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

"""

 (c) 2014 - Copyright Red Hat Inc

 Authors:

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

"""

import flask

import os

import shutil

import tempfile

from math import ceil

import pygit2

from sqlalchemy.exc import SQLAlchemyError

from pygments import highlight

from pygments.lexers import guess_lexer

from pygments.lexers.text import DiffLexer

from pygments.formatters import HtmlFormatter

import progit.doc_utils

import progit.lib

import progit.forms

from progit import (APP, SESSION, LOG, __get_file_in_tree, cla_required,

                    is_repo_admin, generate_gitolite_acls)

@APP.route('/<repo>/request-pulls')</repo>

@APP.route('/fork/<username>/<repo>/request-pulls')</repo></username>

def request_pulls(repo, username=None):

    """ Request pulling the changes from the fork into the project.

    """

    status = flask.request.args.get('status', True)

    repo = progit.lib.get_project(SESSION, repo, user=username)

    if not repo:

        flask.abort(404, 'Project not found')

    if status is False or str(status).lower() == 'closed':

        requests = progit.lib.get_pull_requests(

            SESSION, project_id=repo.id, status=False)

    else:

        requests = progit.lib.get_pull_requests(

            SESSION, project_id=repo.id, status=status)

    return flask.render_template(

        'requests.html',

        select='requests',

        repo=repo,

        username=username,

        requests=requests,

        status=status,

    )

@APP.route('/<repo>/request-pull/<requestid>')</requestid></repo>

@APP.route('/fork/<username>/<repo>/request-pull/<requestid>')</requestid></repo></username>

def request_pull(repo, requestid, username=None):

    """ Request pulling the changes from the fork into the project.

    """

    repo = progit.lib.get_project(SESSION, repo, user=username)

    if not repo:

        flask.abort(404, 'Project not found')

    request = progit.lib.get_pull_request(

        SESSION, project_id=repo.id, requestid=requestid)

    if not request:

        flask.abort(404, 'Pull-request not found')

    if repo.is_fork:

        repopath = os.path.join(APP.config['FORK_FOLDER'], repo.path)

    else:

        repopath = os.path.join(APP.config['GIT_FOLDER'], repo.path)

    repo_obj = pygit2.Repository(repopath)

    if repo.parent:

        parentname = os.path.join(APP.config['GIT_FOLDER'], repo.parent.path)

    else:

        parentname = os.path.join(APP.config['GIT_FOLDER'], repo.path)

    orig_repo = pygit2.Repository(parentname)

    diff_commits = []

    diffs = []

    repo_commit = repo_obj[request.stop_id]

    if not repo_obj.is_empty and not orig_repo.is_empty:

        orig_commit = orig_repo[

            orig_repo.lookup_branch('master').get_object().hex]

        master_commits = [

            commit.oid.hex

            for commit in orig_repo.walk(

                orig_repo.lookup_branch('master').get_object().hex,

                pygit2.GIT_SORT_TIME)

        ]

        repo_commit = repo_obj[request.start_id]

        for commit in repo_obj.walk(

                request.stop_id, pygit2.GIT_SORT_TIME):

            if commit.oid.hex in master_commits:

                break

            diff_commits.append(commit)

            diffs.append(

                repo_obj.diff(

                    repo_obj.revparse_single(commit.parents[0].oid.hex),

                    repo_obj.revparse_single(commit.oid.hex)

                )

            )

    elif orig_repo.is_empty:

        orig_commit = None

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

    else:

        flask.flash(

            'Fork is empty, there are no commits to request pulling',

            'error')

        return flask.redirect(flask.url_for(

            'view_repo', username=username, repo=repo.name))

    html_diffs = []

    for diff in diffs:

        html_diffs.append(

            highlight(

                diff.patch,

                DiffLexer(),

                HtmlFormatter(

                    noclasses=True,

                    style="tango",)

            )

        )

    return flask.render_template(

        'pull_request.html',

        select='requests',

        requestid=requestid,

        repo=repo,

        username=username,

        request=request,

        repo_admin=is_repo_admin(request.repo),

        repo_obj=repo_obj,

        orig_repo=orig_repo,

        diff_commits=diff_commits,

        diffs=diffs,

        html_diffs=html_diffs,

    )

@APP.route('/<repo>/request-pull/merge/<requestid>')</requestid></repo>

@APP.route('/fork/<username>/<repo>/request-pull/merge/<requestid>')</requestid></repo></username>

def merge_request_pull(repo, requestid, username=None):

    """ Request pulling the changes from the fork into the project.

