# Copyright 2015 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Module for integration VM tests for CLI commands.

This module contains the basic functionalities for setting up a VM and testing
the CLI commands.
"""

import logging

from chromite.cli import deploy
from chromite.lib import constants
from chromite.lib import cros_build_lib
from chromite.lib import remote_access
from chromite.lib import vm
from chromite.utils import outcap


class Error(Exception):
    """Base exception for CLI command VM tests."""


class SetupError(Error):
    """Raised when error occurs during test environment setup."""


class TestError(Error):
    """Raised when a command test has failed."""


class CommandError(Error):
    """Raised when error occurs during a command test."""


def _PrintCommandLog(command, content):
    """Print out the log |content| for |command|."""
    if content:
        logging.info(
            "\n----------- Start of %s log -----------\n%s\n"
            "-----------  End of %s log  -----------",
            command,
            content.rstrip(),
            command,
        )


def test_command_decorator(command_name):
    """Decorator that runs the command test function."""

    def Decorator(test_function):
        """Inner decorator that actually wraps the function."""

        def Wrapper(command_test):
            """Wrapper for the test function."""
            command = cros_build_lib.CmdToStr(
                command_test.BuildCommand(command_name)
            )
            logging.info("Running test for %s.", command)
            try:
                test_function(command_test)
                logging.info("Test for %s passed.", command)
            except CommandError as e:
                _PrintCommandLog(command, str(e))
                raise TestError("Test for %s failed." % command)

        return Wrapper

    return Decorator


class CommandVMTest:
    """Base class for CLI command VM tests.

    This class provides the abstract interface for testing CLI commands on a VM.
    The sub-class must define the BuildCommand method in order to be usable. And
    the test functions must use the test_command_decorator decorator.
    """

    def __init__(self, board, image_path):
        """Initializes CommandVMTest.

        Args:
            board: Board for the VM to run tests.
            image_path: Path to the image for the VM to run tests.
        """
        self.board = board
        self.image_path = image_path
        self.port = None
        self.device_addr = None

    def BuildCommand(self, command, device=None, pos_args=None, opt_args=None):
        """Builds a CLI command.

        Args:
            command: The sub-command to build on (e.g. 'flash', 'deploy').
            device: The device's address for the command.
            pos_args: A list of positional arguments for the command.
            opt_args: A list of optional arguments for the command.
        """
        raise NotImplementedError()

    def SetUp(self):
        """Creates and starts the VM instance for testing."""
        self.port = remote_access.GetUnusedPort()
        self.device_addr = "ssh://%s:%d" % (remote_access.LOCALHOST, self.port)
        vm_path = vm.CreateVMImage(
            image=self.image_path, board=self.board, updatable=True
        )
        vm_cmd = [
            "./cros_vm",
            "--ssh-port=%d" % self.port,
            "--copy-on-write",
            "--board=%s" % self.board,
            "--image-path=%s" % vm_path,
            "--start",
        ]
        cros_build_lib.run(vm_cmd, cwd=constants.CHROMITE_BIN_DIR)

    def TearDown(self):
        """Stops the VM instance after testing."""
        if not self.port:
            return
        cros_build_lib.run(
            ["./cros_vm", "--stop", "--ssh-port=%d" % self.port],
            cwd=constants.CHROMITE_BIN_DIR,
            check=False,
        )

    @test_command_decorator("shell")
    def TestShell(self):
        """Tests the shell command."""
        # The path and content of a temporary file for testing shell command.
        path = "/tmp/shell-test"
        content = "shell command test file"

        cmd = self.BuildCommand(
            "shell", device=self.device_addr, opt_args=["--no-known-hosts"]
        )

        logging.info(
            "Test to use shell command to write a file to the VM device."
        )
        write_cmd = cmd + ["--", 'echo "%s" > %s' % (content, path)]
        result = cros_build_lib.run(write_cmd, capture_output=True, check=False)
        if result.returncode:
            logging.error("Failed to write the file to the VM device.")
            raise CommandError(result.stderr)

        logging.info(
            "Test to use shell command to read a file on the VM device."
        )
        read_cmd = cmd + ["--", "cat %s" % path]
        result = cros_build_lib.run(
            read_cmd, capture_output=True, encoding="utf-8", check=False
        )
        if result.returncode or result.stdout.rstrip() != content:
            logging.error("Failed to read the file on the VM device.")
            raise CommandError(result.stderr)

        logging.info(
            "Test to use shell command to remove a file on the VM device."
        )
        remove_cmd = cmd + ["--", "rm %s" % path]
        result = cros_build_lib.run(
            remove_cmd, capture_output=True, check=False
        )
        if result.returncode:
            logging.error("Failed to remove the file on the VM device.")
            raise CommandError(result.stderr)

