#! env/bin/python3

# import the psycopg2 database adapter for PostgreSQL
from psycopg2 import connect, Error
import json
from psycopg2.extras import Json
from psycopg2.extras import json as psycop_json
import sys

def connect_db(db: str,host: str,user: str,passwd: str):
    try:
        # declare a new PostgreSQL connection object
        conn = connect(
            dbname = db,
            user = user,
            host = host,
            password = passwd,
            # attempt to connect for 3 seconds then raise exception
            connect_timeout = 3
        )
        cur = conn.cursor()

    except (Exception, Error) as err:
        #print ("\npsycopg2 connect error:", err)
        #conn = None
        cur = None
    return cur

# use Python's open() function to load the JSON data
with open('postgres-records.json') as json_data:

    # use load() rather than loads() for JSON files
    record_list = json.load(json_data)

# concatenate an SQL string
sql_string = 'INSERT INTO {} '.format( table_name )

# if record list then get column names from first key
if type(record_list) == list:
    first_record = record_list[0]

    columns = list(first_record.keys())
    print ("\ncolumn names:", columns)

# if just one dict obj or nested JSON dict
else:
    print ("Needs to be an array of JSON objects")
    sys.exit()

# enclose the column names within parenthesis
sql_string += "(" + ', '.join(columns) + ")\nVALUES "

# only attempt to execute SQL if cursor is valid
if cur != None:

    try:
        cur.execute( sql_string )
        conn.commit()

        print ('\nfinished INSERT INTO execution')

    except (Exception, Error) as error:
        print("\nexecute_sql() error:", error)
        conn.rollback()

    # close the cursor and connection
    cur.close()
    conn.close()

######################################################3

import psycopg2
from config import config


def insert_vendor(vendor_name):
    """ insert a new vendor into the vendors table """
    sql = """INSERT INTO vendors(vendor_name)
             VALUES(%s) RETURNING vendor_id;"""
    conn = None
    vendor_id = None
    try:
        # read database configuration
        params = config()
        # connect to the PostgreSQL database
        conn = psycopg2.connect(**params)
        # create a new cursor
        cur = conn.cursor()
        # execute the INSERT statement
        cur.execute(sql, (vendor_name,))
        # get the generated id back
        vendor_id = cur.fetchone()[0]
        # commit the changes to the database
        conn.commit()
        # close communication with the database
        cur.close()
    except (Exception, psycopg2.DatabaseError) as error:
        print(error)
    finally:
        if conn is not None:
            conn.close()

    return vendor_id