#-*- 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

    ).order_by(

        model.User.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)

    globalid = get_issue_global_id(session, issue.project.id, issue.id)

    progit.notify.notify_new_comment(issue_comment, globalid)

    return 'Comment added'

def add_issue_tag(session, issue, tag, user, ticketfolder):

    ''' Add a tag 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

        )

    tagobj = get_tag(session, tag)

    if not tagobj:

        tagobj = model.Tag(tag=tag)

        session.add(tagobj)

    issue_tag = model.TagIssue(

        issue_id=issue.id,

        tag=tagobj.tag,

    )

    session.add(issue_tag)

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

    session.flush()

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

    return 'Tag added'

def remove_issue_tags(session, project, tags):

    ''' Removes the specified tag of a project. '''

    if not isinstance(tags, list):

        tags = [tags]

    issues = get_issues(session, project, closed=False, tags=tags)

    issues.extend(get_issues(session, project, closed=True, tags=tags))

    msgs = []

    if not issues:

        raise progit.exceptions.ProgitException(

            'No issue found with the tag: %s' % tag)

    else:

        for issue in issues:

            for issue_tag in issue[0].tags:

                if issue_tag.tag in tags:

                    tag = issue_tag.tag

                    session.delete(issue_tag)

                    msgs.append('Removed tag: %s' % tag)

    return msgs

def edit_issue_tags(session, project, old_tag, new_tag):

    ''' Removes the specified tag of a project. '''

    if not isinstance(old_tag, list):

        old_tags = [old_tag]

    issues = get_issues(session, project, closed=False, tags=old_tags)

    issues.extend(get_issues(session, project, closed=True, tags=old_tags))

    msgs = []

    if not issues:

        raise progit.exceptions.ProgitException(

            'No issue found with the tags: %s' % old_tag)

    else:

        tagobj = get_tag(session, new_tag)

        if not tagobj:

            tagobj = model.Tag(tag=new_tag)

            session.add(tagobj)

        for issue in issues:

            # Drop the old tag

            for issue_tag in issue[0].tags:

                if issue_tag.tag in old_tags:

                    tag = issue_tag.tag

                    session.delete(issue_tag)

            # Add the new one

            issue_tag = model.TagIssue(

                issue_id=issue[0].id,

                tag=new_tag

            )

            session.add(issue_tag)

            msgs.append('Edited tag: %s to %s' % (old_tag, new_tag))

    return msgs

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)

    globalid = get_issue_global_id(session, issue.project.id, issue.id)

    progit.notify.notify_new_issue(issue, globalid)

    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()

    globalid = get_pull_request_global_id(

        session, request.project.id, request.id)

    progit.notify.notify_new_pull_request(request, globalid)

    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, tags=None):

    ''' 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.

    The `tags` argument can be used to filter the issues returned based on

    a certain tag.

    '''

    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'

        )

    if tags is not None and tags != []:

        query = query.filter(

            model.Issue.id == model.TagIssue.issue_id

        ).filter(

            model.TagIssue.tag.in_(tags)

        )

    return query.all()

def get_issue_global_id(session, projectid, issueid):

    ''' Retrieve the global identifier of a specific issue based on its

    identifier.

    '''

    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(

        subquery.c.global_id

    ).filter(

        subquery.c.project_id == projectid

    ).filter(

        subquery.c.issue_id == issueid

    )

    data = query.first()

    return data[0]

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_tags_of_project(session, project):

    ''' Returns the list of tags associated with the issues of a project.

    '''

    query = session.query(

        model.Tag

    ).filter(

        model.Tag.tag == model.TagIssue.tag

    ).filter(

        model.TagIssue.issue_id == model.Issue.id

    ).filter(

        model.Issue.project_id == project.id

    ).order_by(

        model.Tag.tag

    )

    return query.all()

def get_tag(session, tag):

    ''' Returns a Tag object for the given tag text.

    '''

    query = session.query(

        model.Tag

    ).filter(

        model.Tag.tag == tag

    )

    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 get_pull_request_global_id(session, projectid, requestid):

    ''' Retrieve the global identifier of a specific request based on its

    identifier.

    '''

    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(

        subquery.c.global_id

    ).filter(

        subquery.c.project_id == projectid

    ).filter(

        subquery.c.request_id == requestid

    )

    data = query.first()

    return data[0]

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

    ''' Close the provided pull-request.

    '''

    request.status = False

    session.add(request)

    session.flush()

    globalid = get_pull_request_global_id(

        session, request.project.id, request.id)

    if merged == True:

        progit.notify.notify_merge_pull_request(request, user, globalid)