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

"""

 (c) 2014 - Copyright Red Hat Inc

 Authors:

   Pierre-Yves Chibon <pingou@pingoured.fr></pingou@pingoured.fr>

"""

import datetime

import json

import os

import random

import shutil

import string

import tempfile

import uuid

import sqlalchemy

from datetime import timedelta

from sqlalchemy.orm import sessionmaker

from sqlalchemy.orm import scoped_session

from sqlalchemy.orm.exc import NoResultFound

from sqlalchemy.exc import SQLAlchemyError

import pygit2

import progit.exceptions

import progit.notify

from progit import model

def create_session(db_url, debug=False, pool_recycle=3600):

    ''' Create the Session object to use to query the database.

    :arg db_url: URL used to connect to the database. The URL contains

    information with regards to the database engine, the host to connect

    to, the user and password and the database name.

      ie: <engine>://<user>:<password>@<host>/<dbname></dbname></host></password></user></engine>

    :kwarg debug: a boolean specifying wether we should have the verbose

        output of sqlalchemy or not.

    :return a Session that can be used to query the database.

    '''

    engine = sqlalchemy.create_engine(

        db_url, echo=debug, pool_recycle=pool_recycle)

    scopedsession = scoped_session(sessionmaker(bind=engine))

    return scopedsession

def id_generator(size=15, chars=string.ascii_uppercase + string.digits):

    """ Generates a random identifier for the given size and using the

    specified characters.

    If no size is specified, it uses 15 as default.

    If no characters are specified, it uses ascii char upper case and

    digits.

    :arg size: the size of the identifier to return.

    :arg chars: the list of characters that can be used in the

        idenfitier.

    """

    return ''.join(random.choice(chars) for x in range(size))

def commit_to_patch(repo_obj, commits):

    ''' For a given commit (PyGit2 commit object) of a specified git repo,

    returns a string representation of the changes the commit did in a

    format that allows it to be used as patch.

    '''

    if not isinstance(commits, list):

        commits = [commits]

    patch = ""

    for cnt, commit in enumerate(commits):

        if commit.parents:

            diff = commit.tree.diff_to_tree()

            parent = repo_obj.revparse_single('%s^' % commit.oid.hex)

            diff = repo_obj.diff(parent, commit)

        else:

            # First commit in the repo

            diff = commit.tree.diff_to_tree(swap=True)

        subject = message = ''

        if '\n' in commit.message:

            subject, message = commit.message.split('\n', 1)

        else:

            subject = commit.message

        if len(commits) > 1:

            subject = '[PATCH %s/%s] %s' % (cnt + 1, len(commits), subject)

        patch += """From %(commit)s Mon Sep 17 00:00:00 2001

From: %(author_name)s <%(author_email)s>

Date: %(date)s

Subject: %(subject)s

%(msg)s

---

%(patch)s

""" % (

            {

                'commit': commit.oid.hex,

                'author_name': commit.author.name,

                'author_email': commit.author.email,

                'date': datetime.datetime.utcfromtimestamp(

                    commit.commit_time).strftime('%b %d %Y %H:%M:%S +0000'),

                'subject': subject,

                'msg': message,

                'patch': diff.patch,

            }

        )

    return patch

def get_user(session, username):

    ''' Return the user corresponding to this username, or None. '''

    user = session.query(

        model.User

    ).filter(

        model.User.user == username

    ).first()

    return user

def get_user_by_email(session, user_mail):

    ''' Return the user corresponding to this email, or None. '''

    mail = session.query(

        model.UserEmail

    ).filter(

        model.UserEmail.email == user_mail

    ).first()

    if mail:

        return mail.user

def get_user_by_token(session, token):

    ''' Return a specified User via its token.

    :arg session: the session with which to connect to the database.

