###############################################################################
# sgbackup - The SaveGame Backup tool                                         #
#    Copyright (C) 2024  Christian Moser                                      #
#                                                                             #
#    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 3 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, see <https://www.gnu.org/licenses/>.   #
###############################################################################

from gi.repository.GObject import (
    GObject,
    Property,
    Signal,
    SignalFlags,
    signal_accumulator_true_handled,
)

import datetime
import os
import threading
import time

from ..game import Game
from ..settings import settings

class Archiver:
    def __init__(self,key:str,name:str,extensions:list[str],decription:str|None=None):
        self.__key = key
        self.__name = name
        if decription:
            self.__description = decription
        else:
            self.__description = ""
            
        self.__extensions = list(extensions)
            
    @Property(type=str)
    def name(self)->str:
        return self.__name
    
    @Property
    def key(self)->str:
        return self.__key
    
    @Property
    def description(self)->str:
        return self.__description
    
    @Property
    def extensions(self)->list[str]:
        return self.__extensions
    
    def backup(self,game:Game)->bool:
        if not game.get_backup_files():
            return
        filename = self.generate_new_backup_filename()
        dirname = os.path.dirname(filename)
        if not os.path.isdir(dirname):
            os.makedirs(dirname)
            
        self.emit('backup',game,filename)
    
    def generate_new_backup_filename(self,game:Game)->str:
        dt = datetime.datetime.now()
        basename = '.'.join(game.savegame_name,
                            game.savegame_subdir,
                            dt.strftime("%Y%m%d-%H%M%S"),
                            "sgbackup",
                            self.extensions[0])
        return os.path.join(settings.backup_dir,game.savegame_name,game.subdir,basename)
        
    def _backup_progress(self,game:Game,fraction:float,message:str|None):
        if fraction > 1.0:
            fraction = 1.0
        elif fraction < 0.0:
            fraction = 0.0
            
        self.emit("progress",game,fraction,message)
        
        
    @Signal(name="backup",flags=SignalFlags.RUN_FIRST,
            return_type=bool, arg_types=(GObject,str),
            accumulator=signal_accumulator_true_handled)
    def do_backup(self,game:Game,filename:str):
        raise NotImplementedError("{_class}.{function}() is not implemented!",_class=__class__,function="do_backup")
    
    @Signal(name="restore",flags=SignalFlags.RUN_FIRST,
            return_type=bool,arg_types=(str,),
            accumulator=signal_accumulator_true_handled)
    def do_restore(self,filanme:str):
        raise NotImplementedError("{_class}.{function}() is not implemented!",_class=__class__,function="do_restore")
    
    @Signal(name="backup_progress",flags=SignalFlags.RUN_FIRST,
            return_type=bool,arg_types=(Game,float,str))
    def do_backup_progress(self,game:Game,fraction:float,message:str):
        pass
    
    
    
class ArchiverManager(GObject):
    __global_archiver_manager = None
    
    def __init__(self):
        GObject.__init__(self)
        self.__archivers = {}
        
        
    @staticmethod
    def get_global():
        if ArchiverManager.__global_archiver_manager is None:
            ArchiverManager.__global_archiver_manager = ArchiverManager()
            
        return ArchiverManager.__global_archiver_manager
    
    @property
    def standard_archiver(self)->Archiver:
        try:
            return self.__archivers[settings.archiver]
        except:
            return self.__archivers["zipfile"]    
    
    def _on_archiver_backup_progress_single(self,archiver,game,fraction,message):
        pass
    
    def _on_archiver_backup_progress_multi(self,archiver,game,fraction,message):
        pass
    
    def backup(self,game:Game):
        archiver = self.standard_archiver
        archiver.backup(game)
        
    
    def backup_many(self,games:list[Game]):
        def thread_function(game):
            archiver = self.standard_archiver
            self._on_archiver_backup_progress_multi(archiver,game,1.0,"Finished ...")
        
        game_list = list(games)
        threadpool = {}
        
        if len(game_list) > 8:
            n = 8
        else:
            n = len(games)
            
        for i in range(n):
            game=game_list[0]
            del game_list[0]
            
            thread = threading.Thread(thread_function,args=game,daemon=True)
            threadpool.append(thread)
            thread.start()
        
        while threadpool:
            time.sleep(0.25)
            for i in range(len(threadpool)):
                thread = threadpool[i]
                if thread.is_alive():
                    continue
                del threadpool[i]
                
                if game_list:
                    game = game_list[0]
                    del game_list[0]
                    thread = threading.Thread(thread_function,args=game,daemon=True)
                    threadpool.append(thread)
                    thread.start()