# Copyright (C) 2017-2024 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/
import logging

log = logging.getLogger(__name__)


class MaintenanceTask(object):
    human_name = "undefined"

    def __init__(self, db_repo):
        self.db_repo = db_repo

    def run(self):
        """Execute task and return task human value"""
        raise NotImplementedError()


class GitGC(MaintenanceTask):
    human_name = "GIT Garbage collect"

    def _count_objects(self, repo):
        stdout, stderr = repo.run_git_command(["count-objects", "-v"], fail_on_stderr=False)

        errors = " "
        objects = " ".join(stdout.splitlines())

        if stderr:
            errors = "\nSTD ERR:" + "\n".join(stderr.splitlines())
        return objects + errors

    def run(self):
        output = []
        instance = self.db_repo.scm_instance()

        objects_before = self._count_objects(instance)

        log.debug("GIT objects:%s", objects_before)
        cmd = ["gc", "--aggressive"]
        stdout, stderr = instance.run_git_command(cmd, fail_on_stderr=False)

        out = "executed {}".format(" ".join(cmd))
        output.append(out)

        out = ""
        if stderr:
            out += "".join(stderr.splitlines())

        if stdout:
            out += "".join(stdout.splitlines())

        if out:
            output.append(out)

        objects_after = self._count_objects(instance)
        log.debug("GIT objects:%s", objects_after)
        output.append("objects before :" + objects_before)
        output.append("objects after  :" + objects_after)

        return "\n".join(output)


class GitFSCK(MaintenanceTask):
    human_name = "GIT FSCK"

    def run(self):
        output = []
        instance = self.db_repo.scm_instance()

        cmd = ["fsck", "--full"]
        stdout, stderr = instance.run_git_command(cmd, fail_on_stderr=False)

        out = "executed {}".format(" ".join(cmd))
        output.append(out)

        out = ""
        if stderr:
            out += "".join(stderr.splitlines())

        if stdout:
            out += "".join(stdout.splitlines())

        if out:
            output.append(out)

        return "\n".join(output)


class GitRepack(MaintenanceTask):
    human_name = "GIT Repack"

    def run(self):
        output = []
        instance = self.db_repo.scm_instance()
        cmd = ["repack", "-a", "-d", "--window-memory", "10m", "--max-pack-size", "100m"]
        stdout, stderr = instance.run_git_command(cmd, fail_on_stderr=False)

        out = "executed {}".format(" ".join(cmd))
        output.append(out)
        out = ""

        if stderr:
            out += "".join(stderr.splitlines())

        if stdout:
            out += "".join(stdout.splitlines())

        if out:
            output.append(out)

        return "\n".join(output)


class HGVerify(MaintenanceTask):
    human_name = "HG Verify repo"

    def run(self):
        instance = self.db_repo.scm_instance()
        res = instance.verify()
        return res


class HGUpdateCaches(MaintenanceTask):
    human_name = "HG update caches"

    def run(self):
        instance = self.db_repo.scm_instance()
        res = instance.hg_update_cache()
        return res


class HGRebuildFnCaches(MaintenanceTask):
    human_name = "HG rebuild fn caches"

    def run(self):
        instance = self.db_repo.scm_instance()
        res = instance.hg_rebuild_fn_cache()
        return res


class SVNVerify(MaintenanceTask):
    human_name = "SVN Verify repo"

    def run(self):
        instance = self.db_repo.scm_instance()
        res = instance.verify()
        return res


class RepoMaintenance(object):
    """
    Performs maintenance of repository based on it's type
    """

    tasks = {
        "hg": [HGVerify, HGUpdateCaches, HGRebuildFnCaches],
        "git": [GitFSCK, GitGC, GitRepack],
        "svn": [SVNVerify],
    }

    def get_tasks_for_repo(self, db_repo):
        """
        fetches human names of tasks pending for execution for given type of repo
        """
        tasks = []
        for task in self.tasks[db_repo.repo_type]:
            tasks.append(task.human_name)
        return tasks

    def execute(self, db_repo):
        executed_tasks = []
        for task in self.tasks[db_repo.repo_type]:
            output = task.human_name + ":\n" + task(db_repo).run() + "\n--\n"
            executed_tasks.append(output)
        return executed_tasks