    """

    repo = progit.lib.get_project(SESSION, repo, user=username)

    if not repo:

        flask.abort(404, 'Project not found')

    request = progit.lib.get_pull_request(

        SESSION, project_id=repo.id, requestid=requestid)

    if not request:

        flask.abort(404, 'Pull-request not found')

    if not is_repo_admin(repo):

        flask.abort(

            403,

            'You are not allowed to merge pull-request for this project')

    error_output = flask.url_for(

        'request_pull', repo=repo.name, requestid=requestid)

    if username:

        error_output = flask.url_for(

            'fork_request_pull',

            repo=repo.name,

            requestid=requestid,

            username=username)

    # Get the fork

    if request.repo_from.is_fork:

        repopath = os.path.join(

            APP.config['FORK_FOLDER'], request.repo_from.path)

    else:

        repopath = os.path.join(

            APP.config['GIT_FOLDER'], request.repo_from.path)

    fork_obj = pygit2.Repository(repopath)

    # Get the original repo

    parentpath = os.path.join(APP.config['GIT_FOLDER'], request.repo.path)

    orig_repo = pygit2.Repository(parentpath)

    # Clone the original repo into a temp folder

    newpath = tempfile.mkdtemp()

    new_repo = pygit2.clone_repository(parentpath, newpath)

    repo_commit = fork_obj[request.stop_id]

    ori_remote = new_repo.remotes[0]

    # Add the fork as remote repo

    reponame = '%s_%s' % (request.user.user, repo.name)

    remote = new_repo.create_remote(reponame, repopath)

    # Fetch the commits

    remote.fetch()

    merge = new_repo.merge(repo_commit.oid)

    master_ref = new_repo.lookup_reference('HEAD').resolve()

    refname = '%s:%s' % (master_ref.name, master_ref.name)

    if merge.is_uptodate:

        flask.flash('Nothing to do, changes were already merged', 'error')

        progit.lib.close_pull_request(SESSION, request)

        SESSION.commit()

        return flask.redirect(error_output)

    elif merge.is_fastforward:

        master_ref.target = merge.fastforward_oid

        ori_remote.push(refname)

        flask.flash('Changes merged!')

    else:

        new_repo.index.write()

        try:

            tree = new_repo.index.write_tree()

        except pygit2.GitError:

            shutil.rmtree(newpath)

            flask.flash('Merge conflicts!', 'error')

            return flask.redirect(flask.url_for(

                'request_pull',

                repo=repo.name,

                username=username,

                requestid=requestid))

        head = new_repo.lookup_reference('HEAD').get_object()

        commit = new_repo[head.oid]

        sha = new_repo.create_commit(

            'refs/heads/master',

            repo_commit.author,

            repo_commit.committer,

            'Merge #%s `%s`' % (request.id, request.title),

            tree,

            [head.hex, repo_commit.oid.hex])

        ori_remote.push(refname)

        flask.flash('Changes merged!')

    # Update status

    progit.lib.close_pull_request(SESSION, request)

    SESSION.commit()

    shutil.rmtree(newpath)

    return flask.redirect(flask.url_for('view_repo', repo=repo.name))

## Specific actions

@APP.route('/do_fork/<repo>')</repo>

@APP.route('/do_fork/<username>/<repo>')</repo></username>

@cla_required

def fork_project(repo, username=None):

    """ Fork the project specified into the user's namespace

    """

    repo = progit.lib.get_project(SESSION, repo, user=username)

    if repo is None:

        flask.abort(404)

    try:

        message = progit.lib.fork_project(

            session=SESSION,

            repo=repo,

            gitfolder=APP.config['GIT_FOLDER'],

            forkfolder=APP.config['FORK_FOLDER'],

            docfolder=APP.config['DOCS_FOLDER'],

            user=flask.g.fas_user.username)

        SESSION.commit()

        generate_gitolite_acls()

        flask.flash(message)

        return flask.redirect(

            flask.url_for(

                'view_repo',

                username=flask.g.fas_user.username,

                repo=repo.name)

        )

    except progit.exceptions.ProgitException, err:

        flask.flash(str(err), 'error')

    except SQLAlchemyError, err:  # pragma: no cover

        SESSION.rollback()

        flask.flash(str(err), 'error')

    return flask.redirect(flask.url_for('view_repo', repo=repo.name))

