import os
from glob import glob
from itertools import chain
from io import BytesIO

from pytouhou.formats.pbg3 import PBG3
from pytouhou.formats.std import Stage
from pytouhou.formats.ecl import ECL
from pytouhou.formats.anm0 import ANM0
from pytouhou.formats.msg import MSG
from pytouhou.formats.sht import SHT
from pytouhou.formats.exe import SHT as EoSDSHT


from pytouhou.resource.anmwrapper import AnmWrapper


class Directory(object):
    def __init__(self, path):
        self.path = path


    def __enter__(self):
        return self


    def __exit__(self, type, value, traceback):
        return False


    def list_files(self):
        file_list = []
        for path in os.listdir(self.path):
            if os.path.isfile(os.path.join(self.path, path)):
                file_list.append(path)
        return file_list


    def extract(self, name):
        with open(os.path.join(self.path, str(name)), 'rb') as file:
            contents = file.read()
        return contents



class ArchiveDescription(object):
    _formats = {'PBG3': PBG3}

    def __init__(self, path, format_class, file_list=None):
        self.path = path
        self.format_class = format_class
        self.file_list = file_list or []


    def open(self):
        if self.format_class is Directory:
            return self.format_class(self.path)

        file = open(self.path, 'rb')
        instance = self.format_class.read(file)
        return instance


    @classmethod
    def get_from_path(cls, path):
        if os.path.isdir(path):
            instance = Directory(path)
            file_list = instance.list_files()
            return cls(path, Directory, file_list)
        with open(path, 'rb') as file:
            magic = file.read(4)
            file.seek(0)
            format_class = cls._formats[magic]
            instance = format_class.read(file)
            file_list = instance.list_files()
        return cls(path, format_class, file_list)



class Loader(object):
    def __init__(self, game_dir=None):
        self.exe = None
        self.game_dir = game_dir
        self.known_files = {}
        self.instanced_ecls = {}
        self.instanced_anms = {}
        self.instanced_stages = {}
        self.instanced_msgs = {}
        self.instanced_shts = {}


    def scan_archives(self, paths_lists):
        for paths in paths_lists:
            def _expand_paths():
                for path in paths.split(':'):
                    if self.game_dir and not os.path.isabs(path):
                        path = os.path.join(self.game_dir, path)
                    yield glob(path)
            paths = list(chain(*_expand_paths()))
            path = paths[0]
            if os.path.splitext(path)[1] == '.exe':
                self.exe = path
            else:
                archive_description = ArchiveDescription.get_from_path(path)
                for name in archive_description.file_list:
                    self.known_files[name] = archive_description


    def get_file_data(self, name):
        with self.known_files[name].open() as archive:
            content = archive.extract(name)
        return content


    def get_file(self, name):
        with self.known_files[name].open() as archive:
            content = archive.extract(name)
        return BytesIO(content)


    def get_anm(self, name):
        if name not in self.instanced_anms:
            file = self.get_file(name)
            self.instanced_anms[name] = ANM0.read(file) #TODO: modular
        return self.instanced_anms[name]


    def get_stage(self, name):
        if name not in self.instanced_stages:
            file = self.get_file(name)
            self.instanced_stages[name] = Stage.read(file) #TODO: modular
        return self.instanced_stages[name]


    def get_ecl(self, name):
        if name not in self.instanced_ecls:
            file = self.get_file(name)
            self.instanced_ecls[name] = ECL.read(file) #TODO: modular
        return self.instanced_ecls[name]


    def get_msg(self, name):
        if name not in self.instanced_msgs:
            file = self.get_file(name)
            self.instanced_msgs[name] = MSG.read(file) #TODO: modular
        return self.instanced_msgs[name]


    def get_sht(self, name):
        if name not in self.instanced_shts:
            file = self.get_file(name)
            self.instanced_shts[name] = SHT.read(file) #TODO: modular
        return self.instanced_shts[name]


    def get_eosd_characters(self):
        #TODO: Move to pytouhou.games.eosd?
        path = self.exe
        if self.game_dir and not os.path.isabs(path):
            path = os.path.join(self.game_dir, path)
        with open(path, 'rb') as file:
            characters = EoSDSHT.read(file) #TODO: modular
        return characters


    def get_anm_wrapper(self, names, offsets=()):
        return AnmWrapper((self.get_anm(name) for name in names), offsets)


    def get_anm_wrapper2(self, names, offsets=()):
        anms = []

        try:
            for name in names:
                anms.append(self.get_anm(name))
        except KeyError:
            pass

        return AnmWrapper(anms, offsets)