# This file is part of ipsutils.

# ipsutils 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, either version 3 of the License, or
# (at your option) any later version.
#
# ipsutils 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 ipsutils.  If not, see <http://www.gnu.org/licenses/>.

class TaskException(Exception):
    pass

class InternalTaskException(Exception):
    pass

class Controller(object):
    def __init__(self):
        self.stack = []

    def task(self, t):
        """
        t: Task object
        """
        self.stack.append(t)

    def do_tasks(self):
        """ FILO execution of tasks
        """
        if not self.stack:
            raise TaskException("Empty controller stack")
        
        for stack_entry in self.stack:
            status = stack_entry.run()
            if type(status) == type(True):
                if not status:
                    print("Internal error: {0:d}".format(status))
                    exit(status)
            else:
                if status > 0:
                    print("exit: {0:d}".format(status))
                    exit(status)

class Task(object):
    def __init__(self, *args, **kwargs):
        self.name = ''
        if 'name' in kwargs:
            self.name = kwargs['name']
        
        if 'func' in kwargs:
            self.func = kwargs['func']
        else:
            self.func = None
            
        if 'cls' in kwargs:
            self.cls = kwargs['cls']
        else:
            self.cls = object()
    
    def run(self):
        if not self.name:
            raise TaskException("Unnamed task in: {}".format(self.__class__.__name__))
        
        print("+ Running task: {0:s}".format(self.name))
        status = self.task()
        return status
        
    def task(self):
        raise NotImplementedError('Task undefined')


class Internal(Task):
    def __init__(self, *args, **kwargs):
        super(Internal, self).__init__(self, *args, **kwargs)

    def run(self):
        if not self.name:
            raise InternalTaskException("Unnamed task in : {}".format(self.name))
        print("> Running internal task: {0:s}".format(self.name))
        status = self.task()
        return status