# (c) 2012-2013, 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/>.

import ansible.inventory
import ansible.constants as C
import ansible.runner
from ansible.utils.template import template
from ansible import utils
from ansible import errors
import ansible.callbacks
import os
import shlex
import collections
from play import Play
import StringIO
import pipes

SETUP_CACHE = collections.defaultdict(dict)

class PlayBook(object):
    '''
    runs an ansible playbook, given as a datastructure or YAML filename.
    A playbook is a deployment, config management, or automation based
    set of commands to run in series.

    multiple plays/tasks do not execute simultaneously, but tasks in each
    pattern do execute in parallel (according to the number of forks
    requested) among the hosts they address
    '''

    # *****************************************************

    def __init__(self,
        playbook         = None,
        host_list        = C.DEFAULT_HOST_LIST,
        module_path      = None,
        forks            = C.DEFAULT_FORKS,
        timeout          = C.DEFAULT_TIMEOUT,
        remote_user      = C.DEFAULT_REMOTE_USER,
        remote_pass      = C.DEFAULT_REMOTE_PASS,
        sudo_pass        = C.DEFAULT_SUDO_PASS,
        remote_port      = None,
        transport        = C.DEFAULT_TRANSPORT,
        private_key_file = C.DEFAULT_PRIVATE_KEY_FILE,
        callbacks        = None,
        runner_callbacks = None,
        stats            = None,
        sudo             = False,
        sudo_user        = C.DEFAULT_SUDO_USER,
        extra_vars       = None,
        only_tags        = None,
        subset           = C.DEFAULT_SUBSET,
        inventory        = None,
        check            = False,
        diff             = False,
        any_errors_fatal = False):

        """
        playbook:         path to a playbook file
        host_list:        path to a file like /etc/ansible/hosts
        module_path:      path to ansible modules, like /usr/share/ansible/
        forks:            desired level of paralellism
        timeout:          connection timeout
        remote_user:      run as this user if not specified in a particular play
        remote_pass:      use this remote password (for all plays) vs using SSH keys
        sudo_pass:        if sudo==True, and a password is required, this is the sudo password
        remote_port:      default remote port to use if not specified with the host or play
        transport:        how to connect to hosts that don't specify a transport (local, paramiko, etc)
        callbacks         output callbacks for the playbook
        runner_callbacks: more callbacks, this time for the runner API
        stats:            holds aggregrate data about events occuring to each host
        sudo:             if not specified per play, requests all plays use sudo mode
        inventory:        can be specified instead of host_list to use a pre-existing inventory object
        check:            don't change anything, just try to detect some potential changes
        """

        self.SETUP_CACHE = SETUP_CACHE

        if playbook is None or callbacks is None or runner_callbacks is None or stats is None:
            raise Exception('missing required arguments')

        if extra_vars is None:
            extra_vars = {}
        if only_tags is None:
            only_tags = [ 'all' ]

        self.check            = check
        self.diff             = diff
        self.module_path      = module_path
        self.forks            = forks
        self.timeout          = timeout
        self.remote_user      = remote_user
        self.remote_pass      = remote_pass
        self.remote_port      = remote_port
        self.transport        = transport
        self.callbacks        = callbacks
        self.runner_callbacks = runner_callbacks
        self.stats            = stats
        self.sudo             = sudo
        self.sudo_pass        = sudo_pass
        self.sudo_user        = sudo_user
        self.extra_vars       = extra_vars
        self.global_vars      = {}
        self.private_key_file = private_key_file
        self.only_tags        = only_tags
        self.any_errors_fatal = any_errors_fatal

        self.callbacks.playbook = self
        self.runner_callbacks.playbook = self

        if inventory is None:
            self.inventory    = ansible.inventory.Inventory(host_list)
            self.inventory.subset(subset)
        else:
            self.inventory    = inventory

        self.basedir     = os.path.dirname(playbook) or '.'
        utils.plugins.push_basedir(self.basedir)
        vars = {}
        if self.inventory.basedir() is not None:
            vars['inventory_dir'] = self.inventory.basedir()
        self.filename = playbook
        (self.playbook, self.play_basedirs) = self._load_playbook_from_file(playbook, vars)
        ansible.callbacks.load_callback_plugins()

    # *****************************************************

    def _load_playbook_from_file(self, path, vars={}):
        '''
        run top level error checking on playbooks and allow them to include other playbooks.
        '''

        playbook_data  = utils.parse_yaml_from_file(path)
        accumulated_plays = []
        play_basedirs = []

        if type(playbook_data) != list:
            raise errors.AnsibleError("parse error: playbooks must be formatted as a YAML list")

        basedir = os.path.dirname(path) or '.'
        utils.plugins.push_basedir(basedir)
        for play in playbook_data:
            if type(play) != dict:
                raise errors.AnsibleError("parse error: each play in a playbook must be a YAML dictionary (hash), recieved: %s" % play)

            if 'include' in play:
                # a playbook (list of plays) decided to include some other list of plays
                # from another file.  The result is a flat list of plays in the end.

