"""some utilities for cubicweb tools

:organization: Logilab

:copyright: 2001-2008 LOGILAB S.A. (Paris, FRANCE), all rights reserved.

:contact: http://www.logilab.fr/ -- mailto:contact@logilab.fr

"""

__docformat__ = "restructuredtext en"

import os, sys

from os import listdir, makedirs, symlink, environ, chmod, walk, remove

from os.path import exists, join, abspath, normpath

from logilab.common.clcommands import Command as BaseCommand, \

     main_run as base_main_run, register_commands, pop_arg, cmd_run

from logilab.common.compat import any

from cubicweb import warning

from cubicweb import ConfigurationError, ExecutionError

def iter_dir(directory, condition_file=None, ignore=()):

    """iterate on a directory"""

    for sub in listdir(directory):

        if sub in ('CVS', '.svn', '.hg'):

            continue

        if condition_file is not None and \

               not exists(join(directory, sub, condition_file)):

            continue

        if sub in ignore:

            continue

        yield sub

def create_dir(directory):

    """create a directory if it doesn't exist yet"""

    try:

        makedirs(directory)

        print 'created directory', directory

    except OSError, ex:

        import errno

        if ex.errno != errno.EEXIST:

            raise

        print 'directory %s already exists' % directory

def create_symlink(source, target):

    """create a symbolic link"""

    if exists(target):

        remove(target)

    symlink(source, target)

    print '[symlink] %s <-- %s' % (target, source)

def create_copy(source, target):

    import shutil

    print '[copy] %s <-- %s' % (target, source)

    shutil.copy2(source, target)

def rm(whatever):

    import shutil

    shutil.rmtree(whatever)

    print 'removed %s' % whatever

def show_diffs(appl_file, ref_file, askconfirm=True):

    """interactivly replace the old file with the new file according to

    user decision

    """

    import shutil

    p_output = os.popen('diff -u %s %s' % (appl_file, ref_file), 'r')

    diffs = p_output.read()

    if diffs:

        if askconfirm:

            print 

            print diffs

            action = raw_input('replace (N/y/q) ? ').lower()

        else:

            action = 'y'

        if action == 'y':

            try:

                shutil.copyfile(ref_file, appl_file)

            except IOError:

                os.system('chmod a+w %s' % appl_file)

                shutil.copyfile(ref_file, appl_file)

            print 'replaced'

        elif action == 'q':

            sys.exit(0)

        else:

            copy_file = appl_file + '.default'

            copy = file(copy_file, 'w')

            copy.write(open(ref_file).read())

            copy.close()

            print 'keep current version, the new file has been written to', copy_file

    else:

        print 'no diff between %s and %s' % (appl_file, ref_file)

def copy_skeleton(skeldir, targetdir, context,

                  exclude=('*.py[co]', '*.orig', '*~', '*_flymake.py'),

                  askconfirm=False):

    import shutil

    from fnmatch import fnmatch

    skeldir = normpath(skeldir)

    targetdir = normpath(targetdir)

    for dirpath, dirnames, filenames in walk(skeldir):

        tdirpath = dirpath.replace(skeldir, targetdir)

        create_dir(tdirpath)

        for fname in filenames:

            if any(fnmatch(fname, pat) for pat in exclude):

                continue

            fpath = join(dirpath, fname)

            if 'CUBENAME' in fname:

                tfpath = join(tdirpath, fname.replace('CUBENAME', context['cubename']))

            elif 'DISTNAME' in fname:

                tfpath = join(tdirpath, fname.replace('DISTNAME', context['distname']))

            else:

                tfpath = join(tdirpath, fname)

            if fname.endswith('.tmpl'):

                tfpath = tfpath[:-5]

                if not askconfirm or not exists(tfpath) or \

                       confirm('%s exists, overwrite?' % tfpath):

                    fname = fill_templated_file(fpath, tfpath, context)

                    print '[generate] %s <-- %s' % (tfpath, fpath)

            elif exists(tfpath):

                show_diffs(tfpath, fpath, askconfirm)

            else:

                shutil.copyfile(fpath, tfpath)

def fill_templated_file(fpath, tfpath, context):

    fobj = file(tfpath, 'w')

    templated = file(fpath).read()

    fobj.write(templated % context)

    fobj.close()

def restrict_perms_to_user(filepath, log=None):

    """set -rw------- permission on the given file"""

    if log:

        log('set %s permissions to 0600', filepath)

    else:

        print 'set %s permissions to 0600' % filepath

    chmod(filepath, 0600)

def confirm(question, default_is_yes=True):

