# (c) 2012-2014, Michael DeHaan <michael.dehaan@gmail.com>
#
# This file is part of Ansible
#
# Ansible 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.
#
# Ansible 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 Ansible.  If not, see <http://www.gnu.org/licenses/>.

# Make coding more python3-ish
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

from ansible.errors import AnsibleError

from ansible.parsing.mod_args import ModuleArgsParser
from ansible.parsing.splitter import parse_kv
from ansible.parsing.yaml.objects import AnsibleBaseYAMLObject, AnsibleMapping

from ansible.plugins import module_loader, lookup_loader

from ansible.playbook.attribute import Attribute, FieldAttribute
from ansible.playbook.base import Base
from ansible.playbook.become import Become
from ansible.playbook.block import Block
from ansible.playbook.conditional import Conditional
from ansible.playbook.role import Role
from ansible.playbook.taggable import Taggable
from ansible.utils.vars import combine_vars

__all__ = ['Task']

class Task(Base, Conditional, Taggable, Become):

    """
    A task is a language feature that represents a call to a module, with given arguments and other parameters.
    A handler is a subclass of a task.

    Usage:

       Task.load(datastructure) -> Task
       Task.something(...)
    """

    # =================================================================================
    # ATTRIBUTES
    # load_<attribute_name> and
    # validate_<attribute_name>
    # will be used if defined
    # might be possible to define others

    _args                 = FieldAttribute(isa='dict', default=dict())
    _action               = FieldAttribute(isa='string')

    _always_run           = FieldAttribute(isa='bool')
    _any_errors_fatal     = FieldAttribute(isa='bool')
    _async                = FieldAttribute(isa='int', default=0)
    _changed_when         = FieldAttribute(isa='string')
    _delay                = FieldAttribute(isa='int', default=5)
    _delegate_to          = FieldAttribute(isa='string')
    _failed_when          = FieldAttribute(isa='string')
    _first_available_file = FieldAttribute(isa='list')
    _ignore_errors        = FieldAttribute(isa='bool')

    _loop                 = FieldAttribute(isa='string', private=True)
    _loop_args            = FieldAttribute(isa='list', private=True)
    _local_action         = FieldAttribute(isa='string')

    # FIXME: this should not be a Task
    _meta                 = FieldAttribute(isa='string')

    _name                 = FieldAttribute(isa='string', default='')

    _notify               = FieldAttribute(isa='list')
    _poll                 = FieldAttribute(isa='int')
    _register             = FieldAttribute(isa='string')
    _retries              = FieldAttribute(isa='int', default=1)
    _run_once             = FieldAttribute(isa='bool')
    _until                = FieldAttribute(isa='list') # ?

    def __init__(self, block=None, role=None, task_include=None):
        ''' constructors a task, without the Task.load classmethod, it will be pretty blank '''

        self._block        = block
        self._role         = role
        self._task_include = task_include

        super(Task, self).__init__()

    def get_name(self):
       ''' return the name of the task '''

       if self._role and self.name:
           return "%s : %s" % (self._role.get_name(), self.name)
       elif self.name:
           return self.name
       else:
           flattened_args = self._merge_kv(self.args)
           if self._role:
               return "%s : %s %s" % (self._role.get_name(), self.action, flattened_args)
           else:
               return "%s %s" % (self.action, flattened_args)

    def _merge_kv(self, ds):
        if ds is None:
            return ""
        elif isinstance(ds, basestring):
            return ds
        elif isinstance(ds, dict):
            buf = ""
            for (k,v) in ds.iteritems():
                if k.startswith('_'):
                    continue
                buf = buf + "%s=%s " % (k,v)
            buf = buf.strip()
            return buf

    @staticmethod
    def load(data, block=None, role=None, task_include=None, variable_manager=None, loader=None):
        t = Task(block=block, role=role, task_include=task_include)
        return t.load_data(data, variable_manager=variable_manager, loader=loader)

    def __repr__(self):
        ''' returns a human readable representation of the task '''
        return "TASK: %s" % self.get_name()

    def _preprocess_loop(self, ds, new_ds, k, v):
        ''' take a lookup plugin name and store it correctly '''

        loop_name = k.replace("with_", "")
        if new_ds.get('loop') is not None:
            raise AnsibleError("duplicate loop in task: %s" % loop_name, obj=ds)
        if v is None:
            raise AnsibleError("you must specify a value when using %s" % k, obj=ds)
        new_ds['loop'] = loop_name
        new_ds['loop_args'] = v

    def preprocess_data(self, ds):
        '''
        tasks are especially complex arguments so need pre-processing.
        keep it short.
        '''

        assert isinstance(ds, dict)

