# *****************************************************************************
#
# 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; either version 2 of the License, or (at your option) any later
# version.
#
# 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
#
# Module authors:
#   Markus Zolliker <markus.zolliker@psi.ch>
#
# *****************************************************************************

import sys
import os
import re
import builtins
from glob import glob
from itertools import zip_longest
from collections import defaultdict
from os.path import join, isdir, basename, expanduser, exists
from configparser import ConfigParser
from .base import ServiceManager, ServiceDown, UsageError
from .seaman import SeaManager


MAIN = 1
STICK = 2


class Namespace(dict):
    def __init__(self):
        self['Node'] = self.node
        self['Mod'] = self.mod
        for fun in 'Param', 'Command', 'Group':
            self[fun] = self.dummy
        self.init()

    def init(self):
        self.description = ''
        self.sea_cfg = None

    def node(self, equipment_id, description, *args, **kwds):
        self.description = description

    def mod(self, name, cls, description, config=None, **kwds):
        cls = getattr(cls, '__name__', cls)
        if cls.endswith('SeaClient'):
            self.sea_cfg = config

    def dummy(self, *args, **kwds):
        return None

    __builtins__ = builtins


SEAEXT = {'main': '.config', 'stick': '.stick'}


class Reconnect(str):
    """a string tagged with the information that the frappy server is already running

    isinstance(cfg, Reconnect) means: cfg may need reconnection, but not restart
    """
    def __repr__(self):
        return f'Reconnect({str(self)!r})'


class Keep(Reconnect):
    """a string tagged with the information to keep the connection as given

    isinstance(cfg, Reconnect) means: the given cfg is already running, so no reconnection is needed
    """
    def __repr__(self):
        return f'Keep({str(self)!r})'


class FrappyManager(ServiceManager):
    group = 'frappy'
    services = ('main', 'stick', 'addons')
    USAGE = """
    Usage:

      frappy list %(optional_ins)s
      frappy start %(ins)s<service> <cfgfiles>
      frappy restart %(ins)s[<service>] [<cfgfiles>]       %(remark)s
      frappy stop %(ins)s[<service>]                       %(remark)s
      frappy listcfg %(ins)s[<service> | develop]       # list available cfg files

      <service> is one of main, stick, addons
%(legend)s
    """
    # changed in all_info (see docstring there)
    frappy2sea = None
    sea2frappy = None
    list_info = None
    # changed in get_server_state:
    frappy_cfgs = None
    sea_cfgs = None
    state = None
    error = None
    remarks = None
    sea = None

    def config_dirs(self, ins, service):
        cfgpaths = []
        cfgparser = ConfigParser()
        cfgparser.optionxform = str
        cfgfile = self.env[ins].get('FRAPPY_CONFIG_FILE')
        confdir = self.env[ins].get('FRAPPY_CONFDIR')
        if cfgfile:
            cfgfile = self.env[ins]['FRAPPY_CONFIG_FILE'].replace('<SERV>', service)
            cfgparser.read(cfgfile)
            try:
                section = cfgparser['FRAPPY']
            except KeyError:
                raise ValueError('%s does not exist or has no FRAPPY section' % cfgfile)
            confdir = section.get('confdir', confdir)
        for cfgpath in confdir.split(os.pathsep):
            if cfgpath.endswith('<SERV>'):
                cfgpaths.append(expanduser(cfgpath[:-6] + service))
            else:
                scfg = join(cfgpath, service)
                if isdir(scfg):
                    cfgpaths.append(scfg)
                cfgpaths.append(expanduser(cfgpath))
        return cfgpaths

    def prepare_start(self, ins, service, cfg=''):
        start_dir, env = super().prepare_start(ins, service)
        env_update = {}
        for key, value in env.items():
            if '<SERV>' in value:
                env_update[key] = value.replace('<SERV>', service)
                os.environ[key] = env[key]
        cfgpaths = self.config_dirs(ins, service)
        if cfgpaths:
            env_update['FRAPPY_CONFDIR'] = os.pathsep.join(cfgpaths)
        # merge PYTHONPATH from servicemanager.cfg with the one from environment
        pypathlist = []
        for pypath in env.get('PYTHONPATH'), os.environ.get('PYTHONPATH'):
            if pypath is not None:
                pypathlist.extend(p for p in pypath.split(':') if p not in pypathlist)
        if pypathlist:
            env_update['PYTHONPATH'] = os.environ['PYTHONPATH'] = ':'.join(pypathlist)
        return start_dir, dict(env, **env_update)

