#!/usr/bin/env python
# 
# This script completely migrates a <= 0.8.x Trac environment to use the new
# default ticket model introduced in Trac 0.9.
# 
# In particular, this means that the severity field is removed (or rather
# disabled by removing all possible values), and the priority values are
# changed to the more meaningful new defaults.
# 
# Make sure to make a backup of the Trac environment before running this!

import os
import sys

from trac.env import open_environment
from trac.ticket.model import Priority, Severity

priority_mapping = {
    'highest':  'blocker',
    'high':     'critical',
    'normal':   'major',
    'low':      'minor',
    'lowest':   'trivial'
}

def main():
    if len(sys.argv) < 2:
        print >> sys.stderr, 'usage: %s /path/to/projenv' \
                             % os.path.basename(sys.argv[0])
        sys.exit(2)

    env = open_environment(sys.argv[1])
    db = env.get_db_cnx()

    for oldprio, newprio in priority_mapping.items():
        priority = Priority(env, oldprio, db)
        priority.name = newprio
        priority.update(db)

    for severity in list(Severity.select(env, db)):
        severity.delete(db)

    db.commit()

if __name__ == '__main__':
    main()