import logging
import os
import unittest
from datetime import datetime, timedelta
from email.utils import formataddr
from time import sleep

import requests
from django.test import SimpleTestCase, override_settings, tag

from anymail.exceptions import AnymailAPIError
from anymail.message import AnymailMessage

from .utils import AnymailTestMixin, sample_image_path

ANYMAIL_TEST_MAILGUN_API_KEY = os.getenv("ANYMAIL_TEST_MAILGUN_API_KEY")
ANYMAIL_TEST_MAILGUN_DOMAIN = os.getenv("ANYMAIL_TEST_MAILGUN_DOMAIN")


@tag("mailgun", "live")
@unittest.skipUnless(
    ANYMAIL_TEST_MAILGUN_API_KEY and ANYMAIL_TEST_MAILGUN_DOMAIN,
    "Set ANYMAIL_TEST_MAILGUN_API_KEY and ANYMAIL_TEST_MAILGUN_DOMAIN environment"
    " variables to run Mailgun integration tests",
)
@override_settings(
    ANYMAIL={
        "MAILGUN_API_KEY": ANYMAIL_TEST_MAILGUN_API_KEY,
        "MAILGUN_SENDER_DOMAIN": ANYMAIL_TEST_MAILGUN_DOMAIN,
        "MAILGUN_SEND_DEFAULTS": {"esp_extra": {"o:testmode": "yes"}},
    },
    EMAIL_BACKEND="anymail.backends.mailgun.EmailBackend",
)
class MailgunBackendIntegrationTests(AnymailTestMixin, SimpleTestCase):
    """Mailgun API integration tests

    These tests run against the **live** Mailgun API, using the
    environment variable `ANYMAIL_TEST_MAILGUN_API_KEY` as the API key
    and `ANYMAIL_TEST_MAILGUN_DOMAIN` as the sender domain.
    If those variables are not set, these tests won't run.

    """

    def setUp(self):
        super().setUp()
        self.from_email = "from@%s" % ANYMAIL_TEST_MAILGUN_DOMAIN
        self.message = AnymailMessage(
            "Anymail Mailgun integration test",
            "Text content",
            self.from_email,
            ["test+to1@anymail.dev"],
        )
        self.message.attach_alternative("<p>HTML content</p>", "text/html")

    def fetch_mailgun_events(
        self, message_id, event=None, initial_delay=2, retry_delay=2, max_retries=5
    ):
        """Return list of Mailgun events related to message_id"""
        url = "https://api.mailgun.net/v3/%s/events" % ANYMAIL_TEST_MAILGUN_DOMAIN
        auth = ("api", ANYMAIL_TEST_MAILGUN_API_KEY)

        # Despite the docs, Mailgun's events API actually expects the message-id
        # without the <...> brackets (so, not exactly "as returned by the messages API")
        # https://documentation.mailgun.com/api-events.html#filter-field
        params = {"message-id": message_id[1:-1]}  # strip <...>
        if event is not None:
            params["event"] = event

        # It can take a few seconds for the events to show up
        # in Mailgun's logs, so retry a few times if necessary:
        sleep(initial_delay)
        response = None
        for retry in range(max_retries):
            if retry > 0:
                sleep(retry_delay)
            response = requests.get(url, auth=auth, params=params)
            if 200 == response.status_code:
                items = response.json()["items"]
                if len(items) > 0:
                    return items
                # else no matching events found yet, so try again after delay
            elif 500 <= response.status_code < 600:
                # server error (hopefully transient); try again after delay
                pass
            elif 403 == response.status_code:
                # "forbidden": this may be related to API throttling;
                # try again after delay
                pass
            else:
                response.raise_for_status()
        # Max retries exceeded:
        if response is not None and 200 != response.status_code:
            logging.warning(
                "Ignoring Mailgun events API error %d:\n%s"
                % (response.status_code, response.text)
            )
        return None

    def test_simple_send(self):
        # Example of getting the Mailgun send status and message id from the message
        sent_count = self.message.send()
        self.assertEqual(sent_count, 1)

        anymail_status = self.message.anymail_status
        sent_status = anymail_status.recipients["test+to1@anymail.dev"].status
        message_id = anymail_status.recipients["test+to1@anymail.dev"].message_id

        self.assertEqual(sent_status, "queued")  # Mailgun always queues
        # don't know what it'll be, but it should exist:
        self.assertGreater(len(message_id), 0)

        # set of all recipient statuses:
        self.assertEqual(anymail_status.status, {sent_status})
        self.assertEqual(anymail_status.message_id, message_id)

    def test_all_options(self):
        send_at = datetime.now().replace(microsecond=0) + timedelta(minutes=2)
        send_at_timestamp = send_at.timestamp()
        from_email = formataddr(("Test From, with comma", self.from_email))
        message = AnymailMessage(
            subject="Anymail Mailgun all-options integration test",
            body="This is the text body",
            from_email=from_email,
            to=["test+to1@anymail.dev", "Recipient 2 <test+to2@anymail.dev>"],
            cc=["test+cc1@anymail.dev", "Copy 2 <test+cc2@anymail.dev>"],
            bcc=["test+bcc1@anymail.dev", "Blind Copy 2 <test+bcc2@anymail.dev>"],
            reply_to=["reply1@example.com", "Reply 2 <reply2@example.com>"],
            headers={"X-Anymail-Test": "value"},
            metadata={"meta1": "simple string", "meta2": 2},
            send_at=send_at,
            tags=["tag 1", "tag 2"],
            track_clicks=False,
            track_opens=True,
        )
        message.attach("attachment1.txt", "Here is some\ntext for you", "text/plain")
        message.attach("vedhæftet fil.csv", "ID,Name\n1,3", "text/csv")
        cid = message.attach_inline_image_file(
            sample_image_path(), domain=ANYMAIL_TEST_MAILGUN_DOMAIN
        )
        message.attach_alternative(
            "<div>This is the <i>html</i> body <img src='cid:%s'></div>" % cid,
            "text/html",
        )

