from django import http
from django.core.urlresolvers import resolve

from django.shortcuts import render,redirect
from utils.permissions_list import perm_dic
from django.conf import settings


def perm_check(*args,**kwargs):

    request = args[0]
    resolve_url_obj = resolve(request.path)
    current_url_name = resolve_url_obj.url_name  # 當前url的url_name
    print('---perm:',request.user,request.user.is_authenticated(),current_url_name)
    match_results = [None,]
    #match_flag = False
    match_key = None
    # 判断是否登录
    if request.user.is_authenticated() is False:
         return redirect(settings.LOGIN_URL)
    # 循环权限列表
    for permission_key,permission_val in  perm_dic.items():

        per_url_name = permission_val[0]
        per_method  = permission_val[1]
        perm_args = permission_val[2]
        perm_kwargs = permission_val[3]
        perm_hook_func = permission_val[4] if len(permission_val)>4 else None
        # 判断命名空间和权限是否匹配
        if per_url_name == current_url_name: #matches current request url
            # 判断请求方法
            if per_method == request.method: #matches request method
                # if not  perm_args: #if no args defined in perm dic, then set this request to passed perm

                #逐個匹配參數，看每個參數時候都能對應的上。
                args_matched = False #for args only
                for item in perm_args:
                    request_method_func = getattr(request,per_method)
                    if request_method_func.get(item,None):# request字典中有此參數
                        args_matched = True
                    else:
                        print("arg not match......")
                        args_matched = False
                        break  # 有一個參數不能匹配成功，則判定為假，退出該循環。
                else:
                    args_matched = True
                #判断特殊权限，字典匹配有特定值的參數
                kwargs_matched = False
                for k,v in perm_kwargs.items():
                    request_method_func = getattr(request, per_method)
                    arg_val = request_method_func.get(k, None)  # request字典中有此參數
                    print("perm kwargs check:",arg_val,type(arg_val),v,type(v))
                    if arg_val == str(v): #匹配上了特定的參數 及對應的 參數值， 比如，需要request 對象里必須有一個叫 user_id=3的參數
                        kwargs_matched = True
                    else:
                        kwargs_matched = False
                        break # 有一個參數不能匹配成功，則判定為假，退出該循環。
                else:
                    kwargs_matched = True

                #开始匹配自定义的权限钩子函数
                perm_hook_matched = False
                if perm_hook_func:
                    perm_hook_matched = perm_hook_func(request)

                match_results = [args_matched,kwargs_matched,perm_hook_matched]
                print("--->match_results ", match_results)
                if all(match_results): #都匹配上了
                    match_key = permission_key
                    break
    if all(match_results):
        app_name, *per_name = match_key.split('_')
        print("--->matched ",match_results,match_key)
        print(app_name, *per_name)
        perm_obj = '%s.%s' % (app_name,match_key)
        print("perm str:",perm_obj)
        if request.user.has_perm(perm_obj):
            print('當前用戶有此權限')
            return True
        else:
            print('當前用戶沒有該權限')
            return False

    else:
        print("未匹配到權限項，當前用戶無權限")

def check_permission(func):
    def inner(*args,**kwargs):
        if not perm_check(*args,**kwargs):
            request = args[0]
            return http.HttpResponseForbidden("对不起你没有权限")
        return func(*args,**kwargs)
    return  inner