from decimal import Decimal

from rest_framework import serializers
from core.serializers.base import BaseModelSerializer
from apps.projects.models import Project
from apps.workspaces.models import PriceUnit


def validate_thumbnail(value):
    if value is None:
        return value
    max_bytes = 2 * 1024 * 1024
    if getattr(value, "size", 0) > max_bytes:
        raise serializers.ValidationError("Image size must be 2MB or less.")
    content_type = (getattr(value, "content_type", "") or "").lower()
    allowed_types = {"image/jpeg", "image/png", "image/webp"}
    if content_type and content_type not in allowed_types:
        raise serializers.ValidationError("Unsupported image type. Use JPG, PNG, or WebP.")
    return value


class ProjectSerializer(BaseModelSerializer):
    class Meta:
        model = Project
        fields = BaseModelSerializer.Meta.fields + (
            "workspace",
            "name",
            "client",
            "description",
            "thumbnail",
            "is_archived",
            "color",
        )
        read_only_fields = fields

    def to_representation(self, instance):
        representation = super().to_representation(instance)
        request = self.context.get("request")
        if instance.thumbnail:
            thumbnail_url = instance.thumbnail.url
            representation["thumbnail"] = request.build_absolute_uri(thumbnail_url) if request else thumbnail_url
        else:
            representation["thumbnail"] = None
        if instance.client:
            representation['client'] = {
                'id': instance.client.id,
                'name': instance.client.name,
                'thumbnail': (
                    request.build_absolute_uri(instance.client.thumbnail.url)
                    if request and instance.client.thumbnail
                    else instance.client.thumbnail.url
                    if instance.client.thumbnail
                    else None
                ),
            }
        return representation


class ProjectCreateSerializer(serializers.Serializer):
    workspace = serializers.UUIDField()
    name = serializers.CharField(max_length=255)
    client = serializers.UUIDField(required=False, allow_null=True)
    description = serializers.CharField(required=False, allow_blank=True, default="")
    thumbnail = serializers.ImageField(required=False, allow_null=True)
    color = serializers.CharField(max_length=7, required=False, allow_blank=True, default="")

    def validate_thumbnail(self, value):
        return validate_thumbnail(value)


class ProjectUpdateSerializer(serializers.Serializer):
    name = serializers.CharField(max_length=255, required=False)
    client = serializers.UUIDField(required=False, allow_null=True)
    description = serializers.CharField(required=False, allow_blank=True)
    thumbnail = serializers.ImageField(required=False, allow_null=True)
    clear_thumbnail = serializers.BooleanField(required=False, default=False)
    color = serializers.CharField(max_length=7, required=False, allow_blank=True)
    is_archived = serializers.BooleanField(required=False)

    def validate_thumbnail(self, value):
        return validate_thumbnail(value)


class ProjectAccessQuerySerializer(serializers.Serializer):
    workspace = serializers.UUIDField()
    user = serializers.UUIDField()


class ProjectAccessMutationSerializer(serializers.Serializer):
    workspace = serializers.UUIDField()
    user = serializers.UUIDField()
    project_ids = serializers.ListField(
        child=serializers.UUIDField(),
        allow_empty=False,
    )


class ProjectAccessRateMutationSerializer(serializers.Serializer):
    workspace = serializers.UUIDField()
    user = serializers.UUIDField()
    project = serializers.UUIDField()
    hourly_rate = serializers.DecimalField(
        max_digits=10,
        decimal_places=2,
        min_value=Decimal("0.01"),
        required=False,
        allow_null=True,
    )
    currency = serializers.CharField(max_length=3, required=False, default="USD")

    def validate_currency(self, value):
        code = value.upper()
        if not PriceUnit.objects.filter(code=code, is_deleted=False).exists():
            raise serializers.ValidationError("Selected price unit is invalid.")
        return code