from django.shortcuts import render, redirect, get_object_or_404
from django.contrib import messages
from django.core.exceptions import ObjectDoesNotExist, PermissionDenied
from django.contrib.auth.decorators import login_required
from django.http import Http404
from django.views.decorators.http import require_http_methods

from issue.models import *
from issue.forms import *
from issue.notifications import *
from issue.decorators import project_perm_required

import shlex


@login_required
def profile(request):

    c = {
        'groups': request.user.groups.all(),
        'teams': request.user.teams.all(),
    }

    return render(request, 'issue/profile.html', c)


@project_perm_required('manage_global_permission')
def global_permission_list(request):

    permissions = GlobalPermission.objects.all()

    c = {
        'permissions': permissions,
    }

    return render(request, 'issue/global_permission_list.html', c)


@project_perm_required('manage_global_permission')
def global_permission_edit(request, id=None):

    if id:
        permission = get_object_or_404(GlobalPermission, id=id)
        new = False
    else:
        permission = None
        new = True

    form = GlobalPermissionForm(request.POST or None, instance=permission)

    if request.method == 'POST' and form.is_valid():

        permission = form.save()

        if new:
            messages.success(request, 'Permission added successfully.')
        else:
            messages.success(request, 'Permission updated successfully.')

        return redirect('list-global-permission')

    c = {
        'form': form,
    }

    return render(request, 'issue/global_permission_edit.html', c)


@project_perm_required('manage_global_permission')
def global_permission_toggle(request, id, perm):

    permission = get_object_or_404(GlobalPermission, id=id)

    # to be sure to dont modify other attribut with the following trick
    if '-' not in perm:
        raise Http404
    perm = perm.replace('-', '_')

    if hasattr(permission, perm):
        setattr(permission, perm, not getattr(permission, perm))
        permission.save()
    else:
        raise Http404

    return redirect('list-global-permission')


@require_http_methods(["POST"])
@project_perm_required('manage_global_permission')
def global_permission_delete(request, id):

    permission = get_object_or_404(GlobalPermission, id=id)

    permission.delete()

    messages.success(request, 'Permission deleted successfully.')

    return redirect('list-global-permission')


@project_perm_required('manage_project_permission')
def project_permission_list(request, project):

    permissions = ProjectPermission.objects.filter(project=project)

    c = {
        'project': project,
        'permissions': permissions,
    }

    return render(request, 'issue/project_permission_list.html', c)


@project_perm_required('manage_project_permission')
def project_permission_edit(request, project, id=None):

    if id:
        permission = get_object_or_404(ProjectPermission,
                project=project, id=id)
    else:
        permission = None

    form = ProjectPermissionForm(request.POST or None, instance=permission)

    if request.method == 'POST' and form.is_valid():

        permission = form.save(commit=False)
        if not hasattr(permission, 'project'):
            permission.project = project
            messages.success(request, 'Permission added successfully.')
        else:
            messages.success(request, 'Permission updated successfully.')
        permission.save()

        return redirect('list-project-permission', project.name)

    c = {
        'project': project,
        'form': form,
    }

    return render(request, 'issue/project_permission_edit.html', c)


@project_perm_required('manage_project_permission')
def project_permission_toggle(request, project, id, perm):

    permission = get_object_or_404(ProjectPermission, project=project, id=id)

    # to be sure to dont modify other attribut with the following trick
    if '-' not in perm:
        raise Http404
    perm = perm.replace('-', '_')

    if hasattr(permission, perm):
        setattr(permission, perm, not getattr(permission, perm))
        permission.save()
    else:
        raise Http404

    return redirect('list-project-permission', project.name)


@require_http_methods(["POST"])
@project_perm_required('manage_project_permission')
def project_permission_delete(request, project, id):

    permission = get_object_or_404(ProjectPermission, project=project, id=id)

    permission.delete()

    messages.success(request, 'Permission deleted successfully.')

    return redirect('list-project-permission', project.name)


def project_list(request):

    if not request.projects.exists():

        if request.user.has_perm('create_project'):
            messages.info(request, 'Start by creating a project.')
            return redirect('add-project')

    return render(request, 'issue/project_list.html')


@project_perm_required('create_project')
def project_add(request):

    form = AddProjectForm(request.POST or None)

    if request.method == 'POST' and form.is_valid():

        name = form.cleaned_data['display_name']
        if Project.objects.filter(display_name__iexact=name).exists():
            form._errors['display_name'] = ['There is already a project '
                                            'with a similar name.']
        else:
            project = form.save()
            messages.success(request, 'Project added successfully.')
            project.subscribers.add(request.user)
            project.grant_user(request.user)
            return redirect('list-project-permission', project.name)

    c = {
        'form': form,
    }

    return render(request, 'issue/project_add.html', c)


