# -*- coding: utf-8 -*-

# Copyright(C) 2010  Romain Bignon
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, version 3 of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.


from __future__ import with_statement

from logging import warning
import os

from weboob.core.bcall import BackendsCall
from weboob.core.backends import BackendsConfig, BackendsLoader
from weboob.core.scheduler import Scheduler
from weboob.tools.backend import BaseBackend


__all__ = ['Weboob']


class Weboob(object):
    WORKDIR = os.path.join(os.path.expanduser('~'), '.weboob')
    BACKENDS_FILENAME = 'backends'

    def __init__(self, workdir=WORKDIR, backends_filename=None, scheduler=None):
        self.workdir = workdir
        self.backend_instances = {}

        # Scheduler
        if scheduler is None:
            scheduler = Scheduler()
        self.scheduler = scheduler

        # Create WORKDIR
        if not os.path.exists(self.workdir):
            os.mkdir(self.workdir, 0700)
        elif not os.path.isdir(self.workdir):
            warning('"%s" is not a directory' % self.workdir)

        # Backends loader
        self.backends_loader = BackendsLoader()

        # Backend instances config
        if not backends_filename:
            backends_filename = os.path.join(self.workdir, self.BACKENDS_FILENAME)
        elif not backends_filename.startswith('/'):
            backends_filename = os.path.join(self.workdir, backends_filename)
        self.backends_config = BackendsConfig(backends_filename)

    def load_backends(self, caps=None, names=None, storage=None):
        loaded = {}
        self.backends_loader.load_all()
        for backend_name, backend in self.backends_loader.loaded.iteritems():
            if caps is not None and not backend.has_caps(caps) or \
                    names is not None and backend_name not in names:
                continue
            backend_instance = backend.create_instance(self, backend_name, {}, storage)
            self.backend_instances[backend_name] = loaded[backend_name] = backend_instance
        return loaded

    def load_configured_backends(self, caps=None, names=None, storage=None):
        loaded = {}
        for instance_name, backend_name, params in self.backends_config.iter_backends():
            backend = self.backends_loader.get_or_load_backend(backend_name)
            if caps is not None and not backend.has_caps(caps) or \
                    names is not None and instance_name not in names:
                continue
            backend_instance = backend.create_instance(self, instance_name, params, storage)
            self.backend_instances[instance_name] = loaded[instance_name] = backend_instance
        return loaded

    def iter_backends(self, caps=None):
        """
        Iter on each backends.

        Note: each backend is locked when it is returned.

        @param caps  Optional list of capabilities to select backends
        @return  iterator on selected backends.
        """
        for name, backend in sorted(self.backend_instances.iteritems()):
            if caps is None or backend.has_caps(caps):
                with backend:
                    yield backend

    def do(self, function, *args, **kwargs):
        """
        Do calls on loaded backends with specified arguments, in separated
        threads.

        This function has two modes:
        - If 'function' is a string, it calls the method with this name on
          each backends with the specified arguments;
        - If 'function' is a callable, it calls it in a separated thread with
          the locked backend instance at first arguments, and *args and
          **kwargs.

        @param function  backend's method name, or callable object
        @return  an iterator of results
        """
        backends = list(self.iter_backends())
        return BackendsCall(backends, function, *args, **kwargs)

    def do_caps(self, caps, function, *args, **kwargs):
        """
        Do calls on loaded backends with the specified capabilities, in
        separated threads.

        See also documentation of the 'do' method.

        @param caps  list of caps or cap to select backends
        @param function  backend's method name, or callable object
        @return  an iterator of results
        """
        backends = list(self.iter_backends(caps))
        return BackendsCall(backends, function, *args, **kwargs)

    def do_backends(self, backends, function, *args, **kwargs):
        if backends is None:
            backends = list(self.iter_backends())
        elif isinstance(backends, BaseBackend):
            backends = [backends]
        elif isinstance(backends, (str,unicode)):
            backends = [backend for backend in self.iter_backends() if backend.name == backends]
        elif isinstance(backends, (list,tuple)):
            old_backends = backends
            backends = []
            for backend in old_backends:
                if isinstance(backend, (str,unicode)):
                    try:
                        backends.append(self.backends[self.backends.index(backend)])
                    except ValueError:
                        pass
                else:
                    backends.append(backend)
        return BackendsCall(backends, function, *args, **kwargs)

    def schedule(self, interval, function, *args):
        return self.scheduler.schedule(interval, function, *args)

    def repeat(self, interval, function, *args):
        return self.scheduler.repeat(interval, function, *args)

    def want_stop(self):
        return self.scheduler.want_stop()

    def loop(self):
        return self.scheduler.run()