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

"""
 (c) 2017 - Copyright Red Hat Inc

 Authors:
   Patrick Uiterwijk <puiterwijk@redhat.com>

"""

import gc
import os
import os.path
import shutil
import time

from celery import Celery
from celery.result import AsyncResult

import pygit2
import tempfile
import six

import logging

import pagure
from pagure import APP
import pagure.lib
import pagure.lib.git
import pagure.lib.git_auth

logging.config.dictConfig(APP.config.get('LOGGING') or {'version': 1})
_log = logging.getLogger(__name__)


if os.environ.get('PAGURE_BROKER_URL'):
    broker_url = os.environ['PAGURE_BROKER_URL']
elif APP.config.get('BROKER_URL'):
    broker_url = APP.config['BROKER_URL']
else:
    broker_url = 'redis://%s' % APP.config['REDIS_HOST']

conn = Celery('tasks', broker=broker_url, backend=broker_url)
conn.conf.update(APP.config['CELERY_CONFIG'])


def get_result(uuid):
    """ Returns the AsyncResult object for a given task.

    :arg uuid: the unique identifier of the task to retrieve.
    :type uuid: str
    :return: celery.result.AsyncResult

    """
    return AsyncResult(uuid, conn.backend)


def ret(endpoint, **kwargs):
    toret = {'endpoint': endpoint}
    toret.update(kwargs)
    return toret


def gc_clean():
    """ Force a run of the garbage collector. """
    # https://pagure.io/pagure/issue/2302
    gc.collect()


@conn.task
def generate_gitolite_acls(namespace=None, name=None, user=None):
    """ Generate the gitolite configuration file either entirely or for a
    specific project.

    :kwarg namespace: the namespace of the project
    :type namespace: str
    :kwarg name: the name of the project
    :type name: str
    :kwarg user: the user of the project, only set if the project is a fork
    :type user: str

    """
    session = pagure.lib.create_session()
    project = None
    if name and name != -1:
        project = pagure.lib._get_project(
            session, namespace=namespace, name=name, user=user)
    elif name == -1:
        project = name
    helper = pagure.lib.git_auth.get_git_auth_helper(
        APP.config['GITOLITE_BACKEND'])
    helper.generate_acls(project=project)
    session.remove()
    gc_clean()


@conn.task
def create_project(username, namespace, name, add_readme,
                   ignore_existing_repo):
    """ Create a project.

    :kwarg username: the user creating the project
    :type user: str
    :kwarg namespace: the namespace of the project
    :type namespace: str
    :kwarg name: the name of the project
    :type name: str
    :kwarg add_readme: a boolean specifying if the project should be
        created with a README file or not
    :type add_readme: bool
    :kwarg ignore_existing_repo: a boolean specifying whether the creation
        of the project should fail if the repo exists on disk or not
    :type ignore_existing_repo: bool

    """
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace,
                                      name=name)
    with project.lock('WORKER'):
        userobj = pagure.lib.search_user(session, username=username)
        gitrepo = os.path.join(APP.config['GIT_FOLDER'], project.path)

        # Add the readme file if it was asked
        if not add_readme:
            pygit2.init_repository(gitrepo, bare=True)
        else:
            temp_gitrepo_path = tempfile.mkdtemp(prefix='pagure-')
            temp_gitrepo = pygit2.init_repository(temp_gitrepo_path,
                                                  bare=False)
            author = userobj.fullname or userobj.user
            author_email = userobj.default_email
            if six.PY2:
                author = author.encode('utf-8')
                author_email = author_email.encode('utf-8')
            author = pygit2.Signature(author, author_email)
            content = u"# %s\n\n%s" % (name, project.description)
            readme_file = os.path.join(temp_gitrepo.workdir, "README.md")
            with open(readme_file, 'wb') as stream:
                stream.write(content.encode('utf-8'))
            temp_gitrepo.index.add_all()
            temp_gitrepo.index.write()
            tree = temp_gitrepo.index.write_tree()
            temp_gitrepo.create_commit(
                'HEAD', author, author, 'Added the README', tree, [])
            pygit2.clone_repository(temp_gitrepo_path, gitrepo, bare=True)
            shutil.rmtree(temp_gitrepo_path)

