Copyright 2016 Peter Dahlberg

   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 os
import errno
import shlex
from collections import namedtuple
from subprocess import Popen, PIPE

CmdResult = namedtuple("CmdResult", "cmd status stdout stderr")

class GitCommandError(Exception):
    def __init__(self, message, result, *args, **kwargs):
        super().__init__(message, result, *args, **kwargs)
        self.result = result


class Repo:
    def __init__(self, repo_dir, git_cmd="git", default_timeout=None):
        if not os.path.exists(repo_dir):
            raise FileNotFoundError(errno.ENOENT, "Path, does not exist",
                                    repo_dir)
        self.repo_dir = repo_dir
        self.git_cmd = git_cmd
        self.default_timeout = default_timeout

    def __getattr__(self, name):
        name = name.replace("_", "-")
        def cmdcaller(*args, cmd=None, **kwargs):
            cmdargs = shlex.split(cmd) if cmd else args
            return self.cmd(*((self.git_cmd, name) + tuple(cmdargs)), **kwargs)
        return cmdcaller

    def cmd(self, *args, timeout=None, env=None, universal_newlines=True,
            errors_raise=True):
        timeout = timeout if timeout else self.default_timeout
        proc = self.popen_cmd(*args, env=env)
        outs, errs = proc.communicate(timeout=timeout)
        status = proc.wait()
        res = CmdResult(args,status, outs, errs)
        if status != 0 and errors_raise:
            raise GitCommandError("git failed: {}".format(args), res)
        return res

    def popen_cmd(self, *args, env=None, universal_newlines=True):
        return Popen(args, stdout=PIPE, stderr=PIPE, cwd=self.repo_dir, env=env,
                     universal_newlines=universal_newlines,
                     start_new_session=True)

    def is_bare(self):
        result = self.rev_parse("--is-bare-repository")
        return result.stdout.startswith("true")

    def is_repo(self):
        return self.rev_parse("--git-dir", errors_raise=False).status == 0

    def config_get(self, key):
        res = self.config("--get", key)
        return res.stdout.rstrip("\r\n")

def log_git_result(result, out_logger=None, err_logger=None, status_logger=None):
    if status_logger:
        err_logger('%s exit status: %s', result.cmd, result.status)
    if out_logger:
        out_logger('git stdout:\n%s', result.stdout)
    if err_logger:
        err_logger('git stderr:\n%s', result.stderr)