    '''

    user = session.query(

        model.User

    ).filter(

        model.User.token == token

    ).first()

    return user

def get_all_users(session):

    ''' Return the user corresponding to this username, or None. '''

    users = session.query(

        model.User

    ).all()

    return users

def add_issue_comment(session, issue, comment, user, ticketfolder):

    ''' Add a comment to an issue. '''

    user_obj = get_user(session, user)

    if not user_obj:

        user_obj = get_user_by_email(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    issue_comment = model.IssueComment(

        issue_id=issue.id,

        comment=comment,

        user_id=user_obj.id,

    )

    session.add(issue_comment)

    # Make sure we won't have SQLAlchemy error before we create the repo

    session.flush()

    update_git_ticket(issue, repo=issue.project, ticketfolder=ticketfolder)

    progit.notify.notify_new_comment(issue_comment)

    return 'Comment added'

def add_user_to_project(session, project, user):

    ''' Add a specified user to a specified project. '''

    user_obj = get_user(session, user)

    if not user_obj:

        user_obj = get_user_by_email(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    project_user = model.ProjectUser(

        project_id=project.id,

        user_id=user_obj.id,

    )

    session.add(project_user)

    # Make sure we won't have SQLAlchemy error before we create the repo

    session.flush()

    return 'Comment added'

def add_pull_request_comment(session, request, commit, row, comment, user):

    ''' Add a comment to a pull-request. '''

    user_obj = get_user(session, user)

    if not user_obj:

        user_obj = get_user_by_email(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    pr_comment = model.PullRequestComment(

        pull_request_id=request.id,

        commit_id=commit,

        line=row,

        comment=comment,

        user_id=user_obj.id,

    )

    session.add(pr_comment)

    # Make sure we won't have SQLAlchemy error before we create the repo

    session.flush()

    return 'Comment added'

def get_user_project(session, username):

    ''' Retrieve the list of projects managed by a user.

    '''

    query = session.query(

        model.Project

    ).filter(

        model.Project.user == username

    )

    return query.all()

def new_project(session, user, name, gitfolder, docfolder, ticketfolder,

                description=None, parent_id=None):

    ''' Create a new project based on the information provided.

    '''

    gitrepo = os.path.join(gitfolder, '%s.git' % name)

    if os.path.exists(gitrepo):

        raise progit.exceptions.RepoExistsException(

            'The project repo "%s" already exists' % name

        )

    user_obj = get_user(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    project = model.Project(

        name=name,

        description=description,

        user_id=user_obj.id,

        parent_id=parent_id

    )

    session.add(project)

    # Make sure we won't have SQLAlchemy error before we create the repo

    session.flush()

    pygit2.init_repository(gitrepo, bare=True)

    gitrepo = os.path.join(docfolder, project.path)

    if os.path.exists(gitrepo):

        raise progit.exceptions.RepoExistsException(

            'The docs repo "%s" already exists' % project.path

        )

    pygit2.init_repository(gitrepo, bare=True)

    gitrepo = os.path.join(ticketfolder, project.path)

    if os.path.exists(gitrepo):

        raise progit.exceptions.RepoExistsException(

            'The tickets repo "%s" already exists' % project.path

        )

    pygit2.init_repository(gitrepo, bare=True)

    return 'Project "%s" created' % name

def new_issue(session, repo, title, content, user, ticketfolder):

    ''' Create a new issue for the specified repo. '''

    user_obj = get_user(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    issue = model.Issue(

        project_id=repo.id,

        title=title,

        content=content,

        user_id=user_obj.id,

        uid=uuid.uuid4().hex,

    )

    session.add(issue)

    # Make sure we won't have SQLAlchemy error before we create the issue

    session.flush()

    global_id = model.GlobalId(

        project_id=repo.id,

        issue_id=issue.id,

    )

    session.add(global_id)

    session.flush()

    update_git_ticket(issue, repo=repo, ticketfolder=ticketfolder)

    progit.notify.notify_new_issue(issue)

    return 'Issue created'

def new_pull_request(

        session, repo, repo_from, branch, title, user, stop_id,

        start_id=None):

    ''' Create a new pull request on the specified repo. '''

    user_obj = get_user(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    request = model.PullRequest(

        project_id=repo.id,

        project_id_from=repo_from.id,

        branch=branch,

        title=title,

        start_id=start_id,

        stop_id=stop_id,

        user_id=user_obj.id,

    )

    session.add(request)

    # Make sure we won't have SQLAlchemy error before we create the request

    session.flush()

    global_id = model.GlobalId(

        project_id=repo.id,

        request_id=request.id,

    )

    session.add(global_id)

    session.flush()

    progit.notify.notify_new_pull_request(request)

    return 'Request created'

def edit_issue(session, issue, ticketfolder,

               title=None, content=None, status=None):

    ''' Edit the specified issue.

