##
## fix_import_file.py
## Login : <uli@pu.smp.net>
## Started on  Wed Jan 25 17:08:30 2012 Uli Fouquet
## $Id$
## 
## Copyright (C) 2012 Uli Fouquet
## This program is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 2 of the License, or
## (at your option) any later version.
## 
## This program is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
## GNU General Public License for more details.
## 
## You should have received a copy of the GNU General Public License
## along with this program; if not, write to the Free Software
## Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
##
"""
Fix exports from old SIRP portal to make them importable by current portal.

Usage:

Change into this directory, set the options below (files are assumed
to be in the same directory) and then run

  python fix_import_file.py

Errors/warnings will be displayed on the shell, the output will be put
into the specified output file.
"""

##
## CONFIGURATION SECTION
##
# file with input data
INPUT_FILE = 'students_for_reimport.csv'

# file written with modified output
OUTPUT_FILE = 'out.csv'

# keys are fieldnames in input file, values are methods of class
# Converter (see below)
OPTIONS = {
    'sex': 'gender',
    'birthday': 'date',
    'request_date': 'datetime',
    'marit_stat': 'marit_stat',
    'entry_session': 'session',
    'current_session': 'session',
    }

# Mapping input file colnames --> output file colnames
COLNAME_MAPPING = {
    'jamb_reg_no': 'reg_no',
    'birthday': 'date_of_birth',
    }
##
## END OF CONFIG
##

import csv
import datetime
import sys

def convert_fieldnames(fieldnames):
    """Replace input fieldnames by fieldnames of COLNAME_MAPPING.
    """
    header = dict([(name, name) for name in fieldnames])
    for in_name, out_name in COLNAME_MAPPING.items():
        if in_name not in header:
            continue
        header[in_name] = out_name
    return header

class Converters():
    """Converters to turn old-style values into new ones.
    """
    @classmethod
    def session(self, value):
        """ '08' --> '2008'
        """
        try:
            number = int(value)
        except ValueError:
            return 9999
        if number < 14:
            return number + 2000
        elif number in range(2000,2015):
            return number
        else:
            return 9999

    @classmethod
    def marit_stat(self, value):
        """ 'True'/'False' --> 'married'/'unmarried'
        """
        if value == 'True':
            value = 'married'
        elif value == 'False':
            value = 'unmarried'
        else:
            value = ''
        return value

    @classmethod
    def gender(self, value):
        """ 'True'/'False' --> 'female'/'male'
        """
        if value == 'True':
            value = 'female'
        elif value == 'False':
            value = 'male'
        else:
            value = ''
        return value

    @classmethod
    def date(self, value):
        """ 'yyyy/mm/dd' --> 'yyyy-mm-dd'
        """
        if value == "None":
            value = ""
        elif value == "":
            value = ""
        else:
            value = value.replace('/', '-')
            # We add the hash symbol to avoid automatic date transformation
            # in Excel and Calc for further processing
            value += '#'
        return value

    @classmethod
    def datetime(self, value):
        """ 'yyyy/mm/dd' --> 'yyyy-mm-dd'
        """
        #print  "IN: ", value
        if value == "None":
            value = ""
        elif value == "":
            value = ""
        else:
            #value = datetime.datetime.strptime(value, '%Y/%m/%d')
            #value = datetime.datetime.strftime(value, '%Y-%m-%d')
            pass
        #print "OUT: ", value
        return value

reader = csv.DictReader(open(INPUT_FILE, 'rb'))
writer = None

for num, row in enumerate(reader):
    if num == 0:
        writer = csv.DictWriter(open(OUTPUT_FILE, 'wb'), reader.fieldnames)
        print "FIELDS: "
        for x, y in enumerate(reader.fieldnames):
            print x, y
        header = convert_fieldnames(reader.fieldnames)
        writer.writerow(header)
    for key, value in row.items():
        if not key in OPTIONS.keys():
            continue
        conv_name = OPTIONS[key]
        converter = getattr(Converters, conv_name, None)
        if converter is None:
            print "WARNING: cannot find converter %s" % conv_name
            continue
        row[key] = converter(row[key])
    writer.writerow(row)

print "Ouput written to %s" % OUTPUT_FILE