#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @Time    : 2023/4/4 17:29
# @Author  : old tom
# @File    : fu_db_api.py
# @Project : futool-db
# @Desc    :

from sqlalchemy import Connection, text, CursorResult
from fudb.dbapis.fu_collection import split_coll
from psycopg2.extras import execute_values


class SqlExecuteError(Exception):
    def __init__(self, msg=''):
        Exception.__init__(self, msg)


def _select(conn: Connection, sql) -> CursorResult:
    """
    自动关闭连接
    :param conn:
    :return:
    """
    try:
        return conn.execute(text(sql))
    finally:
        conn.close()


def _execute_with_tx(conn: Connection, sql):
    """
    带事务执行SQL
    :return:
    """
    try:
        conn.begin()
        rt = conn.execute(text(sql))
        conn.commit()
        return rt.rowcount
    except Exception as e:
        conn.rollback()
        raise SqlExecuteError(msg=f'sql [{sql}] 执行失败,开始回滚,e={e}')
    finally:
        conn.close()


def select_one(conn: Connection, sql):
    """
    查询一个
    :param conn:
    :param sql:
    :return:
    """
    return _select(conn, sql).fetchone()


def select_all(conn: Connection, sql):
    """
    查询全部
    :param conn:
    :param sql:
    :return:
    """
    return _select(conn, sql).fetchall()


def count(conn: Connection, table):
    """
    统计数据量
    :param conn:
    :param table:
    :return:
    """
    count_tpl = f'select count(1) from {table}'
    return select_one(conn, count_tpl)[0]


def execute_update(conn: Connection, sql):
    """
    带事务执行,可用于insert update delete 语句
    :param conn:
    :param sql:
    :return: 受影响的行数，与java-jdbc的execute_update返回true|false相似,可用于判断是否执行成功
    """
    return _execute_with_tx(conn, sql)


def batch_insert(conn: Connection, db_type, sql_tpl, data, batch_size=1500):
    """
    批量插入
    :param conn: 数据库连接
    :param batch_size: 每次插入量
    :param db_type: 数据库类型
    :param sql_tpl: insert into t1 (f1,f2,f3) values %s
    :param data: [(1,'tom',29),(2,'jack',30)]
    :return:
    """
    handler = BatchInsertHandler(db_type, sql_tpl, data, batch_size)
    insert_sqls = handler.build_insert()
    # 插入都在一个事务内
    row_count = 0
    try:
        conn.begin()
        for sql_set in insert_sqls:
            rt = conn.execute(text(sql_set))
            row_count += rt.rowcount
        conn.commit()
        return row_count
    except Exception as e:
        conn.rollback()
        raise SqlExecuteError(msg=f"批量插入异常,e={e}")
    finally:
        conn.close()


class BatchInsertHandler(object):
    """
    批量插入处理器
    oracle :
         insert all
            into oracle_table ( id, code ) values( 1 , '1' )
            into oracle_table ( id, code ) values( 2 , '2' )
            into oracle_table ( id, code ) values( 3 , '3' )
            into oracle_table ( id, code ) values( 4 , '4' )
        select 1 from dual ;
    postgresql and mysql
        into oracle_table ( id, code ) values( 1 , '1' ),( 2 , '2' ),( 3 , '3' )

    """

    BUILD_INSERT = {
        'oracle': 'build_oracle_insert',
        'postgresql': 'build_pg_insert',
        'mysql': 'build_mysql_insert'
    }

    class NotSupportError(Exception):
        def __init__(self, msg=''):
            Exception.__init__(self, msg)

    def __init__(self, db_type, sql_tpl, data, batch_size):
        """
        :param db_type: 数据库类型
        :param sql_tpl: pg及mysql: insert into t1 (f1,f2,f3) values %s
                        oracle:   into t1 (f1,f2,f3) values %s
        :param data: [(1,'tom',29),(2,'jack',30)]
        :param batch_size:
        """
        if db_type not in ['oracle', 'postgresql']:
            raise self.NotSupportError()
        self.db_type = db_type
        self.sql_tpl = sql_tpl
        self.data = data
        self.batch_size = batch_size

    def _split_data(self):
        return split_coll(self.data, self.batch_size)

    def build_insert(self):
        data_set = self._split_data()
        sql_set = []
        for part in data_set:
            sql_set.append(getattr(self, self.BUILD_INSERT[self.db_type])(part))
        return sql_set

    def build_oracle_insert(self, data_set):
        begin = 'insert all \r '
        for ds in data_set:
            val = '('
            for ele in ds:
                val += "'" + ele + "'," if isinstance(ele, str) else str(ele) + ','
            val = val[0:-1] + ')'
            begin += (self.sql_tpl.replace('%s', val) + ' \r ')
        end = 'select 1 from dual'
        return begin + end

    def build_pg_insert(self, data_set):
        vals = ''
        for ds in data_set:
            val = '('
            for ele in ds:
                val += "'" + ele + "'," if isinstance(ele, str) else str(ele) + ','
            val = val[0:-1] + ')'
            vals += val + ','
        return self.sql_tpl.replace('%s', vals[0:-1])

    def build_mysql_insert(self, data_set):
        return self.build_pg_insert(data_set)