        # Make the repo exportable via apache
        http_clone_file = os.path.join(gitrepo, 'git-daemon-export-ok')
        if not os.path.exists(http_clone_file):
            with open(http_clone_file, 'w') as stream:
                pass

        docrepo = os.path.join(APP.config['DOCS_FOLDER'], project.path)
        if os.path.exists(docrepo):
            if not ignore_existing_repo:
                shutil.rmtree(gitrepo)
                raise pagure.exceptions.RepoExistsException(
                    'The docs repo "%s" already exists' % project.path
                )
        else:
            pygit2.init_repository(docrepo, bare=True)

        ticketrepo = os.path.join(APP.config['TICKETS_FOLDER'], project.path)
        if os.path.exists(ticketrepo):
            if not ignore_existing_repo:
                shutil.rmtree(gitrepo)
                shutil.rmtree(docrepo)
                raise pagure.exceptions.RepoExistsException(
                    'The tickets repo "%s" already exists' % project.path
                )
        else:
            pygit2.init_repository(
                ticketrepo, bare=True,
                mode=pygit2.C.GIT_REPOSITORY_INIT_SHARED_GROUP)

        requestrepo = os.path.join(APP.config['REQUESTS_FOLDER'], project.path)
        if os.path.exists(requestrepo):
            if not ignore_existing_repo:
                shutil.rmtree(gitrepo)
                shutil.rmtree(docrepo)
                shutil.rmtree(ticketrepo)
                raise pagure.exceptions.RepoExistsException(
                    'The requests repo "%s" already exists' % project.path
                )
        else:
            pygit2.init_repository(
                requestrepo, bare=True,
                mode=pygit2.C.GIT_REPOSITORY_INIT_SHARED_GROUP)

        # Install the default hook
        plugin = pagure.lib.plugins.get_plugin('default')
        dbobj = plugin.db_object()
        dbobj.active = True
        dbobj.project_id = project.id
        session.add(dbobj)
        session.flush()
        plugin.set_up(project)
        plugin.install(project, dbobj)
        session.commit()

    generate_gitolite_acls.delay(
        namespace=project.namespace,
        name=project.name,
        user=project.user.user if project.is_fork else None)

    session.remove()
    gc_clean()

    return ret('view_repo', repo=name, namespace=namespace)


@conn.task
def update_git(name, namespace, user, ticketuid=None, requestuid=None):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace, name=name,
                                      user=user)
    with project.lock('WORKER'):
        if ticketuid is not None:
            obj = pagure.lib.get_issue_by_uid(session, ticketuid)
            folder = APP.config['TICKETS_FOLDER']
        elif requestuid is not None:
            obj = pagure.lib.get_request_by_uid(session, requestuid)
            folder = APP.config['REQUESTS_FOLDER']
        else:
            raise NotImplementedError('No ticket ID or request ID provided')

        if obj is None:
            raise Exception('Unable to find object')

        result = pagure.lib.git._update_git(obj, project, folder)

    session.remove()
    gc_clean()
    return result


@conn.task
def clean_git(name, namespace, user, ticketuid):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace, name=name,
                                      user=user)
    with project.lock('WORKER'):
        obj = pagure.lib.get_issue_by_uid(session, ticketuid)
        folder = APP.config['TICKETS_FOLDER']

        if obj is None:
            raise Exception('Unable to find object')

        result = pagure.lib.git._clean_git(obj, project, folder)

    session.remove()
    return result


@conn.task
def update_file_in_git(name, namespace, user, branch, branchto, filename,
                       content, message, username, email):
    session = pagure.lib.create_session()

    userobj = pagure.lib.search_user(session, username=username)
    project = pagure.lib._get_project(session, namespace=namespace, name=name,
                                      user=user)

    with project.lock('WORKER'):
        pagure.lib.git._update_file_in_git(project, branch, branchto, filename,
                                           content, message, userobj, email)

    session.remove()
    return ret('view_commits', repo=project.name, username=user,
               namespace=namespace, branchname=branchto)