        # the new, cleaned datastructure, which will have legacy
        # items reduced to a standard structure suitable for the
        # attributes of the task class
        new_ds = AnsibleMapping()
        if isinstance(ds, AnsibleBaseYAMLObject):
            new_ds.ansible_pos = ds.ansible_pos

        # use the args parsing class to determine the action, args,
        # and the delegate_to value from the various possible forms
        # supported as legacy
        args_parser = ModuleArgsParser(task_ds=ds)
        (action, args, delegate_to) = args_parser.parse()

        new_ds['action']      = action
        new_ds['args']        = args
        new_ds['delegate_to'] = delegate_to

        for (k,v) in ds.iteritems():
            if k in ('action', 'local_action', 'args', 'delegate_to') or k == action or k == 'shell':
                # we don't want to re-assign these values, which were
                # determined by the ModuleArgsParser() above
                continue
            elif k.replace("with_", "") in lookup_loader:
                self._preprocess_loop(ds, new_ds, k, v)
            else:
                new_ds[k] = v

        return super(Task, self).preprocess_data(new_ds)

    def post_validate(self, templar):
        '''
        Override of base class post_validate, to also do final validation on
        the block and task include (if any) to which this task belongs.
        '''

        if self._block:
            self._block.post_validate(templar)
        if self._task_include:
            self._task_include.post_validate(templar)

        super(Task, self).post_validate(templar)

    def get_vars(self):
        all_vars = self.vars.copy()
        if self._block:
            all_vars.update(self._block.get_vars())
        if self._task_include:
            all_vars.update(self._task_include.get_vars())

        #if isinstance(self.args, dict):
        #    all_vars.update(self.args)

        if 'tags' in all_vars:
            del all_vars['tags']
        if 'when' in all_vars:
            del all_vars['when']
        return all_vars

    def copy(self, exclude_block=False):
        new_me = super(Task, self).copy()

        new_me._block = None
        if self._block and not exclude_block:
            new_me._block = self._block.copy()

        new_me._role = None
        if self._role:
            new_me._role = self._role

        new_me._task_include = None
        if self._task_include:
            new_me._task_include = self._task_include.copy()

        return new_me

    def serialize(self):
        data = super(Task, self).serialize()

        if self._block:
            data['block'] = self._block.serialize()

        if self._role:
            data['role'] = self._role.serialize()

        if self._task_include:
            data['task_include'] = self._task_include.serialize()

        return data

    def deserialize(self, data):

        # import is here to avoid import loops
        #from ansible.playbook.task_include import TaskInclude

        block_data = data.get('block')

        if block_data:
            b = Block()
            b.deserialize(block_data)
            self._block = b
            del data['block']

        role_data = data.get('role')
        if role_data:
            r = Role()
            r.deserialize(role_data)
            self._role = r
            del data['role']

        ti_data = data.get('task_include')
        if ti_data:
            #ti = TaskInclude()
            ti = Task()
            ti.deserialize(ti_data)
            self._task_include = ti
            del data['task_include']

        super(Task, self).deserialize(data)

    def evaluate_conditional(self, templar, all_vars):
        if self._block is not None:
            if not self._block.evaluate_conditional(templar, all_vars):
                return False
        if self._task_include is not None:
            if not self._task_include.evaluate_conditional(templar, all_vars):
                return False
        return super(Task, self).evaluate_conditional(templar, all_vars)

    def set_loader(self, loader):
        '''
        Sets the loader on this object and recursively on parent, child objects.
        This is used primarily after the Task has been serialized/deserialized, which
        does not preserve the loader.
        '''

        self._loader = loader

        if self._block:
            self._block.set_loader(loader)
        if self._task_include:
            self._task_include.set_loader(loader)

    def _get_parent_attribute(self, attr, extend=False, combine=False):
        '''
        Generic logic to get the attribute or parent attribute for a task value.
        '''
        value = self._attributes[attr]
        if self._block and (value is None or extend or combine):
            parent_value = getattr(self._block, attr)
            if extend:
                value = self._extend_value(value, parent_value)
            elif combine and isinstance(parent_value, dict) and isinstance(value, dict):
                value = combine_vars(parent_value, value)
            else:
                value = parent_value
        if self._task_include and (value is None or extend or combine):
            parent_value = getattr(self._task_include, attr)
            if extend:
                value = self._extend_value(value, parent_value)
            elif combine:
                value = combine_vars(parent_value, value)
            else:
                value = parent_value
        return value

    def _get_attr_environment(self):
        '''
        Override for the 'tags' getattr fetcher, used from Base.
        '''
        environment = self._attributes['tags']
        if environment is None:
            environment = dict()

        environment = self._get_parent_attribute('environment', combine=True)

        return environment