import json
import os
import pytest
import requests
import signal
import time

from hashlib import sha512
from subprocess import call
from urlparse import urljoin
from uuid import uuid4

from leap.soledad.common.couch import CouchDatabase
from leap.soledad.client import Soledad


#
# default options for all tests
#

DEFAULT_PASSPHRASE = '123'

DEFAULT_URL = 'http://127.0.0.1:2424'
DEFAULT_PRIVKEY = 'soledad_privkey.pem'
DEFAULT_CERTKEY = 'soledad_certkey.pem'
DEFAULT_TOKEN = 'an-auth-token'


def pytest_addoption(parser):
    parser.addoption(
        "--couch-url", type="string", default="http://127.0.0.1:5984",
        help="the url for the couch server to be used during tests")


@pytest.fixture
def couch_url(request):
    url = request.config.getoption('--couch-url')
    request.cls.couch_url = url


@pytest.fixture
def method_tmpdir(request, tmpdir):
    request.instance.tempdir = tmpdir.strpath


#
# remote_db fixture: provides an empty database for a given user in a per
# function scope.
#

class UserDatabase(object):

    def __init__(self, url, uuid):
        self._remote_db_url = urljoin(url, 'user-%s' % uuid)

    def setup(self):
        return CouchDatabase.open_database(
            url=self._remote_db_url, create=True, replica_uid=None)

    def teardown(self):
        requests.delete(self._remote_db_url)


@pytest.fixture()
def remote_db(request):
    couch_url = request.config.option.couch_url

    def create(uuid):
        db = UserDatabase(couch_url, uuid)
        request.addfinalizer(db.teardown)
        return db.setup()
    return create


def get_pid(pidfile):
    if not os.path.isfile(pidfile):
        return 0
    try:
        with open(pidfile) as f:
            return int(f.read())
    except IOError:
        return 0


#
# soledad_server fixture: provides a running soledad server in a per module
# context (same soledad server for all tests in this module).
#

class SoledadServer(object):

    def __init__(self, tmpdir_factory, couch_url):
        tmpdir = tmpdir_factory.mktemp('soledad-server')
        self._pidfile = os.path.join(tmpdir.strpath, 'soledad-server.pid')
        self._logfile = os.path.join(tmpdir.strpath, 'soledad-server.log')
        self._couch_url = couch_url

    def start(self):
        self._create_conf_file()
        # start the server
        call([
            'twistd',
            '--logfile=%s' % self._logfile,
            '--pidfile=%s' % self._pidfile,
            'web',
            '--class=leap.soledad.server.entrypoint.SoledadEntrypoint',
            '--port=tcp:2424'
        ])

    def _create_conf_file(self):
        if not os.access('/etc', os.W_OK):
            return
        if not os.path.isdir('/etc/soledad'):
            os.mkdir('/etc/soledad')
        with open('/etc/soledad/soledad-server.conf', 'w') as f:
            content = '[soledad-server]\ncouch_url = %s' % self._couch_url
            f.write(content)

    def stop(self):
        pid = get_pid(self._pidfile)
        os.kill(pid, signal.SIGKILL)


@pytest.fixture(scope='module')
def soledad_server(tmpdir_factory, request):
    couch_url = request.config.option.couch_url
    server = SoledadServer(tmpdir_factory, couch_url)
    server.start()
    request.addfinalizer(server.stop)
    return server


#
# soledad_dbs fixture: provides all databases needed by soledad server in a per
# module scope (same databases for all tests in this module).
#

def _token_dbname():
    dbname = 'tokens_' + \
        str(int(time.time() / (30 * 24 * 3600)))
    return dbname


class SoledadDatabases(object):

    def __init__(self, url):
        self._token_db_url = urljoin(url, _token_dbname())
        self._shared_db_url = urljoin(url, 'shared')

    def setup(self, uuid):
        self._create_dbs()
        self._add_token(uuid)

    def _create_dbs(self):
        requests.put(self._token_db_url)
        requests.put(self._shared_db_url)

    def _add_token(self, uuid):
        token = sha512(DEFAULT_TOKEN).hexdigest()
        content = {'type': 'Token', 'user_id': uuid}
        requests.put(
            self._token_db_url + '/' + token, data=json.dumps(content))

    def teardown(self):
        requests.delete(self._token_db_url)
        requests.delete(self._shared_db_url)


@pytest.fixture()
def soledad_dbs(request):
    couch_url = request.config.option.couch_url

    def create(uuid):
        db = SoledadDatabases(couch_url)
        request.addfinalizer(db.teardown)
        return db.setup(uuid)
    return create


#
# soledad_client fixture: provides a clean soledad client for a test function.
#

@pytest.fixture()
def soledad_client(tmpdir, soledad_server, remote_db, soledad_dbs, request):
    passphrase = DEFAULT_PASSPHRASE
    server_url = DEFAULT_URL
    token = DEFAULT_TOKEN
    default_uuid = uuid4().hex
    remote_db(default_uuid)
    soledad_dbs(default_uuid)

    # get a soledad instance
    def create(force_fresh_db=False):
        secrets_file = '%s.secret' % default_uuid
        secrets_path = os.path.join(tmpdir.strpath, secrets_file)

        # in some tests we might want to use the same user and remote database
        # but with a clean/empty local database (i.e. download benchmarks), so
        # here we provide a way to do that.
        db_file = '%s.db' % default_uuid
        if force_fresh_db:
            prefix = uuid4().hex
            db_file = prefix + '-' + db_file
        local_db_path = os.path.join(tmpdir.strpath, db_file)

        soledad_client = Soledad(
            default_uuid,
            unicode(passphrase),
            secrets_path=secrets_path,
            local_db_path=local_db_path,
            server_url=server_url,
            cert_file=None,
            auth_token=token)
        request.addfinalizer(soledad_client.close)
        return soledad_client
    return create