@project_perm_required('modify_project')
def project_edit(request, project):

    form = EditProjectForm(request.POST or None, instance=project)

    if request.method == 'POST' and form.is_valid():

        name = form.cleaned_data['display_name']
        if Project.objects.filter(display_name__iexact=name) \
                .exclude(pk=project.pk).exists():
            form._errors['display_name'] = ['There is already a project '
                                            'with a similar name.']
        else:
            project = form.save()
            messages.success(request, 'Project modified successfully.')
            return redirect('list-issue', project.name)

    c = {
        'project': project,
        'form': form,
    }

    return render(request, 'issue/project_edit.html', c)


@require_http_methods(["POST"])
@project_perm_required('delete_project')
def project_delete(request, project):

    project.delete()

    messages.success(request, 'Project deleted successfully.')

    return redirect('list-project')


def issue_list(request, project):

    issues = project.issues

    is_open = ''
    is_close = ''
    is_all = ''
    is_all_query = ""

    query = request.GET.get('q', '')

    if query == '':
        query = 'is:open'

    syntaxe_error = False
    for constraint in shlex.split(query):

        if constraint == '*':
            continue

        args = constraint.split(':')

        if len(args) != 2:
            messages.error(request, 'There is a syntaxe error in your filter.')
            issues = None
            break

        key = args[0]
        value = args[1]

        if key == '':
            continue

        elif key == 'is':
            if value == 'open':
                issues = issues.filter(closed=False)
                is_open = ' active'
            elif value == 'close':
                issues = issues.filter(closed=True)
                is_close = ' active'
            else:
                messages.error(request, "The keyword 'is' must be followed "
                                        "by 'open' or 'close'.")
                issues = None
                break

        elif key == 'label':
            try:
                label = Label.objects.get(project=project,
                        name=value, deleted=False)
            except ObjectDoesNotExist:
                messages.error(request, "The label '%s' does not exist "
                                        "or has been deleted." % value)
                issues = None
                break
            else:
                issues = issues.filter(labels=label)

        elif key == 'milestone':
            try:
                milestone = Milestone.objects.get(project=project, name=value)
            except ObjectDoesNotExist:
                messages.error(request, "The milestone '%s' does not exist."
                        % value)
                issues = None
                break
            else:
                issues = issues.filter(milestone=milestone)

        elif key == 'author' or key == 'user':
            if User.objects.filter(username=value).exists():
                issues = issues.filter(author__username=value)
            else:
                messages.error(request, "The user '%s' does not exist."
                        % value)
                issues = None
                break

        else:
            messages.error(request, "Unknow '%s' filtering criterion." % key)
            issues = None
            break

        if key != 'is':
            is_all_query += ' ' + constraint

    if issues:
        issues = issues.extra(order_by=['-opened_at'])

    if is_open == '' and is_close == '':
        is_all = ' active'

    c = {
        'project': project,
        'issues': issues,
        'query': query,
        'is_open': is_open,
        'is_close': is_close,
        'is_all': is_all,
        'is_all_query': is_all_query[1:],
    }

    return render(request, 'issue/issue_list.html', c)


@login_required
def issue_edit(request, project, issue=None):

    if issue:
        if not request.user.has_perm('modify_issue', project):
            raise PermissionDenied()
        issue = get_object_or_404(Issue, project=project.name, id=issue)
        init_data = {'title': issue.title,
                     'description': issue.description}
    else:
        if not request.user.has_perm('create_issue', project):
            raise PermissionDenied()
        issue = None
        init_data = None

    form = IssueForm(request.POST or init_data)

    if request.method == 'POST' and form.is_valid():

        title = form.cleaned_data['title']
        description = form.cleaned_data['description']

        if issue:

            modified = False

            if issue.title != title:
                old_title = issue.title
                issue.title = title
                issue.save()
                event = Event(issue=issue, author=request.user,
                        code=Event.RENAME,
                        args={'old_title': old_title, 'new_title': title})
                event.save()
                modified = True

            if issue.description != description:
                issue.description = description
                modified = True

            if modified:
                messages.success(request, 'Issue updated successfully.')
            else:
                messages.info(request, 'Issue not modified.')

        else:

            issue = Issue(title=title, author=request.user,
                    project=project, id=Issue.next_id(project))
            issue.save()
            issue.subscribers.add(request.user)
            issue.description = description
            notify_new_issue(issue)
            messages.success(request, 'Issue created successfully.')

