import asyncio
import logging
import unittest
from unittest.case import _Outcome
from .node import Conductor


try:
    from asyncio.runners import _cancel_all_tasks  # pylint: disable=C0412
except ImportError:
    # this is only available in py3.7
    def _cancel_all_tasks(loop):
        pass


class AsyncioTestCase(unittest.TestCase):
    # Implementation inspired by discussion:
    #  https://bugs.python.org/issue32972

    async def asyncSetUp(self):  # pylint: disable=C0103
        pass

    async def asyncTearDown(self):  # pylint: disable=C0103
        pass

    async def doAsyncCleanups(self):  # pylint: disable=C0103
        pass

    def run(self, result=None):  # pylint: disable=R0915
        orig_result = result
        if result is None:
            result = self.defaultTestResult()
            startTestRun = getattr(result, 'startTestRun', None)  # pylint: disable=C0103
            if startTestRun is not None:
                startTestRun()

        result.startTest(self)

        testMethod = getattr(self, self._testMethodName)  # pylint: disable=C0103
        if (getattr(self.__class__, "__unittest_skip__", False) or
                getattr(testMethod, "__unittest_skip__", False)):
            # If the class or method was skipped.
            try:
                skip_why = (getattr(self.__class__, '__unittest_skip_why__', '')
                            or getattr(testMethod, '__unittest_skip_why__', ''))
                self._addSkip(result, self, skip_why)
            finally:
                result.stopTest(self)
            return
        expecting_failure_method = getattr(testMethod,
                                           "__unittest_expecting_failure__", False)
        expecting_failure_class = getattr(self,
                                          "__unittest_expecting_failure__", False)
        expecting_failure = expecting_failure_class or expecting_failure_method
        outcome = _Outcome(result)
        try:
            self._outcome = outcome

            loop = asyncio.new_event_loop()
            try:
                asyncio.set_event_loop(loop)
                loop.set_debug(True)

                with outcome.testPartExecutor(self):
                    self.setUp()
                    loop.run_until_complete(self.asyncSetUp())
                if outcome.success:
                    outcome.expecting_failure = expecting_failure
                    with outcome.testPartExecutor(self, isTest=True):
                        possible_coroutine = testMethod()
                        if asyncio.iscoroutine(possible_coroutine):
                            loop.run_until_complete(possible_coroutine)
                    outcome.expecting_failure = False
                    with outcome.testPartExecutor(self):
                        loop.run_until_complete(self.asyncTearDown())
                        self.tearDown()
            finally:
                try:
                    _cancel_all_tasks(loop)
                    loop.run_until_complete(loop.shutdown_asyncgens())
                finally:
                    asyncio.set_event_loop(None)
                    loop.close()

            self.doCleanups()

            for test, reason in outcome.skipped:
                self._addSkip(result, test, reason)
            self._feedErrorsToResult(result, outcome.errors)
            if outcome.success:
                if expecting_failure:
                    if outcome.expectedFailure:
                        self._addExpectedFailure(result, outcome.expectedFailure)
                    else:
                        self._addUnexpectedSuccess(result)
                else:
                    result.addSuccess(self)
            return result
        finally:
            result.stopTest(self)
            if orig_result is None:
                stopTestRun = getattr(result, 'stopTestRun', None)  # pylint: disable=C0103
                if stopTestRun is not None:
                    stopTestRun()  # pylint: disable=E1102

            # explicitly break reference cycles:
            # outcome.errors -> frame -> outcome -> outcome.errors
            # outcome.expectedFailure -> frame -> outcome -> outcome.expectedFailure
            outcome.errors.clear()
            outcome.expectedFailure = None

            # clear the outcome, no more needed
            self._outcome = None


class IntegrationTestCase(AsyncioTestCase):

    LEDGER = None
    MANAGER = None
    VERBOSITY = logging.WARNING

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.conductor = None
        self.blockchain = None
        self.manager = None
        self.ledger = None
        self.wallet = None
        self.account = None

    async def asyncSetUp(self):
        self.conductor = Conductor(
            ledger_module=self.LEDGER, manager_module=self.MANAGER, verbosity=self.VERBOSITY
        )
        await self.conductor.start()
        self.blockchain = self.conductor.blockchain_node
        self.manager = self.conductor.wallet_node.manager
        self.ledger = self.conductor.wallet_node.ledger
        self.wallet = self.conductor.wallet_node.wallet
        self.account = self.conductor.wallet_node.wallet.default_account

    async def asyncTearDown(self):
        await self.conductor.stop()

    def broadcast(self, tx):
        return self.ledger.broadcast(tx)

    def get_balance(self, account=None, confirmations=0):
        if account is None:
            return self.manager.get_balance(confirmations=confirmations)
        else:
            return account.get_balance(confirmations=confirmations)

    async def on_header(self, height):
        if self.ledger.headers.height < height:
            await self.ledger.on_header.where(
                lambda e: e.height == height
            )
        return True

    def on_transaction_id(self, txid):
        return self.ledger.on_transaction.where(
            lambda e: e.tx.id == txid
        )

    def on_transaction_address(self, tx, address):
        return self.ledger.on_transaction.where(
            lambda e: e.tx.id == tx.id and e.address == address
        )

    async def on_transaction(self, tx):
        addresses = await self.get_tx_addresses(tx, self.ledger)
        await asyncio.wait([
            self.ledger.on_transaction.where(lambda e: e.address == address)  # pylint: disable=W0640
            for address in addresses
        ])

    async def get_tx_addresses(self, tx, ledger):
        addresses = set()
        for txo in tx.outputs:
            address = ledger.hash160_to_address(txo.script.values['pubkey_hash'])
            record = await ledger.db.get_address(address=address)
            if record is not None:
                addresses.add(address)
        return list(addresses)