from app.config import settings

from sqlalchemy import create_engine, text
from sqlalchemy.exc import IntegrityError, OperationalError
#from app import db

AMS_DB_SERVER = 'linode.oneskyit.com'
AMS_DB_PORT = '3306' # default = 3306
AMS_DB_NAME = 'aether_dev' #onesky_ams_dev
AMS_DB_USERNAME = 'onesky_aether'
AMS_DB_PASSWORD = '$onesky.Aether.2020'


connection_string = 'mysql://'+AMS_DB_USERNAME+':'+AMS_DB_PASSWORD+'@'+AMS_DB_SERVER+'/'+AMS_DB_NAME
engine = create_engine(name_or_url=connection_string, pool_size=10, pool_recycle=120, pool_pre_ping=True, echo=True, echo_pool=True, isolation_level='READ COMMITTED')
# NOTE: The default isolation_level is 'REPEATABLE READ'. This can sometimes not show updated data.

db = engine.connect()


# Insert a new record with values given.
def sql_insert(table_name=None, record=None, sql=None, data=None):
    print('** sql_insert() ***')

    if table_name and record:
        fields = []
        values = []
        for key, value in record.items():
            if key != 'id': # A special exception for the id auto increment field.
                fields.append('`'+str(key)+'`')
                values.append(':'+str(key))
        fields_string = ', '.join(fields)
        values_string = ', '.join(values)

        sql_insert = text(
            """
            INSERT INTO `"""+table_name+"""` ("""+fields_string+""") VALUES ("""+values_string+""");
            """
        )
    elif table_name:
        sql_insert = text(
            """
            INSERT INTO `"""+table_name+"""` () VALUES ();
            """
        )
    elif sql:
        sql_insert = text(sql)
    else:
        print('One or more required fields are missing')
        return False


    trans = db.begin()
    try:
        if record:
            result_insert = db.execute(sql_insert, record)
        else:
            result_insert = db.execute(sql_insert)
        trans.commit()
    except OperationalError as e:
        trans.rollback()
        print('*** An exception happened: OperationalError ***')
        print('* This is likely because a field that does not exist. *')
        print(repr(e))
        print('***')
        print(str(e))
        print('^^^ exception ^^^')
        return False
    except IntegrityError as e:
        trans.rollback()
        print('*** An exception happened: IntegrityError ***')
        print('* This is likely because of a duplicate entry for a primary or unique field. *')
        print(repr(e))
        print('***')
        print(str(e))
        print('^^^ exception ^^^')
        return True # NOTE: This is returning True even though there was an exception
    except Exception as e:
        trans.rollback()
        print('*** An exception happened: catch all ***')
        print(repr(e))
        print('***')
        print(str(e))
        print('^^^ exception ^^^')
        return False
    else:
        record_id = result_insert.lastrowid
        if record_id == 0:
            #print('******')
            #print(dir(result_insert))
            #print('******')
            #print(vars(result_insert))
            #print('******')
            return True
        else:
            return record_id


# NOTE: Select records using custom SQL SELECT statements.
def sql_select(sql=None, data=None, table_name=None, record_id=None, record_id_random=None, field_name=None, field_value=None, as_list=False):
    print('*** sql_select() ***')

    if record_id and table_name:
        sql = text(
        """
        SELECT *
        FROM `"""+table_name+"""`
        WHERE `"""+table_name+"""`.id = :record_id
        """
        )
    elif record_id_random and table_name:
        sql = text(
        """
        SELECT *
        FROM `"""+table_name+"""`
        WHERE `"""+table_name+"""`.id_random = :record_id_random
        """
        )
    elif field_name and field_value and table_name:
        sql = text(
        """
        SELECT *
        FROM `"""+table_name+"""`
        WHERE `"""+table_name+"""`."""+field_name+""" = :field_value
        """
        )
    elif table_name:
        sql = text(
        """
        SELECT *
        FROM `"""+table_name+"""`
        """
        )
    elif sql:
        print('SQL found')
        sql = text(sql)
    else:
        print('One or more required fields are missing')
        return False

    try:
        #if record_id or record_id_random:
            #result = db.execute(sql, record_id=record_id, record_id_random=record_id_random)
        #elif field_name and field_value:
            #result = db.execute(sql, field_value=field_value)
        #elif sql and data:
            #result = db.execute(sql, data)
        print('Executing SQL...')
        result = db.execute(sql, data=data, record_id=record_id, record_id_random=record_id_random, table_name=table_name, field_name=field_name, field_value=field_value)
    except Exception as e:
        print('*** An exception happened. ***')
        print(repr(e))
        print('***')
        print(str(e))
        print('^^^ exception ^^^')
        return False
    else:
        if result.rowcount == 1 and as_list:
            print('Single as list')
            record = result.fetchall()
            return record
        elif result.rowcount == 1 and not as_list:
            print('Single as single')
            record = result.fetchone()
            return record
        elif result.rowcount > 1:
            print('List as list')
            records = result.fetchall()
            return records
        else:
            return False