# Copyright 2017-2023 Posit Software, PBC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import logging
import os
import subprocess
import sys

from guild import config
from guild import file_util
from guild import log as loglib
from guild import remote as remotelib
from guild import util
from guild import var

log = logging.getLogger("guild")


def require_env(name):
    if name not in os.environ:
        raise remotelib.OperationError(f"missing required {name} environment variable")


def set_remote_lock(remote_run, remote_name, runs_dir=None):
    assert isinstance(remote_run, remotelib.RunProxy), remote_run
    local_run_dir = _local_run_dir(remote_run, runs_dir)
    _ensure_deleted_locks(local_run_dir)
    _maybe_write_remote_lock_file(remote_run, remote_name, local_run_dir)


def _local_run_dir(remote_run, runs_dir=None):
    runs_dir = runs_dir or var.runs_dir()
    return os.path.join(runs_dir, remote_run.id)


def _ensure_deleted_locks(run_dir):
    util.ensure_deleted(_lock_file_path(run_dir))
    util.ensure_deleted(_remote_lock_file_path(run_dir))


def _lock_file_path(run_dir):
    return os.path.join(run_dir, ".guild", "LOCK")


def _remote_lock_file_path(run_dir):
    return os.path.join(run_dir, ".guild", "LOCK.remote")


def _maybe_write_remote_lock_file(remote_run, remote_name, local_run_dir):
    if remote_run.status == "running":
        _write_remote_lock_file(local_run_dir, remote_name)


def _write_remote_lock_file(run_dir, remote_name):
    with open(_remote_lock_file_path(run_dir), "w") as f:
        f.write(remote_name)


def config_path(path):
    """Returns an absolute path for a config-relative path.

    Variable and user refs are resolved in path.

    If path is None, returns None.
    """
    if path is None:
        return None
    expanded = file_util.expand_path(path)
    config_dir = os.path.dirname(config.user_config_path())
    return os.path.abspath(os.path.join(config_dir, expanded))


def subprocess_call(cmd, extra_env=None, quiet=False, allowed_returncodes=(0,)):
    env = dict(os.environ)
    if extra_env:
        env.update(extra_env)
    p = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, env=env)
    buffer = []
    while True:
        line = p.stdout.readline()
        if not line:
            break
        if quiet:
            buffer.append(line.decode())
        else:
            sys.stderr.write(line.decode())
    returncode = p.wait()
    if returncode not in allowed_returncodes:
        for line in buffer:
            sys.stderr.write(line)
        raise SystemExit(f"error running {cmd[0]} - see above for details", returncode)
    return returncode


def init_env(env_config):
    return _legal_env(_env_for_config(env_config))


def _env_for_config(env_config):
    if isinstance(env_config, dict):
        return env_config
    if isinstance(env_config, str):
        return _env_from_file(env_config)
    if env_config is None:
        return {}
    log.warning("invalid value for remote env %r - ignoring", env_config)
    return {}


def _legal_env(env):
    return {name: str(val) for name, val in env.items() if val}


def _env_from_file(path):
    if path.lower().endswith(".gpg"):
        env_str = _try_read_gpg(path)
    else:
        env_str = util.try_read(path)
    if not env_str:
        log.warning("cannot read remote env from %s - ignorning", path)
        return {}
    return _decode_env(env_str)


def _try_read_gpg(path):
    path = os.path.expanduser(path)
    cmd = _gpg_cmd() + [path]
    log.debug("gpg cmd: %s", cmd)
    try:
        p = subprocess.Popen(
            cmd, env=os.environ, stdout=subprocess.PIPE, stderr=subprocess.PIPE
        )
    except OSError as e:
        log.error("cannot decode %s with command '%s' (%s)", path, " ".join(cmd), e)
        return None
    else:
        out, err = p.communicate()
        if p.returncode != 0:
            log.error(err.decode(errors="replace").strip())
            return None
        return out.decode(errors="replace")


def _gpg_cmd():
    gpg_env = os.getenv("GPG_CMD")
    if gpg_env:
        return util.shlex_split(gpg_env)
    return ["gpg", "-d"]


def _decode_env(s):
    return dict([_split_env_line(line) for line in s.split("\n")])


def _split_env_line(s):
    parts = s.split("=", 1)
    if len(parts) == 1:
        parts.append("")
    return _strip_export(parts[0]), parts[1]


def _strip_export(s):
    s = s.strip()
    if s.startswith("export "):
        s = s[7:]
    return s


def remote_activity(msg, *args):
    """Log remote activity.

    Used to report time consuming work that would otherwise not show
    user feedback. E.g. use when synchronizing meta data.
    """
    log.info(loglib.dim(msg), *args)


def strip_common_config(config):
    """Returns a copy of `config` that does not contain common config.

    Common config is shared across all remote types.

    Common config attributes are: `type`, `description`.
    """
    return remotelib.RemoteConfig(
        {key: config[key]
         for key in config if key not in ("type", "description")}
    )