    '''

    edit = []

    if title and title != issue.title:

        issue.title = title

        edit.append('title')

    if content and content != issue.content:

        issue.content = content

        edit.append('content')

    if status and status != issue.status:

        issue.status = status

        edit.append('status')

    update_git_ticket(issue, repo=issue.project, ticketfolder=ticketfolder)

    if not edit:

        return 'No changes to edit'

    else:

        session.add(issue)

        session.flush()

        return 'Edited successfully issue #%s' % issue.id

def update_project_settings(session, repo, issue_tracker, project_docs):

    ''' Update the settings of a project. '''

    update = []

    if issue_tracker != repo.issue_tracker:

        repo.issue_tracker = issue_tracker

        update.append('issue_tracker')

    if project_docs != repo.project_docs:

        repo.project_docs = project_docs

        update.append('project_docs')

    if not update:

        return 'No settings to change'

    else:

        session.add(repo)

        session.flush()

        return 'Edited successfully setting of repo: %s' % repo.fullname

def fork_project(session, user, repo, gitfolder,

                 forkfolder, docfolder,ticketfolder):

    ''' Fork a given project into the user's forks. '''

    if repo.is_fork:

        reponame = os.path.join(forkfolder, repo.path)

    else:

        reponame = os.path.join(gitfolder, repo.path)

    forkreponame = '%s.git' % os.path.join(forkfolder, user, repo.name)

    if repo.user.user == user:

        raise progit.exceptions.RepoExistsException(

            'You may not fork your own repo')

    if os.path.exists(forkreponame):

        raise progit.exceptions.RepoExistsException(

            'Repo "%s/%s" already exists' % (user, repo.name))

    user_obj = get_user(session, user)

    if not user_obj:

        raise progit.exceptions.ProgitException(

            'No user "%s" found' % user

        )

    project = model.Project(

        name=repo.name,

        description=repo.description,

        user_id=user_obj.id,

        parent_id=repo.id

    )

    session.add(project)

    # Make sure we won't have SQLAlchemy error before we create the repo

    session.flush()

    pygit2.clone_repository(reponame, forkreponame, bare=True)

    gitrepo = os.path.join(docfolder, project.path)

    if os.path.exists(gitrepo):

        raise progit.exceptions.RepoExistsException(

            'The docs "%s" already exists' % project.path

        )

    pygit2.init_repository(gitrepo, bare=True)

    gitrepo = os.path.join(ticketfolder, project.path)

    if os.path.exists(gitrepo):

        raise progit.exceptions.RepoExistsException(

            'The tickets repo "%s" already exists' % project.path

        )

    pygit2.init_repository(gitrepo, bare=True)

    return 'Repo "%s" cloned to "%s/%s"' % (repo.name, user, repo.name)

def list_projects(

        session, username=None, fork=None,

        start=None, limit=None, count=False):

    '''List existing projects

    '''

    projects = session.query(

        model.Project

    ).order_by(

        model.Project.date_created

    )

    if username is not None:

        projects = projects.filter(

            model.User.user == username

        ).filter(

            model.User.id == model.Project.user_id

        )

    if fork is not None:

        if fork is True:

            projects = projects.filter(

                model.Project.parent_id != None

            )

        elif fork is False:

            projects = projects.filter(

                model.Project.parent_id == None

            )

    if start is not None:

        projects = projects.offset(start)

    if limit is not None:

        projects = projects.limit(limit)

    if count:

        return projects.count()

    else:

        return projects.all()

def get_project(session, name, user=None):

    '''Get a project from the database

    '''

    query = session.query(

        model.Project

    ).filter(

        model.Project.name == name

    )

    if user is not None:

        query = query.filter(

            model.User.user == user

        ).filter(

            model.User.id == model.Project.user_id

        ).filter(

            model.Project.parent_id != None

        )

    else:

        query = query.filter(

            model.Project.parent_id == None

        )

    return query.first()

def get_issues(session, repo, status=None, closed=False):

    ''' Retrieve all the issues associated to a project

    Watch out that the closed argument is incompatible with the status

    argument. The closed argument will return all the issues whose status

    is not 'Open', otherwise it will return the issues having the specified

    status.