@APP.route('/<repo>/request-pull/new',</repo>

           methods=('GET', 'POST'))

@APP.route('/<repo>/request-pull/new/<commitid>',</commitid></repo>

           methods=('GET', 'POST'))

@APP.route('/fork/<username>/<repo>/request-pull/new',</repo></username>

           methods=('GET', 'POST'))

@APP.route('/fork/<username>/<repo>/request-pull/new/<commitid>',</commitid></repo></username>

           methods=('GET', 'POST'))

@cla_required

def new_request_pull(repo, username=None, commitid=None):

    """ Request pulling the changes from the fork into the project.

    """

    repo = progit.lib.get_project(SESSION, repo, user=username)

    if not repo:

        flask.abort(404)

    if not is_repo_admin(repo):

        flask.abort(

            403,

            'You are not allowed to create pull-requests for this project')

    if repo.is_fork:

        repopath = os.path.join(APP.config['FORK_FOLDER'], repo.path)

    else:

        repopath = os.path.join(APP.config['GIT_FOLDER'], repo.path)

    repo_obj = pygit2.Repository(repopath)

    if repo.parent:

        parentname = os.path.join(APP.config['GIT_FOLDER'], repo.parent.path)

    else:

        parentname = os.path.join(APP.config['GIT_FOLDER'], repo.path)

    orig_repo = pygit2.Repository(parentname)

    if commitid is None:

        commitid = repo_obj.head.target

        branchname = flask.request.args.get('branch', None)

        if branchname:

            branch = repo_obj.lookup_branch(branchname)

            commitid = branch.get_object().hex

    diff_commits = []

    diffs = []

    if not repo_obj.is_empty and not orig_repo.is_empty:

        orig_commit = orig_repo[

            orig_repo.lookup_branch('master').get_object().hex]

        master_commits = [

            commit.oid.hex

            for commit in orig_repo.walk(

                orig_repo.lookup_branch('master').get_object().hex,

                pygit2.GIT_SORT_TIME)

        ]

        repo_commit = repo_obj[commitid]

        for commit in repo_obj.walk(

                repo_commit.oid.hex, pygit2.GIT_SORT_TIME):

            if commit.oid.hex in master_commits:

                break

            diff_commits.append(commit)

            diffs.append(

                repo_obj.diff(

                    repo_obj.revparse_single(commit.parents[0].oid.hex),

                    repo_obj.revparse_single(commit.oid.hex)

                )

            )

    elif orig_repo.is_empty:

        orig_commit = None

        repo_commit = repo_obj[repo_obj.head.target]

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

    else:

        flask.flash(

            'Fork is empty, there are no commits to request pulling',

            'error')

        return flask.redirect(flask.url_for(

            'view_repo', username=username, repo=repo.name))

    html_diffs = []

    for diff in diffs:

        html_diffs.append(

            highlight(

                diff.patch,

                DiffLexer(),

                HtmlFormatter(

                    noclasses=True,

                    style="tango",)

            )

        )

    form = progit.forms.RequestPullForm()

    if form.validate_on_submit():

        try:

            if orig_commit:

                orig_commit = orig_commit.oid.hex

            parent = repo

            if repo.parent:

                parent = repo.parent

            message = progit.lib.new_pull_request(

                SESSION,

                repo=parent,

                repo_from=repo,

                title=form.title.data,

                start_id=orig_commit,

                stop_id=repo_commit.oid.hex,

                user=flask.g.fas_user.username,

            )

            SESSION.commit()

            flask.flash(message)

            if not parent.is_fork:

                url = flask.url_for(

                    'request_pulls', username=None, repo=parent.name)

            else:

                url = flask.url_for(

                    'request_pulls', username=parent.user, repo=parent.name)

            return flask.redirect(url)

        except progit.exceptions.ProgitException, err:

            flask.flash(str(err), 'error')

        except SQLAlchemyError, err:  # pragma: no cover

            SESSION.rollback()

            flask.flash(str(err), 'error')

    return flask.render_template(

        'pull_request.html',

        select='requests',

        repo=repo,

        username=username,

        commitid=commitid,

        repo_obj=repo_obj,

        orig_repo=orig_repo,

        diff_commits=diff_commits,

        diffs=diffs,

        html_diffs=html_diffs,

        form=form,

    )