# standard imports
import logging

# external imports
from hexathon import valid as valid_hex

logg = logging.getLogger(__name__)


class Extension:

    def __init__(self, chain_spec, resources, proof, signer=None, rpc=None, outputs_writer=None):
        self.resources = resources
        self.proof = proof
        self.chain_spec = chain_spec
        self.signer = signer
        self.rpc = rpc
        self.token_details = None
        self.token_address = None
        self.token_code = None
        self.outputs = []


    # TODO: apply / prepare token can be factored out
    def apply_token(self, token):
        return self.prepare_token(token.name, token.symbol, token.precision, token.code)
         

    def prepare_token(self, name, symbol, precision, code, extra=[], extra_types=[], positions=None):
        self.token_details = {
            'name': name,
            'symbol': symbol,
            'precision': precision,
            'code': code,
            'extra': extra,
            'extra_types': extra_types,
            'positions': positions,
            }


    def prepare_extension(self):
        pass


    def parse_code_as_file(self, v):
        try:
            f = open(v, 'r')
            r = f.read()
            f.close()
            self.parse_code_as_hex(r)
        except FileNotFoundError:
            logg.debug('could not parse code as file: {}'.format(e))
            pass
        except IsADirectoryError:
            logg.debug('could not parse code as file: {}'.format(e))
            pass


    def parse_code_as_hex(self, v):
        try:  
            self.token_code = valid_hex(v)
        except ValueError as e:
            logg.debug('could not parse code as hex: {}'.format(e))
            pass


    def load_code(self, hint=None):
        code = self.token_details['code']
        if hint == 'hex':
            self.token_code = valid_hex(code)
       
        for m in [
                self.parse_code_as_hex,
                self.parse_code_as_file,
                ]:
            m(code)
            if self.token_code != None:
                break
       
        if self.token_code == None:
            raise RuntimeError('could not successfully parse token code')

        return self.token_code


    def process(self, writer=None):
        if writer == None:
            writer = self.outputs_writer

        tasks = [] 
        self.token_address = self.resources['token']['reference']
        
        if self.token_address == None:
            if self.token_details['code'] == None:
                raise RuntimeError('neither token address nor token code has been set')
            self.load_code()
            tasks.append('token')


        for k in self.resources.keys():
            if k == 'token':
                continue
            if self.resources[k]['reference'] != None:
                tasks.append(k)
        
        self.prepare_extension()

        for task in tasks:
            logg.debug('ciceth adapter process {}'.format(task))
            r = getattr(self, 'process_' + task)(writer=writer)

        return self.token_address