from django.template import RequestContext, loader
from datetime import datetime, timedelta
from django.http import HttpResponse, HttpResponseRedirect
from django.core.urlresolvers import reverse_lazy
from django.conf import settings
from models import (
    StatusCheck, GraphiteStatusCheck, JenkinsStatusCheck, HttpStatusCheck,
    StatusCheckResult, UserProfile, Service, Shift, get_duty_officers)
from tasks import run_status_check as _run_status_check
from tasks import update_service as _update_service
from tasks import run_all_checks as _run_all_checks
from django.contrib.auth.decorators import login_required
from django.utils.decorators import method_decorator
from django.views.generic import DetailView, CreateView, UpdateView, ListView, DeleteView
from django import forms
from .graphite import get_data, get_matching_metrics
from .alert import telephone_alert_twiml_callback
from django.contrib.auth.models import User
from django.utils.timezone import utc
from django.core.urlresolvers import reverse
from django.core.exceptions import ValidationError

import requests
import json
import re


class LoginRequiredMixin(object):

    @method_decorator(login_required)
    def dispatch(self, *args, **kwargs):
        return super(LoginRequiredMixin, self).dispatch(*args, **kwargs)


@login_required
def subscriptions(request):
    """ Simple list of all checks """
    t = loader.get_template('cabotapp/subscriptions.html')
    services = Service.objects.all().order_by('alerts_enabled')
    users = User.objects.filter(is_active=True)
    c = RequestContext(request, {
        'services': services,
        'users': users,
        'duty_officers': get_duty_officers(),
    })
    return HttpResponse(t.render(c))


@login_required
def run_status_check(request, pk):
    """Runs a specific check"""
    _run_status_check(check_or_id=pk)
    return HttpResponseRedirect(reverse('check', kwargs={'pk': pk}))


class StatusCheckResultDetailView(LoginRequiredMixin, DetailView):
    model = StatusCheckResult
    context_object_name = 'result'


class SymmetricalForm(forms.ModelForm):
    symmetrical_fields = ()  # Iterable of 2-tuples (field, model)

    def __init__(self, *args, **kwargs):
        super(SymmetricalForm, self).__init__(*args, **kwargs)

        if self.instance and self.instance.pk:
            for field in self.symmetrical_fields:
                self.fields[field].initial = getattr(
                    self.instance, field).all()

    def save(self, commit=True):
        instance = super(SymmetricalForm, self).save(commit=False)
        if commit:
            instance.save()
        if instance.pk:
            for field in self.symmetrical_fields:
                setattr(instance, field, self.cleaned_data[field])
            self.save_m2m()
        return instance

base_widgets = {
    'name': forms.TextInput(attrs={
        'style': 'width:30%',
    }),
    'importance': forms.RadioSelect(),
}


class StatusCheckForm(SymmetricalForm):
    symmetrical_fields = ('service_set',)
    service_set = forms.ModelMultipleChoiceField(
        queryset=Service.objects.all(),
        required=False,
        help_text='Link to service(s).',
        widget=forms.SelectMultiple(
            attrs={
                'data-rel': 'chosen',
                'style': 'width: 70%',
            },
        )
    )


class GraphiteStatusCheckForm(StatusCheckForm):

    class Meta:
        model = GraphiteStatusCheck
        fields = (
            'name',
            'metric',
            'check_type',
            'value',
            'frequency',
            'active',
            'importance',
            'expected_num_hosts',
            'debounce',
        )
        widgets = dict(**base_widgets)
        widgets.update({
            'value': forms.TextInput(attrs={
                'style': 'width: 100px',
                'placeholder': 'threshold value',
            }),
            'metric': forms.TextInput(attrs={
                'style': 'width: 100%',
                'placeholder': 'graphite metric key'
            }),
            'check_type': forms.Select(attrs={
                'data-rel': 'chosen',
            })
        })


class HttpStatusCheckForm(StatusCheckForm):