    def do_start(self, ins, service=None, cfg='', restart=False, wait=False, logger=None, opts=''):
        if self.wildcard(ins) is not None:
            raise UsageError('no wildcards allowed with %s start' % self.group)
        if cfg and not service and len(self.services) != 1:
            raise UsageError('need service to start (one of %s)' % ', '.join(self.services))
        super().do_start(ins, service, cfg, restart, wait, logger, opts=opts)

    def do_restart(self, ins, service=None, cfg=None, logger=None):
        ins_list = super().do_restart(ins, service, cfg, logger)
        if ins_list:  # wildcard used
            # determine running processes with cfg
            cfginfo = {}
            self.get_procs(None, cfginfo)
            cfgs = {i for i, s in cfginfo if s == service or service is None}
            return [i for i in ins_list if i in cfgs]

    def get_nodes(self, ins='', service=None):
        start_dir = ServiceManager.prepare_start(self, ins, None)[0]
        if start_dir not in sys.path:
            sys.path.insert(0, start_dir)
        nodes = []
        services = self.services if service is None else [service]
        for service in services:
            try:
                self.check_running(ins, service)
                nodes.append('localhost:%d' % self.info[ins][service])
            except ServiceDown:
                if len(services) == 1:
                    raise UsageError('frappy %s %s is not running' % (ins, service))
            except KeyError:
                if ins:
                    raise UsageError('unknown instance %s' % ins)
                raise UsageError('missing instance')
        if not nodes:
            raise UsageError(f"frappy {ins}: none of {'/'.join(services)} is running")
        return nodes

    def do_gui(self, ins='', service=None):
        print(f'starting frappy gui {ins} {service or ""}')
        nodes = self.get_nodes(ins, service)

        import logging
        from frappy.gui.qt import QApplication
        from frappy.gui.mainwindow import MainWindow

        app = QApplication([])
        win = MainWindow(nodes, logging.getLogger('gui'))
        win.show()
        return app.exec_()

    def do_cli(self, ins='', service=None):
        nodes = self.get_nodes(ins, service)
        from frappy.client.interactive import init, interact
        init(*nodes)
        interact()

    @staticmethod
    def get_cfg_details(namespace, cfgfile):
        # get sea_cfg option from frappy cfg file
        namespace.init()
        local = {}
        with open(cfgfile, encoding='utf-8') as f:
            exec(f.read(), namespace, local)
        return namespace.description, local.get('sea_cfg', namespace.sea_cfg)

    def cfg_details(self, ins, service, cfg):
        namespace = Namespace()
        for cfgdir in self.config_dirs(ins, service):
            cfgfile = join(cfgdir, f'{cfg}_cfg.py')
            if exists(cfgfile):
                return self.get_cfg_details(namespace, cfgfile)
        raise FileNotFoundError(f'{cfg} not found')

    def is_cfg(self, ins, service, cfg):
        for cfgdir in self.config_dirs(ins, service):
            cfgfile = join(cfgdir, f'{cfg}_cfg.py')
            if exists(cfgfile):
                return True
        return False

    def all_cfg(self, ins, service, details=False):
        """get available cfg files

        :param ins: instance
        :param service: service nor None for all services
        :param details: get details about relation to sea
        :return: see param:`what`

        implicit results:
        self.frappy2sea: a dict <frappycfg> of <seacfg> (including extension .config/.stick/.addon)
        self.sea2frappy: a dict <seacfg> of set of <frappycfg>
        self.list_info: dict <cfgdir> of <cfg> of <description>
        """
        all_cfg = set()
        if not ins:
            return {}
        namespace = Namespace()
        if details:
            self.frappy2sea = f2s = {}
            self.sea2frappy = s2f = {}
            self.list_info = list_info = {}
        for service in [service] if service else self.services:
            for cfgdir in self.config_dirs(ins, service):
                for cfgfile in glob(join(cfgdir, '*_cfg.py')):
                    cfg = basename(cfgfile)[:-7]
                    if details:
                        try:
                            desc, sea_cfg = self.get_cfg_details(namespace, cfgfile)
                        except Exception as e:
                            sea_cfg = None
                            desc = repr(e)
                        if cfg not in all_cfg:
                            if sea_cfg:
                                # sea_info.setdefault(sea_cfg, set()).add(cfg)
                                f2s[cfg] = sea_cfg
                                s2f.setdefault(sea_cfg, set()).add(cfg)
                            list_info.setdefault(cfgdir, {})[cfg] = desc.split('\n', 1)[0]
                    all_cfg.add(cfg)
            # if service == 'main':
            #    sea_info['none.config'] = {''}
        return all_cfg

