import util
from twisted.internet import defer

import stratum.logger
log = stratum.logger.get_logger('coinbaser')

# TODO: Add on_* hooks in the app

class SimpleCoinbaser(object):
    '''This very simple coinbaser uses constant novacoin address
    for all generated blocks.'''

    def __init__(self, bitcoin_rpc, address):
        # Fire callback when coinbaser is ready
        self.on_load = defer.Deferred()

        self.address = address
        self.is_valid = False # We need to check if pool can use this address

        self.bitcoin_rpc = bitcoin_rpc
        self._validate()

    def _validate(self):
        d = self.bitcoin_rpc.validateaddress(self.address)
        d.addCallback(self._address_check)
        d.addErrback(self._failure)

    def _address_check(self, result):
        if result['isvalid']:
            self.is_valid = True
            log.info("Coinbase address '%s' is valid" % self.address)

            if not self.on_load.called:
                self.on_load.callback(True)

        else:
            self.is_valid = False
            log.error("Coinbase address '%s' is NOT valid!" % self.address)

    def _failure(self, failure):
        log.error("Cannot validate Novacoin address '%s'" % self.address)
        raise

    #def on_new_block(self):
    #    pass

    #def on_new_template(self):
    #    pass

    def get_script_pubkey(self):
        if not self.is_valid:
            # Try again, maybe novacoind was down?
            self._validate()
            raise Exception("Coinbase address is not validated!")
        return util.script_to_address(self.address)

    def get_coinbase_data(self):
        return ''