from lxml.etree import parse
from io import BytesIO
from os import unlink
from os.path import isdir, isfile, join
from traceback import print_exc
from typing import Dict, List

from tiramisu import Storage, delete_session, MetaConfig, MixConfig
from rougail import load as rougail_load

from ...controller import Controller
from ...register import register
from ...config import DATABASE_DIR, ROUGAIL_DTD_PATH, get_config
from ...context import Context
from ...utils import _
from ...error import CallError, RegistrationError
from ...logger import log


class Risotto(Controller):

    def __init__(self,
                 test) -> None:
        global conf_storage
        self.cache_root_path = join(get_config().get('cache').get('root_path'), 'servermodel')
        for dirname in [self.cache_root_path, DATABASE_DIR]:
            if not isdir(dirname):
                raise RegistrationError(_(f'unable to find the cache dir "{dirname}"'))
        if not test:
            self.save_storage = Storage(engine='sqlite3', dir_database=DATABASE_DIR)
        self.servermodel = {}
        self.server = {}
        super().__init__(test)

    async def on_join(self,
                      risotto_context: Context) -> None:
        """ pre-load servermodel and server
        """
        await self.load_servermodels(risotto_context)
        await self.load_servers(risotto_context)

    async def load_servermodels(self,
                                risotto_context: Context) -> None:
        """ load all available servermodels
        """
        await log.info_msg(risotto_context,
                           None,
                           'Load servermodels')
        servermodels = await self.call('v1.servermodel.list',
                                       risotto_context)

        # load each servermodels
        for servermodel in servermodels:
            try:
                await self.load_servermodel(risotto_context,
                                            servermodel['servermodel_id'],
                                            servermodel['servermodel_name'])
            except CallError as err:
                pass

        # do link to this servermodel
        for servermodel in servermodels:
            if 'servermodel_parents_id' in servermodel:
                for servermodelparentid in servermodel['servermodel_parents_id']:
                    await self.servermodel_legacy(risotto_context,
                                                  servermodel['servermodel_name'],
                                                  servermodel['servermodel_id'],
                                                  servermodelparentid)

    def get_funcs_filename(self,
                           servermodel_id: int):
        return join(self.cache_root_path, str(servermodel_id), "funcs.py")

    async def load_servermodel(self,
                               risotto_context: Context,
                               servermodel_id: int,
                               servermodel_name: str) -> None:
        """ Loads a servermodel
        """
        cache_file = join(self.cache_root_path, str(servermodel_id), "dictionaries.xml")
        funcs_file = self.get_funcs_filename(servermodel_id)
        await log.info_msg(risotto_context,
                           None,
                           f'Load servermodel {servermodel_name} ({servermodel_id})')

        # use file in cache
        with open(cache_file) as fileio:
            xmlroot = parse(fileio).getroot()
        try:
            self.servermodel[servermodel_id] = await self.build_metaconfig(servermodel_id,
                                                                           servermodel_name,
                                                                           xmlroot,
                                                                           funcs_file)
        except Exception as err:
            if get_config().get('global').get('debug'):
                print_exc()
            msg = _(f'unable to load {servermodel_name}: {err}')
            await log.error_msg(risotto_context,
                                None,
                                msg)

    async def build_metaconfig(self,
                               servermodel_id: int,
                               servermodel_name: str,
                               xmlroot: str,
                               funcs_file: str) -> MetaConfig:
        """ Build metaconfig for a servermodel
        """
        # build tiramisu's session ID
        session_id = f'v_{servermodel_id}'
        optiondescription = rougail_load(xmlroot,
                                         ROUGAIL_DTD_PATH,
                                         funcs_file)

        # build servermodel metaconfig (v_xxx.m_v_xxx)
        metaconfig = await MetaConfig([],
                                      optiondescription=optiondescription,
                                      persistent=True,
                                      session_id=session_id,
                                      storage=self.save_storage)
        mixconfig = await MixConfig(children=[],
                                    optiondescription=optiondescription,
                                    persistent=True,
                                    session_id='m_' + session_id,
                                    storage=self.save_storage)
        await metaconfig.config.add(mixconfig)

        # change default rights
        ro_origin = await metaconfig.property.getdefault('read_only', 'append')
        ro_append = frozenset(ro_origin - {'force_store_value'})
        rw_origin = await metaconfig.property.getdefault('read_write', 'append')
        rw_append = frozenset(rw_origin - {'force_store_value'})
        await metaconfig.property.setdefault(ro_append, 'read_only', 'append')
        await metaconfig.property.setdefault(rw_append, 'read_write', 'append')

        await metaconfig.property.read_only()
        await metaconfig.permissive.add('basic')
        await metaconfig.permissive.add('normal')
        await metaconfig.permissive.add('expert')

        # set informtion and owner
        await metaconfig.owner.set('v_{}'.format(servermodel_name))
        await metaconfig.information.set('servermodel_id', servermodel_id)
        await metaconfig.information.set('servermodel_name', servermodel_name)

