from __future__ import annotations

import re

from django import forms

from .models import SearchProfile
from .taxonomy import (
    EXCLUDED_SKILL_CHOICES,
    EXCLUDED_TITLE_CHOICES,
    SKILL_CHOICES,
    TITLE_CHOICES,
    iter_choices,
)

EMPLOYMENT_CHOICES = (
    ("full_time", "Voltijds"),
    ("part_time", "Deeltijds"),
    ("permanent", "Vast contract"),
    ("fixed_term", "Tijdelijk contract"),
    ("freelance", "Freelance"),
    ("internship", "Stage"),
)

WORKPLACE_CHOICES = (
    ("hybrid", "Hybride"),
    ("remote", "Volledig op afstand"),
    ("on_site", "Op locatie"),
)

REGION_CHOICES = (
    ("Antwerpen", "Antwerpen"),
    ("Brussels Hoofdstedelijk Gewest", "Brussel"),
    ("Henegouwen", "Henegouwen"),
    ("Limburg", "Limburg"),
    ("Luik", "Luik"),
    ("Luxemburg", "Luxemburg"),
    ("Namen", "Namen"),
    ("Oost-Vlaanderen", "Oost-Vlaanderen"),
    ("Vlaams-Brabant", "Vlaams-Brabant"),
    ("Waals-Brabant", "Waals-Brabant"),
    ("West-Vlaanderen", "West-Vlaanderen"),
)


class SearchProfileForm(forms.ModelForm):
    desired_titles = forms.MultipleChoiceField(
        label="Gewenste functietitels",
        required=False,
        choices=TITLE_CHOICES,
        widget=forms.CheckboxSelectMultiple(attrs={"class": "grouped-choices"}),
        help_text="Selecteer alle rollen die bij je zoekrichting passen; de beste titelmatch telt.",
    )
    excluded_titles = forms.MultipleChoiceField(
        label="Uitgesloten functietitels",
        required=False,
        choices=EXCLUDED_TITLE_CHOICES,
        widget=forms.CheckboxSelectMultiple(attrs={"class": "grouped-choices"}),
        help_text="Vacatures met deze titelwoorden worden hard uitgesloten.",
    )
    desired_skills = forms.MultipleChoiceField(
        label="Gewenste skills",
        required=False,
        choices=SKILL_CHOICES,
        widget=forms.CheckboxSelectMultiple(attrs={"class": "grouped-choices"}),
        help_text=(
            "Kies je herkenbare cv-skills ruim. Maximaal vier aangetroffen skills volstaan voor "
            "de volledige skillcomponent; extra keuzes verwateren je score niet."
        ),
    )
    excluded_skills = forms.MultipleChoiceField(
        label="Uitgesloten kenmerken",
        required=False,
        choices=EXCLUDED_SKILL_CHOICES,
        widget=forms.CheckboxSelectMultiple(attrs={"class": "grouped-choices"}),
    )
    allowed_employment_types = forms.MultipleChoiceField(
        label="Toegestane contractvormen",
        required=False,
        choices=EMPLOYMENT_CHOICES,
        widget=forms.CheckboxSelectMultiple,
    )
    preferred_workplace = forms.MultipleChoiceField(
        label="Voorkeurswerkmodel",
        required=False,
        choices=WORKPLACE_CHOICES,
        widget=forms.CheckboxSelectMultiple,
    )
    preferred_regions = forms.MultipleChoiceField(
        label="Voorkeursregio's",
        required=False,
        choices=REGION_CHOICES,
        widget=forms.CheckboxSelectMultiple,
    )
    excluded_regions = forms.MultipleChoiceField(
        label="Uitgesloten regio's",
        required=False,
        choices=REGION_CHOICES,
        widget=forms.CheckboxSelectMultiple,
    )

    class Meta:
        model = SearchProfile
        fields = [
            "name",
            "is_active",
            "home_postal_code",
            "max_distance_km",
            "experience_years",
            "desired_titles",
            "excluded_titles",
            "desired_skills",
            "excluded_skills",
            "allowed_employment_types",
            "preferred_workplace",
            "preferred_regions",
            "excluded_regions",
            "recommendation_threshold",
            "top_match_threshold",
            "digest_time",
            "learning_enabled",
        ]
        labels = {
            "name": "Naam",
            "is_active": "Actief profiel",
            "home_postal_code": "Thuispostcode",
            "max_distance_km": "Maximale afstand (km)",
            "experience_years": "Relevante IT-ervaring",
            "recommendation_threshold": "Aanbevelingsdrempel",
            "top_match_threshold": "Topmatchdrempel",
            "digest_time": "Tijdstip dagelijkse samenvatting",
            "learning_enabled": "Gecontroleerd leren",
        }
        help_texts = {
            "home_postal_code": (
                "Vier cijfers volstaan. Gemeente en coördinaten worden veilig afgeleid wanneer "
                "lokale geodata beschikbaar is."
            ),
            "experience_years": (
                "Optionele profielcontext. Deze waarde telt nooit mee voor je matchscore en "
                "kan een vacature niet uitsluiten."
            ),
            "learning_enabled": "Past alleen zachte voorkeuren aan; harde regels blijven vast.",
        }
        widgets = {
            "home_postal_code": forms.TextInput(
                attrs={"inputmode": "numeric", "pattern": "[0-9]{4}", "maxlength": 4}
            ),
            "digest_time": forms.TimeInput(attrs={"type": "time"}),
        }

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.fields["home_postal_code"].widget.attrs["maxlength"] = 4
        if not self.instance or not self.instance.pk:
            return
        for field_name in (
            "desired_titles",
            "excluded_titles",
            "desired_skills",
            "excluded_skills",
            "allowed_employment_types",
            "preferred_workplace",
            "preferred_regions",
            "excluded_regions",
        ):
            self._include_existing_choices(field_name)

    def _include_existing_choices(self, field_name: str) -> None:
        field = self.fields[field_name]
        stored = getattr(self.instance, field_name, [])
        existing_by_casefold = {
            str(value).casefold(): str(value) for value, _label in iter_choices(field.choices)
        }
        extra = [
            (str(value), str(value))
            for value in stored
            if str(value).casefold() not in existing_by_casefold
        ]
        if extra:
            field.choices = [*field.choices, ("Eerder opgeslagen", tuple(extra))]
        field.initial = [
            existing_by_casefold.get(str(value).casefold(), str(value)) for value in stored
        ]

    def clean_home_postal_code(self) -> str:
        value = str(self.cleaned_data.get("home_postal_code") or "").strip()
        if value and not re.fullmatch(r"\d{4}", value):
            raise forms.ValidationError("Gebruik een Belgische postcode van vier cijfers.")
        return value

    def clean(self):
        cleaned = super().clean()
        overlap_checks = (
            ("desired_titles", "excluded_titles", "functietitels"),
            ("desired_skills", "excluded_skills", "skills"),
            ("preferred_regions", "excluded_regions", "regio's"),
        )
        for desired_field, excluded_field, label in overlap_checks:
            overlap = set(cleaned.get(desired_field) or []) & set(cleaned.get(excluded_field) or [])
            if overlap:
                self.add_error(
                    excluded_field,
                    f"Dezelfde {label} kunnen niet tegelijk gewenst en uitgesloten zijn.",
                )
        return cleaned