    def do_listcfg(self, ins='', service='', prt=print):
        if not ins:
             raise UsageError('missing instance')
        self.all_cfg(ins, service, True)
        seacfgpat = re.compile(r'(.*)(\.config|\.stick|\.addon)')
        keylen = max((max(len(k) for k in cfgs) for cfgs in self.list_info.values()), default=1)
        ambiguous = set()
        for cfgdir, cfgs in self.list_info.items():
            if cfgs:
                prt('')
                prt('--- %s:' % cfgdir)
                for cfg, desc in sorted(cfgs.items(), key=lambda v: (v[0].lower(), v)):
                    seacfg = self.frappy2sea.get(cfg)
                    if seacfg:
                        name, ext = seacfgpat.match(seacfg).groups()
                        if name == cfg or name + 'stick' == cfg:
                            prefix = '* '
                        else:
                            prefix = f'* ({name}{ext}) '
                        if len(self.sea2frappy[seacfg]) > 1:
                            prefix = '!' + prefix[1:]
                            ambiguous.add(seacfg)
                        desc = prefix + desc
                    prt('%s %s' % (cfg.ljust(keylen), desc))
        prt(' ')
        gap = ' ' * keylen
        prt(f'{gap} * need sea')
        if ambiguous:
            prt(f'{gap} ! {len(ambiguous)} ambiguous mappings sea -> frappy')

    def treat_args(self, argdict, unknown=(), extra=()):
        cfg = None
        extra = list(extra)
        for arg in unknown:
            if arg.startswith('-'):  # this is an option
                extra.append(arg)
            elif cfg is None:
                cfg = arg
            else:
                cfg = ''
        if cfg:
            if cfg == 'develop':
                argdict['service'] = cfg
                return super().treat_args(argdict, (), extra)
            if (',' in cfg or cfg.endswith('.cfg') or
                    self.is_cfg(argdict.get('ins'), argdict.get('service'), cfg)):
                return super().treat_args(argdict, (), [cfg] + extra)
        return super().treat_args(argdict, unknown, extra)

    def check_cfg_file(self, ins, service, cfg, needsea=False):
        if cfg == 'none':
            return ''
        try:
            desc, sea_cfg = self.cfg_details(self, ins, service, cfg)
            if needsea and not sea_cfg:
                return None
            return cfg
        except Exception:
            return cfg + '?'

    def get_server_state(self, ins, givencfgs):
        """get proposed configuration and an overview of the running servers

        :param ins: the instance to be checked for
        :param givencfgs: a dict <service> of cfg given by the ECS
        :return: a dict <service> of cfg, where cfg is either:
                - a bare string: this cfg is proposed to change to this value
                - Reconnect(cfg): the frappy server is running as expected, but the given cfg does not match
                - Keep(cfg): no change needed
                remark: Reconnect amd Keep inherit from str, so Reconnect(cfg) == cfg is always True

        implicit results:
        self.remarks: a dict <service> of remark (why should this be changed?)
        self.frappy_cfgs: a dict <service> of running cfgs
        self.sea_cfgs: a dict <service> of sea cfgs (without ending .config/.stick/.addon)
        self.state: a dict ('sea <service>' | 'frappy <service>') of cfg summarizing the state of all servers
                    a change of self.state indicates that the configuration may need to be reevaluated
        self.error: there is an ambiguity for the mapping seacfg -> frappycfg
        self.sea: a fresh SeaManager instance
        """
        self.frappy_cfgs = self.get_cfg(ins, None)  # dict <service> of running frappy servers
        self.sea = SeaManager()
        seaconfig = self.sea.get_cfg(ins, 'sea')
        sealist = seaconfig.split('/')  # <config>, <stick>, <addon1>, <addon2> ...
        if len(sealist) < 2:
            sealist.append('')

