import csv

import random

import StringIO

from django.core.mail import send_mass_mail

from django.db.models import Q

from django.http import HttpResponse

from django.http import HttpResponseBadRequest, HttpResponseNotAllowed

from django.shortcuts import render, redirect, get_object_or_404

from django.template import Context, Template

from django.views.decorators.http import require_POST

from account.decorators import login_required

# @@@ switch to pinax-teams

from symposion.teams.models import Team

from symposion.conf import settings

from symposion.proposals.models import ProposalBase, ProposalSection

from symposion.utils.mail import send_email

from symposion.reviews.forms import ReviewForm, SpeakerCommentForm

from symposion.reviews.forms import BulkPresentationForm

from symposion.reviews.models import (

    ReviewAssignment, Review, LatestVote, ProposalResult, NotificationTemplate,

    ResultNotification

)

def access_not_permitted(request):

    return render(request, "symposion/reviews/access_not_permitted.html")

def proposals_generator(request, queryset, user_pk=None, check_speaker=True):

    for obj in queryset:

        # @@@ this sucks; we can do better

        if check_speaker:

            if request.user in [s.user for s in obj.speakers()]:

                continue

        try:

            obj.result

        except ProposalResult.DoesNotExist:

            ProposalResult.objects.get_or_create(proposal=obj)

        obj.comment_count = obj.result.comment_count

        obj.score = obj.result.score

        obj.total_votes = obj.result.vote_count

        obj.plus_two = obj.result.plus_two

        obj.plus_one = obj.result.plus_one

        obj.minus_one = obj.result.minus_one

        obj.minus_two = obj.result.minus_two

        lookup_params = dict(proposal=obj)

        if user_pk:

            lookup_params["user__pk"] = user_pk

        else:

            lookup_params["user"] = request.user

        try:

            obj.user_vote = LatestVote.objects.get(**lookup_params).vote

            obj.user_vote_css = LatestVote.objects.get(**lookup_params).css_class()

        except LatestVote.DoesNotExist:

            obj.user_vote = None

            obj.user_vote_css = "no-vote"

        yield obj

VOTE_THRESHOLD = settings.SYMPOSION_VOTE_THRESHOLD

POSITIVE = "positive"

NEGATIVE = "negative"

INDIFFERENT = "indifferent"

CONTROVERSIAL = "controversial"

TOO_FEW = "too_few"

REVIEW_STATUS_FILTERS = {

    # proposals with at least VOTE_THRESHOLD reviews and at least one +2 and no -2s, sorted by

    # the 'score'

    POSITIVE: lambda qs: qs.filter(result__vote_count__gte=VOTE_THRESHOLD, result__plus_two__gt=0,

                                result__minus_two=0).order_by("-result__score"),

    # proposals with at least VOTE_THRESHOLD reviews and at least one -2 and no +2s, reverse

    # sorted by the 'score'

    NEGATIVE: lambda qs: qs.filter(result__vote_count__gte=VOTE_THRESHOLD, result__minus_two__gt=0,

                                result__plus_two=0).order_by("result__score"),

    # proposals with at least VOTE_THRESHOLD reviews and neither a +2 or a -2, sorted by total

    # votes (lowest first)

    INDIFFERENT: lambda qs: qs.filter(result__vote_count__gte=VOTE_THRESHOLD, result__minus_two=0,

                                   result__plus_two=0).order_by("result__vote_count"),

    # proposals with at least VOTE_THRESHOLD reviews and both a +2 and -2, sorted by total

    # votes (highest first)

    CONTROVERSIAL: lambda qs: qs.filter(result__vote_count__gte=VOTE_THRESHOLD,

                                     result__plus_two__gt=0, result__minus_two__gt=0)

         .order_by("-result__vote_count"),

    # proposals with fewer than VOTE_THRESHOLD reviews

    TOO_FEW: lambda qs: qs.filter(result__vote_count__lt=VOTE_THRESHOLD)

