import argparse

import logging

from pgtoolkit import pgmanager, config

from pgtoolkit.coloredformatter import ColoredFormatter

from pgtoolkit.highlight import highlight

class ConnectionInfoNotFound(Exception):    

    pass

class ToolBase:

    def __init__(self, name, desc):

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

        self.parser.add_argument('-d', dest='debug', action='store_true',

            help='Debug mode - print database queries.')

        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()

        self.target_isolation_level = None

    def init(self):

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

        self.args = self.parser.parse_args()

        self.init_logging()

    def init_logging(self):

        # logging

        handler = logging.StreamHandler()

        format = ColoredFormatter(highlight(1,7,0)+'%(asctime)s %(levelname)-5s'+highlight(0)+' %(message)s', '%H:%M:%S')

        handler.setFormatter(format)

        handler.setLevel(logging.DEBUG)

        self.log = logging.getLogger('main')

        self.log.addHandler(handler)

        self.log.setLevel(logging.DEBUG)

        if self.args.debug:

            handler = logging.StreamHandler()

            handler.setFormatter(format)

            handler.setLevel(logging.DEBUG)

            logger = logging.getLogger('pgmanager_sql')

            logger.addHandler(handler)

            logger.setLevel(logging.DEBUG)

    def prepare_conn_from_metadb(self, name, lookup_name):

        '''Create connection in pgmanager using meta DB.

        name -- Name for connection in pgmanager.

        lookup_name -- Name of connection in meta DB.

        '''

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

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

            row = curs.fetchone_dict()

            curs.connection.commit()

            if row:

                self.pgm.create_conn(name=name,

                    isolation_level=self.target_isolation_level,

                    **row)

                return True

    def prepare_conn_from_config(self, name, lookup_name):

        '''Create connection in pgmanager using info in config.databases.'''

        if self.config.databases:

            if lookup_name in self.config.databases:

                dsn = self.config.databases[lookup_name]

                self.pgm.create_conn(name=name,

                    isolation_level=self.target_isolation_level,

                    dsn=dsn)

                return True

    def prepare_conns_from_cmdline_args(self, *pgm_names):

        if self.config.meta_db:

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

        for name in pgm_names:

            lookup_name = self.args.__dict__[name]

            found = self.prepare_conn_from_config(name, lookup_name)

            if not found and self.config.meta_db:

                found = self.prepare_conn_from_metadb(name, lookup_name)

            if not found:

                raise ConnectionInfoNotFound('Connection name "%s" not found in config nor in meta DB.' % lookup_name)

        if self.config.meta_db:

            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.prepare_conns_from_cmdline_args('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.prepare_conns_from_cmdline_args('src', 'dst')