from flask import render_template, request, flash, redirect, url_for, session
from typing import Dict
from pymysql.cursors import Cursor
from .get_db import get_db

def get_current_user(cursor: Cursor, phone_number: str):
    sql = "SELECT Username FROM Users WHERE Phone_number = %s"
    cursor.execute(sql, (phone_number,))
    return cursor.fetchone()

def verify_user(cursor: Cursor, phone_number: str, password: str) -> str:
    sql = """
    SELECT Password FROM Users WHERE Phone_number = %s;
    """
    cursor.execute(sql, (phone_number,))
    record = cursor.fetchone()
    if not record:
        return "NO_USER"
    if record[0] != password:
        return "WRONG_PASSWORD"
    return "USER_VERIFIED"

class ModifyInfo:
    def __init__(self, form: Dict[str, str], user_phone: str):
        self.phone_number = user_phone
        print(form)
        modifyType = form['modifyType']
        self.new_password = form.get('encryptedNewPassword', None)
        self.new_phone_number = form.get('mobileNo', None)
        self.new_username = form.get('username', None)
        modifyType2command = {
            '删除账户': 'delete account',
            '修改密码': 'modify Password',
            '修改手机号': 'modify Phone_Number',
            '修改用户名': 'modify Username'
        }
        self.sql_dict = {
            'delete account': 'DELETE FROM Users WHERE Phone_number = %s;',
            'modify Password': 'UPDATE Users SET Password = %s WHERE Phone_number = %s;',
            'modify Phone_Number': 'UPDATE Users SET Phone_number = %s WHERE Phone_number = %s;',
            'modify Username': 'UPDATE Users SET Username = %s WHERE Phone_number = %s;'
        }
        self.sql_args_dict = {
            'delete account': (self.phone_number,),
            'modify Password': (self.new_password, self.phone_number),
            'modify Phone_Number': (self.new_phone_number, self.phone_number),
            'modify Username': (self.new_username, self.phone_number)
        }
        self.ok_message_dict = {
            'delete account': "删除账户成功",
            'modify Password': "修改密码成功",
            'modify Phone_Number': "修改手机号成功",
            'modify Username': "修改用户名成功"
        }
        self.fail_message_dict = {
            'delete account': "数据库异常，删除账户失败",
            'modify Password': "数据库异常，修改密码失败",
            'modify Phone_Number': "数据库异常，修改手机号失败",
            'modify Username': "数据库异常，修改用户名失败"
        }
        self.command = modifyType2command[modifyType]

    def get_sql(self):
        return self.sql_dict[self.command]

    def get_args(self):
        return self.sql_args_dict[self.command]

    def get_ok_message(self):
        return self.ok_message_dict[self.command]

    def get_fail_message(self):
        return self.fail_message_dict[self.command]

def modify():
    if request.method == 'GET':
        user_phone = session.get('user_id')
        db = get_db()
        cursor = db.cursor()
        current_user = get_current_user(cursor, user_phone)
        if not current_user:
            session.clear()
            return redirect(url_for('login'))
        return render_template('modify.html', current_user_phone=user_phone, current_username=current_user[0])

    if request.method == 'POST':
        user_phone = session.get('user_id')
        password = request.form['encryptedPassword']
        db = get_db()
        cursor = db.cursor()

        verify_info = verify_user(cursor, user_phone, password)
        if verify_info == "NO_USER":
            session.clear()
            return redirect(url_for('login'))
        elif verify_info == "WRONG_PASSWORD":
            flash("密码错误")
            db.close()
            return redirect(url_for('modify'))

        modifyInfo = ModifyInfo(request.form, user_phone)

        if modifyInfo.command == 'modify Phone_Number':
            check_sql = "SELECT COUNT(*) FROM Users WHERE Phone_number = %s;"
            cursor.execute(check_sql, (modifyInfo.new_phone_number,))
            if cursor.fetchone()[0] > 0:
                flash("手机号已存在，请使用其他手机号")
                db.close()
                return redirect(url_for('modify'))

        try:
            cursor.execute(modifyInfo.get_sql(), modifyInfo.get_args())
            db.commit()
            flash(modifyInfo.get_ok_message())
            db.close()
            if modifyInfo.command in ['modify Phone_Number', 'modify Password', 'delete account']:
                session.clear()
                session.pop("user_id", None)
                return redirect(url_for('login'))
            elif modifyInfo.command == 'modify Username':
                return redirect(url_for('modify'))
        except Exception as e:
            db.rollback()
            print(e)
            flash(modifyInfo.get_fail_message())
            db.close()
            return redirect(url_for('modify'))