        .order_by("result__vote_count"),

}

# Returns a list of all proposals, proposals reviewed by the user, or the proposals the user has

# yet to review depending on the link user clicks in dashboard

@login_required

def review_section(request, section_slug, assigned=False, reviewed="all"):

    if not request.user.has_perm("reviews.can_review_%s" % section_slug):

        return access_not_permitted(request)

    section = get_object_or_404(ProposalSection, section__slug=section_slug)

    queryset = ProposalBase.objects.filter(kind__section=section.section)

    if assigned:

        assignments = ReviewAssignment.objects.filter(user=request.user)\

            .values_list("proposal__id")

        queryset = queryset.filter(id__in=assignments)

    # passing reviewed in from reviews.urls and out to review_list for

    # appropriate template header rendering

    if reviewed == "all":

        queryset = queryset.select_related("result").select_subclasses()

        reviewed = "all_reviews"

    elif reviewed == "reviewed":

        queryset = queryset.filter(reviews__user=request.user)

        reviewed = "user_reviewed"

    else:

        queryset = queryset.exclude(reviews__user=request.user).exclude(

            speaker__user=request.user)

        reviewed = "user_not_reviewed"

    # lca2017 #21 -- chairs want to be able to see their own proposals in the list

    check_speaker = not request.user.has_perm("reviews.can_manage_%s" % section_slug)

    proposals = proposals_generator(request, queryset, check_speaker=check_speaker)

    ctx = {

        "proposals": proposals,

        "section": section,

        "reviewed": reviewed,

    }

    return render(request, "symposion/reviews/review_list.html", ctx)

@login_required

def review_all_proposals_csv(request):

    ''' Returns a CSV representation of all of the proposals this user has

    permisison to review. '''

    response = HttpResponse("text/csv")

    response['Content-Disposition'] = 'attachment; filename="proposals.csv"'

    writer = csv.writer(response, quoting=csv.QUOTE_NONNUMERIC)

    queryset = ProposalBase.objects.filter()

    # The fields from each proposal object to report in the csv

    fields = [

        "id", "proposal_type", "speaker_name","speaker_email", "title",

        "submitted", "cancelled", "status",

        "score", "total_votes", "minus_two", "minus_one", "plus_one", "plus_two",

    ]

    # Fields are the heading

    writer.writerow(fields)

    for proposal in proposals_generator(request, queryset, check_speaker=False):

        proposal.speaker_name = proposal.speaker.name

        section_slug = proposal.kind.section.slug

        if not request.user.has_perm("reviews.can_review_%s" % section_slug):

            continue

        csv_line = [getattr(proposal, field) for field in fields]

        # Enusre that unicode items are handled properly.

        for i, item in enumerate(csv_line):

            if isinstance(item, unicode):

                csv_line[i] = item.encode("utf8")

        writer.writerow(csv_line)

    return response

@login_required

def review_random_proposal(request, section_slug):

    # lca2017 #16 view for random proposal

    if not request.user.has_perm("reviews.can_review_%s" % section_slug):

        return access_not_permitted(request)

    section = get_object_or_404(ProposalSection, section__slug=section_slug)

    queryset = ProposalBase.objects.filter(kind__section=section.section)

    # Remove ones already reviewed

    queryset = queryset.exclude(reviews__user=request.user)

    # Remove talks the reviewer can't vote on -- their own.

    queryset = queryset.exclude(speaker__user=request.user)

    queryset = queryset.exclude(additional_speakers__user=request.user)

    if len(queryset) == 0:

        return redirect("review_section", section_slug=section_slug, reviewed="all")

    # Direct reviewers to underreviewed proposals

    too_few_set = REVIEW_STATUS_FILTERS[TOO_FEW](queryset)

    if len(too_few_set) > 0:

    # Realistically, there shouldn't be all that many proposals to choose

    # from, so this should be cheap.

    return redirect("review_detail", pk=chosen.pk)

@login_required

def review_list(request, section_slug, user_pk):

