#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
# 2010-2015 Nico Schottelius (nico-cdist at schottelius.org)
#
# This file is part of cdist.
#
# cdist 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.
#
# cdist 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 cdist. If not, see <http://www.gnu.org/licenses/>.
#
#

import logging
import os
import sys
import time
import itertools
import tempfile
import socket

import cdist
import cdist.hostsource

import cdist.exec.local
import cdist.exec.remote
import cdist.util.ipaddr as ipaddr

from cdist import core
from cdist.util.remoteutil import inspect_ssh_mux_opts


class Config(object):
    """Cdist main class to hold arbitrary data"""

    def __init__(self, local, remote, dry_run=False, jobs=None):

        self.local = local
        self.remote = remote
        self.log = logging.getLogger(self.local.target_host[0])
        self.dry_run = dry_run
        self.jobs = jobs

        self.explorer = core.Explorer(self.local.target_host, self.local,
                                      self.remote, jobs=self.jobs)
        self.manifest = core.Manifest(self.local.target_host, self.local)
        self.code = core.Code(self.local.target_host, self.local, self.remote)

    def _init_files_dirs(self):
        """Prepare files and directories for the run"""
        self.local.create_files_dirs()
        self.remote.create_files_dirs()

    @staticmethod
    def hosts(source):
        try:
            yield from cdist.hostsource.HostSource(source)()
        except (IOError, OSError, UnicodeError) as e:
            raise cdist.Error(
                    "Error reading hosts from \'{}\': {}".format(
                        source, e))

    @classmethod
    def _check_and_prepare_args(cls, args):
        if args.manifest == '-' and args.hostfile == '-':
            raise cdist.Error(("Cannot read both, manifest and host file, "
                               "from stdin"))

        # if no host source is specified then read hosts from stdin
        if not (args.hostfile or args.host):
            args.hostfile = '-'

        initial_manifest_tempfile = None
        if args.manifest == '-':
            # read initial manifest from stdin
            try:
                handle, initial_manifest_temp_path = tempfile.mkstemp(
                        prefix='cdist.stdin.')
                with os.fdopen(handle, 'w') as fd:
                    fd.write(sys.stdin.read())
            except (IOError, OSError) as e:
                raise cdist.Error(("Creating tempfile for stdin data "
                                   "failed: %s" % e))

            args.manifest = initial_manifest_temp_path
            import atexit
            atexit.register(lambda: os.remove(initial_manifest_temp_path))

        # default remote cmd patterns
        args.remote_exec_pattern = None
        args.remote_copy_pattern = None

        args_dict = vars(args)
        # if remote-exec and/or remote-copy args are None then user
        # didn't specify command line options nor env vars:
        # inspect multiplexing options for default cdist.REMOTE_COPY/EXEC
        if (args_dict['remote_copy'] is None or
                args_dict['remote_exec'] is None):
            mux_opts = inspect_ssh_mux_opts()
            if args_dict['remote_exec'] is None:
                args.remote_exec_pattern = cdist.REMOTE_EXEC + mux_opts
            if args_dict['remote_copy'] is None:
                args.remote_copy_pattern = cdist.REMOTE_COPY + mux_opts

    @classmethod
    def _base_root_path(cls, args):
        if args.out_path:
            base_root_path = args.out_path
        else:
            base_root_path = tempfile.mkdtemp()
        return base_root_path

    @classmethod
    def commandline(cls, args):
        """Configure remote system"""
        import multiprocessing

        # FIXME: Refactor relict - remove later
        log = logging.getLogger("cdist")

        cls._check_and_prepare_args(args)

        process = {}
        failed_hosts = []
        time_start = time.time()

        base_root_path = cls._base_root_path(args)

        hostcnt = 0
        for host in itertools.chain(cls.hosts(args.host),
                                    cls.hosts(args.hostfile)):
            hostdir = cdist.str_hash(host)
            host_base_path = os.path.join(base_root_path, hostdir)

            log.debug("Base root path for target host \"{}\" is \"{}\"".format(
                host, host_base_path))

            hostcnt += 1
            if args.parallel:
                log.debug("Creating child process for %s", host)
                process[host] = multiprocessing.Process(
                        target=cls.onehost,
                        args=(host, host_base_path, hostdir, args, True))
                process[host].start()
            else:
                try:
                    cls.onehost(host, host_base_path, hostdir,
                                args, parallel=False)
                except cdist.Error as e:
                    failed_hosts.append(host)

        # Catch errors in parallel mode when joining
        if args.parallel:
            for host in process.keys():
                log.debug("Joining process %s", host)
                process[host].join()

                if not process[host].exitcode == 0:
                    failed_hosts.append(host)

        time_end = time.time()
        log.info("Total processing time for %s host(s): %s", hostcnt,
                 (time_end - time_start))

        if len(failed_hosts) > 0:
            raise cdist.Error("Failed to configure the following hosts: " +
                              " ".join(failed_hosts))

    @classmethod
    def _resolve_remote_cmds(cls, args, host_base_path):
        control_path = os.path.join(host_base_path, "ssh-control-path")
        # If we constructed patterns for remote commands then there is
        # placeholder for ssh ControlPath, format it and we have unique
        # ControlPath for each host.
        #
        # If not then use args.remote_exec/copy that user specified.
        if args.remote_exec_pattern:
            remote_exec = args.remote_exec_pattern.format(control_path)
        else:
            remote_exec = args.remote_exec
        if args.remote_copy_pattern:
            remote_copy = args.remote_copy_pattern.format(control_path)
        else:
            remote_copy = args.remote_copy
        return (remote_exec, remote_copy, )

