from rest_framework.serializers import ModelSerializer, SerializerMethodField, CharField

from .models import State, Ticket, Workflow, Transition, CustomField


class WorkflowSerializer(ModelSerializer):
    class Meta:
        model = Workflow
        fields = '__all__'

class StateSerializer(ModelSerializer):
    class Meta:
        model = State
        fields = '__all__'

class WorkflowSimpleSerializer(ModelSerializer):
    class Meta:
        model = Workflow
        fields = ['id', 'name']

class StateSimpleSerializer(ModelSerializer):
    class Meta:
        model = State
        fields = ['id', 'name']

class TransitionSerializer(ModelSerializer):
    source_state_ = StateSimpleSerializer(source='source_state', read_only=True)
    destination_state_ = StateSimpleSerializer(source='destination_state', read_only=True)
    class Meta:
        model = Transition
        fields = '__all__'
    @staticmethod
    def setup_eager_loading(queryset):
        """ Perform necessary eager loading of data. """
        queryset = queryset.select_related('source_state','destination_state')
        return queryset


class CustomFieldSerializer(ModelSerializer):
    class Meta:
        model = CustomField
        fields = '__all__'


class TicketCreateSerializer(ModelSerializer):
    class Meta:
        model=Ticket
        fields=['title','workflow','ticket_data']
        
class TicketSerializer(ModelSerializer):
    workflow_ = WorkflowSimpleSerializer(source='workflow', read_only=True)
    state_ = StateSimpleSerializer(source='state', read_only=True)

    class Meta:
        model = Ticket
        fields = '__all__'
    
    @staticmethod
    def setup_eager_loading(queryset):
        queryset = queryset.select_related('workflow','state')
        return queryset