    # if they're not a reviewer admin and they aren't the person whose

    # review list is being asked for, don't let them in

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        if not request.user.pk == user_pk:

            return access_not_permitted(request)

    queryset = ProposalBase.objects.select_related("speaker__user", "result")

    reviewed = LatestVote.objects.filter(user__pk=user_pk).values_list("proposal", flat=True)

    queryset = queryset.filter(pk__in=reviewed)

    proposals = queryset.order_by("submitted")

    admin = request.user.has_perm("reviews.can_manage_%s" % section_slug)

    proposals = proposals_generator(request, proposals, user_pk=user_pk, check_speaker=not admin)

    ctx = {

        "proposals": proposals,

    }

    return render(request, "symposion/reviews/review_list.html", ctx)

@login_required

def review_admin(request, section_slug):

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    def reviewers():

        already_seen = set()

        for team in Team.objects.filter(permissions__codename="can_review_%s" % section_slug):

            for membership in team.memberships.filter(Q(state="member") | Q(state="manager")):

                user = membership.user

                if user.pk in already_seen:

                    continue

                already_seen.add(user.pk)

                user.comment_count = Review.objects.filter(

                    user=user,

                    proposal__kind__section__slug=section_slug,

                ).count()

                user_votes = LatestVote.objects.filter(

                    user=user,

                    proposal__kind__section__slug=section_slug,

                )

                print section_slug

                print [vote.proposal.kind.section.slug for vote in user_votes]

                user.total_votes = user_votes.exclude(

                    vote=LatestVote.VOTES.ABSTAIN,

                ).count()

                user.plus_two = user_votes.filter(

                    vote=LatestVote.VOTES.PLUS_TWO,

                ).count()

                user.plus_one = user_votes.filter(

                    vote=LatestVote.VOTES.PLUS_ONE,

                ).count()

                user.minus_one = user_votes.filter(

                    vote=LatestVote.VOTES.MINUS_ONE,

                ).count()

                user.minus_two = user_votes.filter(

                    vote=LatestVote.VOTES.MINUS_TWO,

                ).count()

                user.abstain = user_votes.filter(

                    vote=LatestVote.VOTES.ABSTAIN,

                ).count()

                if user.total_votes == 0:

                    user.average = "-"

                else:

                    user.average = (

                        ((user.plus_two * 2) + user.plus_one) -

                        ((user.minus_two * 2) + user.minus_one)

                    ) / (user.total_votes * 1.0)

                yield user

    reviewers_sorted = list(reviewers())

    reviewers_sorted.sort(key= lambda reviewer: 0 - reviewer.total_votes)

    ctx = {

        "section_slug": section_slug,

        "reviewers": reviewers_sorted,

    }

    return render(request, "symposion/reviews/review_admin.html", ctx)

# FIXME: This view is too complex according to flake8

@login_required

def review_detail(request, pk):

    proposals = ProposalBase.objects.select_related("result").select_subclasses()

    proposal = get_object_or_404(proposals, pk=pk)

    if not request.user.has_perm("reviews.can_review_%s" % proposal.kind.section.slug):

        return access_not_permitted(request)

    speakers = [s.user for s in proposal.speakers()]

    if not request.user.is_superuser and request.user in speakers:

        return access_not_permitted(request)

    admin = request.user.has_perm("reviews.can_manage_%s" % proposal.kind.section.slug)

    try:

        latest_vote = LatestVote.objects.get(proposal=proposal, user=request.user)

    except LatestVote.DoesNotExist:

        latest_vote = None

    if request.method == "POST":

        if request.user in speakers:

            return access_not_permitted(request)

        if "vote_submit" in request.POST or "vote_submit_and_random" in request.POST:

            review_form = ReviewForm(request.POST)

            if review_form.is_valid():

                review = review_form.save(commit=False)

                review.user = request.user

                review.proposal = proposal

                review.save()

                if "vote_submit_and_random" in request.POST:

                    next_page = redirect("user_random", proposal.kind.section.slug)

                    next_page["Location"] += "#invalid_fragment"  # Hack.

