"""Procurement item and attachment serializers."""

from drf_spectacular.utils import extend_schema_field
from rest_framework import serializers

from communications import comments_helpers
from procurement.models import ProcurementItem, ProcurementItemAttachment

from .common import _validate_expected_delivery_dates


class ProcurementItemAttachmentSerializer(serializers.ModelSerializer):
    uploaded_by_name = serializers.CharField(
        source="uploaded_by.get_full_name",
        read_only=True,
    )
    download_url = serializers.SerializerMethodField()
    thumbnail_url = serializers.SerializerMethodField()

    class Meta:
        model = ProcurementItemAttachment
        fields = [
            "id",
            "file_name",
            "file_size",
            "mime_type",
            "uploaded_by",
            "uploaded_by_name",
            "created_at",
            "download_url",
            "thumbnail_url",
        ]
        read_only_fields = fields

    def get_download_url(self, obj) -> str:
        return f"/api/v1/procurement/items/{obj.item_id}/attachments/{obj.id}/"

    def get_thumbnail_url(self, obj) -> str | None:
        from procurement.media import procurement_attachment_media_kind

        if not procurement_attachment_media_kind(obj):
            return None
        return (
            f"/api/v1/procurement/items/{obj.item_id}/attachments/{obj.id}/thumbnail/"
        )


class ProcurementItemSerializer(serializers.ModelSerializer):
    """Сериализатор для позиций заявки."""

    estimated_unit_price = serializers.DecimalField(
        max_digits=12,
        decimal_places=2,
        required=False,
        allow_null=True,
    )
    ordered_quantity = serializers.IntegerField(
        required=False,
        allow_null=True,
        min_value=0,
    )
    received_quantity = serializers.IntegerField(
        required=False,
        allow_null=True,
        min_value=0,
    )
    expected_delivery_dates = serializers.ListField(
        child=serializers.CharField(allow_blank=False, trim_whitespace=True),
        required=False,
        allow_empty=True,
    )
    initial_comment = serializers.CharField(
        write_only=True,
        required=False,
        allow_blank=True,
    )
    total_price = serializers.DecimalField(
        max_digits=12, decimal_places=2, read_only=True
    )
    execution_status_display = serializers.SerializerMethodField()
    comments_count = serializers.SerializerMethodField()
    attachments = ProcurementItemAttachmentSerializer(many=True, read_only=True)
    attachments_count = serializers.IntegerField(
        source="attachments.count",
        read_only=True,
    )

    @extend_schema_field(serializers.IntegerField())
    def get_comments_count(self, obj):
        annotated_count = getattr(obj, "comments_count", None)
        if annotated_count is not None:
            return annotated_count

        from communications.comments_helpers import get_comment_count

        return get_comment_count(obj)

    @extend_schema_field(serializers.CharField())
    def get_execution_status_display(self, obj):
        return obj.execution_status_display

    class Meta:
        model = ProcurementItem
        fields = [
            "id",
            "request",
            "name",
            "description",
            "quantity",
            "unit",
            "estimated_unit_price",
            "total_price",
            "ordered_quantity",
            "received_quantity",
            "supplier_info",
            "links",
            "expected_delivery_dates",
            "actual_unit_price",
            "execution_status",
            "execution_status_display",
            "defective_at",
            "executor_comment",
            "initial_comment",
            "comments_count",
            "attachments",
            "attachments_count",
            "equipment",
            "created_at",
        ]
        read_only_fields = [
            "id",
            "created_at",
            "total_price",
            "execution_status_display",
            "defective_at",
            "comments_count",
            "attachments",
            "attachments_count",
        ]

    def validate_expected_delivery_dates(self, value):
        return _validate_expected_delivery_dates(value)

    def create(self, validated_data):
        initial_comment = validated_data.pop("initial_comment", "").strip()
        item = super().create(validated_data)
        request = self.context.get("request")
        author = getattr(request, "user", None)
        if initial_comment and author and author.is_authenticated:
            comments_helpers.create_comment(
                obj=item,
                author=author,
                content=initial_comment,
            )
        return item


class ProcurementItemCreateSerializer(serializers.ModelSerializer):
    """Сериализатор для создания позиций (без request)."""

    estimated_unit_price = serializers.DecimalField(
        max_digits=12,
        decimal_places=2,
        required=False,
        allow_null=True,
    )
    ordered_quantity = serializers.IntegerField(
        required=False,
        allow_null=True,
        min_value=0,
    )
    received_quantity = serializers.IntegerField(
        required=False,
        allow_null=True,
        min_value=0,
    )
    expected_delivery_dates = serializers.ListField(
        child=serializers.CharField(allow_blank=False, trim_whitespace=True),
        required=False,
        allow_empty=True,
    )
    initial_comment = serializers.CharField(
        write_only=True,
        required=False,
        allow_blank=True,
    )

    class Meta:
        model = ProcurementItem
        fields = [
            "id",
            "name",
            "description",
            "quantity",
            "unit",
            "estimated_unit_price",
            "ordered_quantity",
            "received_quantity",
            "supplier_info",
            "links",
            "expected_delivery_dates",
            "actual_unit_price",
            "execution_status",
            "executor_comment",
            "initial_comment",
        ]
        read_only_fields = ["id"]

    def validate_expected_delivery_dates(self, value):
        return _validate_expected_delivery_dates(value)


class ProcurementItemEditSerializer(ProcurementItemCreateSerializer):
    """Сериализатор для редактирования позиций внутри заявки."""

    id = serializers.IntegerField(required=False)

    class Meta:
        model = ProcurementItem
        fields = [
            "id",
            "name",
            "description",
            "quantity",
            "unit",
            "estimated_unit_price",
            "supplier_info",
            "links",
            "initial_comment",
        ]