from django.shortcuts import render
from django.http import HttpResponseRedirect, Http404
from django.urls import reverse
from django.contrib.auth.decorators import login_required

from .models import Topic,Entry
from .forms import TopicForm,EntryForm

def check_topic_owner(request,istopic):
    if istopic!=request.user:
        raise Http404
         
        

# Create your views here.
def index(request):
    """ 学习笔记的主页 """
    return render(request, 'learning_logs/index.html')
    
@login_required    
def topics(request):
    """show all topics"""
    topics=Topic.objects.filter(owner=request.user).order_by('date_added')
    context={'topics':topics}
    return render(request,'learning_logs/topics.html',context)
    
@login_required 
def topic(request, topic_id):
    """ 显示单个主题及其所有的条目 """
    topic = Topic.objects.get(id=topic_id)
    check_topic_owner(request,topic.owner)
    
    entries = topic.entry_set.order_by('-date_added')
    context = {'topic': topic, 'entries': entries}
    return render(request, 'learning_logs/topic.html', context)
    
@login_required 
def new_topic(request):
    if request.method !='POST':
        form=TopicForm()
    else:
        form=TopicForm(request.POST)
        if form.is_valid():
            new_topic=form.save(commit=False)
            new_topic.owner= request.user
            new_topic.sage()
            return HttpResponseRedirect(reverse('learning_logs:topics'))
    context={'form':form}
    return render(request, 'learning_logs/new_topic.html', context)
    
@login_required     
def new_entry(request, topic_id):
    topic=Topic.objects.get(id=topic_id)
    check_topic_owner(request,topic.owner)
    if request.method !='POST':
        form= EntryForm()
    else:
        form=EntryForm(data=request.POST)
        if form.is_valid():
            new_entry=form.save(commit=False)
            new_entry.topic=topic
            new_entry.save()
            return HttpResponseRedirect(reverse('learning_logs:topic',args=[topic_id]))
    context={'topic':topic,'form':form}
    return render(request, 'learning_logs/new_entry.html',context)
    
@login_required     
def edit_entry(request,entry_id):
    entry=Entry.objects.get(id=entry_id)
    topic=entry.topic
    check_topic_owner(request,topic.owner)
    
    if request.method != 'POST':
        form=EntryForm(instance=entry)
    else:
        form=EntryForm(instance=entry,data=request.POST)
        if form.is_valid():
            form.save()
            return HttpResponseRedirect(reverse('learning_logs:topic',args=[topic.id]))
    context={'entry':entry,'topic':topic,'form':form}
    return render(request,'learning_logs/edit_entry.html', context)
    


