# Copyright (c) 2006,2007,2008 Mitch Garnaat http://garnaat.org/
#
# Permission is hereby granted, free of charge, to any person obtaining a
# copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish, dis-
# tribute, sublicense, and/or sell copies of the Software, and to permit
# persons to whom the Software is furnished to do so, subject to the fol-
# lowing conditions:
#
# The above copyright notice and this permission notice shall be included
# in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
# OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABIL-
# ITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
# SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, 
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
# IN THE SOFTWARE.
import boto

def get_manager(cls):
    """
    Returns the appropriate Manager class for a given Model class.  It does this by
    looking in the boto config for a section like this:
        [DB]
        db_type = SimpleDB
        db_user = <aws access key id>
        db_passwd = <aws secret access key>
        db_name = my_domain
        [DB_TestBasic]
        db_type = SimpleDB
        db_user = <another aws access key id>
        db_passwd = <another aws secret access key>
        db_name = basic_domain
        db_port = 1111
    The values in the DB section are "generic values" that will be used if nothing more
    specific is found.  You can also create a section for a specific Model class that
    gives the db info for that class.  In the example above, TestBasic is a Model subclass.
    """
    db_user = boto.config.get('DB', 'db_user', None)
    db_passwd = boto.config.get('DB', 'db_passwd', None)
    db_type = boto.config.get('DB', 'db_type', 'SimpleDB')
    db_name = boto.config.get('DB', 'db_name', None)
    db_table = boto.config.get('DB', 'db_table', None)
    db_host = boto.config.get('DB', 'db_host', None)
    db_port = boto.config.getint('DB', 'db_port', 0)
    sql_dir = boto.config.get('DB', 'sql_dir', None)
    debug = boto.config.getint('DB', 'debug', 0)
    db_section = 'DB_' + cls.__name__
    if boto.config.has_section(db_section):
        db_user = boto.config.get(db_section, 'db_user', db_user)
        db_passwd = boto.config.get(db_section, 'db_passwd', db_passwd)
        db_type = boto.config.get(db_section, 'db_type', db_type)
        db_name = boto.config.get(db_section, 'db_name', db_name)
        db_table = boto.config.get(db_section, 'db_table', db_table)
        db_host = boto.config.get(db_section, 'db_host', db_host)
        db_port = boto.config.getint(db_section, 'db_port', db_port)
        debug = boto.config.getint(db_section, 'debug', debug)
    if db_type == 'SimpleDB':
        from sdbmanager import SDBManager
        return SDBManager(cls, db_name, db_user, db_passwd,
                          db_host, db_port, db_table, sql_dir)
    elif db_type == 'PostgreSQL':
        from pgmanager import PGManager
        if db_table:
            return PGManager(cls, db_name, db_user, db_passwd,
                             db_host, db_port, db_table, sql_dir)
        else:
            return None
    else:
        raise ValueError, 'Unknown db_type: %s' % db_type