    @test_command_decorator("debug")
    def TestDebug(self):
        """Tests the debug command."""
        logging.info("Test to start and debug a new process on the VM device.")
        exe_path = "/bin/bash"
        start_cmd = self.BuildCommand(
            "debug", device=self.device_addr, opt_args=["--exe", exe_path]
        )
        result = cros_build_lib.run(
            start_cmd, capture_output=True, check=False, input="\n"
        )
        if result.returncode:
            logging.error(
                "Failed to start and debug a new process on the VM device."
            )
            raise CommandError(result.stderr)

        logging.info("Test to attach a running process on the VM device.")
        with remote_access.ChromiumOSDeviceHandler(
            remote_access.LOCALHOST, port=self.port
        ) as device:
            exe = "update_engine"
            pids = device.GetRunningPids(exe, full_path=False)
            if not pids:
                logging.error("Failed to find any running process to debug.")
                raise CommandError()
            pid = pids[0]
            attach_cmd = self.BuildCommand(
                "debug", device=self.device_addr, opt_args=["--pid", str(pid)]
            )
            result = cros_build_lib.run(
                attach_cmd, capture_output=True, check=False, input="\n"
            )
            if result.returncode:
                logging.error(
                    "Failed to attach a running process on the VM device."
                )
                raise CommandError(result.stderr)

    @test_command_decorator("flash")
    def TestFlash(self):
        """Tests the flash command."""
        # We explicitly disable reboot after the update because VMs sometimes do
        # not come back after reboot. The flash command does not need to verify
        # the integrity of the updated image. We have AU tests for that.
        cmd = self.BuildCommand(
            "flash",
            device=self.device_addr,
            pos_args=["latest"],
            opt_args=["--no-wipe", "--no-reboot"],
        )

        logging.info("Test to flash the VM device with the latest image.")
        result = cros_build_lib.run(cmd, capture_output=True, check=False)
        if result.returncode:
            logging.error("Failed to flash the VM device.")
            raise CommandError(result.stderr)

    @test_command_decorator("deploy")
    def TestDeploy(self):
        """Tests the deploy command."""
        packages = ["dev-python/cherrypy", "app-portage/portage-utils"]
        # Set the installation root to /usr/local so that the command does not
        # attempt to remount rootfs (which leads to VM reboot).
        cmd = self.BuildCommand(
            "deploy",
            device=self.device_addr,
            pos_args=packages,
            opt_args=["--log-level=info", "--root=/usr/local"],
        )

        logging.info("Test to uninstall packages on the VM device.")
        with outcap.OutputCapturer() as output:
            result = cros_build_lib.run(cmd + ["--unmerge"], check=False)

        if result.returncode:
            logging.error("Failed to uninstall packages on the VM device.")
            raise CommandError(result.stderr)

        captured_output = output.GetStdout() + output.GetStderr()
        for event in deploy.BrilloDeployOperation.UNMERGE_EVENTS:
            if event not in captured_output:
                logging.error(
                    "Strings used by deploy.BrilloDeployOperation to update "
                    "the progress bar have been changed. Please update the "
                    "strings in UNMERGE_EVENTS"
                )
                raise CommandError()

        logging.info("Test to install packages on the VM device.")
        with outcap.OutputCapturer() as output:
            result = cros_build_lib.run(cmd, check=False)

        if result.returncode:
            logging.error("Failed to install packages on the VM device.")
            raise CommandError(result.stderr)

        captured_output = output.GetStdout() + output.GetStderr()
        for event in deploy.BrilloDeployOperation.MERGE_EVENTS:
            if event not in captured_output:
                logging.error(
                    "Strings used by deploy.BrilloDeployOperation to update "
                    "the progress bar have been changed. Please update the "
                    "strings in MERGE_EVENTS"
                )
                raise CommandError()

        # Verify that the packages are installed.
        with remote_access.ChromiumOSDeviceHandler(
            remote_access.LOCALHOST, port=self.port
        ) as device:
            try:
                device.run(["python", "-c", '"import cherrypy"'])
                device.run(["qmerge", "-h"])
            except cros_build_lib.RunCommandError as e:
                logging.error(
                    "Unable to verify packages installed on VM: %s", e
                )
                raise CommandError()

    def RunTests(self):
        """Calls the test functions."""
        self.TestShell()
        # TestDebug broken (crbug.com/863122)
        self.TestFlash()
        self.TestDeploy()

    def Run(self):
        """Runs the tests."""
        try:
            self.SetUp()
            self.RunTests()
            logging.info("All tests completed successfully.")
        finally:
            self.TearDown()