from django.shortcuts import render, redirect
from django.http import HttpResponse, HttpResponseRedirect, Http404, JsonResponse

from django.urls import reverse, resolve
from django.template import Context, loader
import re, io
from PIL import Image
from pathlib import Path
import django.forms as forms
import troggle.settings as settings

from django.views.decorators.csrf import ensure_csrf_cookie
from .auth import login_required_if_public

from troggle.lib import version_control

MAX_IMAGE_WIDTH = 1000
MAX_IMAGE_HEIGHT = 800

THUMBNAIL_WIDTH = 200
THUMBNAIL_HEIGHT = 200

def get_dir(path):
    "From a path sent from urls.py, determine the directory."
    if "/" in path:
        return path.rsplit('/', 1)[0]
    else:
        return ""

def image_selector(request, path):
    '''Returns available images'''
    directory = get_dir(path)
    thumbnailspath = Path(settings.EXPOWEB) / directory / "t"
    thumbnails = []
    if thumbnailspath.is_dir():
        for f in thumbnailspath.iterdir():
            if f.is_file():
                if directory:
                    base = f"{directory}/"
                else:
                    base = ""
                thumbnail_url = reverse('expopage', args=["%st/%s" % (base, f.name)])
                name_base = f.name.rsplit('.', 1)[0]
                page_path_base = Path(settings.EXPOWEB) / directory / "l"
                if ((page_path_base / ("%s.htm" % name_base)).is_file()):
                    page_url = reverse('expopage', args=["%sl/%s.htm" % (base, name_base)])
                else:
                    page_url = reverse('expopage', args=["%s/l/%s.html" % (base, name_base)])
            
                thumbnails.append({"thumbnail_url": thumbnail_url, "page_url": page_url})
    
    return render(request, 'image_selector.html', {'thumbnails': thumbnails})

@login_required_if_public
@ensure_csrf_cookie
def new_image_form(request, path):
    '''Manages a form to upload new images'''
    directory = get_dir(path)
    if request.method == 'POST':
        form = NewWebImageForm(request.POST, request.FILES, directory = directory)
        if form.is_valid():
            f = request.FILES["file_"]
            binary_data = io.BytesIO()
            for chunk in f.chunks():
                binary_data.write(chunk)
            i = Image.open(binary_data)
            width, height = i.size
            if width > MAX_IMAGE_WIDTH or height > MAX_IMAGE_HEIGHT:
                scale = max(width / MAX_IMAGE_WIDTH, height / MAX_IMAGE_HEIGHT)
                i  = i.resize((int(width / scale), int(height / scale)), Image.ANTIALIAS)
            tscale = max(width / THUMBNAIL_WIDTH, height / THUMBNAIL_HEIGHT)
            thumbnail  = i.resize((int(width / tscale), int(height / tscale)), Image.ANTIALIAS)
            ib = io.BytesIO()
            i.save(ib, format="png")
            tb = io.BytesIO()
            thumbnail.save(tb, format="png")
            image_rel_path, thumb_rel_path, desc_rel_path = form.get_rel_paths()
            image_page_template = loader.get_template('image_page_template.html')
            image_page = image_page_template.render({'header': form.cleaned_data["header"], 'description': form.cleaned_data["description"], 
                                                     'photographer': form.cleaned_data["photographer"], 'year': form.cleaned_data["year"],
                                                     'filepath': f'/{image_rel_path}'
                                                     })
            image_path, thumb_path, desc_path = form.get_full_paths()
            # Create directories if required
            for full_path in image_path, thumb_path, desc_path:
                print(full_path, full_path.parent)
                full_path.parent.mkdir(parents=False, exist_ok=True)
            try:
                change_message = form.cleaned_data["change_message"]
                version_control.write_and_commit([(desc_path, image_page, "utf-8"),
                                                  (image_path, ib.getbuffer(), False),
                                                  (thumb_path, tb.getbuffer(), False)], 
                                                 f'{change_message} - online adding of an image')
            except version_control.WriteAndCommitError as e:
                return JsonResponse({"error": e.message})
            linked_image_template = loader.get_template('linked_image_template.html')
            html_snippet = linked_image_template.render({'thumbnail_url': f'/{thumb_rel_path}', 'page_url': f'/{desc_rel_path}'}, request)
            return JsonResponse({"html": html_snippet})
    else:
        form = NewWebImageForm(directory = directory)
    template = loader.get_template('new_image_form.html')
    htmlform = template.render({'form': form, 'path': path}, request)
    return JsonResponse({"form": htmlform})
    
class NewWebImageForm(forms.Form):
    '''The form used by the editexpopage function
    '''
    header = forms.CharField(widget=forms.TextInput(attrs={'size':'60', 'placeholder': "Enter title (displayed as a header and in the tab)"}))
    file_ = forms.FileField()
    description = forms.CharField(widget=forms.Textarea(attrs={"cols":80, "rows":20, 'placeholder': "Describe the photo (using HTML)"}))
    photographer = forms.CharField(widget=forms.TextInput(attrs={'size':'60', 'placeholder': "Photographers name"}), required = False)
    year = forms.CharField(widget=forms.TextInput(attrs={'size':'60', 'placeholder': "Year photo was taken"}), required = False)
    change_message = forms.CharField(widget=forms.Textarea(attrs={"cols":80, "rows":3, 'placeholder': "Descibe the change made (for git)"}))
    
    def __init__(self, *args, **kwargs):
        self.directory = Path(kwargs.pop('directory'))
        super(forms.Form, self).__init__(*args, **kwargs)

    def get_rel_paths(self):
        f = self.cleaned_data['file_']
        return [self.directory / "i" / (f.name.rsplit('.', 1)[0] + ".png"),
                self.directory / "t" / (f.name.rsplit('.', 1)[0] + ".png"),
                self.directory / "l" / (f.name.rsplit('.', 1)[0] + ".html")]

    def get_full_paths(self):
        return [Path(settings.EXPOWEB) / x for x in self.get_rel_paths()]
    
    def clean_file_(self):
        for rel_path, full_path in zip(self.get_rel_paths(), self.get_full_paths()):
            if full_path.exists():
                raise forms.ValidationError("File already exists in %s" % rel_path)
        return self.cleaned_data['file_']
        
class HTMLarea(forms.Textarea):
    template_name = "widgets/HTMLarea.html"