# Copyright lowRISC contributors.
# Licensed under the Apache License, Version 2.0, see LICENSE for details.
# SPDX-License-Identifier: Apache-2.0

import logging as log
import os
import re
import shlex
import subprocess

from Launcher import Launcher, LauncherError


class LocalLauncher(Launcher):
    """
    Implementation of Launcher to launch jobs in the user's local workstation.
    """

    # Misc common LocalLauncher settings.
    max_odirs = 5

    def __init__(self, deploy):
        '''Initialize common class members.'''

        super().__init__(deploy)

        # Popen object when launching the job.
        self.process = None

    def _do_launch(self):
        # Update the shell's env vars with self.exports. Values in exports must
        # replace the values in the shell's env vars if the keys match.
        exports = os.environ.copy()
        if self.deploy.exports:
            exports.update(self.deploy.exports)

        # Clear the magic MAKEFLAGS variable from exports if necessary. This
        # variable is used by recursive Make calls to pass variables from one
        # level to the next. Here, self.cmd is a call to Make but it's
        # logically a top-level invocation: we don't want to pollute the flow's
        # Makefile with Make variables from any wrapper that called dvsim.
        if 'MAKEFLAGS' in exports:
            del exports['MAKEFLAGS']

        self._dump_env_vars(exports)

        args = shlex.split(self.deploy.cmd)
        try:
            f = open(self.deploy.get_log_path(),
                     "w",
                     encoding="UTF-8",
                     errors="surrogateescape")
            f.write("[Executing]:\n{}\n\n".format(self.deploy.cmd))
            f.flush()
            self.process = subprocess.Popen(args,
                                            bufsize=4096,
                                            universal_newlines=True,
                                            stdout=f,
                                            stderr=f,
                                            env=exports)
        except subprocess.SubprocessError as e:
            raise LauncherError('IO Error: {}\nSee {}'.format(
                e, self.deploy.get_log_path()))
        finally:
            self._close_process()

        self._link_odir("D")

    def poll(self):
        '''Check status of the running process

        This returns 'D', 'P' or 'F'. If 'D', the job is still running. If 'P',
        the job finished successfully. If 'F', the job finished with an error.

        This function must only be called after running self.dispatch_cmd() and
        must not be called again once it has returned 'P' or 'F'.
        '''

        assert self.process is not None
        if self.process.poll() is None:
            return 'D'

        self.exit_code = self.process.returncode
        status = 'P' if self._has_passed() else 'F'

        self._post_finish(status)
        return status

    def _post_finish(self, status):
        super()._post_finish(status)
        self._close_process()
        self.process = None

    def kill(self):
        '''Kill the running process.

        This must be called between dispatching and reaping the process (the
        same window as poll()).

        '''
        assert self.process is not None
        self.kill_remote_job()

        # Try to kill the running process. Send SIGTERM first, wait a bit,
        # and then send SIGKILL if it didn't work.
        self.process.terminate()
        try:
            self.process.wait(timeout=2)
        except subprocess.TimeoutExpired:
            self.process.kill()

        self._post_finish('K')

    def _close_process(self):
        '''Close the file descriptors associated with the process.'''

        assert self.process
        if self.process.stdout:
            self.process.stdout.close()

    def kill_remote_job(self):
        '''
        If jobs are run in remote server, need to use another command to kill them.
        '''
        # TODO: Currently only support lsf, may need to add support for GCP later.

        # If use lsf, kill it by job ID.
        if re.match("^bsub", self.deploy.sim_cfg.job_prefix):
            # get job id from below string
            # Job <xxxxxx> is submitted to default queue
            grep_cmd = "grep -m 1 -E \'" + "^Job <" + "\' " + \
                self.deploy.get_log_path()
            (status, rslt) = subprocess.getstatusoutput(grep_cmd)
            if rslt != "":
                job_id = rslt.split('Job <')[1].split('>')[0]
                try:
                    subprocess.run(["bkill", job_id], check=True)
                except Exception as e:
                    log.error("%s: Failed to run bkill\n", e)