    @classmethod
    def onehost(cls, host, host_base_path, host_dir_name, args, parallel):
        """Configure ONE system"""

        log = logging.getLogger(host)

        try:
            remote_exec, remote_copy = cls._resolve_remote_cmds(host_base_path)
            log.debug("remote_exec for host \"{}\": {}".format(
                host, remote_exec))
            log.debug("remote_copy for host \"{}\": {}".format(
                host, remote_copy))

            target_host = ipaddr.resolve_target_addresses(host)
            log.debug("target_host: {}".format(target_host))

            local = cdist.exec.local.Local(
                target_host=target_host,
                base_root_path=host_base_path,
                host_dir_name=host_dir_name,
                initial_manifest=args.manifest,
                add_conf_dirs=args.conf_dir)

            remote = cdist.exec.remote.Remote(
                target_host=target_host,
                remote_exec=remote_exec,
                remote_copy=remote_copy)

            c = cls(local, remote, dry_run=args.dry_run, jobs=args.jobs)
            c.run()

        except cdist.Error as e:
            log.error(e)
            if parallel:
                # We are running in our own process here, need to sys.exit!
                sys.exit(1)
            else:
                raise

        except KeyboardInterrupt:
            # Ignore in parallel mode, we are existing anyway
            if parallel:
                sys.exit(0)
            # Pass back to controlling code in sequential mode
            else:
                raise

    def run(self):
        """Do what is most often done: deploy & cleanup"""
        start_time = time.time()

        self._init_files_dirs()

        self.explorer.run_global_explorers(self.local.global_explorer_out_path)
        self.manifest.run_initial_manifest(self.local.initial_manifest)
        self.iterate_until_finished()

        self.local.save_cache()
        self.log.info("Finished successful run in %s seconds",
                      time.time() - start_time)

    def object_list(self):
        """Short name for object list retrieval"""
        for cdist_object in core.CdistObject.list_objects(
                self.local.object_path, self.local.type_path,
                self.local.object_marker_name):
            if cdist_object.cdist_type.is_install:
                self.log.debug(("Running in config mode, ignoring install "
                                "object: {0}").format(cdist_object))
            else:
                yield cdist_object

    def iterate_once(self):
        """
            Iterate over the objects once - helper method for
            iterate_until_finished
        """
        objects_changed = False

        for cdist_object in self.object_list():
            if cdist_object.requirements_unfinished(cdist_object.requirements):
                """We cannot do anything for this poor object"""
                continue

            if cdist_object.state == core.CdistObject.STATE_UNDEF:
                """Prepare the virgin object"""

                self.object_prepare(cdist_object)
                objects_changed = True

            if cdist_object.requirements_unfinished(cdist_object.autorequire):
                """The previous step created objects we depend on -
                   wait for them
                """
                continue

            if cdist_object.state == core.CdistObject.STATE_PREPARED:
                self.object_run(cdist_object)
                objects_changed = True

        return objects_changed

    def iterate_until_finished(self):
        """
            Go through all objects and solve them
            one after another
        """

        objects_changed = True

        while objects_changed:
            objects_changed = self.iterate_once()

        # Check whether all objects have been finished
        unfinished_objects = []
        for cdist_object in self.object_list():
            if not cdist_object.state == cdist_object.STATE_DONE:
                unfinished_objects.append(cdist_object)

        if unfinished_objects:
            info_string = []

            for cdist_object in unfinished_objects:

                requirement_names = []
                autorequire_names = []

                for requirement in cdist_object.requirements_unfinished(
                        cdist_object.requirements):
                    requirement_names.append(requirement.name)

                for requirement in cdist_object.requirements_unfinished(
                        cdist_object.autorequire):
                    autorequire_names.append(requirement.name)

                requirements = "\n        ".join(requirement_names)
                autorequire = "\n        ".join(autorequire_names)
                info_string.append(("%s requires:\n"
                                    "        %s\n"
                                    "%s ""autorequires:\n"
                                    "        %s" % (
                                        cdist_object.name,
                                        requirements, cdist_object.name,
                                        autorequire)))

            raise cdist.UnresolvableRequirementsError(
                    ("The requirements of the following objects could not be "
                     "resolved:\n%s") % ("\n".join(info_string)))

    def object_prepare(self, cdist_object):
        """Prepare object: Run type explorer + manifest"""
        self.log.info(
                "Running manifest and explorers for " + cdist_object.name)
        self.explorer.run_type_explorers(cdist_object)
        self.manifest.run_type_manifest(cdist_object)
        cdist_object.state = core.CdistObject.STATE_PREPARED

    def object_run(self, cdist_object):
        """Run gencode and code for an object"""

        self.log.debug("Trying to run object %s" % (cdist_object.name))
        if cdist_object.state == core.CdistObject.STATE_DONE:
            raise cdist.Error(("Attempting to run an already finished "
                               "object: %s"), cdist_object)

        cdist_type = cdist_object.cdist_type

        # Generate
        self.log.info("Generating code for %s" % (cdist_object.name))
        cdist_object.code_local = self.code.run_gencode_local(cdist_object)
        cdist_object.code_remote = self.code.run_gencode_remote(cdist_object)
        if cdist_object.code_local or cdist_object.code_remote:
            cdist_object.changed = True

        # Execute
        if not self.dry_run:
            if cdist_object.code_local or cdist_object.code_remote:
                self.log.info("Executing code for %s" % (cdist_object.name))
            if cdist_object.code_local:
                self.code.run_code_local(cdist_object)
            if cdist_object.code_remote:
                self.code.transfer_code_remote(cdist_object)
                self.code.run_code_remote(cdist_object)
        else:
            self.log.info("Skipping code execution due to DRY RUN")

        # Mark this object as done
        self.log.debug("Finishing run of " + cdist_object.name)
        cdist_object.state = core.CdistObject.STATE_DONE