import argparse

from pgtookit import pgmanager, config

class ToolBase:

    def __init__(self, name, desc):

        self.parser = argparse.ArgumentParser(description=desc)

        self.config = config.ConfigParser()

        self.config.add_argument('databases', type=dict)

        self.config.add_argument('meta_db')

        self.config.add_argument('meta_query')

        self.pgm = pgmanager.get_instance()

    def init(self):

        self.config.load('pgtoolkit.conf')

        self.args = self.parser.parse_args()

    def buildconn(self, name, targetname):

        with self.pgm.cursor('meta') as curs:

            curs.execute(self.config.meta_query, [targetname])

            row = curs.fetchone_dict()

            curs.connection.commit()

            if not row:

                raise Exception('Unknown database "%s"' % targetname)

            self.pgm.create_conn(name=name, **row)

    def prepareconns(self, *args):        

        if self.config.meta_db:

            self.pgm.create_conn(name='meta', dsn=self.config.meta_db)

            for name in args:

                self.buildconn(name, self.args.__dict__[name])

            self.pgm.close_conn('meta')

class SimpleTool(ToolBase):

    def __init__(self, name, desc):

        ToolBase.__init__(self, name, desc)        

        self.parser.add_argument('target', metavar='target', type=str, help='Target database')

    def init(self):

        ToolBase.init(self)

        self.prepareconns('target')

class SrcDstTool(ToolBase):

    def __init__(self, name, desc):

        ToolBase.__init__(self, name, desc)        

        self.parser.add_argument('src', metavar='source', type=str, help='Source database')

        self.parser.add_argument('dst', metavar='destination', type=str, help='Destination database')

    def init(self):

        ToolBase.init(self)

        self.prepareconns('src', 'dst')