from __future__ import annotations

import json
import unittest
from datetime import datetime, timedelta
from typing import Any
from unittest.mock import MagicMock, Mock

import aiohttp
import aiohttp.test_utils
import aiotools
from aiohttp import web, web_request
from diskcache import Cache
from freezegun import freeze_time

from matrix_alertbot.alertmanager import AlertmanagerClient
from matrix_alertbot.errors import (
    AlertmanagerServerError,
    AlertNotFoundError,
    InvalidDurationError,
    SilenceExpiredError,
    SilenceNotFoundError,
)


class FakeTimeDelta:
    def __init__(self, seconds: int) -> None:
        self.seconds = seconds

    def __radd__(self, other: Any) -> datetime:
        return datetime.utcfromtimestamp(self.seconds)


class AbstractFakeAlertmanagerServer:
    def __init__(self) -> None:
        self.app = web.Application()
        self.app.router.add_routes(
            [
                web.get("/api/v2/alerts", self.get_alerts),
                web.get("/api/v2/silences", self.get_silences),
                web.post("/api/v2/silences", self.create_silence),
                web.delete("/api/v2/silence/{silence}", self.delete_silence),
            ]
        )
        self.app["silences"] = [
            {"id": "silence1", "status": {"state": "active"}},
            {"id": "silence2", "status": {"state": "expired"}},
        ]

        self.runner = web.AppRunner(self.app)

    async def __aenter__(self) -> AbstractFakeAlertmanagerServer:
        await self.start()
        return self

    async def __aexit__(self, *args: Any) -> None:
        await self.stop()

    async def start(self) -> None:
        self.port = aiohttp.test_utils.unused_port()

        await self.runner.setup()

        site = web.TCPSite(self.runner, "localhost", self.port)
        await site.start()

    async def stop(self) -> None:
        await self.runner.cleanup()

    async def get_alerts(self, request: web_request.Request) -> web.Response:
        raise NotImplementedError

    async def get_silences(self, request: web_request.Request) -> web.Response:
        raise NotImplementedError

    async def create_silence(self, request: web_request.Request) -> web.Response:
        raise NotImplementedError

    async def delete_silence(self, request: web_request.Request) -> web.Response:
        raise NotImplementedError


class FakeAlertmanagerServer(AbstractFakeAlertmanagerServer):
    async def get_alerts(self, request: web_request.Request) -> web.Response:
        return web.Response(
            body=json.dumps(
                [
                    {
                        "fingerprint": "fingerprint1",
                        "labels": {"alertname": "alert1"},
                        "status": {"state": "active"},
                    },
                    {
                        "fingerprint": "fingerprint2",
                        "labels": {"alertname": "alert2"},
                        "status": {
                            "state": "suppressed",
                            "silencedBy": ["silence1", "silence2"],
                        },
                    },
                ]
            ),
            content_type="application/json",
        )

    async def get_silences(self, request: web_request.Request) -> web.Response:
        return web.Response(
            body=json.dumps(self.app["silences"]), content_type="application/json"
        )

    async def create_silence(self, request: web_request.Request) -> web.Response:
        silences = self.app["silences"]

        silence = await request.json()
        if silence["id"] is None:
            silence["id"] = "silence1"
        silence["status"] = {"state": "active"}
        silences.append(silence)

        return web.Response(
            body=json.dumps({"silenceID": silence["id"]}),
            content_type="application/json",
        )

    async def delete_silence(self, request: web_request.Request) -> web.Response:
        silence_id = request.match_info["silence"]
        for i, silence in enumerate(self.app["silences"]):
            if silence["id"] == silence_id:
                del self.app["silences"][i]
                break

        return web.Response(status=200, content_type="application/json")


class FakeAlertmanagerServerWithoutAlert(FakeAlertmanagerServer):
    async def get_alerts(self, request: web_request.Request) -> web.Response:
        return web.Response(body=json.dumps([]), content_type="application/json")


class FakeAlertmanagerServerWithErrorAlerts(FakeAlertmanagerServer):
    async def get_alerts(self, request: web_request.Request) -> web.Response:
        return web.Response(status=500)


class FakeAlertmanagerServerWithoutSilence(FakeAlertmanagerServer):
    def __init__(self) -> None:
        super().__init__()
        self.app["silences"] = []


class FakeAlertmanagerServerWithErrorSilences(FakeAlertmanagerServer):
    async def get_silences(self, request: web_request.Request) -> web.Response:
        return web.Response(status=500)


class FakeAlertmanagerServerWithErrorCreateSilence(FakeAlertmanagerServer):
    async def create_silence(self, request: web_request.Request) -> web.Response:
        return web.Response(status=500)


