from app.core.datasource.datasource import DataSourceBase
from pyhive import hive
from pyhive.exc import DatabaseError
from configs.logging import logger
from utils import flat_map

class HiveDS(DataSourceBase):
    type = 'hive'

    def __init__(self, host, port, username, password, database_name, type='hive'):
        DataSourceBase.__init__(self, host, port, username, password, database_name, type)
        self.host = host
        self.port = port
        self.username = username
        self.password = password
        self.database_name = 'default' if not database_name else database_name

    @property
    def jdbc_url(self):
        return f'jdbc:hive2://{self.host}:{self.port}/{self.database_name}'

    @property
    def jdbc_driver_class(self):
        return 'org.apache.hive.jdbc.HiveDriver'

    @property
    def connection_str(self):
        pass

    def _execute_sql(self, sqls):
        conn = None
        res = []
        try:
            conn = hive.Connection(host=self.host, port=self.port, username=self.username, database=self.database_name)

            cursor = conn.cursor()
            for sql in sqls:
                cursor.execute(sql)
                res.append(cursor.fetchall())
            logger.info(res)
        except Exception as e:
            logger.error(e)

        finally:
            if conn is not None:
                conn.close()
        return res

    def is_connect(self):
        sql = 'select 1'
        res = self._execute_sql([sql])
        logger.info(res)
        if res:
            return True
        else:
            return False


    def get_preview_data(self, table_name, limit=100):
        sql1 = f'describe {self.database_name}.{table_name}'
        sql2 = f"SELECT * FROM {table_name} LIMIT {limit}"
        res = self._execute_sql([sql1, sql2])
        logger.info(res)
        return {
            'header': flat_map(lambda x: [':'.join(x[:2])], res[0]),
            'content': res[1]
        }

    def list_tables(self):
        sql = f'show tables'
        res = self._execute_sql([sql])
        return flat_map(lambda x: x, res[0])


    def get_table_schema(self, table_name):
        logger.info(self.database_name)
        sql = f'describe {self.database_name}.{table_name}'
        res = self._execute_sql([sql])
        if res:
            print(res[0])
            res = [[str(i) , *x]for i, x in enumerate(filter(lambda x: x[0] != '', res[0]))]
            logger.info(res)
            return flat_map(lambda x: [':'.join(x[:3])], res)
        else:
            raise Exception('table not found')