                else:

                    next_page = redirect(request.path)

                return next_page

            else:

                message_form = SpeakerCommentForm()

        elif "message_submit" in request.POST and admin:

            message_form = SpeakerCommentForm(request.POST)

            if message_form.is_valid():

                message = message_form.save(commit=False)

                message.user = request.user

                message.proposal = proposal

                message.save()

                for speaker in speakers:

                    if speaker and speaker.email:

                        ctx = {

                            "proposal": proposal,

                            "message": message,

                            "reviewer": False,

                        }

                        send_email(

                            [speaker.email], "proposal_new_message",

                            context=ctx

                        )

                return redirect(request.path)

            else:

                initial = {}

                if latest_vote:

                    initial["vote"] = latest_vote.vote

                if request.user in speakers:

                    review_form = None

                else:

                    review_form = ReviewForm(initial=initial)

        elif "result_submit" in request.POST:

            if admin:

                result = request.POST["result_submit"]

                if result == "accept":

                    proposal.result.status = "accepted"

                    proposal.result.save()

                elif result == "reject":

                    proposal.result.status = "rejected"

                    proposal.result.save()

                elif result == "undecide":

                    proposal.result.status = "undecided"

                    proposal.result.save()

                elif result == "standby":

                    proposal.result.status = "standby"

                    proposal.result.save()

            return redirect(request.path)

    else:

        initial = {}

        if latest_vote:

            initial["vote"] = latest_vote.vote

        if request.user in speakers:

            review_form = None

        else:

            review_form = ReviewForm(initial=initial)

        message_form = SpeakerCommentForm()

    proposal.comment_count = proposal.result.comment_count

    proposal.total_votes = proposal.result.vote_count

    proposal.plus_two = proposal.result.plus_two

    proposal.plus_one = proposal.result.plus_one

    proposal.minus_one = proposal.result.minus_one

    proposal.minus_two = proposal.result.minus_two

    reviews = Review.objects.filter(proposal=proposal).order_by("-submitted_at")

    messages = proposal.messages.order_by("submitted_at")

    return render(request, "symposion/reviews/review_detail.html", {

        "proposal": proposal,

        "latest_vote": latest_vote,

        "reviews": reviews,

        "review_messages": messages,

        "review_form": review_form,

        "message_form": message_form,

        "is_manager": admin

    })

@login_required

@require_POST

def review_delete(request, pk):

    review = get_object_or_404(Review, pk=pk)

    section_slug = review.section

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    review = get_object_or_404(Review, pk=pk)

    review.delete()

    return redirect("review_detail", pk=review.proposal.pk)

@login_required

def review_status(request, section_slug=None, key=None):

    if not request.user.has_perm("reviews.can_review_%s" % section_slug):

        return access_not_permitted(request)

    ctx = {

        "section_slug": section_slug,

        "vote_threshold": VOTE_THRESHOLD,

    }

    queryset = ProposalBase.objects.select_related("speaker__user", "result").select_subclasses()

    if section_slug:

        queryset = queryset.filter(kind__section__slug=section_slug)

    proposals = dict((key, filt(queryset)) for key, filt in REVIEW_STATUS_FILTERS.items())

    admin = request.user.has_perm("reviews.can_manage_%s" % section_slug)

    for status in proposals:

        if key and key != status:

            continue

        proposals[status] = list(proposals_generator(request, proposals[status], check_speaker=not admin))

    if key:

        ctx.update({

            "key": key,

            "proposals": proposals[key],

        })

    else:

        ctx["proposals"] = proposals

    return render(request, "symposion/reviews/review_stats.html", ctx)

@login_required

def review_assignments(request):

    if not request.user.groups.filter(name="reviewers").exists():

        return access_not_permitted(request)

    assignments = ReviewAssignment.objects.filter(

        user=request.user,

        opted_out=False

    )

    return render(request, "symposion/reviews/review_assignment.html", {

        "assignments": assignments,

    })

@login_required

@require_POST

def review_assignment_opt_out(request, pk):

    review_assignment = get_object_or_404(

        ReviewAssignment, pk=pk, user=request.user)

    if not review_assignment.opted_out:

        review_assignment.opted_out = True

        review_assignment.save()