    class Meta:
        model = HttpStatusCheck
        fields = (
            'name',
            'endpoint',
            'username',
            'password',
            'text_match',
            'status_code',
            'timeout',
            'frequency',
            'importance',
            'active',
            'debounce',
        )
        widgets = dict(**base_widgets)
        widgets.update({
            'endpoint': forms.TextInput(attrs={
                'style': 'width: 100%',
                'placeholder': 'https://www.arachnys.com',
            }),
            'username': forms.TextInput(attrs={
                'style': 'width: 30%',
            }),
            'password': forms.TextInput(attrs={
                'style': 'width: 30%',
            }),
            'text_match': forms.TextInput(attrs={
                'style': 'width: 100%',
                'placeholder': '[Aa]rachnys\s+[Rr]ules',
            }),
            'status_code': forms.TextInput(attrs={
                'style': 'width: 20%',
                'placeholder': '200',
            }),
        })


class JenkinsStatusCheckForm(StatusCheckForm):

    class Meta:
        model = JenkinsStatusCheck
        fields = (
            'name',
            'importance',
            'debounce',
            'max_queued_build_time',
        )
        widgets = dict(**base_widgets)


class UserProfileForm(forms.ModelForm):

    class Meta:
        model = UserProfile
        exclude = ('user',)


class ServiceForm(forms.ModelForm):

    class Meta:
        model = Service
        template_name = 'service_form.html'
        fields = (
            'name',
            'url',
            'users_to_notify',
            'status_checks',
            'email_alert',
            'hipchat_alert',
            'sms_alert',
            'telephone_alert',
            'alerts_enabled',
            'hackpad_id',
        )
        widgets = {
            'name': forms.TextInput(attrs={'style': 'width: 30%;'}),
            'url': forms.TextInput(attrs={'style': 'width: 70%;'}),
            'status_checks': forms.SelectMultiple(attrs={
                'data-rel': 'chosen',
                'style': 'width: 70%',
            }),
            'users_to_notify': forms.CheckboxSelectMultiple(),
            'hackpad_id': forms.TextInput(attrs={'style': 'width:30%;'}),
        }

    def __init__(self, *args, **kwargs):
        ret = super(ServiceForm, self).__init__(*args, **kwargs)
        self.fields['users_to_notify'].queryset = User.objects.filter(
            is_active=True)
        return ret

    def clean_hackpad_id(self):
        value = self.cleaned_data['hackpad_id']
        if not value:
            return ''
        for pattern in settings.RECOVERY_SNIPPETS_WHITELIST:
            if re.match(pattern, value):
                return value
        raise ValidationError('Please specify a valid JS snippet link')


class CheckCreateView(LoginRequiredMixin, CreateView):
    template_name = 'cabotapp/statuscheck_form.html'

    def form_valid(self, form):
        form.instance.created_by = self.request.user
        return super(CheckCreateView, self).form_valid(form)

    def get_initial(self):
        if self.initial:
            initial = self.initial
        else:
            initial = {}
        metric = self.request.GET.get('metric')
        if metric:
            initial['metric'] = metric
        service_id = self.request.GET.get('service')
        if service_id:
            try:
                service = Service.objects.get(id=service_id)
                initial['service_set'] = [service]
            except Service.DoesNotExist:
                pass
        return initial

    def get_success_url(self):
        return reverse('check', kwargs={'pk': self.object.id})


class CheckUpdateView(LoginRequiredMixin, UpdateView):
    template_name = 'cabotapp/statuscheck_form.html'

    def get_success_url(self):
        return reverse('check', kwargs={'pk': self.object.id})


class GraphiteCheckCreateView(CheckCreateView):
    model = GraphiteStatusCheck
    form_class = GraphiteStatusCheckForm


class GraphiteCheckUpdateView(CheckUpdateView):
    model = GraphiteStatusCheck
    form_class = GraphiteStatusCheckForm


class HttpCheckCreateView(CheckCreateView):
    model = HttpStatusCheck
    form_class = HttpStatusCheckForm


class HttpCheckUpdateView(CheckUpdateView):
    model = HttpStatusCheck
    form_class = HttpStatusCheckForm


class JenkinsCheckCreateView(CheckCreateView):
    model = JenkinsStatusCheck
    form_class = JenkinsStatusCheckForm


