from django import forms
from django.conf import settings
from django.db import transaction

from . import images, parsing
from .models import Comment, Recipe


class MultipleFileInput(forms.ClearableFileInput):
    allow_multiple_selected = True


class MultipleImageField(forms.FileField):
    widget = MultipleFileInput

    def clean(self, data, initial=None):
        files = data if isinstance(data, (list, tuple)) else ([data] if data else [])
        if len(files) > settings.IMAGE_MAX_PER_RECIPE:
            raise forms.ValidationError(f"Höchstens {settings.IMAGE_MAX_PER_RECIPE} Bilder auf einmal.")
        cleaned = []
        for f in files:
            f = super().clean(f, initial)
            try:
                images.validate(f)
            except images.ImageError as error:
                raise forms.ValidationError(f"{f.name}: {error}") from None
            cleaned.append(f)
        return cleaned


def photo_field(label="Fotos"):
    return MultipleImageField(
        label=label,
        required=False,
        widget=MultipleFileInput(attrs={"accept": "image/*"}),
        help_text=f"JPEG, PNG, WebP oder HEIC, max. {settings.IMAGE_MAX_UPLOAD_MB} MB pro Bild. "
        "Am Handy kannst du direkt die Kamera wählen.",
    )


class RecipeForm(forms.ModelForm):
    ingredients_text = forms.CharField(
        label="Zutaten",
        required=False,
        widget=forms.Textarea(attrs={"rows": 10, "placeholder": "200 g Mehl\n2 Eier\n1 Prise Salz\n\nFür die Soße:\n1 Dose Tomaten"}),
        help_text="Eine Zutat pro Zeile. Gruppen mit Doppelpunkt am Ende, z. B. „Für die Soße:“.",
    )
    steps_text = forms.CharField(
        label="Zubereitung",
        required=False,
        widget=forms.Textarea(attrs={"rows": 10, "placeholder": "Ofen auf 180 °C vorheizen.\n\nMehl und Eier verrühren."}),
        help_text="Schritte durch eine Leerzeile trennen (ohne Leerzeilen ist jede Zeile ein Schritt).",
    )
    tags_text = forms.CharField(
        label="Tags",
        required=False,
        widget=forms.TextInput(attrs={"placeholder": "pasta, vegetarisch, schnell", "autocapitalize": "none"}),
        help_text="Kommagetrennt, werden kleingeschrieben gespeichert.",
    )
    source_url = forms.URLField(label="Quelle (URL)", required=False, max_length=1000, assume_scheme="https")
    photos = photo_field()

    class Meta:
        model = Recipe
        fields = ["title", "description", "servings", "servings_label", "prep_minutes", "cook_minutes",
                  "visibility", "source_url", "author_notes"]
        widgets = {
            "description": forms.Textarea(attrs={"rows": 3}),
            "author_notes": forms.Textarea(attrs={"rows": 3, "placeholder": "Tipps, Abwandlungen, was beim nächsten Mal anders …"}),
            "servings": forms.NumberInput(attrs={"min": 1, "max": 100, "inputmode": "numeric"}),
            "prep_minutes": forms.NumberInput(attrs={"min": 0, "inputmode": "numeric"}),
            "cook_minutes": forms.NumberInput(attrs={"min": 0, "inputmode": "numeric"}),
            "visibility": forms.RadioSelect,
        }

    field_order = ["title", "description", "servings", "servings_label", "prep_minutes", "cook_minutes",
                   "ingredients_text", "steps_text", "tags_text", "photos", "author_notes", "source_url", "visibility"]

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields["servings"].min_value = 1
        recipe = self.instance
        if recipe.pk and not self.is_bound:
            # setdefault: an AI draft passed as initial wins over the stored values
            self.initial.setdefault("ingredients_text", parsing.ingredients_to_text(recipe.ingredients.all()))
            self.initial.setdefault("steps_text", parsing.steps_to_text([s.text for s in recipe.steps.all()]))
            self.initial.setdefault("tags_text", ", ".join(t.name for t in recipe.tags.all()))
        if recipe.pk:
            remaining = settings.IMAGE_MAX_PER_RECIPE - recipe.images.count()
            self.fields["photos"].label = "Weitere Fotos"
            if remaining <= 0:
                del self.fields["photos"]

    def clean_servings(self):
        servings = self.cleaned_data["servings"]
        if not servings or servings < 1 or servings > 100:
            raise forms.ValidationError("Bitte eine Zahl zwischen 1 und 100 angeben.")
        return servings

    def clean(self):
        cleaned = super().clean()
        cleaned["ingredients"] = parsing.parse_ingredients(cleaned.get("ingredients_text", ""))
        cleaned["steps"] = parsing.parse_steps(cleaned.get("steps_text", ""))
        cleaned["tags"] = parsing.parse_tags(cleaned.get("tags_text", ""))
        photos = cleaned.get("photos") or []
        if self.instance.pk and photos:
            if self.instance.images.count() + len(photos) > settings.IMAGE_MAX_PER_RECIPE:
                self.add_error("photos", f"Ein Rezept kann höchstens {settings.IMAGE_MAX_PER_RECIPE} Bilder haben.")
        return cleaned

    @transaction.atomic
    def save(self, owner=None):
        recipe = super().save(commit=False)
        if owner is not None and not recipe.pk:
            recipe.owner = owner
        recipe.save()
        recipe.set_ingredients(self.cleaned_data["ingredients"])
        recipe.set_steps(self.cleaned_data["steps"])
        recipe.set_tags(self.cleaned_data["tags"])
        return recipe


class PhotoUploadForm(forms.Form):
    photos = photo_field("Fotos hinzufügen")


class SearchForm(forms.Form):
    q = forms.CharField(label="Suche", required=False, widget=forms.SearchInput(attrs={"placeholder": "Titel, Zutat, Tag …"}))
    zutat = forms.CharField(label="Mit Zutaten", required=False, widget=forms.TextInput(attrs={"placeholder": "z. B. zucchini, feta"}))
    tag = forms.CharField(required=False, widget=forms.HiddenInput)
    ansicht = forms.ChoiceField(
        label="Anzeigen",
        required=False,
        choices=[("", "Alle Rezepte"), ("meine", "Meine Rezepte"), ("favoriten", "Favoriten")],
    )

    def ingredient_terms(self):
        return [t.strip() for t in self.cleaned_data.get("zutat", "").split(",") if t.strip()]


class CommentForm(forms.ModelForm):
    class Meta:
        model = Comment
        fields = ["text"]
        widgets = {"text": forms.Textarea(attrs={"rows": 3, "placeholder": "Hast du es nachgekocht? Tipps?", "maxlength": 2000})}
        labels = {"text": "Kommentar schreiben"}