Source code for purchase.serializers

from datetime import timedelta
from rest_framework import serializers
from .models import PurchaseRequisition, SupplierBid, PurchaseOrder




class PurchaseRequisitionSerializer(serializers.ModelSerializer):


    class Meta:
        model = PurchaseRequisition
        read_only_fields = ["status"]
        exclude = ["inventory"]






class PurchaseRequisitionVendorSerializer(serializers.ModelSerializer):
    procurement_officer = serializers.StringRelatedField(
        source="inventory.procurement_officer"
    )
    item_name = serializers.StringRelatedField(source="inventory.item_name")



    class Meta:
        model = PurchaseRequisition
        exclude = ["status", "inventory"]






class SupplierBidSerializer(serializers.ModelSerializer):
    requisition_number = serializers.ReadOnlyField(
        source="requisition.requisition_number"
    )



    class Meta:
        model = SupplierBid
        read_only_fields = ["status", "requisition_number"]
        exclude = ["supplier", "requisition"]






class SupplierBidProcurementOfficerSerializer(serializers.ModelSerializer):
    supplier_company_name = serializers.ReadOnlyField(
        source="supplier.vendor.user.company_name"
    )
    supplier_rating = serializers.ReadOnlyField(source="supplier.vendor.vendor_rating")
    total_ratings = serializers.ReadOnlyField(source="supplier.vendor.total_ratings")
    weight_unit_price = serializers.FloatField(
        write_only=True, required=True, min_value=0.0, max_value=1.0
    )
    weight_total_cost = serializers.FloatField(
        write_only=True, required=True, min_value=0.0, max_value=1.0
    )
    weight_days_delivery = serializers.FloatField(
        write_only=True, required=True, min_value=0.0, max_value=1.0
    )
    weight_supplier_rating = serializers.FloatField(
        write_only=True, required=True, min_value=0.0, max_value=1.0
    )
    weight_total_ratings = serializers.FloatField(
        write_only=True, required=True, min_value=0.0, max_value=1.0
    )



    class Meta:
        model = SupplierBid
        read_only_fields = [
            "quantity_fulfilled",
            "unit_price",
            "date_submitted",
            "days_delivery",
            "attachments",
            "comments",
            "status",
            "supplier_company_name",
            "supplier_rating",
            "total_ratings",
        ]
        exclude = ["requisition", "supplier"]




    def validate(self, attrs):
        weights = [
            attrs.get("weight_unit_price", 0.0),
            attrs.get("weight_total_cost", 0.0),
            attrs.get("weight_days_delivery", 0.0),
            attrs.get("weight_supplier_rating", 0.0),
            attrs.get("weight_total_ratings", 0.0),
        ]

        total_weight = sum(weights)

        if total_weight != 1.0:
            raise serializers.ValidationError(
                {
                    "weight_unit_price": "The sum of weights must be equal to 1.0",
                    "weight_total_cost": "The sum of weights must be equal to 1.0",
                    "weight_days_delivery": "The sum of weights must be equal to 1.0",
                    "weight_supplier_rating": "The sum of weights must be equal to 1.0",
                    "weight_total_ratings": "The sum of weights must be equal to 1.0",
                }
            )

        return attrs






class SupplierBidProcurementOfficerStatusSerializer(serializers.ModelSerializer):


    class Meta:
        model = SupplierBid
        fields = ["status"]






class PurchaseOrderSerializer(serializers.ModelSerializer):
    delivery_location = serializers.ReadOnlyField(
        source="bid.requisition.inventory.location"
    )
    quantity_ordered = serializers.SerializerMethodField()
    unit_price = serializers.SerializerMethodField()
    expected_delivery_date = serializers.SerializerMethodField()



    class Meta:
        model = PurchaseOrder
        fields = "__all__"




    def get_quantity_ordered(self, instance) -> int:
        return instance.bid.quantity_fulfilled




    def get_unit_price(self, instance) -> float:
        return instance.bid.unit_price




    def get_expected_delivery_date(self, instance) -> str:
        return instance.date_ordered + timedelta(days=instance.bid.days_delivery)






class PurchaseOrderStatusSerializer(serializers.ModelSerializer):


    class Meta:
        model = PurchaseOrder
        fields = ["status"]