'''

web 处理相关函数

'''

from flask import request, make_response, send_file

import json





def get_user_ip():

    '''

    获取登录用户ip

    :return:

    '''

    if request.headers.get('X-Forwarded-For'):

        return request.headers['X-Forwarded-For']

    elif request.headers.get('X-Real-IP'):

        return request.headers.get('X-Real-IP')

    else:

        return request.remote_addr





def get_user_agent():

    '''

    获取ua

    :return:

    '''

    return request.headers.get('User-Agent')





def get_req_para(req=request):

    '''

    获取http请求的参数

    '''

    if req.method in ['GET']:

        args = request.args

        return args.to_dict()

    else:

        res = req.get_data()

        try:

            the_para = json.loads(res)

            return the_para

        except Exception:

            try:

                return req.form

            except Exception:

                raise ValueError





def is_empty(value):

    '''

    校验是否为空

    :param value:

    :return:

    '''

    if isinstance(value, list):

        return value == []

    if isinstance(value, dict):

        return value == {}

    if isinstance(value, str):

        return value == ''

    return value is None





def validate_params(req_dict, verify_dict):

    '''

    校验请求参数

    :return:

    '''

    for key, check in verify_dict.items():

        param = req_dict.get(key)

        name = check['name']

        for k in check:

            if k in ['not_empty', 'required'] and is_empty(param):

                return f"{name}不能为空"

            if k == 'length':

                len_li = check['length']

                if param:

                    if len(str(param)) < len_li[0]:

                        return f"{name}长度低于限制"

                    elif len(str(param)) > len_li[1]:

                        return f"{name}长度超出限制"

            if k == 'equals':

                equals = check['equals']

                if param not in equals:

                    return f"{name}非法字符"

            if k == 'funcs':

                funcs = check['funcs']

                for func in funcs:

                    print(func)

                    res = func(param)

                    print(res)

                    if res:

                        return f"{name}{res}"

    return False





def generate_download_file(output_file, filename):

    '''

    生成文件导出到前端

    :return:

    '''

    # as_attachment：是否在headers中添加Content-Disposition

    # attachment_filename：下载时使用的文件名

    # conditional: 是否支持断点续传

    fv = send_file(output_file, as_attachment=True, download_name=filename, conditional=True)

    fv.headers['Access-Control-Expose-Headers'] = 'Content-Disposition'

    fv.headers['Content-Disposition'] += "; filename*=utf-8''{}".format(filename)

    fv.headers["Cache-Control"] = "no_store"

    fv.headers["max-age"] = 1

    return make_response(fv)





if __name__ == '__main__':

    pass