        return redirect('show-issue', project.name, issue.id)

    c = {
        'project': project,
        'form': form,
        'issue': issue,
    }

    return render(request, 'issue/issue_edit.html', c)


def issue(request, project, issue):

    issue = get_object_or_404(Issue, project=project, id=issue)

    labels = Label.objects.filter(project=project, deleted=False) \
        .exclude(id__in=issue.labels.all().values_list('id'))
    milestones = Milestone.objects.filter(project=project)
    if issue.milestone:
        milestones = milestones.exclude(name=issue.milestone.name)

    events = issue.events.all()

    if request.user.has_perm('create_comment', project):
        form = CommentForm(request.POST or None)
    else:
        form = None

    c = {
        'labels': labels,
        'milestones': milestones,
        'project': project,
        'issue': issue,
        'events': events,
        'form': form,
    }

    return render(request, 'issue/issue.html', c)


@login_required
def issue_edit_comment(request, project, issue, comment=None):

    issue = get_object_or_404(Issue, project=project, id=issue)

    if comment:
        if not request.user.has_perm('modify_comment', project):
            raise PermissionDenied()
        event = get_object_or_404(Event, code=Event.COMMENT,
                issue=issue, id=comment)
        init_data = {'comment': event.additionnal_section}
    else:
        if not request.user.has_perm('create_comment', project):
            raise PermissionDenied()
        event = None
        init_data = None

    form = CommentForm(request.POST or init_data)

    if request.method == 'POST' and form.is_valid():

        comment = form.cleaned_data['comment']

        if event:

            if event.additionnal_section != comment:
                event.additionnal_section = comment
                event.save()
                messages.success(request, 'Comment modified successfully.')
            else:
                messages.info(request, 'Comment not modified.')

        else:

            event = Event(issue=issue, author=request.user,
                    code=Event.COMMENT, additionnal_section=comment)
            event.save()
            issue.subscribers.add(request.user)
            notify_new_comment(event)
            messages.success(request, 'Comment added successfully.')

        return redirect('show-issue', project.name, issue.id)

    c = {
        'project': project,
        'issue': issue,
        'form': form,
    }

    return render(request, 'issue/issue_comment.html', c)


@require_http_methods(["POST"])
@project_perm_required('delete_comment')
def issue_delete_comment(request, project, issue, comment):

    comment = get_object_or_404(Event,
            issue__project=project, issue__id=issue, id=comment)

    comment.delete()
    messages.success(request, 'Comment deleted successfully.')

    return redirect('show-issue', project.name, issue)


@project_perm_required('manage_issue')
def issue_close(request, project, issue):

    issue = get_object_or_404(Issue, project=project, id=issue, closed=False)

    issue.closed = True
    issue.save()

    event = Event(issue=issue, author=request.user, code=Event.CLOSE)
    event.save()

    notify_close_issue(event)

    return redirect('list-issue', project.name)


@project_perm_required('manage_issue')
def issue_reopen(request, project, issue):

    issue = get_object_or_404(Issue, project=project, id=issue, closed=True)

    issue.closed = False
    issue.save()

    event = Event(issue=issue, author=request.user, code=Event.REOPEN)
    event.save()

    notify_reopen_issue(event)

    return redirect('show-issue', project.name, issue.id)


@require_http_methods(["POST"])
@project_perm_required('delete_issue')
def issue_delete(request, project, issue):

    issue = get_object_or_404(Issue, project=project, id=issue)

    issue.delete()

    messages.success(request, 'Issue deleted successfully.')

    return redirect('list-issue', project.name)


@project_perm_required('manage_tags')
def issue_add_label(request, project, issue, label):

    issue = get_object_or_404(Issue, project=project, id=issue)
    label = get_object_or_404(Label, project=project, id=label)

    issue.add_label(request.user, label)

    return redirect('show-issue', project.name, issue.id)


@project_perm_required('manage_tags')
def issue_remove_label(request, project, issue, label):

    issue = get_object_or_404(Issue, project=project, id=issue)
    label = get_object_or_404(Label, project=project, id=label)

    issue.remove_label(request.user, label)

    return redirect('show-issue', project.name, issue.id)


@project_perm_required('manage_tags')
def issue_add_milestone(request, project, issue, milestone):

    issue = get_object_or_404(Issue, project=project, id=issue)
    milestone = get_object_or_404(Milestone, project=project, name=milestone)

    issue.add_milestone(request.user, milestone)

    return redirect('show-issue', project.name, issue.id)