@conn.task
def delete_branch(name, namespace, user, branchname):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace, name=name,
                                      user=user)
    with project.lock('WORKER'):
        repo_obj = pygit2.Repository(pagure.get_repo_path(project))

        try:
            branch = repo_obj.lookup_branch(branchname)
            branch.delete()
        except pygit2.GitError as err:
            _log.exception(err)

    session.remove()
    return ret('view_repo', repo=name, namespace=namespace, username=user)


@conn.task
def fork(name, namespace, user_owner, user_forker, editbranch, editfile):
    """ Forks the specified project for the specified user.

    :arg namespace: the namespace of the project
    :type namespace: str
    :arg name: the name of the project
    :type name: str
    :arg user_owner: the user of which the project is forked, only set
        if the project is already a fork
    :type user_owner: str
    :arg user_forker: the user forking the project
    :type user_forker: str
    :kwarg editbranch: the name of the branch in which the user asked to
        edit a file
    :type editbranch: str
    :kwarg editfile: the file the user asked to edit
    :type editfile: str

    """
    session = pagure.lib.create_session()

    repo_from = pagure.lib._get_project(
        session, namespace=namespace, name=name, user=user_owner)
    repo_to = pagure.lib._get_project(
        session, namespace=namespace, name=name, user=user_forker)

    with repo_to.lock('WORKER'):
        reponame = os.path.join(APP.config['GIT_FOLDER'], repo_from.path)
        forkreponame = os.path.join(APP.config['GIT_FOLDER'], repo_to.path)

        frepo = pygit2.clone_repository(reponame, forkreponame, bare=True)
        # Clone all the branches as well
        for branch in frepo.listall_branches(pygit2.GIT_BRANCH_REMOTE):
            branch_obj = frepo.lookup_branch(branch, pygit2.GIT_BRANCH_REMOTE)
            branchname = branch_obj.branch_name.replace(
                branch_obj.remote_name, '', 1)[1:]
            if branchname in frepo.listall_branches(pygit2.GIT_BRANCH_LOCAL):
                continue
            frepo.create_branch(branchname, frepo.get(branch_obj.target.hex))

        # Create the git-daemon-export-ok file on the clone
        http_clone_file = os.path.join(forkreponame, 'git-daemon-export-ok')
        if not os.path.exists(http_clone_file):
            with open(http_clone_file, 'w'):
                pass

        docrepo = os.path.join(APP.config['DOCS_FOLDER'], repo_to.path)
        if os.path.exists(docrepo):
            shutil.rmtree(forkreponame)
            raise pagure.exceptions.RepoExistsException(
                'The docs "%s" already exists' % repo_to.path
            )
        pygit2.init_repository(docrepo, bare=True)

        ticketrepo = os.path.join(APP.config['TICKETS_FOLDER'], repo_to.path)
        if os.path.exists(ticketrepo):
            shutil.rmtree(forkreponame)
            shutil.rmtree(docrepo)
            raise pagure.exceptions.RepoExistsException(
                'The tickets repo "%s" already exists' % repo_to.path
            )
        pygit2.init_repository(
            ticketrepo, bare=True,
            mode=pygit2.C.GIT_REPOSITORY_INIT_SHARED_GROUP)

        requestrepo = os.path.join(APP.config['REQUESTS_FOLDER'], repo_to.path)
        if os.path.exists(requestrepo):
            shutil.rmtree(forkreponame)
            shutil.rmtree(docrepo)
            shutil.rmtree(ticketrepo)
            raise pagure.exceptions.RepoExistsException(
                'The requests repo "%s" already exists' % repo_to.path
            )
        pygit2.init_repository(
            requestrepo, bare=True,
            mode=pygit2.C.GIT_REPOSITORY_INIT_SHARED_GROUP)

        pagure.lib.notify.log(
            repo_to,
            topic='project.forked',
            msg=dict(
                project=repo_to.to_json(public=True),
                agent=user_forker,
            ),
        )

    del frepo
    session.remove()

    generate_gitolite_acls(
        namespace=repo_to.namespace,
        name=repo_to.name,
        user=repo_to.user.user if repo_to.is_fork else None)
    gc_clean()

    if editfile is None:
        return ret('view_repo', repo=name, namespace=namespace,
                   username=user_forker)
    else:
        return ret('edit_file', repo=name, namespace=namespace,
                   username=user_forker, branchname=editbranch,
                   filename=editfile)


