']

if os.getuid() != 0 and not config["allow_user"]:
    print "ERROR: Super-user privileges required. Please re-run with " \
          "sudo or as root."
    sys.exit(1)

if config["random_seed"] is not None:
    logging.info("Random seed: %d" % config["random_seed"])
    random.seed(config["random_seed"])

# Remove python's signal handler which raises KeyboardError. Exiting from an
# exception waits for all threads to terminate which might not happen.
signal.signal(signal.SIGINT, signal.SIG_DFL)

if __name__ == "__main__":
    logging.info("*** TEST RUN START: " + time.asctime())
    result = unittest.TextTestRunner(verbosity=_verb).run(suite)
    if oftest.testutils.skipped_test_count > 0:
        ts = " tests"
        if oftest.testutils.skipped_test_count == 1: ts = " test"
        logging.info("Skipped " + str(oftest.testutils.skipped_test_count) + ts)
        print("Skipped " + str(oftest.testutils.skipped_test_count) + ts)
    logging.info("*** TEST RUN END  : " + time.asctime())
    if result.failures or result.errors:
        # exit(1) hangs sometimes
        os._exit(1)
    if oftest.testutils.skipped_test_count > 0 and config["fail_skipped"]:
        os._exit(1)