        # return configuration
        return metaconfig

    async def servermodel_legacy(self,
                                 risotto_context: Context,
                                 servermodel_name: str,
                                 servermodel_id: int,
                                 servermodel_parent_id: int) -> None:
        """ Make link between parent and children
        """
        if servermodel_parent_id is None:
            return
        if not self.servermodel.get(servermodel_parent_id):
            msg = _(f'Servermodel with id {servermodel_parent_id} not loaded, skipping legacy for servermodel {servermodel_name} ({servermodel_id})')
            await log.error_msg(risotto_context,
                                None,
                                msg)
            return
        servermodel_parent = self.servermodel[servermodel_parent_id]
        servermodel_parent_name = await servermodel_parent.information.get('servermodel_name')
        msg = _(f'Create legacy of servermodel {servermodel_name} ({servermodel_id}) with parent {servermodel_parent_name} ({servermodel_parent_id})')
        await log.info_msg(risotto_context,
                           None,
                           msg)

        # do link
        mix = await servermodel_parent.config.get('m_v_' + str(servermodel_parent_id))
        try:
            await mix.config.add(self.servermodel[servermodel_id])
        except Exception as err:
            await log.error_msg(risotto_context,
                                None,
                                str(err))

    async def load_servers(self,
                           risotto_context: Context) -> None:
        """ load all available servers
        """
        await log.info_msg(risotto_context,
                           None,
                           f'Load servers')
        # get all servers
        servers = await self.call('v1.server.list',
                                  risotto_context)
        # loads servers
        for server in servers:
            try:
                await self.load_server(risotto_context,
                                       server['server_id'],
                                       server['server_name'],
                                       server['server_servermodel_id'])
            except Exception as err:
                if get_config().get('global').get('debug'):
                    print_exc()
                server_name = server['server_name']
                server_id = server['server_id']
                msg = _(f'unable to load server {server_name} ({server_id}): {err}')
                await log.error_msg(risotto_context,
                                    None,
                                    msg)

    async def load_server(self,
                          risotto_context: Context,
                          server_id: int,
                          server_name: str,
                          server_servermodel_id: int) -> None:
        """ Loads a server
        """
        if server_id in self.server:
            return
        await log.info_msg(risotto_context,
                           None,
                           f'Load server {server_name} ({server_id})')
        if not server_servermodel_id in self.servermodel:
            msg = f'unable to find servermodel with id {server_servermodel_id}'
            await log.error_msg(risotto_context,
                                None,
                                msg)
            raise CallError(msg)

        # check if server was already created
        session_id = f's_{server_id}'

        # get the servermodel's metaconfig
        metaconfig = self.servermodel[server_servermodel_id]

        # create server configuration and server 'to deploy' configuration and store it
        self.server[server_id] = {'server': await self.build_config(session_id,
                                                                    server_id,
                                                                    server_name,
                                                                    metaconfig),
                                 'server_to_deploy': await self.build_config(f'std_{server_id}',
                                                                             server_id,
                                                                             server_name,
                                                                             metaconfig),
                                 'funcs_file': self.get_funcs_filename(server_servermodel_id)}

    async def build_config(self,
                           session_id: str,
                           server_id: int,
                           server_name: str,
                           metaconfig: MetaConfig) -> None:
        """ build server's config
        """
        config = await metaconfig.config.new(session_id,
                                             storage=self.save_storage,
                                             persistent=True)
        await config.information.set('server_id', server_id)
        await config.information.set('server_name', server_name)
        await config.owner.set(server_name)
        await config.property.read_only()
        return config

    @register('v1.server.created')
    async def server_created(self,
                             risotto_context: Context,
                             server_id: int,
                             server_name: str,
                             server_servermodel_id: int) -> None:
        """ Loads server's configuration when a new server is created
        """
        await self.load_server(risotto_context,
                               server_id,
                               server_name,
                               server_servermodel_id)

    @register('v1.server.deleted')
    async def server_deleted(self,
                             server_id: int) -> None:
        # delete config to it's parents
        for server_type in ['server', 'server_to_deploy']:
            config = self.server[server_id]['server']
            for parent in await config.config.parents():
                await parent.config.pop(await config.config.name())
                delete_session(storage=self.save_storage,
                               session_id=await config.config.name())
        # delete metaconfig
        del self.server[server_id]