class FakeAlertmanagerServerWithErrorDeleteSilence(FakeAlertmanagerServer):
    async def delete_silence(self, request: web_request.Request) -> web.Response:
        return web.Response(status=500)


class AlertmanagerClientTestCase(unittest.IsolatedAsyncioTestCase):
    async def asyncSetUp(self) -> None:
        self.fake_fingerprints = Mock(return_value=["fingerprint1", "fingerprint2"])
        self.fake_cache = MagicMock(spec=Cache)
        self.fake_cache.__getitem__ = self.fake_fingerprints

    async def test_get_alerts_happy(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                alerts = await alertmanager.get_alerts()

        self.assertEqual(
            [
                {
                    "fingerprint": "fingerprint1",
                    "labels": {"alertname": "alert1"},
                    "status": {"state": "active"},
                },
                {
                    "fingerprint": "fingerprint2",
                    "labels": {"alertname": "alert2"},
                    "status": {
                        "state": "suppressed",
                        "silencedBy": ["silence1", "silence2"],
                    },
                },
            ],
            alerts,
        )

    async def test_get_alerts_empty(self) -> None:
        async with FakeAlertmanagerServerWithoutAlert() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                alerts = await alertmanager.get_alerts()

        self.assertEqual([], alerts)

    async def test_get_alerts_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorAlerts() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.get_alerts()

    async def test_get_silences_happy(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silences = await alertmanager.get_silences()

        self.assertEqual(
            [
                {"id": "silence1", "status": {"state": "active"}},
                {"id": "silence2", "status": {"state": "expired"}},
            ],
            silences,
        )

    async def test_get_silences_empty(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silences = await alertmanager.get_silences()

        self.assertEqual([], silences)

    async def test_get_silences_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorSilences() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.get_silences()

    async def test_get_alert_happy(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                alert = await alertmanager.get_alert("fingerprint1")

        self.assertEqual(
            {
                "fingerprint": "fingerprint1",
                "labels": {"alertname": "alert1"},
                "status": {"state": "active"},
            },
            alert,
        )

    async def test_get_alert_raise_alert_not_found(self) -> None:
        async with FakeAlertmanagerServerWithoutAlert() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertNotFoundError):
                    await alertmanager.get_alert("fingerprint1")

    async def test_get_alert_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorAlerts() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.get_alert("fingerprint1")

    async def test_get_silence_happy(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silence1 = await alertmanager.get_silence("silence1")
                silence2 = await alertmanager.get_silence("silence2")

        self.assertEqual(
            {"id": "silence1", "status": {"state": "active"}},
            silence1,
        )
        self.assertEqual(
            {"id": "silence2", "status": {"state": "expired"}},
            silence2,
        )

    async def test_get_silence_raise_silence_not_found(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(SilenceNotFoundError):
                    await alertmanager.get_silence("silence1")

    async def test_get_silence_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorSilences() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.get_silence("silence1")

    @freeze_time(datetime.utcfromtimestamp(0))
    async def test_create_silence(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silence_id = await alertmanager.create_silence(
                    "fingerprint1", "user", 86400
                )
                silence = await alertmanager.get_silence("silence1")

        self.assertEqual("silence1", silence_id)
        self.assertEqual(
            {
                "id": "silence1",
                "status": {"state": "active"},
                "matchers": [
                    {
                        "name": "alertname",
                        "value": "alert1",
                        "isRegex": False,
                        "isEqual": True,
                    }
                ],
                "createdBy": "user",
                "startsAt": "1970-01-01T00:00:00",
                "endsAt": "1970-01-02T00:00:00",
                "comment": "Acknowledge alert from Matrix",
            },
            silence,
        )

    @freeze_time(datetime.utcfromtimestamp(0))
    async def test_create_silence_with_id(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silence_id = await alertmanager.create_silence(
                    "fingerprint1", "user", 86400, "silence2"
                )
                silence = await alertmanager.get_silence("silence2")

        self.assertEqual("silence2", silence_id)
        self.assertEqual(
            {
                "id": "silence2",
                "status": {"state": "active"},
                "matchers": [
                    {
                        "name": "alertname",
                        "value": "alert1",
                        "isRegex": False,
                        "isEqual": True,
                    }
                ],
                "createdBy": "user",
                "startsAt": "1970-01-01T00:00:00",
                "endsAt": "1970-01-02T00:00:00",
                "comment": "Acknowledge alert from Matrix",
            },
            silence,
        )

