from rest_framework import serializers
from .models import Project, Task
from accounts.serializers import UserSerializer

class TaskSerializer(serializers.ModelSerializer):
    class Meta:
        model = Task
        fields = ['id', 'project', 'title', 'description', 'assigned_to', 
                  'status', 'priority', 'due_date', 'created_at', 'updated_at']
        read_only_fields = ['id', 'project', 'created_at', 'updated_at']

from django.contrib.auth import get_user_model

User = get_user_model()

class TaskDetailSerializer(TaskSerializer):
    assigned_to = UserSerializer(read_only=True)
    assigned_to_id = serializers.PrimaryKeyRelatedField(
        source='assigned_to', 
        queryset=User.objects.all(),
        required=False, allow_null=True
    )

    class Meta(TaskSerializer.Meta):
        fields = TaskSerializer.Meta.fields + ['assigned_to_id']

class ProjectSerializer(serializers.ModelSerializer):
    task_count = serializers.SerializerMethodField()

    class Meta:
        model = Project
        fields = ['id', 'name', 'description', 'status', 'created_by', 'created_at', 'updated_at', 'task_count']
        read_only_fields = ['id', 'created_by', 'created_at', 'updated_at', 'task_count']

    def get_task_count(self, obj):
        return obj.tasks.count()

class ProjectDetailSerializer(ProjectSerializer):
    tasks = TaskSerializer(many=True, read_only=True)
    created_by = UserSerializer(read_only=True)

    class Meta(ProjectSerializer.Meta):
        fields = ProjectSerializer.Meta.fields + ['tasks']