    @register('v1.servermodel.created')
    async def servermodel_created(self,
                                  risotto_context: Context,
                                  servermodel_id: int,
                                  servermodel_name: str,
                                  servermodel_parents_id: List[int]) -> None:
        """ when servermodels are created, load it and do link
        """
        await self.load_and_link_servermodel(risotto_context,
                                             servermodel_id,
                                             servermodel_name,
                                             servermodel_parents_id)


    async def load_and_link_servermodel(self,
                                        risotto_context: Context,
                                        servermodel_id: int,
                                        servermodel_name: str,
                                        servermodel_parents_id: List[int]) -> None:
        await self.load_servermodel(risotto_context,
                                    servermodel_id,
                                    servermodel_name)
        if servermodel_parents_id is not None:
            for servermodelparentid in servermodel_parents_id:
                await self.servermodel_legacy(risotto_context,
                                              servermodel_name,
                                              servermodel_id,
                                              servermodelparentid)

    async def servermodel_delete(self,
                                 servermodel_id: int) -> List[MetaConfig]:
        metaconfig = self.servermodel.pop(servermodel_id)
        mixconfig = await metaconfig.config.list()[0]
        children = []
        for child in await mixconfig.config.list():
            children.append(child)
            await mixconfig.config.pop(await child.config.name())
        await metaconfig.config.pop(await mixconfig.config.name())
        delete_session(storage=self.save_storage,
                       session_id=await mixconfig.config.name())
        del mixconfig
        for parent in await metaconfig.config.parents():
            await parent.config.pop(await metaconfig.config.name())
        delete_session(storage=self.save_storage,
                       session_id=await metaconfig.config.name())
        return children
#
#    @register('v1.servermodel.updated')
#    async def servermodel_updated(self,
#                                  risotto_context: Context,
#                                  servermodel_id: int,
#                                  servermodel_name: str,
#                                  servermodel_parents_id: List[int]) -> None:
#        log.info_msg(risotto_context,
#                     None,
#                     f'Reload servermodel {servermodel_name} ({servermodel_id})')
#        # unlink cache to force download new aggregated file
#        cache_file = join(self.cache_root_path, str(servermodel_id)+".xml")
#        if isfile(cache_file):
#            unlink(cache_file)
#
#        # store all informations
#        if servermodel_id in self.servermodel:
#            old_values = await self.servermodel[servermodel_id].value.exportation()
#            old_permissives = await self.servermodel[servermodel_id].permissive.exportation()
#            old_properties = await self.servermodel[servermodel_id].property.exportation()
#            children = await self.servermodel_delete(servermodel_id)
#        else:
#            old_values = None
#
#        # create new one
#        await self.load_and_link_servermodel(risotto_context,
#                                             servermodel_id,
#                                             servermodel_name,
#                                             servermodel_parents_id)
#
#        # migrates informations
#        if old_values is not None:
#            await self.servermodel[servermodel_id].value.importation(old_values)
#            await self.servermodel[servermodel_id].permissive.importation(old_permissives)
#            await self.servermodel[servermodel_id].property.importation(old_properties)
#            for child in children:
#                await self.servermodel_legacy(risotto_context,
#                                              await child.information.get('servermodel_name'),
#                                              await child.information.get('servermodel_id'),
#                                              servermodel_id)

    @register('v1.config.configuration.server.get')
    async def get_configuration(self,
                                risotto_context: Context,
                                server_name: str,
                                deployed: bool) -> bytes:
        server = await self.call('v1.server.describe',
                                 risotto_context,
                                 server_name=server_name)
        server_id = server['server_id']
        if server_id not in self.server:
            msg = _(f'cannot find server with id {server_id}')
            await log.error_msg(risotto_context,
                                None,
                                msg)
            raise CallError(msg)

        if deployed:
            server = self.server[server_id]['server']
        else:
            server = self.server[server_id]['server_to_deploy']

        await server.property.read_only()
        try:
            configuration = await server.value.dict(fullpath=True,
                                                    leader_to_list=True)
        except:
            if deployed:
                msg = _(f'No configuration available for server {server_id}')
            else:
                msg = _(f'No undeployed configuration available for server {server_id}')
            await log.error_msg(risotto_context,
                                None,
                                msg)
            raise CallError(msg)
        return {'server_name': server_name,
                'deployed': deployed,
                'configuration': configuration}

    @register('v1.config.configuration.server.deploy', 'v1.config.configuration.server.updated')
    async def deploy_configuration(self,
                                   risotto_context: Context,
                                   server_name: str) -> Dict:
        """Copy values, permissions, permissives from config 'to deploy' to active config
        """
        server = await self.call('v1.server.describe',
                                 risotto_context,
                                 server_name=server_name)
        server_id = server['server_id']
        # FIXME is server_to_deploy working?
        config = self.server[server_id]['server']
        config_std = self.server[server_id]['server_to_deploy']

        # when deploy, calculate force_store_value
        ro = await config_std.property.getdefault('read_only', 'append')
        if 'force_store_value' not in ro:
            ro = frozenset(list(ro) + ['force_store_value'])
            await config_std.property.setdefault(ro, 'read_only', 'append')
            rw = await config_std.property.getdefault('read_write', 'append')
            rw = frozenset(list(rw) + ['force_store_value'])
            await config_std.property.setdefault(rw, 'read_write', 'append')
            await config_std.property.add('force_store_value')

        # copy informations from server 'to deploy' configuration to server configuration
        await config.value.importation(await config_std.value.exportation())
        await config.permissive.importation(await config_std.permissive.exportation())
        await config.property.importation(await config_std.property.exportation())

        return {'server_id': server_id,
                'server_name': server_name,
                'deployed': True}