#!/usr/bin/env python3
#
# Copyright (c) 2016-present, Facebook, Inc.
# All rights reserved.
#
# This source code is licensed under the BSD-style license found in the
# LICENSE file in the root directory of this source tree. An additional grant
# of patent rights can be found in the PATENTS file in the same directory.

import os
import pathlib
import subprocess
import sys

import eden.thrift
import eden.thrift.client
import pexpect

from .lib.find_executables import FindExe
from .lib.service_test_case import ServiceTestCaseBase, service_test
from .lib.temporary_directory import TemporaryDirectoryMixin


@service_test
class RestartTest(ServiceTestCaseBase, TemporaryDirectoryMixin):
    def setUp(self) -> None:
        self.tmp_dir = self.make_temporary_directory()

        def ensure_stopped() -> None:
            stop_cmd = [FindExe.EDEN_CLI, "--config-dir", self.tmp_dir, "stop"]
            subprocess.call(stop_cmd)

        self.addCleanup(ensure_stopped)

    def _spawn_restart(self, *args: str) -> "pexpect.spawn[bytes]":
        restart_cmd = [
            FindExe.EDEN_CLI,
            "--config-dir",
            self.tmp_dir,
            "restart",
            "--daemon-binary",
            FindExe.FAKE_EDENFS,
        ]
        restart_cmd.extend(args)

        print("Retarting eden: %r" % (restart_cmd,))
        return pexpect.spawn(
            restart_cmd[0], restart_cmd[1:], logfile=sys.stdout.buffer, timeout=5
        )

    def _start_fake_edenfs(self) -> int:
        daemon = self.spawn_fake_edenfs(eden_dir=pathlib.Path(self.tmp_dir))
        return daemon.process_id

    def test_restart_starts_edenfs_if_not_running(self) -> None:
        """
        Run "eden restart".  It should start it without prompting since edenfs
        is not already running.
        """
        p = self._spawn_restart()
        p.expect_exact("Eden is not currently running.  Starting it...")
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid ([0-9]+)\)")
        int(p.match.group(1))
        p.wait()
        self.assertEqual(p.exitstatus, 0)

    def _get_thrift_client(self) -> eden.thrift.EdenClient:
        return eden.thrift.create_thrift_client(self.tmp_dir)

    def test_restart(self) -> None:
        self._start_fake_edenfs()

        # Run "eden restart"
        # It should prompt since we are about to do a non-graceful restart.
        p = self._spawn_restart()
        p.expect_exact("About to perform a full restart of Eden")
        p.expect_exact(
            "Note: this will temporarily disrupt access to your Eden-managed "
            "repositories"
        )
        p.expect_exact("Proceed? [y/N] ")
        p.sendline("y")
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid [0-9]+\)")
        p.expect_exact("Successfully restarted edenfs.")
        p.expect_exact(
            "Note: any programs running inside of an Eden-managed "
            "directory will need to cd"
        )
        p.wait()
        self.assertEqual(p.exitstatus, 0)

    def test_restart_sigkill(self) -> None:
        self._start_fake_edenfs()

        # Tell the fake edenfs binary to ignore attempts to stop it
        with self._get_thrift_client() as client:
            client.setOption("honor_stop", "false")

        # Run "eden restart".  It should have to kill eden with SIGKILL during the
        # restart operation.
        # Explicitly pass in a shorter than normal shutdown timeout just to reduce the
        # amount of time required for the test.
        p = self._spawn_restart("--shutdown-timeout=1")
        p.expect_exact("About to perform a full restart of Eden")
        p.expect_exact(
            "Note: this will temporarily disrupt access to your Eden-managed "
            "repositories"
        )
        p.expect_exact("Proceed? [y/N] ")
        p.sendline("y")
        p.expect(
            r"sent shutdown request, but edenfs did not exit within "
            r"[.0-9]+ seconds. Attempting SIGKILL."
        )
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid [0-9]+\)")
        p.expect_exact("Successfully restarted edenfs.")
        p.expect_exact(
            "Note: any programs running inside of an Eden-managed "
            "directory will need to cd"
        )
        p.wait()
        self.assertEqual(p.exitstatus, 0)

    def test_restart_force(self) -> None:
        self._start_fake_edenfs()

        # "eden restart --force" should not prompt if the user wants to proceed
        p = self._spawn_restart("--force")
        p.expect_exact("About to perform a full restart of Eden")
        p.expect_exact(
            "Note: this will temporarily disrupt access to your Eden-managed "
            "repositories"
        )
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid [0-9]+\)")
        p.expect_exact("Successfully restarted edenfs.")
        p.expect_exact(
            "Note: any programs running inside of an Eden-managed "
            "directory will need to cd"
        )
        p.wait()
        self.assertEqual(p.exitstatus, 0)

    def test_restart_while_starting(self) -> None:
        orig_pid = self._start_fake_edenfs()

        # Tell the fake edenfs daemon to report its status as "starting"
        with self._get_thrift_client() as client:
            client.setOption("status", "starting")

        # "eden restart" should not restart if edenfs is still starting
        p = self._spawn_restart()
        p.expect_exact(f"The current edenfs daemon (pid {orig_pid}) is still starting")
        p.expect_exact("Use --force if you want to forcibly restart the current daemon")
        p.wait()
        self.assertEqual(p.exitstatus, 1)

        # "eden restart --force" should force the restart anyway
        p = self._spawn_restart("--force")
        p.expect_exact(f"The current edenfs daemon (pid {orig_pid}) is still starting")
        p.expect_exact("Forcing a full restart...")
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid [0-9]+\)")
        p.expect_exact("Successfully restarted edenfs.")
        p.expect_exact(
            "Note: any programs running inside of an Eden-managed "
            "directory will need to cd"
        )
        p.wait()
        self.assertEqual(p.exitstatus, 0)

    def test_restart_unresponsive_thrift(self) -> None:
        orig_pid = self._start_fake_edenfs()

        # Rename the thrift socket so that "eden restart" will not be able to
        # communicate with the existing daemon.
        os.rename(
            os.path.join(self.tmp_dir, eden.thrift.client.SOCKET_PATH),
            os.path.join(self.tmp_dir, "old.socket"),
        )

        # "eden restart" should not restart if it cannot confirm the current health of
        # edenfs.
        p = self._spawn_restart()
        p.expect_exact(
            f"Found an existing edenfs daemon (pid {orig_pid} that does not "
            "seem to be responding to thrift calls."
        )
        p.expect_exact("Use --force if you want to forcibly restart the current daemon")
        p.wait()
        self.assertEqual(p.exitstatus, 1)

        # "eden restart --force" should force the restart anyway
        p = self._spawn_restart("--force")
        p.expect_exact(
            f"Found an existing edenfs daemon (pid {orig_pid} that does not "
            "seem to be responding to thrift calls."
        )
        p.expect_exact("Forcing a full restart...")
        p.expect_exact("Starting fake edenfs daemon")
        p.expect(r"Started edenfs \(pid [0-9]+\)")
        p.expect_exact("Successfully restarted edenfs.")
        p.expect_exact(
            "Note: any programs running inside of an Eden-managed "
            "directory will need to cd"
        )
        p.wait()
        self.assertEqual(p.exitstatus, 0)