@project_perm_required('manage_tags')
def issue_remove_milestone(request, project, issue, milestone):

    issue = get_object_or_404(Issue, project=project, id=issue)
    milestone = get_object_or_404(Milestone, project=project, name=milestone)

    issue.remove_milestone(request.user, milestone)

    return redirect('show-issue', project.name, issue.id)


def label_list(request, project):

    labels = project.labels.filter(deleted=False)

    c = {
        'project': project,
        'labels': labels,
    }

    return render(request, 'issue/label_list.html', c)


@project_perm_required('manage_tags')
def label_edit(request, project, id=None):

    if id:
        label = get_object_or_404(Label, project=project, id=id)
    else:
        label = None

    form = LabelForm(request.POST or None, instance=label)

    if request.method == 'POST' and form.is_valid():

        similar = Label.objects.filter(project=project,
                name=form.cleaned_data['name'], deleted=False)

        if label:
            similar = similar.exclude(pk=label.pk)

        if similar.exists():

            form._errors['name'] = ['There is already a label with this name.']

        else:

            if label:
                form.save()
                messages.success(request, 'Label modified successfully.')
            else:
                label = form.save(commit=False)
                label.project = project
                label.save()
                messages.success(request, 'Label added successfully.')

            issue = request.GET.get('issue')
            if issue:
                return redirect('add-label-to-issue', project.name,
                        issue, label.id)

            return redirect('list-label', project.name)

    c = {
        'project': project,
        'form': form,
        'label': label,
    }

    return render(request, 'issue/label_edit.html', c)


@require_http_methods(["POST"])
@project_perm_required('delete_tags')
def label_delete(request, project, id):

    label = get_object_or_404(Label, project=project, id=id)

    for issue in label.issues.all():
        issue.remove_label(request.user, label)
    label.deleted = True
    label.save()

    messages.success(request, "Label deleted successfully.")

    return redirect('list-label', project.name)


def milestone_list(request, project):

    show = request.GET.get('show', 'open')

    if show == 'open':
        milestones = project.milestones.filter(closed=False)
    elif show == 'close':
        milestones = project.milestones.filter(closed=True)
    elif show == 'all':
        milestones = project.milestones.all()
    else:
        messages.error(request, 'There is an error in your filter.')
        milestones = None

    c = {
        'project': project,
        'milestones': milestones,
        'show': show,
    }

    return render(request, 'issue/milestone_list.html', c)


@project_perm_required('manage_tags')
def milestone_edit(request, project, name=None):

    if name:
        milestone = get_object_or_404(Milestone, project=project, name=name)
    else:
        milestone = None

    form = MilestoneForm(request.POST or None, instance=milestone)

    if request.method == 'POST' and form.is_valid():

        similar = Milestone.objects.filter(project=project,
                name=form.cleaned_data['name'])

        if milestone:
            similar = similar.exclude(pk=milestone.pk)

        if similar.exists():

            form._errors['name'] = ['There is already a milestone '
                                    'with this name.']

        else:

            if milestone:
                if name != form.cleaned_data['name']:
                    for issue in milestone.issues.all():
                        event = Event(issue=issue, author=request.user,
                                code=Event.CHANGE_MILESTONE, args={
                                    'old_milestone': name,
                                    'new_milestone': form.cleaned_data['name']
                                })
                        event.save()
                form.save()
                messages.success(request, 'Milestone modified successfully.')
            else:
                milestone = form.save(commit=False)
                milestone.project = project
                milestone.save()
                messages.success(request, 'Milestone added successfully.')

            issue = request.GET.get('issue')
            if issue:
                return redirect('add-milestone-to-issue', project.name, issue,
                        milestone.name)

            return redirect('list-milestone', project.name)

    c = {
        'project': project,
        'form': form,
        'milestone': milestone,
    }

    return render(request, 'issue/milestone_edit.html', c)


@project_perm_required('manage_tags')
def milestone_close(request, project, name):

    milestone = get_object_or_404(Milestone, project=project, name=name)

    milestone.closed = True
    milestone.save()

    return redirect('list-milestone', project.name)


@project_perm_required('manage_tags')
def milestone_reopen(request, project, name):

    milestone = get_object_or_404(Milestone, project=project, name=name)

    milestone.closed = False
    milestone.save()

    return redirect('list-milestone', project.name)


@require_http_methods(["POST"])
@project_perm_required('delete_tags')
def milestone_delete(request, project, name):

    milestone = get_object_or_404(Milestone, project=project, name=name)

    for issue in milestone.issues.all():
        issue.remove_milestone(request.user, milestone)
    milestone.delete()

    messages.success(request, "Label deleted successfully.")

