import logging
import traceback
import os
import sys
import optparse
import errno
import pwd

import wizard
from wizard import util

logging_setup = False

def boolish(val):
    """
    Parse the contents of an environment variable as a boolean.
    This recognizes more values as ``False`` than :func:`bool` would.

        >>> boolish("0")
        False
        >>> boolish("no")
        False
        >>> boolish("1")
        True
    """
    try:
        return bool(int(val))
    except (ValueError, TypeError):
        if val == "No" or val == "no" or val == "false" or val == "False":
            return False
        return bool(val)

def makeLogger(options, numeric_args):
    global logging_setup
    if logging_setup: return logging.getLogger()
    logger = logging.getLogger()
    logger.handlers = [] # under certain cases, a spurious stream handler is set. We don't know why
    logger.setLevel(logging.INFO)
    stderr = logging.StreamHandler(sys.stderr)
    stderr.setFormatter(logging.Formatter('%(levelname)s: %(message)s'))
    if not options.quiet: logger.addHandler(stderr)
    else: logger.addHandler(NullLogHandler()) # prevent default
    if options.log_file:
        file = logging.FileHandler(options.log_file)
        logformatter = logging.Formatter("%(asctime)s %(levelname)s: %(message)s", "%Y-%m-%d %H:%M")
        file.setFormatter(logformatter)
        logger.addHandler(file)
    if options.debug:
        logger.setLevel(logging.DEBUG)
    else:
        stderr.setLevel(logging.WARNING)
        if options.verbose:
            stderr.setLevel(logging.INFO)
        if options.log_file:
            file.setLevel(logging.INFO)
    def our_excepthook(type, value, tb):
        logging.error("".join(traceback.format_exception(type,value,tb)))
        sys.exit(1)
    sys.excepthook = our_excepthook
    logging_setup = True
    return logger

def makeBaseArgs(options, **grab):
    """Takes parsed options, and breaks them back into a command
    line string that we can pass into a subcommand"""
    args = []
    grab["debug"]   = "--debug"
    grab["verbose"] = "--verbose"
    grab["quiet"]   = "--quiet"
    #grab["log_db"] = "--log-db"
    for k,flag in grab.items():
        value = getattr(options, k)
        if not value: continue
        args.append(flag)
        if type(value) is not bool:
            args.append(str(value))
    return args

def security_check_homedir(location):
    """
    Performs a check against a directory to determine if current
    directory's owner has a home directory that is a parent directory.
    This protects against malicious mountpoints, and is roughly equivalent
    to the suexec checks.
    """
    try:
        uid = util.get_dir_uid(location)
        real = os.path.realpath(location)
        if not real.startswith(pwd.getpwuid(uid).pw_dir + "/"):
            logging.error("Security check failed, owner of deployment and "
                    "owner of home directory mismatch for %s" % location)
            return False
    except KeyError:
        logging.error("Security check failed, could not look up "
                "owner of %s (uid %d)" % (location, uid))
        return False
    except OSError as e:
        logging.error("OSError: %s" % str(e))
        return False
    return True

def calculate_log_name(log_dir, i):
    """
    Calculates a log entry given a numeric identifier, and
    directory under operation.
    """
    return os.path.join(log_dir, "%04d.log" % i)

def create_logdir(log_dir):
    """
    Creates a log directory and chmods it 777 to enable de-priviledged
    processes to create files.
    """
    try:
        os.mkdir(log_dir)
    except OSError as e:
        if e.errno != errno.EEXIST:
            raise
        #if create_subdirs:
        #    log_dir = os.path.join(log_dir, str(int(time.time())))
        #    os.mkdir(log_dir) # if fails, be fatal
        #    # XXX: update last symlink
    os.chmod(log_dir, 0o777)

def open_reports(log_dir, names=('warnings', 'errors')):
    """
    Opens a number of reports files for auxiliary reporting.  You can override what
    log files to generate using ``names``, which corresponds to the tuple
    of report files you will receive, i.e. the default returns a tuple
    ``(warnings.txt file object, errors.txt file object)``. Note that this will
    delete any information that was previously in the file (but those logfiles
    are backed up).
    """
    # must not be on AFS, since subprocesses won't be
    # able to write to the logfiles do the to the AFS patch.
    files = [os.path.join(os.path.join(log_dir, "%s.txt" % x)) for x in names]
    for f in files:
        util.safe_unlink(f)
    return (open(f, "w") for f in files)

class NullLogHandler(logging.Handler):
    """Log handler that doesn't do anything"""
    def emit(self, record):
        pass

class WizardOptionParser(optparse.OptionParser):
    """Configures some default user-level options"""
    def __init__(self, *args, **kwargs):
        kwargs["add_help_option"] = False
        optparse.OptionParser.__init__(self, *args, **kwargs)
    def parse_all(self, argv):
        self.add_option("-h", "--help", action="help", help=optparse.SUPPRESS_HELP)
        group = optparse.OptionGroup(self, "Common Options")
        group.add_option("-v", "--verbose", dest="verbose", action="store_true",
                default=boolish(os.getenv("WIZARD_VERBOSE")), help="Turns on verbose output.  Envvar is WIZARD_VERBOSE")
        group.add_option("--debug", dest="debug", action="store_true",
                default=boolish(os.getenv("WIZARD_DEBUG")), help="Turns on debugging output.  Envvar is WIZARD_DEBUG")
        group.add_option("-q", "--quiet", dest="quiet", action="store_true",
                default=boolish(os.getenv("WIZARD_QUIET")), help="Turns off output to stdout. Envvar is WIZARD_QUIET")
        group.add_option("--log-file", dest="log_file", metavar="FILE",
                default=None, help="Logs verbose output to file")
        self.add_option_group(group)
        options, numeric_args = self.parse_args(argv)
        makeLogger(options, numeric_args)
        # we're going to process the global --log-dir/--seen dependency here
        if hasattr(options, "seen") and hasattr(options, "log_dir"):
            if not options.seen and options.log_dir:
                options.seen = os.path.join(options.log_dir, "seen.txt")
        return options, numeric_args

class OptionBaton(object):
    """Command classes may define options that they sub-commands may
    use.  Since wizard --global-command subcommand is not a supported
    mode of operation, these options have to be passed down the command
    chain until a option parser is ready to take it; this baton is
    what is passed down."""
    def __init__(self):
        self.store = {}
    def add(self, *args, **kwargs):
        key = kwargs["dest"] # require this to be set
        self.store[key] = optparse.make_option(*args, **kwargs)
    def push(self, option_parser, *args):
        """Hands off parameters to option parser"""
        for key in args:
            option_parser.add_option(self.store[key])

class Error(wizard.Error):
    """Base error class for all command errors"""
    pass