                tokens = shlex.split(play['include'])

                incvars = vars.copy()
                if 'vars' in play:
                    if isinstance(play['vars'], dict):
                        incvars.update(play['vars'])
                    elif isinstance(play['vars'], list):
                        for v in play['vars']:
                            incvars.update(v)

                # allow key=value parameters to be specified on the include line
                # to set variables

                for t in tokens[1:]:

                    (k,v) = t.split("=", 1)
                    incvars[k] = template(basedir, v, incvars)

                included_path = utils.path_dwim(basedir, template(basedir, tokens[0], incvars))
                (plays, basedirs) = self._load_playbook_from_file(included_path, incvars)
                for p in plays:
                    # support for parameterized play includes works by passing
                    # those variables along to the subservient play
                    if 'vars' not in p:
                        p['vars'] = {}
                    if isinstance(p['vars'], dict):
                        p['vars'].update(incvars)
                    elif isinstance(p['vars'], list):
                        # nobody should really do this, but handle vars: a=1 b=2
                        p['vars'].extend([dict(k=v) for k,v in incvars.iteritems()])

                accumulated_plays.extend(plays)
                play_basedirs.extend(basedirs)

            else:

                # this is a normal (non-included play)
                accumulated_plays.append(play)
                play_basedirs.append(basedir)

        return (accumulated_plays, play_basedirs)

    # *****************************************************

    def run(self):
        ''' run all patterns in the playbook '''
        plays = []
        matched_tags_all = set()
        unmatched_tags_all = set()

        # loop through all patterns and run them
        self.callbacks.on_start()
        for (play_ds, play_basedir) in zip(self.playbook, self.play_basedirs):
            play = Play(self, play_ds, play_basedir)
            assert play is not None
            
            matched_tags, unmatched_tags = play.compare_tags(self.only_tags)
            matched_tags_all = matched_tags_all | matched_tags
            unmatched_tags_all = unmatched_tags_all | unmatched_tags

            # if we have matched_tags, the play must be run.
            # if the play contains no tasks, assume we just want to gather facts
            # in this case there are actually 3 meta tasks (handler flushes) not 0
            # tasks, so that's why there's a check against 3
            if (len(matched_tags) > 0 or len(play.tasks()) == 3):
                plays.append(play)

        # if the playbook is invoked with --tags that don't exist at all in the playbooks
        # then we need to raise an error so that the user can correct the arguments.
        unknown_tags = set(self.only_tags) - (matched_tags_all | unmatched_tags_all)
        unknown_tags.discard('all')

        if len(unknown_tags) > 0:
            unmatched_tags_all.discard('all')
            msg = 'tag(s) not found in playbook: %s.  possible values: %s'
            unknown = ','.join(sorted(unknown_tags))
            unmatched = ','.join(sorted(unmatched_tags_all))
            raise errors.AnsibleError(msg % (unknown, unmatched))

        for play in plays:
            ansible.callbacks.set_play(self.callbacks, play)
            ansible.callbacks.set_play(self.runner_callbacks, play)
            if not self._run_play(play):
                break
            ansible.callbacks.set_play(self.callbacks, None)
            ansible.callbacks.set_play(self.runner_callbacks, None)

        # summarize the results
        results = {}
        for host in self.stats.processed.keys():
            results[host] = self.stats.summarize(host)
        return results

    # *****************************************************

    def _async_poll(self, poller, async_seconds, async_poll_interval):
        ''' launch an async job, if poll_interval is set, wait for completion '''

        results = poller.wait(async_seconds, async_poll_interval)

        # mark any hosts that are still listed as started as failed
        # since these likely got killed by async_wrapper
        for host in poller.hosts_to_poll:
            reason = { 'failed' : 1, 'rc' : None, 'msg' : 'timed out' }
            self.runner_callbacks.on_failed(host, reason)
            results['contacted'][host] = reason

        return results

    # *****************************************************

    def _list_available_hosts(self, *args):
        ''' returns a list of hosts that haven't failed and aren't dark '''

        return [ h for h in self.inventory.list_hosts(*args) if (h not in self.stats.failures) and (h not in self.stats.dark)]