        all_cfg = self.all_cfg(ins, None, True)
        proposed_cfg = {}
        self.sea_cfgs = {}
        self.remarks = {}
        self.error = False
        self.state = {}
        result = {}
        for (service, ext), seacfg in zip_longest(SEAEXT.items(), sealist[0:2], fillvalue=(None, None)):
            if service:
                self.sea_cfgs[service] = seacfg
                proposed = self.sea2frappy.get(seacfg + ext) or set()
                if seaconfig:
                    proposed_cfg[service] = proposed
                    self.state[f'sea {service}'] = seacfg

        running_addons = self.frappy_cfgs.get('addons')
        running_addons = [v.strip() for v in running_addons.split(',') if v.strip()]
        proposed_addons = []  # use list instead of set for keeping order
        running_sea_addons = set()
        for cfg in running_addons:
            seacfg = self.frappy2sea.get(cfg.strip())
            if seacfg is None:
                proposed_addons.append(cfg)  # addons with no sea cfg should be kept
            elif seacfg.endswith('.addon') and seacfg[:-6] in sealist[2:]:
                proposed_addons.append(cfg)
                running_sea_addons.add(seacfg)

        for scfg in sealist[2:]:
            seacfg = scfg + '.addon'
            if seacfg not in running_sea_addons:
                proposed = self.sea2frappy.get(seacfg) or set()
                if proposed:
                    if len(proposed) > 1:
                        self.error = f'ambiguous frappy cfg for {seacfg}.addon: {proposed}'
                    else:
                        proposed = list(proposed)[0]
                        if proposed not in proposed_addons:
                            proposed_addons.append(proposed)
        self.sea_cfgs['addons'] = ','.join(sealist[2:])
        if proposed_addons:  # and set(proposed_addons) != set(running_addons):
            proposed_cfg['addons'] = {','.join(proposed_addons)}

        for service in FrappyManager.services:
            given = givencfgs.get(service)
            running = self.frappy_cfgs.get(service)
            available = proposed_cfg.get(service)

            if running:
                self.state[f'frappy {service}'] = running

            if seaconfig and (available or running in self.frappy2sea):
                # we get here when the sea server is running and either at least one of:
                # - the sea config is matching any frappy cfg
                # - the running frappy cfg is matching a sea config
                if not available:
                    self.remarks[service] = 'no frappy config'
                    continue
                proposed = list(available)[0] if len(available) == 1 else None
                if proposed is None:
                    running = None
                    for item in available:
                        if item == given:
                            proposed = item
                        if item == running:
                            running = item
                    if running and not proposed:
                        proposed = running
                if proposed is None:
                    self.remarks[service] = 'ambiguous frappy cfg'
                    self.error = f'ambiguous frappy cfg for {seacfg}: {available}'
                else:
                    self.remarks[service] = ''
                    if running == proposed:
                        if given == running:
                            result[service] = Keep(running)
                    elif running:
                        result[service] = proposed
                        self.remarks[service] = 'restart frappy'
                    else:
                        result[service] = proposed
            else:
                # we get here when sea is not running or all of:
                # - the sea config has no matching frappy cfg
                # - the frappy cfg has no matching sea config
                if running:
                    if self.frappy2sea.get(running, '').endswith(ext):
                        result[service] = running
                        self.remarks[service] = 'restart frappy to start sea'
                    elif given != running:
                        result[service] = Reconnect(running)
                        self.remarks[service] = 'reconnect needed'
                    else:
                        result[service] = Keep(running)
                        self.remarks[service] = ''
                elif given:
                    if self.frappy2sea.get(given, '').endswith(ext):
                        result[service] = running
                        self.remarks[service] = 'restart frappy and sea'
                    elif ':' in given:
                        self.remarks[service] = 'external device'
                    elif given in all_cfg:
                        result[service] = running
                        self.remarks[service] = 'restart frappy'
                    else:
                        result[service] = ''
                        self.remarks[service] = f'unknown frappy cfg {given}'

        return result