    '''

    subquery = session.query(

        model.GlobalId,

        sqlalchemy.over(

            sqlalchemy.func.row_number(),

            partition_by=model.GlobalId.project_id,

            order_by=model.GlobalId.id

        ).label('global_id')

    ).subquery()

    query = session.query(

        model.Issue,

        subquery.c.global_id

    ).filter(

        subquery.c.issue_id == model.Issue.id

    ).filter(

        subquery.c.project_id == model.Issue.project_id

    ).filter(

        model.Issue.project_id == repo.id

    ).order_by(

        model.Issue.id

    )

    if status is not None and not closed:

        query = query.filter(

            model.Issue.status == status

        )

    if closed:

        query = query.filter(

            model.Issue.status != 'Open'

        )

    return query.all()

def get_issue(session, projectid, issueid):

    ''' Retrieve the specified issue

    '''

    subquery = session.query(

        model.GlobalId,

        sqlalchemy.over(

            sqlalchemy.func.row_number(),

            partition_by=model.GlobalId.project_id,

            order_by=model.GlobalId.id

        ).label('global_id')

    ).subquery()

    query = session.query(

        model.Issue

    ).filter(

        model.Issue.project_id == projectid

    ).filter(

        model.Issue.project_id == projectid

    ).filter(

        subquery.c.project_id == model.Issue.project_id

    ).filter(

        subquery.c.issue_id == model.Issue.id

    ).filter(

        subquery.c.global_id == issueid

    ).order_by(

        model.Issue.id

    )

    return query.first()

def get_pull_requests(

        session, project_id=None, project_id_from=None, status=None):

    ''' Retrieve the specified issue

    '''

    subquery = session.query(

        model.GlobalId,

        sqlalchemy.over(

            sqlalchemy.func.row_number(),

            partition_by=model.GlobalId.project_id,

            order_by=model.GlobalId.id

        ).label('global_id')

    ).subquery()

    query = session.query(

        model.PullRequest,

        subquery.c.global_id

    ).filter(

        subquery.c.request_id == model.PullRequest.id

    ).filter(

        subquery.c.project_id == model.PullRequest.project_id

    ).order_by(

        model.PullRequest.id

    )

    if project_id:

        query = query.filter(

            model.PullRequest.project_id == project_id

        )

    if project_id_from:

        query = query.filter(

            model.PullRequest.project_id_from == project_id_from

        )

    if status is not None:

        query = query.filter(

            model.PullRequest.status == status

        )

    return query.all()

def get_pull_request(

        session, requestid, project_id=None, project_id_from=None):

    ''' Retrieve the specified issue

    '''

    subquery = session.query(

        model.GlobalId,

        sqlalchemy.over(

            sqlalchemy.func.row_number(),

            partition_by=model.GlobalId.project_id,

            order_by=model.GlobalId.id

        ).label('global_id')

    ).subquery()

    query = session.query(

        model.PullRequest

    ).filter(

        subquery.c.project_id == model.PullRequest.project_id

    ).filter(

        subquery.c.request_id == model.PullRequest.id

    ).filter(

        subquery.c.global_id == requestid

    ).order_by(

        model.PullRequest.id

    )

    if project_id:

        query = query.filter(

            model.PullRequest.project_id == project_id

        )

    if project_id_from:

        query = query.filter(

            model.PullRequest.project_id_from == project_id_from

        )

    return query.first()

def close_pull_request(session, request, user, merged=True):

    ''' Close the provided pull-request.

    '''

    request.status = False

    session.add(request)

    session.flush()

    if merged == True:

        progit.notify.notify_merge_pull_request(request, user)

    else:

        progit.notify.notify_cancelled_pull_request(request, user)

def get_issue_statuses(session):

    ''' Return the complete list of status an issue can have.

    '''

    output = []

    statuses = session.query(model.StatusIssue).all()

    for status in statuses:

        output.append(status.status)

    return output

def generate_gitolite_acls(session, configfile):

    ''' Generate the configuration file for gitolite for all projects

    on the forge.

