import pymysql.cursors


def char_width(string):
    iChineseChar = 0
    iEnglishChar = 0
    for char in string:
        if len(char.encode("utf-8")) > 2:
            iChineseChar += 1
        else:
            iEnglishChar += 1
    return (iChineseChar * 2) + iEnglishChar


def char_equal_width(string, length):
    endadd = ""
    if char_width(string) > length:
        length = length - 2
        endadd = ".."
    new_char = ""
    new_char_len = 0
    for i in range(len(string)):
        this = string[i]
        this_len = char_width(this)
        if new_char_len + this_len > length:
            break
        else:
            new_char += this
            new_char_len += this_len
    a = length - new_char_len
    new_char += a * "\x20"
    new_char_len += a
    new_char += endadd
    new_char_len += char_width(endadd)
    return new_char


def char_line(str_list, len_list):
    o = ""
    l = len(str_list)
    for i in range(l):
        this = str(str_list[i])
        if i == 0:
            o += "|"
        if i >= 0:
            o += " " + char_equal_width(this, len_list[i]) + " " + "|"
        if i == (l - 1):
            o += "\n"
    return o


def show_table(table_head: list, table_body: list, max_char_line=5):
    table_body.insert(0, table_head)
    o = ""
    width_list = [
        max(m) if max(m) <= 20 else 20
        for m in [
            [char_width(str(value[i])) for value in table_body]
            for i in range(len(table_head))
        ]
    ]
    horizontal = ""
    l = len(table_head)
    for i in range(l):
        if i == 0:
            horizontal += "+"
        if i >= 0:
            horizontal += "-" * (width_list[i] + 2) + "+"
        if i == (l - 1):
            horizontal += "\n"
    h = len(table_body)
    l = h if h <= (max_char_line + 1) else (max_char_line + 1)
    for i in range(l):
        this = table_body[i]
        if i == 0:
            o += horizontal
        if i >= 0:
            o += char_line(this, width_list)
        if i == 0:
            o += horizontal
        if i == (l - 1):
            o += horizontal
        if i == (l - 1) and h > l:
            o += str(h - 1) + " rows in set, the rest have been omitted." + "\n"
    return o


class MySQL:
    __conn__ = None
    __curr__ = None
    __sqls__ = None
    __data__ = None

    def __init__(self, **kwargs):
        if kwargs:
            self.connect(**kwargs)

    def connect(self, host=None, port=0, user=None, password='', database=None, charset='', cursor='Dict'):
        if self.__conn__:
            raise Exception('连接已存在 | Connection already exists.')
        match cursor:
            case 'Index':
                cursorClass = pymysql.cursors.Cursor
            case 'Dict':
                cursorClass = pymysql.cursors.DictCursor
            case _:
                cursorClass = pymysql.cursors.DictCursor
        self.__conn__ = pymysql.connect(
            host=host, port=port,
            user=user, password=password,
            database=database, charset=charset,
            autocommit=True,
            connect_timeout=10,
            cursorclass=cursorClass,
            client_flag=pymysql.constants.CLIENT.MULTI_STATEMENTS
        )
        self.__curr__ = self.__conn__.cursor()
        return self

    def execute(self, *args):
        if self.__curr__ is None:
            raise Exception('连接不存在 | Connection does not exist.')
        self.__sqls__ = str(*args)
        self.__curr__.execute(*args)
        return self

    def count(self):
        if self.__curr__ is None:
            raise Exception('连接不存在 | Connection does not exist.')
        return self.__curr__.rowcount

    def brief(self):
        if self.__curr__ is None:
            raise Exception('连接不存在 | Connection does not exist.')
        if not self.__sqls__:
            send = ''
        else:
            send = self.__sqls__
        if not self.__data__:
            recv = ''
        else:
            data = self.__data__
            recv = show_table([str(k) for k in data[0].keys()], [[v for k, v in data[i].items()] for i in range(len(data))], 5)
        return '[->]' + '\n' + send + '\n' + '[<-]' + '\n' + recv

    def fetchall(self):
        if self.__curr__ is None:
            raise Exception('连接不存在 | Connection does not exist.')
        res = self.__curr__.fetchall()
        self.__data__ = res
        return res

    def fetchone(self):
        if self.__curr__ is None:
            raise Exception('连接不存在 | Connection does not exist.')
        return self.__curr__.fetchone()

    def close(self):
        if self.__curr__ or self.__conn__:
            self.__curr__.close()
            self.__conn__.close()
            self.__curr__ = None
            self.__conn__ = None
        return True


if __name__ == '__main__':
    # Example.
    connConfig = {
        "host": "127.0.0.1", "port": 3306, "user": "root", "password": "root", "database": "db", "charset": "utf8",
    }
    sqlConnect = MySQL(**connConfig, cursor='Dict')
    sqlConnect.execute('''
    CREATE TABLE `user` (
        `uid`              int(11)     NOT NULL AUTO_INCREMENT,
        `username`         char(20)    DEFAULT NULL,
        `email`            varchar(64) DEFAULT NULL,
        `phone`            char(11)    DEFAULT NULL,
        `password`         char(32)    DEFAULT NULL,
        PRIMARY KEY (`uid`),
        UNIQUE KEY `username` (`username`),
        UNIQUE KEY `email` (`email`),
        UNIQUE KEY `phone` (`phone`)
    )
    ENGINE=MyISAM AUTO_INCREMENT=10000 DEFAULT CHARSET=utf8;
    ''')
    print('RowCounts:', sqlConnect.count(), 'SqlResult:', sqlConnect.fetchall())
    sqlConnect.execute('''
    INSERT INTO user (username,email,phone,password) VALUES ("刘德华","10000@example.com","13512310000","0123456789abcdef0123456789abcdef");
    ''')
    print('RowCounts:', sqlConnect.count(), 'SqlResult:', sqlConnect.fetchall())
    sqlConnect.execute('''
    INSERT INTO user (username,email,phone,password) VALUES ("周润发","10002@example.com","13512310002","0123456789abcdef0123456789abcdef");
    ''')
    print('RowCounts:', sqlConnect.count(), 'SqlResult:', sqlConnect.fetchall())
    sqlConnect.execute('''
    SELECT * FROM user WHERE uid LIKE "1%";
    ''')
    print('RowCounts:', sqlConnect.count(), 'SqlResult:', sqlConnect.fetchall())
    sqlConnect.execute('''
    DROP TABLE user;
        ''')
    print('RowCounts:', sqlConnect.count(), 'SqlResult:', sqlConnect.fetchall())
    sqlConnect.close()