        ReviewAssignment.create_assignments(

            review_assignment.proposal, origin=ReviewAssignment.AUTO_ASSIGNED_LATER)

    return redirect("review_assignments")

@login_required

def review_bulk_accept(request, section_slug):

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    if request.method == "POST":

        form = BulkPresentationForm(request.POST)

        if form.is_valid():

            talk_ids = form.cleaned_data["talk_ids"].split(",")

            talks = ProposalBase.objects.filter(id__in=talk_ids).select_related("result")

            for talk in talks:

                talk.result.status = "accepted"

                talk.result.save()

            return redirect("review_section", section_slug=section_slug)

    else:

        form = BulkPresentationForm()

    return render(request, "symposion/reviews/review_bulk_accept.html", {

        "form": form,

    })

@login_required

def result_notification(request, section_slug, status):

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    proposals = ProposalBase.objects.filter(kind__section__slug=section_slug, result__status=status).select_related("speaker__user", "result").select_subclasses()

    notification_templates = NotificationTemplate.objects.all()

    ctx = {

        "section_slug": section_slug,

        "status": status,

        "proposals": proposals,

        "notification_templates": notification_templates,

    }

    return render(request, "symposion/reviews/result_notification.html", ctx)

@login_required

def result_notification_prepare(request, section_slug, status):

    if request.method != "POST":

        return HttpResponseNotAllowed(["POST"])

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    proposal_pks = []

    try:

        for pk in request.POST.getlist("_selected_action"):

            proposal_pks.append(int(pk))

    except ValueError:

        return HttpResponseBadRequest()

    proposals = ProposalBase.objects.filter(

        kind__section__slug=section_slug,

        result__status=status,

    )

    proposals = proposals.filter(pk__in=proposal_pks)

    proposals = proposals.select_related("speaker__user", "result")

    proposals = proposals.select_subclasses()

    notification_template_pk = request.POST.get("notification_template", "")

    if notification_template_pk:

        notification_template = NotificationTemplate.objects.get(pk=notification_template_pk)

    else:

        notification_template = None

    ctx = {

        "section_slug": section_slug,

        "status": status,

        "notification_template": notification_template,

        "proposals": proposals,

        "proposal_pks": ",".join([str(pk) for pk in proposal_pks]),

    }

    return render(request, "symposion/reviews/result_notification_prepare.html", ctx)

@login_required

def result_notification_send(request, section_slug, status):

    if request.method != "POST":

        return HttpResponseNotAllowed(["POST"])

    if not request.user.has_perm("reviews.can_manage_%s" % section_slug):

        return access_not_permitted(request)

    if not all([k in request.POST for k in ["proposal_pks", "from_address", "subject", "body"]]):

        return HttpResponseBadRequest()

    try:

        proposal_pks = [int(pk) for pk in request.POST["proposal_pks"].split(",")]

    except ValueError:

        return HttpResponseBadRequest()

    proposals = ProposalBase.objects.filter(

        kind__section__slug=section_slug,

        result__status=status,

    )

    proposals = proposals.filter(pk__in=proposal_pks)

    proposals = proposals.select_related("speaker__user", "result")

    proposals = proposals.select_subclasses()

    notification_template_pk = request.POST.get("notification_template", "")

    if notification_template_pk:

        notification_template = NotificationTemplate.objects.get(pk=notification_template_pk)

    else:

        notification_template = None

    emails = []

    for proposal in proposals:

        rn = ResultNotification()

        rn.proposal = proposal

        rn.template = notification_template

        rn.to_address = proposal.speaker_email

        rn.from_address = request.POST["from_address"]

        rn.subject = request.POST["subject"]

        rn.body = Template(request.POST["body"]).render(

            Context({

                "proposal": proposal.notification_email_context()

            })

        )

        rn.save()

        emails.append(rn.email_args)

    send_mass_mail(emails)

    return redirect("result_notification", section_slug=section_slug, status=status)