    '''

    config = []

    for project in session.query(model.Project).all():

        if project.parent_id:

            config.append('repo forks/%s' % project.fullname)

        else:

            config.append('repo %s' % project.fullname)

        config.append('  RW+ = %s' % project.user.user)

        for user in project.users:

            if user != project.user:

                config.append('  RW+ = %s' % user.user.user)

        config.append('')

        config.append('repo docs/%s' % project.fullname)

        config.append('  RW+ = %s' % project.user.user)

        for user in project.users:

            if user != project.user:

                config.append('  RW+ = %s' % user.user.user)

        config.append('')

        config.append('repo tickets/%s' % project.fullname)

        config.append('  RW+ = %s' % project.user.user)

        for user in project.users:

            if user != project.user:

                config.append('  RW+ = %s' % user.user.user)

        config.append('')

    with open(configfile, 'w') as stream:

        for row in config:

            stream.write(row + '\n')

def set_up_user(session, username, fullname, user_email):

    ''' Set up a new user into the database or update its information. '''

    user = get_user(session, username)

    if not user:

        user = model.User(

            user=username,

            fullname=fullname)

        session.add(user)

        session.flush()

    if user.fullname != fullname:

        user.fullname = fullname

        session.add(user)

        session.flush()

    emails = [email.email for email in user.emails]

    if user_email not in emails:

        useremail = model.UserEmail(

            user_id=user.id,

            email=user_email)

        session.add(useremail)

        session.flush()

def update_user_ssh(session, user, ssh_key):

    ''' Set up a new user into the database or update its information. '''

    if isinstance(user, basestring):

        user = get_user(session, user)

    message = 'Nothing to update'

    if ssh_key != user.public_ssh_key:

        user.public_ssh_key = ssh_key

        session.add(user)

        session.flush()

        message = 'Public ssh key updated'

    return message

def issue_to_json(issue):

    """ Convert all the data related to an issue (a ticket) as json object.

    """

    output = {

        'title': issue.title,

        'content': issue.content,

        'status': issue.status,

        'date_created': issue.date_created.strftime('%s'),

        'user': {

            'name': issue.user.user,

            'emails': [email.email for email in issue.user.emails],

        }

    }

    comments = []

    for comment in issue.comments:

        cmt = {

            'id': comment.id,

            'comment': comment.comment,

            'parent': comment.parent_id,

            'date_created': comment.date_created.strftime('%s'),

            'user': {

                'name': comment.user.user,

                'emails': [email.email for email in comment.user.emails],

            }

        }

        comments.append(cmt)

    output['comments'] = comments

    return json.dumps(output)

def update_git_ticket(issue, repo, ticketfolder):

    """ Update the given issue in its git.

    This method forks the provided repo, add/edit the issue whose file name

    is defined by the uid field of the issue and if there are additions/

    changes commit them and push them back to the original repo.

    """

    # Get the fork

    repopath = os.path.join(ticketfolder, repo.path)

    ticket_repo = pygit2.Repository(repopath)

    # Clone the repo into a temp folder

    newpath = tempfile.mkdtemp()

    new_repo = pygit2.clone_repository(repopath, newpath)

    file_path = os.path.join(newpath, issue.uid)

    # Get the current index

    index = new_repo.index

    # Are we adding files

    added = False

    if not os.path.exists(file_path):

        added = True

    # Write down what changed

    with open(file_path, 'w') as stream:

        stream.write(issue_to_json(issue))

    # Retrieve the list of files that changed

    diff = new_repo.diff()

    files = [patch.new_file_path for patch in diff]

    # Add the changes to the index

    if added:

        index.add(issue.uid)

    for filename in files:

        index.add(filename)

    # If not change, return

    if not files and not added:

        shutil.rmtree(newpath)

        return

    # See if there is a parent to this commit

    parent = None

    try:

        parent = new_repo.head.get_object().oid

    except pygit2.GitError:

        pass

    parents = []

    if parent:

        parents.append(parent)

    # Author/commiter will always be this one

    author = pygit2.Signature(name='progit', email='progit')

    # Actually commit

    sha = new_repo.create_commit(

        'refs/heads/master',

        author,

        author,

        'Updated ticket %s: %s' % (issue.uid, issue.title),