    # *****************************************************

    def _run_task_internal(self, task):
        ''' run a particular module step in a playbook '''

        hosts = self._list_available_hosts()
        self.inventory.restrict_to(hosts)

        runner = ansible.runner.Runner(
            pattern=task.play.hosts, inventory=self.inventory, module_name=task.module_name,
            module_args=task.module_args, forks=self.forks,
            remote_pass=self.remote_pass, module_path=self.module_path,
            timeout=self.timeout, remote_user=task.play.remote_user,
            remote_port=task.play.remote_port, module_vars=task.module_vars,
            private_key_file=self.private_key_file,
            setup_cache=self.SETUP_CACHE, basedir=task.play.basedir,
            conditional=task.only_if, callbacks=self.runner_callbacks,
            sudo=task.sudo, sudo_user=task.sudo_user,
            transport=task.transport, sudo_pass=task.sudo_pass, is_playbook=True,
            check=self.check, diff=self.diff, environment=task.environment, complex_args=task.args
        )

        if task.async_seconds == 0:
            results = runner.run()
        else:
            results, poller = runner.run_async(task.async_seconds)
            self.stats.compute(results)
            if task.async_poll_interval > 0:
                # if not polling, playbook requested fire and forget, so don't poll
                results = self._async_poll(poller, task.async_seconds, task.async_poll_interval)

        contacted = results.get('contacted',{})
        dark      = results.get('dark', {})

        self.inventory.lift_restriction()

        if len(contacted.keys()) == 0 and len(dark.keys()) == 0:
            return None

        return results

    # *****************************************************

    def _run_task(self, play, task, is_handler):
        ''' run a single task in the playbook and recursively run any subtasks.  '''

        ansible.callbacks.set_task(self.callbacks, task)
        ansible.callbacks.set_task(self.runner_callbacks, task)

        self.callbacks.on_task_start(template(play.basedir, task.name, task.module_vars, lookup_fatal=False), is_handler)
        if hasattr(self.callbacks, 'skip_task') and self.callbacks.skip_task:
            ansible.callbacks.set_task(self.callbacks, None)
            ansible.callbacks.set_task(self.runner_callbacks, None)
            return True
        
        # load up an appropriate ansible runner to run the task in parallel
        results = self._run_task_internal(task)

        # if no hosts are matched, carry on
        hosts_remaining = True
        if results is None:
            hosts_remaining = False
            results = {}
 
        contacted = results.get('contacted', {})
        self.stats.compute(results, ignore_errors=task.ignore_errors)

        # add facts to the global setup cache
        for host, result in contacted.iteritems():
            facts = result.get('ansible_facts', {})
            self.SETUP_CACHE[host].update(facts)
            # extra vars need to always trump - so update  again following the facts
            self.SETUP_CACHE[host].update(self.extra_vars)
            if task.register:
                if 'stdout' in result:
                    result['stdout_lines'] = result['stdout'].splitlines()
                self.SETUP_CACHE[host][task.register] = result

        # also have to register some failed, but ignored, tasks
        if task.ignore_errors and task.register:
            failed = results.get('failed', {})
            for host, result in failed.iteritems():
                if 'stdout' in result:
                    result['stdout_lines'] = result['stdout'].splitlines()
                self.SETUP_CACHE[host][task.register] = result

        # flag which notify handlers need to be run
        if len(task.notify) > 0:
            for host, results in results.get('contacted',{}).iteritems():
                if results.get('changed', False):
                    for handler_name in task.notify:
                        self._flag_handler(play, template(play.basedir, handler_name, task.module_vars), host)

        ansible.callbacks.set_task(self.callbacks, None)
        ansible.callbacks.set_task(self.runner_callbacks, None)
        return hosts_remaining

    # *****************************************************

    def _flag_handler(self, play, handler_name, host):
        '''
        if a task has any notify elements, flag handlers for run
        at end of execution cycle for hosts that have indicated
        changes have been made
        '''

        found = False
        for x in play.handlers():
            if handler_name == template(play.basedir, x.name, x.module_vars):
                found = True
                self.callbacks.on_notify(host, x.name)
                x.notified_by.append(host)
        if not found:
            raise errors.AnsibleError("change handler (%s) is not defined" % handler_name)

    # *****************************************************

    def _do_setup_step(self, play):
        ''' get facts from the remote system '''

        host_list = self._list_available_hosts(play.hosts)

        if play.gather_facts is False:
            return {}
        elif play.gather_facts is None:
            host_list = [h for h in host_list if h not in self.SETUP_CACHE or 'module_setup' not in self.SETUP_CACHE[h]]
            if len(host_list) == 0:
                return {}

        self.callbacks.on_setup()
        self.inventory.restrict_to(host_list)
        
        ansible.callbacks.set_task(self.callbacks, None)
        ansible.callbacks.set_task(self.runner_callbacks, None)

