import mariadb
import os


def getConnection():
    try:
        user = os.environ["DB_USER"]
        password = os.environ["DB_PASS"]
        host = os.environ["DB_HOST"]
        database = os.environ["DB_NAME"]

        conn = mariadb.connect(
            user = user,
            password = password,
            host = host,
            database = database
        )
        conn.autocommit = False

        return conn
    except mariadb.Error as err:
        raise Exception("Error when connecting to database: {}".format(err))
    except KeyError as err:
        raise Exception("Database configuration variable {} not available".format(err))



def getMany(stmt, params, objName):
    dbh = None
    cur = None
    try:
        dbh = getConnection()
        objs = []
        cur = dbh.cursor(dictionary=True)
        cur.execute(stmt, params)
        for obj in cur:
            objs.append(obj)
        return objs
    except Exception as err:
        print("Error in getMany({}): {}".format(objName, err))
        return str(err), 500
    finally:
        print("return connection in getMany({})".format(objName))
        if cur:
            cur.close()
        if dbh:
            dbh.close()


def getOne(stmt, params, objName):
    dbh = None
    cur = None
    try:
        dbh = getConnection()
        cur = dbh.cursor(dictionary=True)
        cur.execute(stmt, params)
        obj = cur.next()
        if not obj:
            return "{} not found".format(objName), 404
        invObj = cur.next()
        if invObj:
            return "More than one {} by that id ({}, {})".format(objName, id, invObj), 500
        return obj
    except Exception as err:
        print("Error in getOne({}): {}".format(objName, err))
        return str(err), 500
    finally:
        print("return connection in getOne({})".format(objName))
        if cur:
            cur.close()
        if dbh:
            dbh.close()
    
def putOne(stmt, params, objName):
    dbh = None
    cur = None
    try:
        dbh = getConnection()
        cur = dbh.cursor(dictionary=True)
        cur.execute(stmt, params)
        dbh.commit()
        return "{} successfully inserted with primary key {}".format(objName, cur.lastrowid), 202
    except mariadb.Error as err:
        dbh.rollback()
        print("Database error in putOne({}): {}".format(objName, err))
        return str(err), 500
    except Exception as err:
        dbh.rollback()
        print("Error in putOne({}): {}".format(objName, err))
        return str(err), 500
    finally:
        print("return connection in getOne({})".format(objName))
        if cur:
            cur.close()
        if dbh:
            dbh.close()

def call(procName):
    dbh = None
    cur = None
    try:
        dbh = getConnection()
        cur = dbh.cursor(dictionary=True)
        cur.execute("CALL {}(null)".format(procName))
        dbh.commit()
        return "{} successfully called".format(procName), 202
    except mariadb.Error as err:
        dbh.rollback()
        print("Database error in call {}: {}".format(procName, err))
        return str(err), 500
    except Exception as err:
        dbh.rollback()
        print("Some error in call {}: {}".format(procName, err))
        return str(err), 500
    finally:
        print("return connection in call {}".format(procName))
        if cur:
            cur.close()
        if dbh:
            dbh.close()