    return redirect('list-milestone', project.name)


def team_list(request):

    teams = Team.objects.all()

    c = {
        'teams': teams,
    }

    return render(request, 'issue/team_list.html', c)


def team(request, team):

    team = get_object_or_404(Team, pk=team)

    c = {
        'team': team,
    }

    return render(request, 'issue/team.html', c)


@project_perm_required('manage_team')
def team_edit(request, team=None):

    if team:
        team = get_object_or_404(Team, pk=team)

    form = TeamForm(request.POST or None, instance=team)

    if request.method == 'POST' and form.is_valid():

        formteam = form.save()
        if team:
            messages.success(request, 'Team modified successfully.')
        else:
            messages.success(request, 'Team added successfully.')

        return redirect('show-team', formteam.pk)

    c = {
        'team': team,
        'form': form,
    }

    return render(request, 'issue/team_edit.html', c)


@project_perm_required('manage_team')
def team_add_user(request, team, user):

    team = get_object_or_404(Team, pk=team)
    user = get_object_or_404(User, pk=user)

    if user in team.users.all():
        messages.warning(request, 'This user already belong to this team.')
    else:
        team.users.add(user)
        team.save()
        messages.success(request, 'User added to team successfully.')

    return redirect('show-team', team.pk)


@project_perm_required('manage_team')
def team_remove_user(request, team, user):

    team = get_object_or_404(Team, pk=team)
    user = get_object_or_404(User, pk=user)

    if user in team.users.all():
        team.users.remove(user)
        team.save()
        messages.success(request, 'User removed from team successfully.')
    else:
        messages.error(request, 'This user does not belong to this team.')

    return redirect('show-team', team.pk)


@project_perm_required('manage_team')
def team_add_group(request, team, group):

    team = get_object_or_404(Team, pk=team)
    group = get_object_or_404(Group, pk=group)

    if group in team.groups.all():
        messages.warning(request, 'This group already belong to this team.')
    else:
        team.groups.add(group)
        team.save()
        messages.success(request, 'Group added to team successfully.')

    return redirect('show-team', team.pk)


@project_perm_required('manage_team')
def team_remove_group(request, team, group):

    team = get_object_or_404(Team, pk=team)
    group = get_object_or_404(Group, pk=group)

    if group in team.groups.all():
        team.groups.remove(group)
        team.save()
        messages.success(request, 'Group removed from team successfully.')
    else:
        messages.error(request, 'This group does not belong to this team.')

    return redirect('show-team', team.pk)


@require_http_methods(["POST"])
@project_perm_required('manage_team')
def team_delete(request, team):

    team = get_object_or_404(Team, pk=team)

    team.delete()
    messages.success(request, 'Team deleted successfully.')

    return redirect('list-team')


@login_required
def project_subscribe(request, project):

    user = User.objects.get(username=request.user.username)

    if project.subscribers.filter(username=user.username).exists():
        messages.warning(request,
                'You are already subscribed to this project.')
    else:
        project.subscribers.add(user)
        project.save()
        messages.success(request,
                'You have been subscribed to this project successfully.')

    next = request.GET.get('next')
    if next:
        return redirect(next)
    else:
        return redirect('list-issue', project.name)


@login_required
def project_unsubscribe(request, project):

    user = User.objects.get(username=request.user.username)

    if project.subscribers.filter(username=user.username).exists():
        project.subscribers.remove(user)
        project.save()
        messages.success(request, 'You will not receive any notifications '
                                  'for this project anymore.')
    else:
        messages.warning(request, 'You are not subscribed to this project.')

    next = request.GET.get('next')
    if next:
        return redirect(next)
    else:
        return redirect('list-issue', project.name)


@login_required
def issue_subscribe(request, project, issue):

    issue = get_object_or_404(Issue, project=project.name, id=issue)
    user = User.objects.get(username=request.user.username)

    if issue.subscribers.filter(username=user.username).exists():
        messages.warning(request, 'You are already subscribed to this issue.')
    else:
        issue.subscribers.add(user)
        issue.save()
        messages.success(request,
                'You have been subscribed to this issue successfully.')

    return redirect('show-issue', project.name, issue.id)


@login_required
def issue_unsubscribe(request, project, issue):

    issue = get_object_or_404(Issue, project=project.name, id=issue)
    user = User.objects.get(username=request.user.username)

    if issue.subscribers.filter(username=user.username).exists():
        issue.subscribers.remove(user)
        issue.save()
        messages.success(request, 'You will not receive any notifications '
                                  'for this issue anymore.')
    else:
        messages.warning(request, 'You are not subscribed to this issue.')

    return redirect('show-issue', project.name, issue.id)