Add phase 5: link import, Instagram fallback and share target

- SSRF-safe fetcher: public IPs only, connects to the checked address,
  redirects re-validated, size/time limits, honest user agent
- schema.org/Recipe JSON-LD extraction (graphs, HowToSections, ISO
  durations, yields, keywords, images) without extra dependencies;
  AI fallback on plain page text when no structured recipe exists
- Instagram: one login-free request to the public embed page; when
  Instagram withholds the caption, the import page explains how to paste
  the text or import a screenshot instead
- Suggested source photo can be downloaded and attached on save
- Text import works without AI (text becomes the description)
- Installable PWA with manifest, icons and Android share target
- Offline tests for SSRF rules, parsers, Instagram and import views

Co-Authored-By: Claude Opus 5.5 <[email protected]>

recipes/import_views.py

@@ -4,15 +4,30 @@ Every path ends in the normal recipe form, pre-filled as an editable draft and p
 recipes:create. Nothing is saved before the user presses "Speichern".
 """
 
+import re
+from urllib.parse import urlencode
+
 from django import forms
 from django.contrib import messages
 from django.shortcuts import redirect, render
 from django.urls import reverse
-from django.views.decorators.http import require_POST
+from django.views.decorators.http import require_GET, require_POST
 
-from . import ai, images
+from . import ai, images, instagram, schema_org
+from .fetch import FetchError, fetch
 from .forms import MultipleFileInput, MultipleImageField, RecipeForm
 
+_URL_RE = re.compile(r"https?://[^\s<>\"']+")
+
+
+class LinkImportForm(forms.Form):
+    url = forms.URLField(
+        label="Link",
+        max_length=2000,
+        assume_scheme="https",
+        widget=forms.URLInput(attrs={"placeholder": "https://… (Rezeptseite oder Instagram)", "inputmode": "url"}),
+    )
+
 
 class PhotoImportForm(forms.Form):
     photos = MultipleImageField(
@@ -48,11 +63,15 @@ def render_draft(request, initial, notice, ai_draft=None, extra_context=None):
     })
 
 
-def import_start(request, photo_form=None, text_form=None):
+def import_start(request, photo_form=None, text_form=None, link_form=None, instagram_failed=False, status=200):
+    if link_form is None:
+        link_form = LinkImportForm(initial={"url": request.GET.get("url", "")})
     return render(request, "recipes/import.html", {
         "photo_form": photo_form or PhotoImportForm(),
         "text_form": text_form or TextImportForm(),
-    })
+        "link_form": link_form,
+        "instagram_failed": instagram_failed,
+    }, status=status)
 
 
 @require_POST
@@ -74,6 +93,11 @@ def import_text(request):
     form = TextImportForm(request.POST)
     if not form.is_valid():
         return import_start(request, text_form=form)
+    if not ai.is_configured():
+        # Without AI the pasted text becomes the description; the user splits it up by hand.
+        initial = {"description": form.cleaned_data["text"], "source_url": form.cleaned_data["source_url"]}
+        return render_draft(request, initial, "Text übernommen (KI nicht eingerichtet – bitte Zutaten und "
+                                              "Schritte aus der Beschreibung in die passenden Felder übertragen)")
     try:
         draft = ai.structure_text(request.user, form.cleaned_data["text"])
     except ai.AIError as error:
@@ -81,3 +105,87 @@ def import_text(request):
         return import_start(request, text_form=form)
     initial = {**draft.to_form_initial(), "source_url": form.cleaned_data["source_url"]}
     return render_draft(request, initial, "Aus dem Text erkannt", ai_draft=draft)
+
+
+@require_POST
+def import_link(request):
+    form = LinkImportForm(request.POST)
+    if not form.is_valid():
+        return import_start(request, link_form=form, status=400)
+    url = form.cleaned_data["url"]
+    code = instagram.shortcode(url)
+    if code:
+        return _import_instagram(request, url, code, form)
+    if instagram.is_instagram(url):
+        form.add_error("url", "Bitte den Link zu einem einzelnen Beitrag oder Reel verwenden.")
+        return import_start(request, link_form=form, status=400)
+    return _import_website(request, url, form)
+
+
+def _instagram_fallback(request, url, form, reason):
+    messages.warning(request, f"{reason} Füge die Beschreibung des Beitrags unten ein – oder lade einen Screenshot hoch.")
+    text_form = TextImportForm(initial={"source_url": url})
+    return import_start(request, link_form=form, text_form=text_form, instagram_failed=True)
+
+
+def _import_instagram(request, url, code, form):
+    try:
+        caption, image = instagram.fetch_caption(code)
+    except instagram.InstagramUnavailable:
+        return _instagram_fallback(request, url, form, "Instagram lässt den automatischen Abruf gerade nicht zu.")
+    extra = {"import_image_url": image} if image else {}
+    if not ai.is_configured():
+        initial = {"description": caption, "source_url": url, **extra}
+        return render_draft(request, initial, "Beschreibung von Instagram übernommen (KI nicht eingerichtet – "
+                                              "bitte Zutaten und Schritte selbst aufteilen)")
+    try:
+        draft = ai.structure_text(request.user, caption, hint="Beschreibung (Caption) eines Instagram-Beitrags:")
+    except ai.AIError as error:
+        messages.error(request, error.user_message)
+        return import_start(request, link_form=form, text_form=TextImportForm(initial={"text": caption, "source_url": url}))
+    return render_draft(request, {**draft.to_form_initial(), "source_url": url, **extra}, "Aus Instagram erkannt",
+                        ai_draft=draft)
+
+
+def _import_website(request, url, form):
+    try:
+        result = fetch(url)
+    except FetchError as error:
+        form.add_error("url", error.user_message)
+        return import_start(request, link_form=form, status=400)
+    if result.status >= 400:
+        form.add_error("url", f"Die Seite antwortete mit Fehler {result.status}.")
+        return import_start(request, link_form=form, status=400)
+    if "html" not in result.content_type.lower():
+        form.add_error("url", "Unter dem Link liegt keine Webseite.")
+        return import_start(request, link_form=form, status=400)
+
+    initial, image, page = schema_org.extract(result.text)
+    extra = {"source_url": url, **({"import_image_url": image} if image else {})}
+    if initial:
+        return render_draft(request, {**initial, **extra}, "Von der Webseite übernommen")
+    if not ai.is_configured():
+        form.add_error("url", "Auf der Seite wurde kein strukturiertes Rezept gefunden, und die KI ist nicht "
+                              "eingerichtet. Kopiere den Rezepttext und trag ihn von Hand ein.")
+        return import_start(request, link_form=form, status=400)
+    text = page.title.strip() + "\n\n" + page.visible_text()
+    try:
+        draft = ai.structure_text(request.user, text, hint=f"Text der Webseite {url}:")
+    except ai.AIError as error:
+        form.add_error("url", error.user_message)
+        return import_start(request, link_form=form, status=400)
+    return render_draft(request, {**draft.to_form_initial(), **extra}, "Von der Webseite (per KI) erkannt",
+                        ai_draft=draft)
+
+
+@require_GET
+def share_target(request):
+    """Web Share Target (Android PWA): 'Teilen → Kochbuch' lands here with title/text/url."""
+    for value in (request.GET.get("url", ""), request.GET.get("text", ""), request.GET.get("title", "")):
+        match = _URL_RE.search(value)
+        if match:
+            return redirect(f"{reverse('recipes:import')}?{urlencode({'url': match.group(0)})}")
+    text = request.GET.get("text", "").strip()
+    if text:
+        return import_start(request, text_form=TextImportForm(initial={"text": text}))
+    return redirect("recipes:import")