        # push any variables down to the system
        setup_results = ansible.runner.Runner(
            pattern=play.hosts, module_name='setup', module_args={}, inventory=self.inventory,
            forks=self.forks, module_path=self.module_path, timeout=self.timeout, remote_user=play.remote_user,
            remote_pass=self.remote_pass, remote_port=play.remote_port, private_key_file=self.private_key_file,
            setup_cache=self.SETUP_CACHE, callbacks=self.runner_callbacks, sudo=play.sudo, sudo_user=play.sudo_user,
            transport=play.transport, sudo_pass=self.sudo_pass, is_playbook=True, module_vars=play.vars,
            check=self.check, diff=self.diff
        ).run()
        self.stats.compute(setup_results, setup=True)

        self.inventory.lift_restriction()

        # now for each result, load into the setup cache so we can
        # let runner template out future commands
        setup_ok = setup_results.get('contacted', {})
        for (host, result) in setup_ok.iteritems():
            self.SETUP_CACHE[host].update({'module_setup': True})
            self.SETUP_CACHE[host].update(result.get('ansible_facts', {}))
        return setup_results

    # *****************************************************


    def generate_retry_inventory(self, replay_hosts):
        '''
        called by /usr/bin/ansible when a playbook run fails. It generates a inventory 
        that allows re-running on ONLY the failed hosts.  This may duplicate some
        variable information in group_vars/host_vars but that is ok, and expected.
        ''' 

        buf = StringIO.StringIO()
        for x in replay_hosts:
            buf.write("%s\n" % x)
        basedir = self.inventory.basedir()
        filename = "%s.retry" % os.path.basename(self.filename)
        filename = filename.replace(".yml","")

        if not os.path.exists('/var/tmp/ansible'):
            try:
                os.makedirs('/var/tmp/ansible')
            except:
                pass
        filename = os.path.join('/var/tmp/ansible', filename)

        try:
            fd = open(filename, 'w')
            fd.write(buf.getvalue())
            fd.close()
            return filename
        except:
            pass
        return None

    # *****************************************************

    def _run_play(self, play):
        ''' run a list of tasks for a given pattern, in order '''

        self.callbacks.on_play_start(play.name)
        # if no hosts matches this play, drop out
        if not self.inventory.list_hosts(play.hosts):
            self.callbacks.on_no_hosts_matched()
            return True

        # get facts from system
        self._do_setup_step(play)

        # now with that data, handle contentional variable file imports!

        all_hosts = self._list_available_hosts(play.hosts)
        play.update_vars_files(all_hosts)

        serialized_batch = []
        if play.serial <= 0:
            serialized_batch = [all_hosts]
        else:
            # do N forks all the way through before moving to next
            while len(all_hosts) > 0:
                play_hosts = []
                for x in range(play.serial):
                    if len(all_hosts) > 0:
                        play_hosts.append(all_hosts.pop())
                serialized_batch.append(play_hosts)

        for on_hosts in serialized_batch:

            self.inventory.also_restrict_to(on_hosts)

            for task in play.tasks():

                if task.meta is not None:

                    # meta tasks are an internalism and are not valid for end-user playbook usage
                    # here a meta task is a placeholder that signals handlers should be run
 
                    if task.meta == 'flush_handlers':
                        for handler in play.handlers():
                            if len(handler.notified_by) > 0:
                                self.inventory.restrict_to(handler.notified_by)
                                self._run_task(play, handler, True)
                                self.inventory.lift_restriction()
                                new_list = handler.notified_by[:]
                                for host in handler.notified_by:
                                    if host in on_hosts:
                                        while host in new_list:
                                            new_list.remove(host)
                                handler.notified_by = new_list

                        continue

                hosts_count = len(self._list_available_hosts(play.hosts))

                # only run the task if the requested tags match
                should_run = False
                for x in self.only_tags:

                    for y in task.tags:
                        if (x==y):
                            should_run = True
                            break

                if should_run:
                    if not self._run_task(play, task, False):
                        # whether no hosts matched is fatal or not depends if it was on the initial step.
                        # if we got exactly no hosts on the first step (setup!) then the host group
                        # just didn't match anything and that's ok
                        return False

                host_list = self._list_available_hosts(play.hosts)

                if task.any_errors_fatal and len(host_list) < hosts_count:
                    host_list = None

                # if no hosts remain, drop out
                if not host_list:
                    self.callbacks.on_no_hosts_remaining()
                    return False

            # run notify actions
            #for handler in play.handlers():
            #    if len(handler.notified_by) > 0:
            #        self.inventory.restrict_to(handler.notified_by)
            #        self._run_task(play, handler, True)
            #        self.inventory.lift_restriction()
            #        handler.notified_by = []
            #    handler.notified_by = []

            self.inventory.lift_also_restriction()

        return True

