"""
 __init__.py
 ~~~~~~~~
 初始化 app
 注册蓝图到 app
 日志及环境配置

 :author: Fufu, 2019年9月2日
"""
import logging
import os
from collections import namedtuple
from datetime import datetime, date
from decimal import Decimal

from concurrent_log_handler import ConcurrentRotatingFileHandler
from flask import Flask as _Flask, render_template
from flask.json import JSONEncoder as _JSONEncoder, jsonify
from werkzeug.middleware.proxy_fix import ProxyFix

from .forms import csrf
from .libs.exceptions import APIException, APIServerError, APIFailure
from .libs.helper import is_accept_json, get_int
from .models import db, DBModel
from .models.dbcache import init_db_cache
from .services.auth import oauth, login_manager
from .services.mail import mail
from .services.observers import observer
from .views import init_blueprint, init_template_global


class JSONEncoder(_JSONEncoder):
 """重写 Flask JSON encoder"""

 def default(self, o):
 """
 支持 DBModel 和日期时间. (注: ``UUID``, ``dataclasses`` 等未继承)

 e.g.::

 # {job_number: 114, mobile: "13880000009", last_login: "2019-09-10 09:04:59", status: 1}
 return jsonify(TBUser.query.get(114).hide_keys('realname', 'role_id'))

 :param o:
 :return:
 """
 if isinstance(o, datetime):
 return o.strftime('%Y-%m-%d %H:%M:%S')
 if isinstance(o, date):
 return o.strftime('%Y-%m-%d')
 if isinstance(o, Decimal):
 return float(o)
 if hasattr(o, 'keys') and hasattr(o, '__getitem__'):
 return dict(o)
 raise APIServerError()


class Flask(_Flask):
 json_encoder = JSONEncoder

 def make_response(self, rv):
 """
 支持视图函数直接返回 DBModel, list, dict(1.1.0+官方支持)

 e.g.::

 # {job_number: 114, mobile: "13880000009", last_login: "2019-09-10 09:04:59", status: 1}
 return TBUser.query.get(114).hide_keys('realname', 'role')

 :param rv:
 :return:
 """
 if isinstance(rv, set):
 rv = list(rv)
 if isinstance(rv, (list, dict, DBModel)):
 rv = jsonify(rv)
 return super(Flask, self).make_response(rv=rv)


def init_config(app, config_name=None, config=None):
 """
 加载各类环境配置

 :param app: Flask
 :param config_name: str, 指定配置文件名或环境变量配置名 e.g. development / testing / production
 :param config: str / dict 最高优先级配置, 字典或文件名
 :return: None
 """
 # 加载生产环境配置
 app.config.from_object('app.conf.secret_settings')
 app.config.from_object('app.conf.settings')

 # 加载指定名称的文件配置
 if not config_name:
 config_name = os.getenv(app.config.get('APP_NAME', 'FLASK_CONFIG'))
 if config_name:
 try:
 app.config.from_object('app.conf.{}_settings'.format(config_name))
 except ImportError:
 pass

 # 加载指定的参数配置
 if config is not None:
 if isinstance(config, dict):
 app.config.update(config)
 elif config.endswith('.py'):
 app.config.from_pyfile(config, silent=True)


def init_logger(app):
 """
 初始化日志(按大小滚动)

 :param app: Flask
 :return: None
 """
 log_maxsize = app.config.get('LOG_MAXSIZE', 100)
 log_backup = app.config.get('LOG_BACKUP', 20)
 log_level = app.config.get('LOG_LEVEL', logging.INFO)
 app_log = app.config.get('LOG_FILE')
 if not app_log:
 app_log = os.path.join(os.path.dirname(app.root_path), 'logs', 'app.log')
 fh = ConcurrentRotatingFileHandler(app_log, maxBytes=log_maxsize * 1024 * 1024, backupCount=log_backup,
 encoding='utf-8', use_gzip=True)
 fh.setLevel(log_level)
 fh.setFormatter(logging.Formatter(
 app.config.get('LOG_FORMAT', '%(asctime)s %(levelname)s %(module)s.%(funcName)s: %(message)s')))
 app.logger.addHandler(fh)
 app.logger.setLevel(logging.DEBUG if app.debug else log_level)


def init_error(app):
 """
 全局异常处理

 :param app: Flask
 :return: None
 """

 @app.errorhandler(Exception)
 def global_exception_handler(e):
 # 500 错误时记录日志
 code = getattr(e, 'code', 500)
 code in app.config.get('EXCEPTION_LOG_CODE', [500]) and app.logger.error(e, exc_info=True)

 if isinstance(e, APIException):
 return e
 if app.debug:
 raise e

 # 自定义异常描述
 err = namedtuple('MyError', ['code', 'description'])(
 code, app.config.get('EXCEPTION_DESC', {}).get(code, getattr(e, 'description', str(e)))
 )

 if app.config.get('API') or is_accept_json():
 return APIFailure(description=err.description)

 return render_template('base-msg.html', e=err), code


def create_app(config_name=None, config=None):
 """
 初始化 Flask 应用

 :param config_name: str
 :param config: str / dict 扩展配置或配置文件
 :return: Flask
 """
 app = Flask(__name__)

 # 加载环境配置
 init_config(app, config_name=config_name, config=config)

 x_for = get_int(app.config.get('PROXY_FIX_X_FOR'))
 if x_for:
 app.wsgi_app = ProxyFix(app.wsgi_app, x_for=x_for, x_host=x_for)

 # 日志配置
 init_logger(app)

 # 自定义错误页
 init_error(app)

 # 注册蓝图
 init_blueprint(app)

 # 注册 OAuth2
 oauth.init_app(app)

 # 注册 flask_login
 login_manager.init_app(app)

 # 注册邮件
 mail.init_app(app)

 # 注册自定义信号
 observer.init_app(app)

 # CSRF 保护
 csrf.init_app(app)

 # 注册模板全局函数
 init_template_global(app)

 # 初始化数据库配置
 db.init_app(app)
 with app.app_context():
 db.create_all()
 init_db_cache(app)

 @app.after_request
 def after_request(resp):
 if app.debug and app.config.get('DEBUG_RESPONSE') and is_accept_json():
 app.logger.debug("Response: {}, {}, {}".format(resp.status, resp.mimetype, resp.get_data(as_text=True)))
 return resp

 return app