#!/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
    port_count        : (Optional) Number of ports in dataplane
    base_of_port      : (Optional) Base OpenFlow port number in dataplane
    base_if_index     : (Optional) Base OS network interface for dataplane
    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
    test_mod_map      : Dictionary indexed by module names and whose value
                        is the module reference
    all_tests         : Dictionary indexed by module reference and whose
                        value is a list of functions in that module
</pre>

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
that defines the function platform_config_update and then use the
parameter --platform=gp104 on the command line.

If platform_config_update does not set config["port_map"], an attempt
is made to generate a default map via the function default_port_map_setup.
This will use "local" and "remote" for platform names if available
and generate a sequential map based on the values of base_of_port and
base_if_index in the configuration structure.

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 Consider moving oft up a level

Current test case setup:
    Files in this or sub directories (or later, directory specified on 
command line) 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

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

##@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 = {
    "platform"           : "local",
    "controller_host"    : "127.0.0.1",
    "controller_port"    : 6633,
    "port_count"         : 4,
    "base_of_port"       : 1,
    "base_if_index"      : 1,
    "test_spec"          : "all",
    "test_dir"           : ".",
    "log_file"           : "oft.log",
    "list"               : False,
    "debug"              : _debug_default,
    "dbg_level"          : _debug_level_default,
    "port_map"           : {}
}

#@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] = eval("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
    for key in cfg_dflt.keys():
        eval("parser.set_defaults("+key+"=cfg_dflt['"+key+"'])")

    #@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("-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("--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", action="store_true",
                      help="List all tests and exit")
    parser.add_option("--verbose", action="store_true",
                      help="Short cut for --debug=verbose")
    # 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 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 default_port_map_setup(config):
    """
    Setup the OF port mapping based on config
    @param config The OFT configuration structure
    @return Port map dictionary
    """
    if (config["base_of_port"] is None) or not config["port_count"]:
        return None
    port_map = {}
    if config["platform"] == "local":
        # For local, use every other veth port
        for idx in range(config["port_count"]):
            port_map[config["base_of_port"] + idx] = "veth" + \
                str(config["base_if_index"] + (2 * idx))
    elif config["platform"] == "remote":
        # For remote, use eth ports
        for idx in range(config["port_count"]):
            port_map[config["base_of_port"] + idx] = "eth" + \
                str(config["base_if_index"] + idx)
    else:
        return None

    logging.info("Built default port map")
    return port_map

def test_list_generate(config):
    """Generate the list of all known tests indexed by module name

    Conventions:  Test files must implement the function test_set_init

    Test cases are classes that implement runTest

    @param config The oft configuration dictionary
    @returns An array of triples (mod-name, module, [tests]) where 
    mod-name is the string (filename) of the module, module is the
    value returned from __import__'ing the module and [tests] is an
    array of strings giving the test cases from the module.  
    """

    # Find and import test files
    p1 = Popen(["find", config["test_dir"], "-type","f"], stdout = PIPE)
    p2 = Popen(["xargs", "grep", "-l", "-e", "^def test_set_init"], 
                stdin=p1.stdout, stdout=PIPE)

    all_tests = {}
    mod_name_map = {}
    # There's an extra empty entry at the end of the list 
    filelist = p2.communicate()[0].split("\n")[:-1]
    for file in filelist:
        if file[-1:] == '~':
            continue
        modfile = file.lstrip('./')[:-3]

        try:
            mod = __import__(modfile)
        except:
            logging.warning("Could not import file " + file)
            continue
        mod_name_map[modfile] = mod
        added_fn = False
        for fn in dir(mod):
            if 'runTest' in dir(eval("mod." + fn)):
                if not added_fn:
                    mod_name_map[modfile] = mod
                    all_tests[mod] = []
                    added_fn = True
                all_tests[mod].append(fn)
    config["all_tests"] = all_tests
    config["mod_name_map"] = mod_name_map

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

def add_test(suite, mod, name):
    logging.info("Adding test " + mod.__name__ + "." + name)
    suite.addTest(eval("mod." + name)())

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 " "

#
# Main script
#

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

test_list_generate(config)

# Check if test list is requested; display and exit if so
if config["list"]:
    did_print = False
    print "\nTest List:"
    for mod in config["all_tests"].keys():
        if config["test_spec"] != "all" and \
                config["test_spec"] != mod.__name__:
            continue
        did_print = True
        desc = mod.__doc__.strip()
        desc = desc.split('\n')[0]
        start_str = "  Module " + mod.__name__ + ": "
        print start_str + _space_to(22, start_str) + desc
        for test in config["all_tests"][mod]:
            desc = eval('mod.' + test + '.__doc__.strip()')
            desc = desc.split('\n')[0]
            start_str = "    " + test + ":"
            print start_str + _space_to(22, start_str) + desc
        print
    if not did_print:
        print "No tests found for " + config["test_spec"]
    sys.exit(0)

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

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

if config["test_spec"] == "all":
    for mod in config["all_tests"].keys(): 
       for test in config["all_tests"][mod]:
           add_test(suite, mod, test)

else:
    for ts_entry in config["test_spec"].split(","):
        parts = ts_entry.split(".")

        if len(parts) == 1: # Either a module or test name
            if ts_entry in config["mod_name_map"].keys():
                mod = config["mod_name_map"][ts_entry]
                for test in config["all_tests"][mod]:
                    add_test(suite, mod, test)
            else: # Search for matching tests
                test_found = False
                for mod in config["all_tests"].keys():
                    if ts_entry in config["all_tests"][mod]:
                        add_test(suite, mod, ts_entry)
                        test_found = True
                if not test_found:
                    die("Could not find module or test: " + ts_entry)

        elif len(parts) == 2: # module.test
            if parts[0] not in config["mod_name_map"]:
                die("Unknown module in test spec: " + ts_entry)
            mod = config["mod_name_map"][parts[0]]
            if parts[1] in config["all_tests"][mod]:
                add_test(suite, mod, parts[1])
            else:
                die("No known test matches: " + ts_entry)

        else:
            die("Bad test spec: " + ts_entry)

# Check if platform specified
if config["platform"]:
    _imp_string = "from " + config["platform"] + " import *"
    logging.info("Importing platform: " + _imp_string)
    try:
        exec(_imp_string)
    except:
        logging.warn("Failed to import " + config["platform"] + " file")

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

if not config["port_map"]:
    # Try to set up default port mapping if not done by platform
    config["port_map"] = default_port_map_setup(config)

if not config["port_map"]:
    die("Interface port map is not defined.  Exiting")

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

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

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

if os.getuid() != 0:
    print "ERROR: Super-user privileges required. Please re-run with " \
          "sudo or as root."
    exit(1)

logging.info("*** TEST RUN START: " + time.asctime())
unittest.TextTestRunner(verbosity=_verb).run(suite)
logging.info("*** TEST RUN END  : " + time.asctime())