# -*- coding: utf-8 -*-

"""
 (c) 2015-2019 - Copyright Red Hat Inc

 Authors:
   Pierre-Yves Chibon <pingou@pingoured.fr>

"""
from __future__ import print_function, unicode_literals, absolute_import

import logging
import subprocess

import pygit2

import pagure
import pagure.exceptions


_log = logging.getLogger(__name__)


def get_pygit2_version():
    """ Return pygit2 version as a tuple of integers.
    This is needed for correct version comparison.
    """
    return tuple([int(i) for i in pygit2.__version__.split(".")])


def run_command(command):
    _log.info("Running command: %s", command)
    try:
        out = subprocess.check_output(command, stderr=subprocess.STDOUT)
        _log.info("   command ran successfully")
        _log.debug("Output: %s" % out)
    except subprocess.CalledProcessError as err:
        _log.debug(
            "Command FAILED: {cmd} returned code {code} with the "
            "following output: {output}".format(
                cmd=err.cmd, code=err.returncode, output=err.output
            )
        )
        raise pagure.exceptions.PagureException(
            "Did not manage to rebase this pull-request"
        )


class PagureRepo(pygit2.Repository):
    """ An utility class allowing to go around pygit2's inability to be
    stable.

    """

    @staticmethod
    def clone(path_from, path_to, checkout_branch=None, bare=False):
        """ Clone the git repo at the specified path to the specified location.

        This method is meant to replace pygit2.clone_repository which for us
        leaks file descriptors on large project leading to "Too many open files
        error" which then prevent some tasks from completing.

        :arg path_from: the path or url of the git repository to clone
        :type path_from: str
        :arg path_to: the path where the git repository should be cloned
        :type path_to: str
        :
        """
        cmd = ["git", "clone", path_from, path_to]
        if checkout_branch:
            cmd.extend(["-b", checkout_branch])
        if bare:
            cmd.append("--bare")

        run_command(cmd)

    @staticmethod
    def push(remote, refname):
        """ Push the given reference to the specified remote. """
        pygit2_version = get_pygit2_version()
        if pygit2_version >= (0, 22):
            remote.push([refname])
        else:
            remote.push(refname)

    def pull(self, remote_name="origin", branch="master", force=False):
        """ pull changes for the specified remote (defaults to origin).

        Code from MichaelBoselowitz at:
        https://github.com/MichaelBoselowitz/pygit2-examples/blob/
            68e889e50a592d30ab4105a2e7b9f28fac7324c8/examples.py#L58
        licensed under the MIT license.
        """

        for remote in self.remotes:
            if remote.name == remote_name:
                remote.fetch()
                remote_master_id = self.lookup_reference(
                    "refs/remotes/origin/%s" % branch
                ).target

                if force:
                    repo_branch = self.lookup_reference(
                        "refs/heads/%s" % branch
                    )
                    repo_branch.set_target(remote_master_id)

                merge_result, _ = self.merge_analysis(remote_master_id)
                # Up to date, do nothing
                if merge_result & pygit2.GIT_MERGE_ANALYSIS_UP_TO_DATE:
                    return
                # We can just fastforward
                elif merge_result & pygit2.GIT_MERGE_ANALYSIS_FASTFORWARD:
                    self.checkout_tree(self.get(remote_master_id))
                    master_ref = self.lookup_reference(
                        "refs/heads/%s" % branch
                    )
                    master_ref.set_target(remote_master_id)
                    self.head.set_target(remote_master_id)
                elif merge_result & pygit2.GIT_MERGE_ANALYSIS_NORMAL:
                    raise pagure.exceptions.GitConflictsException(
                        "Pulling remote changes leads to a conflict"
                    )
                else:
                    _log.debug(
                        "Unexpected merge result: %s"
                        % (pygit2.GIT_MERGE_ANALYSIS_NORMAL)
                    )
                    raise AssertionError("Unknown merge analysis result")