from rest_framework import serializers

from apps.accounts.serializers import PkAsIdMixin
from apps.farms.models import Cycle, Flock, Kandang, Site


class SiteSerializer(PkAsIdMixin, serializers.ModelSerializer):
    class Meta:
        model = Site
        fields = ["id", "site_name", "user", "created_at", "updated_at"]
        read_only_fields = ["id", "created_at", "updated_at"]


class FeedInButtonUrlSerializer(serializers.Serializer):
    label = serializers.CharField(max_length=50, required=False, allow_blank=True, default="")
    url = serializers.URLField(max_length=500)


class KandangSerializer(PkAsIdMixin, serializers.ModelSerializer):
    feed_in_button_urls = FeedInButtonUrlSerializer(many=True, required=False)

    class Meta:
        model = Kandang
        fields = [
            "id",
            "kandang_name",
            "feed_in_button_urls",
            "site",
            "created_at",
            "updated_at",
        ]
        read_only_fields = ["id", "created_at", "updated_at"]

    def validate_feed_in_button_urls(self, value):
        cleaned = []
        for item in value or []:
            url = str(item.get("url", "")).strip()
            if not url:
                continue
            label = str(item.get("label", "") or "").strip()[:50]
            cleaned.append({"label": label, "url": url})
        return cleaned

    def update(self, instance, validated_data):
        urls = validated_data.pop("feed_in_button_urls", None)
        instance = super().update(instance, validated_data)
        if urls is not None:
            instance.feed_in_button_urls = urls
            instance.save(update_fields=["feed_in_button_urls", "updated_at"])
        return instance

    def to_representation(self, instance):
        data = super().to_representation(instance)
        urls = data.get("feed_in_button_urls") or []
        if not isinstance(urls, list):
            urls = []
        data["feed_in_button_urls"] = [
            {"label": str(item.get("label", "") or ""), "url": str(item.get("url", "") or "")}
            for item in urls
            if isinstance(item, dict) and str(item.get("url", "") or "").strip()
        ]
        return data


class FlockSerializer(PkAsIdMixin, serializers.ModelSerializer):
    class Meta:
        model = Flock
        fields = ["id", "flock_name", "kandang", "created_at", "updated_at"]
        read_only_fields = ["id", "created_at", "updated_at"]


class CycleSerializer(PkAsIdMixin, serializers.ModelSerializer):
    kandang = serializers.PrimaryKeyRelatedField(queryset=Kandang.objects.all())
    kandang_name = serializers.CharField(source="kandang.kandang_name", read_only=True)
    chick_in_weight = serializers.IntegerField(source="doc_in_weight")
    current_day = serializers.IntegerField(read_only=True)
    visible_through_date = serializers.DateField(read_only=True)
    soft_end_date = serializers.SerializerMethodField()

    class Meta:
        model = Cycle
        fields = [
            "id",
            "kandang",
            "kandang_name",
            "total_days",
            "current_day",
            "visible_through_date",
            "soft_end_date",
            "start_date",
            "end_date",
            "chick_in_weight",
            "doc_in_count",
            "feed_initial_balance",
            "feed_initial_balance_date",
            "status",
            "proposed_end_date",
            "close_requested_at",
            "close_requested_by",
            "created_at",
            "updated_at",
        ]
        read_only_fields = [
            "id",
            "kandang_name",
            "feed_initial_balance",
            "feed_initial_balance_date",
            "end_date",
            "status",
            "proposed_end_date",
            "close_requested_at",
            "close_requested_by",
            "created_at",
            "updated_at",
            "soft_end_date",
        ]

    def get_soft_end_date(self, obj: Cycle):
        return obj.soft_end_date()

    def validate(self, attrs):
        attrs.pop("status", None)
        # Defense in depth: end_date is read-only (GM approve only).
        attrs.pop("end_date", None)
        if self.instance is None:
            attrs.setdefault("total_days", 1)
        start = attrs.get("start_date", getattr(self.instance, "start_date", None))
        end = getattr(self.instance, "end_date", None) if self.instance else None
        if start and end and end < start:
            raise serializers.ValidationError({"end_date": "Must be on or after start_date."})
        return attrs

    def to_representation(self, instance):
        return super().to_representation(instance)