        message.send()
        # Mailgun always queues:
        self.assertEqual(message.anymail_status.status, {"queued"})
        message_id = message.anymail_status.message_id

        events = self.fetch_mailgun_events(message_id, event="accepted")
        if events is None:
            self.skipTest(
                "No Mailgun 'accepted' event after 30sec -- can't complete this test"
            )
            return

        event = events.pop()
        # don't care about order:
        self.assertCountEqual(event["tags"], ["tag 1", "tag 2"])
        # all metadata values become strings:
        self.assertEqual(
            event["user-variables"], {"meta1": "simple string", "meta2": "2"}
        )

        self.assertEqual(event["message"]["scheduled-for"], send_at_timestamp)
        self.assertIn(
            event["recipient"],
            [
                "test+to1@anymail.dev",
                "test+to2@anymail.dev",
                "test+cc1@anymail.dev",
                "test+cc2@anymail.dev",
                "test+bcc1@anymail.dev",
                "test+bcc2@anymail.dev",
            ],
        )

        headers = event["message"]["headers"]
        self.assertEqual(headers["from"], from_email)
        self.assertEqual(
            headers["to"], "test+to1@anymail.dev, Recipient 2 <test+to2@anymail.dev>"
        )
        self.assertEqual(
            headers["subject"], "Anymail Mailgun all-options integration test"
        )

        attachments = event["message"]["attachments"]
        if len(attachments) == 3:
            # The inline attachment shouldn't be in the event message.attachments array,
            # but sometimes is included for the accepted event (see #172)
            inline_attachment = attachments.pop(0)
            self.assertEqual(inline_attachment["filename"], cid)
            self.assertEqual(inline_attachment["content-type"], "image/png")
        self.assertEqual(len(attachments), 2)
        self.assertEqual(attachments[0]["filename"], "attachment1.txt")
        self.assertEqual(attachments[0]["content-type"], "text/plain")
        self.assertEqual(attachments[1]["filename"], "vedhæftet fil.csv")
        self.assertEqual(attachments[1]["content-type"], "text/csv")

        # No other fields are verifiable from the event data.
        # (We could try fetching the message from event["storage"]["url"]
        # to verify content and other headers.)

    def test_per_recipient_options(self):
        message = AnymailMessage(
            from_email=formataddr(("Test From", self.from_email)),
            to=["test+to1@anymail.dev", '"Recipient 2" <test+to2@anymail.dev>'],
            subject="Anymail Mailgun per-recipient options test",
            body="This is the text body",
            merge_metadata={
                "test+to1@anymail.dev": {"meta1": "one", "meta2": "two"},
                "test+to2@anymail.dev": {"meta1": "recipient 2"},
            },
            headers={
                "List-Unsubscribe-Post": "List-Unsubscribe=One-Click",
                "List-Unsubscribe": "<mailto:unsubscribe@example.com>",
                "X-Custom-Header": "default",
            },
            merge_headers={
                "test+to1@anymail.dev": {
                    "List-Unsubscribe": "<https://example.com/a/>",
                    "X-Custom-Header": "custom",
                },
                "test+to2@anymail.dev": {
                    "List-Unsubscribe": "<https://example.com/b/>",
                },
            },
        )
        message.send()
        recipient_status = message.anymail_status.recipients
        self.assertEqual(recipient_status["test+to1@anymail.dev"].status, "queued")
        self.assertEqual(recipient_status["test+to2@anymail.dev"].status, "queued")

    def test_stored_template(self):
        message = AnymailMessage(
            # name of a real template named in Anymail's Mailgun test account:
            template_id="test-template",
            # Mailgun templates don't define subject:
            subject="Your order %recipient.order%",
            # Mailgun templates don't define sender:
            from_email=formataddr(("Test From>", self.from_email)),
            to=["test+to1@anymail.dev"],
            # metadata and merge_data must not have any conflicting keys
            # when using template_id:
            metadata={"meta1": "simple string", "meta2": 2},
            merge_data={
                "test+to1@anymail.dev": {
                    "name": "Test Recipient",
                }
            },
            merge_global_data={
                "order": "12345",
            },
        )
        message.send()
        recipient_status = message.anymail_status.recipients
        self.assertEqual(recipient_status["test+to1@anymail.dev"].status, "queued")

    # As of Anymail 0.10, this test is no longer possible, because
    # Anymail now raises AnymailInvalidAddress without even calling Mailgun
    # def test_invalid_from(self):
    #     self.message.from_email = 'webmaster'
    #     with self.assertRaises(AnymailAPIError) as cm:
    #         self.message.send()
    #     err = cm.exception
    #     self.assertEqual(err.status_code, 400)
    #     self.assertIn("'from' parameter is not a valid address", str(err))

    @override_settings(
        ANYMAIL={
            "MAILGUN_API_KEY": "Hey, that's not an API key",
            "MAILGUN_SENDER_DOMAIN": ANYMAIL_TEST_MAILGUN_DOMAIN,
            "MAILGUN_SEND_DEFAULTS": {"esp_extra": {"o:testmode": "yes"}},
        }
    )
    def test_invalid_api_key(self):
        with self.assertRaises(AnymailAPIError) as cm:
            self.message.send()
        err = cm.exception
        self.assertEqual(err.status_code, 401)
        # Mailgun doesn't offer any additional explanation in its response body
        # self.assertIn("Forbidden", str(err))