@conn.task
def pull_remote_repo(remote_git, branch_from):
    clonepath = pagure.get_remote_repo_path(remote_git, branch_from,
                                            ignore_non_exist=True)
    repo = pygit2.clone_repository(
        remote_git, clonepath, checkout_branch=branch_from)

    del repo
    gc_clean()
    return clonepath


@conn.task
def refresh_pr_cache(name, namespace, user):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace,
                                      name=name, user=user)

    pagure.lib.reset_status_pull_request(session, project)

    session.remove()
    gc_clean()


@conn.task
def merge_pull_request(name, namespace, user, requestid, user_merger):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace,
                                      name=name, user=user)
    with project.lock('WORKER'):
        request = pagure.lib.search_pull_requests(
            session, project_id=project.id, requestid=requestid)
        _log.debug(
            'Merging pull-request: %/#%s', request.project.fullname,
            request.id)
        pagure.lib.git.merge_pull_request(
            session, request, user_merger, APP.config['REQUESTS_FOLDER'])

    refresh_pr_cache.delay(name, namespace, user)
    session.remove()
    gc_clean()
    return ret('view_repo', repo=name, username=user, namespace=namespace)


@conn.task
def add_file_to_git(name, namespace, user, user_attacher, issueuid, filename):
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace,
                                      name=name, user=user)
    with project.lock('WORKER'):
        issue = pagure.lib.get_issue_by_uid(session, issueuid)
        user_attacher = pagure.lib.search_user(session, username=user_attacher)

        from_folder = APP.config['ATTACHMENTS_FOLDER']
        to_folder = APP.config['TICKETS_FOLDER']
        _log.info(
            'Adding file %s from %s to %s', filename, from_folder, to_folder)
        pagure.lib.git._add_file_to_git(
            project, issue,
            from_folder,
            to_folder,
            user_attacher,
            filename)

    session.remove()
    gc_clean()


@conn.task
def project_dowait(name, namespace, user):
    """ This is a task used to test the locking systems.

    It should never be allowed to be called in production instances, since that
    would allow an attacker to basically DOS a project by calling this
    repeatedly. """
    assert APP.config.get('ALLOW_PROJECT_DOWAIT', False)

    session = pagure.lib.create_session()

    project = pagure.lib._get_project(session, namespace=namespace,
                                      name=name, user=user)
    with project.lock('WORKER'):
        time.sleep(10)

    session.remove()
    gc_clean()

    return ret('view_repo', repo=name, username=user, namespace=namespace)


@conn.task
def sync_pull_ref(name, namespace, user, requestid):
    """ Synchronize a pull/ reference from the content in the forked repo,
    allowing local checkout of the pull-request.
    """
    session = pagure.lib.create_session()

    project = pagure.lib._get_project(
        session, namespace=namespace, name=name, user=user)

    with project.lock('WORKER'):
        request = pagure.lib.search_pull_requests(
            session, project_id=project.id, requestid=requestid)
        _log.debug(
            'Update pull refs of: %s#%s',
            request.project.fullname, request.id)

        if request.remote:
            # Get the fork
            repopath = pagure.get_remote_repo_path(
                request.remote_git, request.branch_from)
        else:
            # Get the fork
            repopath = pagure.get_repo_path(request.project_from)
        _log.debug('   working on the repo in: %s', repopath)

        repo_obj = pygit2.Repository(repopath)
        pagure.lib.git.update_pull_ref(request, repo_obj)

    session.remove()
    gc_clean()