    """ask for confirmation and return true on positive answer"""

    if default_is_yes:

        input_str = '%s [Y/n]: '

    else:

        input_str = '%s [y/N]: '

    answer = raw_input(input_str % (question)).strip().lower()

    if default_is_yes:

        if answer in ('n', 'no'):

            return False

        return True

    if answer in ('y', 'yes'):

        return True

    return False

def read_config(config_file):

    """read the application configuration from a file and return it as a

    dictionnary

    :type config_file: str

    :param config_file: path to the configuration file

    :rtype: dict

    :return: a dictionary with specified values associated to option names 

    """

    from logilab.common.fileutils import lines

    config = current = {}

    try:

        for line in lines(config_file, comments='#'):

            try:

                option, value = line.split('=', 1)

            except ValueError:

                option = line.strip().lower()

                if option[0] == '[':

                    # start a section

                    section = option[1:-1]

                    assert not config.has_key(section), \

                           'Section %s is defined more than once' % section

                    config[section] = current = {}

                    continue

                print >> sys.stderr, 'ignoring malformed line\n%r' % line

                continue

            option = option.strip().replace(' ', '_')

            value = value.strip()

            current[option] = value or None

    except IOError, ex:

        warning('missing or non readable configuration file %s (%s)',

                config_file, ex)

    return config

def env_path(env_var, default, name):

    """get a path specified in a variable or using the default value and return

    it.

    :type env_var: str

    :param env_var: name of an environment variable

    :type default: str

    :param default: default value if the environment variable is not defined

    :type name: str

    :param name: the informal name of the path, used for error message

    :rtype: str

    :return: the value of the environment variable or the default value

    :raise `ConfigurationError`: if the returned path does not exist

    """

    path = environ.get(env_var, default)

    if not exists(path):

        raise ConfigurationError('%s path %s doesn\'t exist' % (name, path))

    return abspath(path)

_HDLRS = {}

class metacmdhandler(type):

    def __new__(mcs, name, bases, classdict):

        cls = super(metacmdhandler, mcs).__new__(mcs, name, bases, classdict)

        if getattr(cls, 'cfgname', None) and getattr(cls, 'cmdname', None):

            _HDLRS.setdefault(cls.cmdname, []).append(cls)

        return cls

class CommandHandler(object):

    """configuration specific helper for cubicweb-ctl commands"""

    __metaclass__ = metacmdhandler

    def __init__(self, config):

        self.config = config

class Command(BaseCommand):

    """base class for cubicweb-ctl commands"""

    def config_helper(self, config, required=True, cmdname=None):

        if cmdname is None:

            cmdname = self.name

        for helpercls in _HDLRS.get(cmdname, ()):

            if helpercls.cfgname == config.name:

                return helpercls(config)

        if config.name == 'all-in-one':

            for helpercls in _HDLRS.get(cmdname, ()):

                if helpercls.cfgname == 'repository':

                    return helpercls(config)

        if required:

            msg = 'No helper for command %s using %s configuration' % (

                cmdname, config.name)

            raise ConfigurationError(msg)

    def fail(self, reason):

        print "command failed:", reason

        sys.exit(1)

def main_run(args, doc):

    """command line tool"""

    try:

        base_main_run(args, doc)

    except ConfigurationError, err:

        print 'ERROR: ', err

        sys.exit(1)

    except ExecutionError, err:

        print err

        sys.exit(2)

CONNECT_OPTIONS = (

    ("user",

     {'short': 'u', 'type' : 'string', 'metavar': '<user>',

      'help': 'connect as <user> instead of being prompted to give it.',

      }

     ),

    ("password",

     {'short': 'p', 'type' : 'password', 'metavar': '<password>',

      'help': 'automatically give <password> for authentication instead of \

being prompted to give it.',

      }),

    ("host",

     {'short': 'H', 'type' : 'string', 'metavar': '<hostname>',

      'default': 'all-in-one',

      'help': 'specify the name server\'s host name. Will be detected by \

broadcast if not provided.',

      }),

    )

def config_connect(appid, optconfig):

    from cubicweb.dbapi import connect

    from getpass import getpass

    user = optconfig.user

    if not user:

        user = raw_input('login: ')

    password = optconfig.password

    if not password:

        password = getpass('password: ')

    return connect(user=user, password=password, host=optconfig.host, database=appid)