class JenkinsCheckUpdateView(CheckUpdateView):
    model = JenkinsStatusCheck
    form_class = JenkinsStatusCheckForm


class StatusCheckListView(LoginRequiredMixin, ListView):
    model = StatusCheck
    context_object_name = 'checks'

    def get_queryset(self):
        return StatusCheck.objects.all().order_by('name').prefetch_related('service_set')


class StatusCheckDeleteView(LoginRequiredMixin, DeleteView):
    model = StatusCheck
    success_url = reverse_lazy('checks')
    context_object_name = 'check'
    template_name = 'cabotapp/statuscheck_confirm_delete.html'


class StatusCheckDetailView(LoginRequiredMixin, DetailView):
    model = StatusCheck
    context_object_name = 'check'
    template_name = 'cabotapp/statuscheck_detail.html'

    def render_to_response(self, context, *args, **kwargs):
        if context == None:
            context = {}
        context['checkresults'] = self.object.statuscheckresult_set.order_by(
            '-time_complete')[:100]
        return super(StatusCheckDetailView, self).render_to_response(context, *args, **kwargs)


class UserProfileUpdateView(LoginRequiredMixin, UpdateView):
    model = UserProfile
    success_url = reverse_lazy('subscriptions')
    form_class = UserProfileForm

    def get_object(self, *args, **kwargs):
        try:
            return self.model.objects.get(user=self.kwargs['pk'])
        except self.model.DoesNotExist:
            user = User.objects.get(id=self.kwargs['pk'])
            profile = UserProfile(user=user)
            profile.save()
            return profile


class ServiceListView(LoginRequiredMixin, ListView):
    model = Service
    context_object_name = 'services'

    def get_queryset(self):
        return Service.objects.all().order_by('name').prefetch_related('status_checks')


class ServiceDetailView(LoginRequiredMixin, DetailView):
    model = Service
    context_object_name = 'service'


class ServiceCreateView(LoginRequiredMixin, CreateView):
    model = Service
    form_class = ServiceForm

    def get_success_url(self):
        return reverse('service', kwargs={'pk': self.object.id})


class ServiceUpdateView(LoginRequiredMixin, UpdateView):
    model = Service
    form_class = ServiceForm

    def get_success_url(self):
        return reverse('service', kwargs={'pk': self.object.id})


class ServiceDeleteView(LoginRequiredMixin, DeleteView):
    model = Service
    success_url = reverse_lazy('services')
    context_object_name = 'service'
    template_name = 'cabotapp/service_confirm_delete.html'


class ShiftListView(LoginRequiredMixin, ListView):
    model = Shift
    context_object_name = 'shifts'

    def get_queryset(self):
        return Shift.objects.filter(
            end__gt=datetime.utcnow().replace(tzinfo=utc),
            deleted=False).order_by('start')


# Misc JSON api and other stuff

def twiml_callback(request, service_id):
    service = Service.objects.get(id=service_id)
    twiml = telephone_alert_twiml_callback(service)
    return HttpResponse(twiml, content_type='application/xml')


def checks_run_recently(request):
    """
    Checks whether or not stuff is running by looking to see if checks have run in last 10 mins
    """
    ten_mins = datetime.utcnow().replace(tzinfo=utc) - timedelta(minutes=10)
    most_recent = StatusCheckResult.objects.filter(time_complete__gte=ten_mins)
    if most_recent.exists():
        return HttpResponse('Checks running')
    return HttpResponse('Checks not running')


def jsonify(d):
    return HttpResponse(json.dumps(d), content_type='application/json')


@login_required
def graphite_api_data(request):
    metric = request.GET.get('metric')
    data = None
    matching_metrics = None
    try:
        data = get_data(metric)
    except requests.exceptions.RequestException, e:
        pass
    if not data:
        try:
            matching_metrics = get_matching_metrics(metric)
        except requests.exceptions.RequestException, e:
            return jsonify({'status': 'error', 'message': str(e)})
        matching_metrics = {'metrics': matching_metrics}
    return jsonify({'status': 'ok', 'data': data, 'matchingMetrics': matching_metrics})