"""
Migration script to add an inheritable column to the following tables:
library_info_association, library_folder_info_association.
Also, in case of sqlite check if the previous migration script deleted the 
request table and if so, restore the table.
"""

from sqlalchemy import *
from migrate import *
from migrate.changeset import *
from galaxy.model.custom_types import *
import datetime
now = datetime.datetime.utcnow
import logging
log = logging.getLogger( __name__ )

metadata = MetaData( migrate_engine )

def upgrade():
    print __doc__
    
    #
    # In case of sqlite, check if the previous migration script deleted the 
    # request table and if so, restore the table.
    #
    if migrate_engine.name == 'sqlite':
        if not migrate_engine.has_table('request'):
            # load the tables referenced in foreign keys 
            metadata.reflect(only=['form_values', 'request_type', 'galaxy_user'])
            # create a temporary table
            Request_table = Table( 'request', metadata,
                                    Column( "id", Integer, primary_key=True),
                                    Column( "create_time", DateTime, default=now ),
                                    Column( "update_time", DateTime, default=now, onupdate=now ),
                                    Column( "name", TrimmedString( 255 ), nullable=False ),
                                    Column( "desc", TEXT ),
                                    Column( "form_values_id", Integer, ForeignKey( "form_values.id" ), index=True ),
                                    Column( "request_type_id", Integer, ForeignKey( "request_type.id" ), index=True ),
                                    Column( "user_id", Integer, ForeignKey( "galaxy_user.id" ), index=True ),
                                    Column( "deleted", Boolean, index=True, default=False ) )
            try:
                Request_table.create()
            except Exception, e:
                log.debug( "Creating request table failed: %s" % str( e ) )  

    metadata.reflect()
    
    LibraryInfoAssociation_table = Table( "library_info_association", metadata, autoload=True )
    c = Column( "inheritable", Boolean, index=True, default=False )
    c.create( LibraryInfoAssociation_table )
    assert c is LibraryInfoAssociation_table.c.inheritable
    cmd = "UPDATE library_info_association SET inheritable = false"
    try:
        db_session.execute( cmd )
    except Exception, e:
        log.debug( "Setting value of column inheritable to false in library_info_association failed: %s" % ( str( e ) ) )
    
    LibraryFolderInfoAssociation_table = Table( "library_folder_info_association", metadata, autoload=True )
    c = Column( "inheritable", Boolean, index=True, default=False )
    c.create( LibraryFolderInfoAssociation_table )
    assert c is LibraryFolderInfoAssociation_table.c.inheritable
    cmd = "UPDATE library_folder_info_association SET inheritable = false"
    try:
        db_session.execute( cmd )
    except Exception, e:
        log.debug( "Setting value of column inheritable to false in library_folder_info_association failed: %s" % ( str( e ) ) )

def downgrade():
    pass