# -*- coding: utf-8 -*-
import StringIO
import hashlib
import sys
import os
import os.path
import zlib
import datetime
import fileinput
import logging
import pickle
logger = logging.getLogger(__name__)

from permission import *
from config import config

class ObjectError(Exception):
    pass;

class Object:
    def __init__(self, owner, hash = None):
        self.owner = owner
        if hash is None:
            hash = hashlib.sha1(owner).hexdigest()
        self.hash = hash
        self.owner_path = os.path.join(config.root, owner)
        self.object_path = os.path.join(self.owner_path, hash[:2], hash[2:])
        
class ObjectReader(Object):
    def __init__(self, owner, hash = None):
        Object.__init__(self, owner, hash)
        if not os.path.exists(self.object_path):
            logger.error("Object {} can't be found for user {}".format(self.hash,
                                                                        self.owner))
            raise ObjectError

    def get_permission(self, user):
        with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
            for line in file:
                name, perm, key = line.split()
                if name == user:
                    return int(perm)
            return None

    def get_key(self, user):
        with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
            for line in file:
                name, perm, key = line.split()
                if name == user:
                    return key
            return None

    def get_permission_key(self, user):
        with open(os.path.join(self.object_path, 'permissions'), 'r') as file:
            for line in file:
                name, perm, key = line.split()
                if name == user:
                    return (int(perm), key)
            return (None, None)

    def get_child_list(self, user):
        perm = self.get_permission(user)
        if not perm & LIST:
            logger.error("User {} doesn't have the list permission for object {}"
                          .format(user, self.hash))
            raise PermissionError

        file = open(os.path.join(self.object_path, 'childs'), 'r')
        result = []
        for line in file:
            name = line.rstrip('\n')
            try:
                child = ObjectReader(self.owner, name)
            except ObjectError:
                logger.error("Object {} can't be find for user {}".format(self.hash,
                                                                           self.owner))
            else:
                perm, key = child.get_permission_key(user)
                if perm > 0:
                    result.append((name, perm, key))

        file.close()
        return result

    def get_content(self, user):
        perm, key = self.get_permission_key(user)
        if not perm & READ :
            logger.error("User {} doesn't have read access to object {}"
                          .format(user, self.hash))
            raise PermissionError

        file = open(os.path.join(self.path, "object"), 'r')
        content = file.read()
        file.close()
        return content, key
    
    def get_registration_data(self):
        pass

class ObjectWriter(Object):
    def __init__(self, owner, hash = None):
        Object.__init__(self, owner, hash)
        if not os.path.exists(self.owner_path):
            logger.error("User {} is not registered".format(self.owner))
        os.makedirs(self.object_path)
        for filename in ['permissions', 'childs', 'object']:
            file=open(os.path.join(self.object_path, filename), "w")
            file.close()
        
        
if __name__ == '__main__':
    pass