#!/usr/bin/env python
import sys
import os
import re
# import time
import logging
import argparse as arg
import psycopg2 as pg
from psycopg2.extensions import AsIs

from classes.CustomFormater import CustomFormatter
from classes.Timer import Timer

# Schema name is NAMEDATALEN-1 (PGSQL source code)
#  -> src/include/pg_config_manual.h
def check_schema_name(arg_value, pat=re.compile(r"^[a-z0-9A-Z]{1,63}$")):
    if not pat.match(arg_value):
        raise ValueError
    return arg_value


def parse_args():
    """
    Parse arguments
    """
    parser = arg.ArgumentParser('Process csv files from INSEE')

    parser.add_argument('--source', '-s', 
            help='csv source directory',
            default='exports')

    parser.add_argument('--connection-file', '-f', 
            help='Postgresql connexion file',
            default='.pgconn'
    )
    
    # As whe use AsIs function to not include '' in our sql queries for schema
    # name, me mus ensure that it is not contains SQL special characters 
    # like comments --, final coma etc and avoid SQL injection
    parser.add_argument('--schema-name',
            help='Database schema name',
            type=check_schema_name,
            default='insee'
    )

    debug_group = parser.add_mutually_exclusive_group()
    debug_group.add_argument('--verbose', '-V',
            help='Verbose output',
            action='store_true')
    debug_group.add_argument('--debug', '-d',
            help='Activate debug mode',
            action='store_true')
    return parser.parse_args()

if __name__ == '__main__':
    args = parse_args()
    #logging.basicConfig(level=logging.DEBUG)
    logger = logging.getLogger()
    tty_handler = logging.StreamHandler()

    # create console handler with a higher log level
    tty_handler.setFormatter(CustomFormatter())
    logger.addHandler(tty_handler)
    
    if args.verbose is True:
        logger.setLevel(logging.INFO)
        logger.info('VERBOSE mode activated')
    
    if args.debug is True:
        logger.setLevel(logging.DEBUG)
        logger.debug('DEBUG mode activated')
    
    t = Timer(logger=logger.info)
    logging.debug('Import pgsql connection file {}'.format(args.connection_file))
    with open(args.connection_file) as cf:    
        pg_conn = cf.read()
    
    t.start('Create database schema')
    conn = pg.connect(pg_conn)
    with conn.cursor() as curs:
        curs.execute('CREATE SCHEMA IF NOT EXISTS %s', (AsIs(args.schema_name),))
        curs.execute("""
        CREATE TABLE IF NOT EXISTS %(schema)s.region (
        id_region serial PRIMARY KEY,
        reg VARCHAR(2) unique,
        ncc VARCHAR(200),
        libelle VARCHAR(200)
        );""", 
        {'schema':AsIs(args.schema_name)})
        
        curs.execute(""" 
            CREATE TABLE IF NOT EXISTS %(schema)s.departement (
            id_departement serial PRIMARY KEY,
            dep VARCHAR(3) unique,
            ncc VARCHAR(200),
            libelle VARCHAR(200),
            reg VARCHAR(2) REFERENCES %(schema)s.region(reg)
            );""",
            {'schema':AsIs(args.schema_name)})

        curs.execute(""" 
            CREATE TABLE IF NOT EXISTS %(schema)s.commune (
            id_commune serial PRIMARY KEY,
            com VARCHAR(5) unique,
            ncc VARCHAR(200),
            libelle VARCHAR(200),
            dep VARCHAR(3) REFERENCES %(schema)s.departement(dep),
            superf FLOAT CONSTRAINT SUPERFICIE_POSITIVE CHECK (superf > 0)
            );""",
            {'schema':AsIs(args.schema_name)})

        curs.execute("""
            CREATE TABLE IF NOT EXISTS %(schema)s.cheflieudepartement(
            dep VARCHAR(3) REFERENCES %(schema)s.departement(dep),
            cheflieudep VARCHAR(5) REFERENCES %(schema)s.commune(com),
            PRIMARY KEY (dep, cheflieudep)
            );""",
            {'schema':AsIs(args.schema_name)})
        
        curs.execute("""
            CREATE TABLE IF NOT EXISTS %(schema)s.cheflieuregion(
            reg VARCHAR(3) REFERENCES %(schema)s.region(reg),
            cheflieureg VARCHAR(5) REFERENCES %(schema)s.commune(com),
            PRIMARY KEY (reg, cheflieureg)
            );""",
            {'schema':AsIs(args.schema_name)})

        curs.execute("""
            CREATE TABLE IF NOT EXISTS %(schema)s.indicateur(
            id_indicateur INTEGER PRIMARY KEY,
            libelle VARCHAR(200)
            );""",
            {'schema':AsIs(args.schema_name)})

        curs.execute(""" 
            CREATE TABLE IF NOT EXISTS %(schema)s.statistique(
            com VARCHAR(5) REFERENCES %(schema)s.commune(com),
            id_indicateur INTEGER REFERENCES %(schema)s.indicateur(id_indicateur),
            date_debut SMALLINT,
            date_fin SMALLINT CONSTRAINT APRES_DATEDEBUT CHECK (date_fin > date_debut),
            valeur float,
            PRIMARY KEY (com,id_indicateur,date_debut)
            );""",
            {'schema':AsIs(args.schema_name)})
    t.stop()
    
    t.start('Import data from csv files')
    with conn.cursor() as curs:
        curs.execute('SET search_path TO {}'.format(args.schema_name))
        csvs = {
            'region': {'col': ('reg', 'ncc', 'libelle'), 'null':''},
            'departement': {'col': ('dep', 'ncc', 'libelle', 'reg'), 'null': ''},
            'commune': {'col': ('com', 'ncc', 'libelle', 'dep', 'superf'), 'null':''},
            'cheflieudepartement': {'col': ('cheflieudep', 'dep'), 'null':''},
            'cheflieuregion': {'col': ('cheflieureg', 'reg'), 'null':''},
            'indicateur': {'col': ('id_indicateur', 'libelle'), 'null':''},
            'statistique': {
                'col': (
                    'com',
                    'id_indicateur',
                    'date_debut',
                    'date_fin',
                    'valeur'
                ), 
                'null':'null'
            }
        }
        for csv, params in csvs.items():
            logging.debug('Process csv file : {} with {}'.format(csv, params))
            with open( args.source + '/' + csv + '.csv') as f:
                with conn.cursor() as curs:
                    curs.copy_from(
                        f,
                        csv,
                        sep=',',
                        columns=params['col'],
                        null=params['null']
                    )
                conn.commit()
    t.stop()
    
    conn.close()