from sqlalchemy import (Column, Integer, MetaData, String, Table,
                        create_engine, text, Float, DateTime, ForeignKey)
from sqlalchemy_utils.functions import create_database, database_exists

configure_pg = {"user": "postgres",
                'password': '88488848',
                'dns': 'dbserver.home',
                "port": 5432,
                'prefix': 'postgresql+psycopg2',
                'postfix': ''
                }

configure_mssql = {"user": "sa",
                   'password': '88488848',
                   'dns': 'dbserver.home',
                   "port": 1433,
                   'prefix': 'mssql+pymssql',
                   'postfix': '?charset=utf8'
                   }

configure_mysql = {"user": "root",
                   'password': '88488848',
                   'dns': 'dbserver.home',
                   "port": 3306,
                   'prefix': 'mysql+mysqlconnector',
                   'postfix': ''
                   }

config = {'mssql': configure_mssql,
          'mysql': configure_mysql, 'postgresql': configure_pg}

database_name = 'testdb'
table_sensor_location = "sensor_location"
table_sensor_data = "sensor_data"


def linkdb(targetstr):
    """
    連接不同的數(shù)據(jù)庫(kù)

    Args:
        targetstr (string): 數(shù)據(jù)庫(kù)名稱

    Returns:
        engine: 用于后續(xù)的數(shù)據(jù)庫(kù)連接
    """
    if targetstr in config.keys():
        item = config[targetstr]
        connectstring = f"{item['prefix']}://{item['user']}:{item['password']}@{item['dns']}:{item['port']}/{database_name}{item['postfix']}"
        engine = create_engine(connectstring, echo=True, future=True)

    # 如果數(shù)據(jù)庫(kù)不存在，則創(chuàng)建之
    if not database_exists(engine.url):
        create_database(engine.url)

    # 做一個(gè)測(cè)試，不針對(duì)任何表
    with engine.connect() as conn:
        result = conn.execute(text("select 'hello world'"))
        print(result.all())
    return engine


def createtbs(connector):
    """"
    創(chuàng)建數(shù)據(jù)庫(kù)中的2張表。用于保存?zhèn)鞲衅鲾?shù)據(jù)與傳感器本身的信息
    """
    metadata_obj = MetaData()

    # 描述傳感器的表
    sensor_location_tb = Table(
        table_sensor_location,
        metadata_obj,
        Column('id', Integer, primary_key=True, autoincrement=False),
        Column('location', String(30), nullable=False)
    )

    # 保存?zhèn)鞲衅鲾?shù)據(jù)的表
    sensor_data_tb = Table(
        table_sensor_data,
        metadata_obj,
        Column('id', Integer, primary_key=True, autoincrement=False),
        Column('sensor_id', ForeignKey(
            f'{table_sensor_location}.id'), nullable=False),
        Column('area', String(30)),
        Column('pm25', Float),
        Column('timestamp', DateTime)
    )
    print(sensor_data_tb.compile())

    # 創(chuàng)建并返回表
    metadata_obj.create_all(connector)
    return sensor_data_tb, sensor_location_tb


def tableinfo(connector, tablename):
    """
    獲得指定表名的相關(guān)元數(shù)據(jù)信息

    Args:
        connector (engine): 數(shù)據(jù)庫(kù)連接器
        tablename (string): 要查詢的表名
    """
    metadata_obj = MetaData()
    some_table = Table(tablename, metadata_obj, autoload_with=connector)
    print([c.name for c in some_table.columns])


def gensonsorinfo(connector):
    with connector.connect() as conn:
        conn.execute(text(f"INSERT INTO {table_sensor_location} (id, location) VALUES (:x, :y)"),
                     [{"x": 1, "y": '1號(hào)樓'}, {"x": 2, "y": '2號(hào)樓'}])

        conn.commit()

        result = conn.execute(
            text(f"SELECT id, location FROM {table_sensor_location}"))
        for x, y in result:
            print(f"id: {x}  location: {y}")


# 依次連接多個(gè)數(shù)據(jù)庫(kù)。從而驗(yàn)證代碼的一致性
for dbname in config.keys():
    con = linkdb(dbname)
    createtbs(con)
    tableinfo(con, table_sensor_data)
    tableinfo(con, table_sensor_location)
    gensonsorinfo(con)