import hashlib
from django.core.urlresolvers import reverse
from django.template import RequestContext
from django.shortcuts import render, redirect, get_object_or_404
from django.http import HttpResponseRedirect

from boards import forms
import boards
from boards import utils
from boards.forms import ThreadForm, PostForm, SettingsForm, PlainErrorList, \
    ThreadCaptchaForm, PostCaptchaForm

from boards.models import Post, Admin, Tag, User, RANK_USER, RANK_MODERATOR, NO_PARENT
from boards import authors
import neboard


def index(request, page=0):
    context = _init_default_context(request)

    if utils.need_include_captcha(request):
        threadFormClass = ThreadCaptchaForm
        kwargs = {'request': request}
    else:
        threadFormClass = ThreadForm
        kwargs = {}

    if request.method == 'POST':
        form = threadFormClass(request.POST, request.FILES,
                               error_class=PlainErrorList, **kwargs)

        if form.is_valid():
            return _new_post(request, form)
    else:
        form = threadFormClass(error_class=PlainErrorList, **kwargs)

    threads = Post.objects.get_threads(page=int(page))

    context['threads'] = None if len(threads) == 0 else threads
    context['form'] = form
    context['pages'] = range(Post.objects.get_thread_page_count())

    return render(request, 'boards/posting_general.html',
                  context)


def _new_post(request, form, thread_id=boards.models.NO_PARENT):
    """Add a new post (in thread or as a reply)."""

    data = form.cleaned_data

    title = data['title']
    text = data['text']

    if 'image' in data.keys():
        image = data['image']
    else:
        image = None

    ip = _get_client_ip(request)

    tags = []

    new_thread = thread_id == boards.models.NO_PARENT
    if new_thread:
        tag_strings = data['tags']

        if tag_strings:
            tag_strings = tag_strings.split(' ')
            for tag_name in tag_strings:
                tag_name = tag_name.strip()
                if len(tag_name) > 0:
                    tag, created = Tag.objects.get_or_create(name=tag_name)
                    tags.append(tag)

    # TODO Add a possibility to define a link image instead of an image file.
    # If a link is given, download the image automatically.

    post = Post.objects.create_post(title=title, text=text, ip=ip,
                                    parent_id=thread_id, image=image,
                                    tags=tags)

    thread_to_show = (post.id if new_thread else thread_id)

    if new_thread:
        return redirect(thread, post_id=thread_to_show)
    else:
        return redirect(reverse(thread,
                                kwargs={'post_id': thread_to_show}) + '#'
                        + str(post.id))


def tag(request, tag_name, page=0):
    """Get all tag threads (posts without a parent)."""

    tag = get_object_or_404(Tag, name=tag_name)
    threads = Post.objects.get_threads(tag=tag, page=int(page))

    if request.method == 'POST':
        form = ThreadForm(request.POST, request.FILES,
                          error_class=PlainErrorList)
        if form.is_valid():
            return _new_post(request, form)
    else:
        form = forms.ThreadForm(initial={'tags': tag_name},
                                error_class=PlainErrorList)

    context = _init_default_context(request)
    context['threads'] = None if len(threads) == 0 else threads
    context['tag'] = tag_name
    context['pages'] = range(Post.objects.get_thread_page_count(tag=tag))

    context['form'] = form

    return render(request, 'boards/posting_general.html',
                  context)


def thread(request, post_id):
    """Get all thread posts"""

    if utils.need_include_captcha(request):
        postFormClass = PostCaptchaForm
        kwargs = {'request': request}
    else:
        postFormClass = PostForm
        kwargs = {}

    if request.method == 'POST':
        form = postFormClass(request.POST, request.FILES,
                             error_class=PlainErrorList, **kwargs)
        if form.is_valid():
            return _new_post(request, form, post_id)
    else:
        form = postFormClass(error_class=PlainErrorList, **kwargs)

    posts = Post.objects.get_thread(post_id)

    context = _init_default_context(request)

    context['posts'] = posts
    context['form'] = form

    return render(request, 'boards/thread.html', context)


def login(request):
    """Log in as admin"""

    if 'name' in request.POST and 'password' in request.POST:
        request.session['admin'] = False

        isAdmin = len(Admin.objects.filter(name=request.POST['name'],
                                           password=request.POST[
                                               'password'])) > 0

        if isAdmin:
            request.session['admin'] = True

            response = HttpResponseRedirect('/')

        else:
            response = render(request, 'boards/login.html', {'error': 'Login error'})
    else:
        response = render(request, 'boards/login.html', {})

    return response


def logout(request):
    request.session['admin'] = False
    return HttpResponseRedirect('/')


def settings(request):
    """User's settings"""

    context = _init_default_context(request)

    if request.method == 'POST':
        form = SettingsForm(request.POST)
        if form.is_valid():
            selected_theme = form.cleaned_data['theme']

            user = _get_user(request)
            user.save_setting('theme', selected_theme)

        return redirect(settings)
    else:
        selected_theme = _get_theme(request)
        form = SettingsForm(initial={'theme': selected_theme})
        context['form'] = form

        return render(request, 'boards/settings.html', context)


def all_tags(request):
    """All tags list"""

    context = _init_default_context(request)
    context['all_tags'] = Tag.objects.get_not_empty_tags()

    return render(request, 'boards/tags.html', context)


def jump_to_post(request, post_id):
    """Determine thread in which the requested post is and open it's page"""

    post = get_object_or_404(Post, id=post_id)

    if boards.models.NO_PARENT == post.parent:
        return redirect(thread, post_id=post.id)
    else:
        parent_thread = get_object_or_404(Post, id=post.parent)
        return redirect(reverse(thread, kwargs={'post_id': parent_thread.id})
                        + '#' + str(post.id))


def authors(request):
    context = _init_default_context(request)
    context['authors'] = boards.authors.authors

    return render(request, 'boards/authors.html', context)


def delete(request, post_id):
    user = _get_user(request)
    post = get_object_or_404(Post, id=post_id)

    if user.is_moderator():
        Post.objects.delete_post(post)

    if NO_PARENT == post.parent:
        return redirect(index)
    else:
        return redirect(thread, post_id=post.parent)


def _get_theme(request):
    """Get user's CSS theme"""

    user = _get_user(request)
    theme = user.get_setting('theme')
    if not theme:
        theme = neboard.settings.DEFAULT_THEME

    return theme


def _get_client_ip(request):
    x_forwarded_for = request.META.get('HTTP_X_FORWARDED_FOR')
    if x_forwarded_for:
        ip = x_forwarded_for.split(',')[-1].strip()
    else:
        ip = request.META.get('REMOTE_ADDR')
    return ip


def _init_default_context(request):
    """Create context with default values that are used in most views"""

    context = RequestContext(request)
    context['tags'] = Tag.objects.get_popular_tags()
    context['theme'] = _get_theme(request)
    context['user'] = _get_user(request)

    return context


def _get_user(request):
    """Get current user from the session"""

    session = request.session
    if not 'user_id' in session:
        request.session.save()

        md5 = hashlib.md5()
        md5.update(session.session_key)
        new_id = md5.hexdigest()

        user = User.objects.create(user_id=new_id, rank=RANK_USER)

        session['user_id'] = user.id
    else:
        user = User.objects.get(id=session['user_id'])

    return user