    @freeze_time(datetime.utcfromtimestamp(0))
    async def test_create_silence_with_indefinite_duration(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silence_id = await alertmanager.create_silence("fingerprint1", "user")
                silence = await alertmanager.get_silence("silence1")

        self.assertEqual("silence1", silence_id)
        self.assertEqual(
            {
                "id": "silence1",
                "status": {"state": "active"},
                "matchers": [
                    {
                        "name": "alertname",
                        "value": "alert1",
                        "isRegex": False,
                        "isEqual": True,
                    }
                ],
                "createdBy": "user",
                "startsAt": "1970-01-01T00:00:00",
                "endsAt": "1980-01-01T00:00:00",
                "comment": "Acknowledge alert from Matrix",
            },
            silence,
        )

    @freeze_time(datetime.utcfromtimestamp(0))
    async def test_create_silence_with_max_duration(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                silence_id = await alertmanager.create_silence(
                    "fingerprint1", "user", int(timedelta.max.total_seconds())
                )
                silence = await alertmanager.get_silence("silence1")

        self.assertEqual("silence1", silence_id)
        self.assertEqual(
            {
                "id": "silence1",
                "status": {"state": "active"},
                "matchers": [
                    {
                        "name": "alertname",
                        "value": "alert1",
                        "isRegex": False,
                        "isEqual": True,
                    }
                ],
                "createdBy": "user",
                "startsAt": "1970-01-01T00:00:00",
                "endsAt": "1980-01-01T00:00:00",
                "comment": "Acknowledge alert from Matrix",
            },
            silence,
        )

    @freeze_time(datetime.utcfromtimestamp(0))
    async def test_create_silence_raise_duration_error(self) -> None:
        async with FakeAlertmanagerServerWithoutSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(InvalidDurationError):
                    await alertmanager.create_silence("fingerprint1", "user", -1)

    async def test_create_silence_raise_alert_not_found(self) -> None:
        async with FakeAlertmanagerServerWithoutAlert() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(AlertNotFoundError):
                    await alertmanager.create_silence("fingerprint1", "user")

    async def test_create_silence_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorCreateSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                await alertmanager.get_alert("fingerprint1")

                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.create_silence("fingerprint1", "user")

    async def test_delete_silence(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                await alertmanager.delete_silence("silence1")
                silences = await alertmanager.get_silences()

        self.assertEqual([{"id": "silence2", "status": {"state": "expired"}}], silences)

    async def test_delete_silence_raise_silence_expired(self) -> None:
        async with FakeAlertmanagerServer() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                with self.assertRaises(SilenceExpiredError):
                    await alertmanager.delete_silence("silence2")
                silences = await alertmanager.get_silences()

        self.assertEqual(
            [
                {"id": "silence1", "status": {"state": "active"}},
                {"id": "silence2", "status": {"state": "expired"}},
            ],
            silences,
        )

    async def test_delete_silence_raise_alertmanager_error(self) -> None:
        async with FakeAlertmanagerServerWithErrorDeleteSilence() as fake_alertmanager_server:
            port = fake_alertmanager_server.port
            alertmanager = AlertmanagerClient(
                f"http://localhost:{port}", self.fake_cache
            )
            async with aiotools.closing_async(alertmanager):
                await alertmanager.get_alert("fingerprint1")

                with self.assertRaises(AlertmanagerServerError):
                    await alertmanager.delete_silence("silence1")

    async def test_find_alert_happy(self) -> None:
        alertmanager = AlertmanagerClient("http://localhost", self.fake_cache)
        alert = alertmanager._find_alert(
            "fingerprint1", [{"fingerprint": "fingerprint1"}]
        )
        self.assertEqual({"fingerprint": "fingerprint1"}, alert)

    async def test_find_alert_raise_alert_not_found(self) -> None:
        alertmanager = AlertmanagerClient("http://localhost", self.fake_cache)

        with self.assertRaises(AlertNotFoundError):
            alertmanager._find_alert("fingerprint1", [])

        with self.assertRaises(AlertNotFoundError):
            alertmanager._find_alert("fingerprint2", [{"fingerprint": "fingerprint1"}])

    async def test_find_silence_happy(self) -> None:
        alertmanager = AlertmanagerClient("http://localhost", self.fake_cache)
        silence = alertmanager._find_silence("silence1", [{"id": "silence1"}])
        self.assertEqual({"id": "silence1"}, silence)

    async def test_find_silence_raise_silence_not_found(self) -> None:
        alertmanager = AlertmanagerClient("http://localhost", self.fake_cache)

        with self.assertRaises(SilenceNotFoundError):
            alertmanager._find_silence("silence1", [])

        with self.assertRaises(SilenceNotFoundError):
            alertmanager._find_silence("silence2", [{"id": "silence1"}])


if __name__ == "__main__":
    unittest.main()