# -*- coding:utf-8 -*-

import json
import re
from typing import Dict, List

import pymysql


class MySQLColumn(object):
    def __init__(self,
                 column_name: str,
                 column_type: str,
                 column_comment: str,
                 ordinal_position: str,
                 is_nullable: bool):
        self.COLUMN_NAME = column_name
        self.COLUMN_TYPE = column_type
        self.COLUMN_COMMENT = column_comment
        self.ORDINAL_POSITION = ordinal_position
        self.IS_NULLABLE = is_nullable
        self._dict = {
            'COLUMN_NAME': column_name,
            'COLUMN_TYPE': column_type,
            'COLUMN_COMMENT': column_comment,
            'ORDINAL_POSITION': ordinal_position,
            'IS_NULLABLE': is_nullable,
        }

    def __str__(self):
        return json.dumps(self._dict, ensure_ascii=False)


class MySQLHandler:
    def __init__(self, host: str, port: int, username: str, password: str, database: str = None):
        """
        MySQL工具包
        Args:
            host: 实例地址
            port: 端口
            username: 用户名
            password: 密码
        """
        self.jdbcUrl = "jdbc:mysql://%s:%s" % (host, port)
        self.username = username
        self.password = password
        self.connection = pymysql.connect(
            host=host,
            port=port,
            user=username,
            password=password,
            database=database,
            charset='utf8'
        )
        self.connection.autocommit(True)

    def list_tables(self,
                    database: str = None,
                    exclude_regex: List[str] = None,
                    table_regex: List[str] = None) -> Dict[str, str]:
        """
        列出指定数据库中的表
        Args:
            database: 数据库名称
            exclude_regex: 不要的数据表正则
            table_regex: 想要的数据表正则
        Returns: 表及注释
        """
        assert database is not None
        curs = self.connection.cursor()
        curs.execute('SET NAMES utf8')
        curs.execute(f'use {database}')
        sql = "SELECT TABLE_NAME, TABLE_COMMENT " \
              "  FROM information_schema.TABLES " \
              f" WHERE TABLE_SCHEMA='{database}' AND TABLE_TYPE = 'BASE TABLE'"
        curs.execute(sql)
        rows = curs.fetchall()
        tables = {}
        for each_row in rows:
            if exclude_regex:
                exclude = False
                for regex in exclude_regex:
                    if re.match(regex, each_row[0]):
                        exclude = True
                        break
                if exclude:
                    continue
            if table_regex:
                match = False
                for regex in table_regex:
                    if re.match(regex, each_row[0]):
                        match = True
                        break
                if not match:
                    continue
            tables[each_row[0]] = each_row[1]
        return tables

    def list_columns(self, database: str, table_name: str) -> List[MySQLColumn]:
        """
        列出指定数据库、指定表的字段及字段的其他信息
        Args:
            database: 数据库
            table_name: 表
        Returns: 字段及字段的其他信息
        """
        assert database is not None
        assert table_name is not None
        curs = self.connection.cursor()
        curs.execute('SET NAMES utf8')
        curs.execute(f'use {database}')
        detail_names = ['COLUMN_TYPE', 'COLUMN_COMMENT', 'ORDINAL_POSITION', 'IS_NULLABLE']
        sql = "SELECT COLUMN_NAME, %s" \
              "  FROM information_schema.COLUMNS " \
              " WHERE TABLE_SCHEMA = '%s' AND TABLE_NAME = '%s'"
        sql = sql % (', '.join(detail_names), database, table_name)
        curs.execute(sql)
        rows = curs.fetchall()
        columns = []
        for each_row in rows:
            column_name = each_row[0]
            column_type = each_row[1]
            column_comment = each_row[2]
            ordinal_position = each_row[3]
            is_nullable = each_row[4]
            mysql_column = MySQLColumn(column_name, column_type, column_comment, ordinal_position, is_nullable)
            columns.append(mysql_column)
        return columns

    def query(self, sql: str):
        curs = self.connection.cursor()
        curs.execute('SET NAMES utf8')
        curs.execute(sql)
        rows = curs.fetchall()
        return rows

    def query_column_hive_metadata(self, table_name: str):
        curs = self.connection.cursor()
        curs.execute('SET NAMES utf8')
        sql = f'SELECT' \
              f'	t.TBL_NAME,' \
              f'	c.COLUMN_NAME,' \
              f'	c.TYPE_NAME,' \
              f'	c.`COMMENT` ' \
              f'FROM ' \
              f' hive.TBLS t' \
              f' LEFT JOIN hive.SDS s ON t.SD_ID = s.SD_ID' \
              f' LEFT JOIN hive.COLUMNS_V2 c ON s.CD_ID = c.CD_ID' \
              f' LEFT JOIN hive.TBLS tbs ON s.SD_ID = tbs.SD_ID ' \
              f'WHERE t.TBL_NAME = "{table_name}"'
        curs.execute(sql)
        column_info = curs.fetchall()
        return column_info

    def query_tbl_hive_metadata(self, table_name: str):
        curs = self.connection.cursor()
        curs.execute('SET NAMES utf8')
        sql = f'SELECT' \
              f'	tp.PARAM_KEY,' \
              f'	tp.PARAM_VALUE ' \
              f'FROM' \
              f'	hive.TABLE_PARAMS tp' \
              f'	LEFT JOIN hive.TBLS t ON tp.TBL_ID = t.TBL_ID ' \
              f'WHERE' \
              f'	t.TBL_NAME = "{table_name}"'
        curs.execute(sql)
        column_info = curs.fetchall()
        return column_info


if __name__ == '__main__':
    mysql_handler = MySQLHandler(
        'rm-m5e76y41wq677ogz7.mysql.rds.aliyuncs.com',
        3306,
        'bigdata_sync',
        '76iW6SG2K6RGN2X68EQb'
    )
    database_ame = 'ik_bms_production'
    tables = mysql_handler.list_tables(database_ame)
    for table_name, table_comment in tables.items():
        print(f'{table_name}\t{table_comment}')
        columns = mysql_handler.list_columns(database_ame, table_name)
        for col in columns:
            print(col)
        break