#
# This file is part of gunicorn released under the MIT license.
# See the NOTICE for more information.

import io
import logging
import os
import shutil
import socket
import tempfile
from datetime import timedelta
from types import SimpleNamespace

from gunicorn.config import Config
from gunicorn.instrument.statsd import Statsd


class StatsdTestException(Exception):
    pass


class MockSocket:
    "Pretend to be a UDP socket"
    def __init__(self, failp):
        self.failp = failp
        self.msgs = []  # accumulate messages for later inspection

    def send(self, msg):
        if self.failp:
            raise StatsdTestException("Should not interrupt the logger")

        sock_dir = tempfile.mkdtemp()
        sock_file = os.path.join(sock_dir, "test.sock")

        server = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
        client = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)

        try:
            server.bind(sock_file)
            client.connect(sock_file)

            client.send(msg)
            self.msgs.append(server.recv(1024))

        finally:
            client.close()
            server.close()
            shutil.rmtree(sock_dir)

    def reset(self):
        self.msgs = []


def test_statsd_fail():
    "UDP socket fails"
    logger = Statsd(Config())
    logger.sock = MockSocket(True)
    logger.info("No impact on logging")
    logger.debug("No impact on logging")
    logger.critical("No impact on logging")
    logger.error("No impact on logging")
    logger.warning("No impact on logging")
    logger.exception("No impact on logging")


def test_statsd_host_initialization():
    c = Config()
    c.set('statsd_host', 'unix:test.sock')
    logger = Statsd(c)
    logger.info("Can be initialized and used with a UDS socket")

    # Can be initialized and used with a UDP address
    c.set('statsd_host', 'host:8080')
    logger = Statsd(c)
    logger.info("Can be initialized and used with a UDP socket")


def test_dogstatsd_tags():
    c = Config()
    tags = 'yucatan,libertine:rhubarb'
    c.set('dogstatsd_tags', tags)
    logger = Statsd(c)
    logger.sock = MockSocket(False)
    logger.info("Twill", extra={"mtype": "gauge", "metric": "barb.westerly",
                                "value": 2})
    assert logger.sock.msgs[0] == b"barb.westerly:2|g|#" + tags.encode('ascii')


def test_instrument():
    logger = Statsd(Config())
    # Capture logged messages
    sio = io.StringIO()
    logger.error_log.addHandler(logging.StreamHandler(sio))
    logger.sock = MockSocket(False)

    # Regular message
    logger.info("Blah", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"gunicorn.test:666|g"
    assert sio.getvalue() == "Blah\n"
    logger.sock.reset()

    # Only metrics, no logging
    logger.info("", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"gunicorn.test:666|g"
    assert sio.getvalue() == "Blah\n"  # log is unchanged
    logger.sock.reset()

    # Debug logging also supports metrics
    logger.debug("", extra={"mtype": "gauge", "metric": "gunicorn.debug", "value": 667})
    assert logger.sock.msgs[0] == b"gunicorn.debug:667|g"
    assert sio.getvalue() == "Blah\n"  # log is unchanged
    logger.sock.reset()

    logger.critical("Boom")
    assert logger.sock.msgs[0] == b"gunicorn.log.critical:1|c|@1.0"
    logger.sock.reset()

    logger.access(SimpleNamespace(status="200 OK"), None, {}, timedelta(seconds=7))
    assert logger.sock.msgs[0] == b"gunicorn.request.duration:7000.0|ms"
    assert logger.sock.msgs[1] == b"gunicorn.requests:1|c|@1.0"
    assert logger.sock.msgs[2] == b"gunicorn.request.status.200:1|c|@1.0"


def test_prefix():
    c = Config()
    c.set("statsd_prefix", "test.")
    logger = Statsd(c)
    logger.sock = MockSocket(False)

    logger.info("Blah", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"test.gunicorn.test:666|g"


def test_prefix_no_dot():
    c = Config()
    c.set("statsd_prefix", "test")
    logger = Statsd(c)
    logger.sock = MockSocket(False)

    logger.info("Blah", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"test.gunicorn.test:666|g"


def test_prefix_multiple_dots():
    c = Config()
    c.set("statsd_prefix", "test...")
    logger = Statsd(c)
    logger.sock = MockSocket(False)

    logger.info("Blah", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"test.gunicorn.test:666|g"


def test_prefix_nested():
    c = Config()
    c.set("statsd_prefix", "test.asdf.")
    logger = Statsd(c)
    logger.sock = MockSocket(False)

    logger.info("Blah", extra={"mtype": "gauge", "metric": "gunicorn.test", "value": 666})
    assert logger.sock.msgs[0] == b"test.asdf.gunicorn.test:666|g"
