import math
from datetime import timedelta
from django.utils import timezone
from rest_framework import serializers
KINDS=['metric','flower-status','collector-status','worker-online','worker-offline','worker-heartbeat','task-sent','task-received','task-started','task-succeeded','task-failed','task-retried','task-revoked','task-rejected']
class MetricPayload(serializers.Serializer):
    cpu=serializers.FloatField(min_value=0,max_value=100)
    ram=serializers.FloatField(min_value=0,max_value=100)
    disk=serializers.FloatField(min_value=0,max_value=100)
    boot_id=serializers.CharField(max_length=100,required=False)
    services=serializers.DictField(child=serializers.BooleanField(),required=False)
    outbox=serializers.IntegerField(min_value=0,required=False)
class WorkerPayload(serializers.Serializer):
    hostname=serializers.CharField(max_length=255)
    active=serializers.IntegerField(min_value=0,required=False,default=0)
    processed=serializers.IntegerField(min_value=0,required=False,default=0)
class TaskPayload(serializers.Serializer):
    uuid=serializers.CharField(max_length=200)
    name=serializers.CharField(max_length=255,required=False,allow_blank=True)
    hostname=serializers.CharField(max_length=255,required=False,allow_blank=True)
    runtime=serializers.FloatField(min_value=0,required=False,allow_null=True)
    retries=serializers.IntegerField(min_value=0,required=False,default=0)
class StatusPayload(serializers.Serializer):
    online=serializers.BooleanField()
    checked_at=serializers.DateTimeField(required=False)
class Envelope(serializers.Serializer):
    id=serializers.UUIDField()
    kind=serializers.ChoiceField(choices=KINDS)
    occurred_at=serializers.DateTimeField()
    payload=serializers.DictField()
    def validate(self,data):
        if data['occurred_at']>timezone.now()+timedelta(minutes=5):
            raise serializers.ValidationError('Zeitstempel liegt zu weit in der Zukunft')
        cls=MetricPayload if data['kind']=='metric' else WorkerPayload if data['kind'].startswith('worker-') else TaskPayload if data['kind'].startswith('task-') else StatusPayload
        s=cls(data=data['payload']); s.is_valid(raise_exception=True)
        for field in ('cpu','ram','disk','runtime'):
            value=s.validated_data.get(field)
            if value is not None and not math.isfinite(value):
                raise serializers.ValidationError('Messwerte müssen endlich sein')
        services=s.validated_data.get('services',{})
        if len(services)>20 or any(len(k)>50 for k in services):
            raise serializers.ValidationError('Maximal 20 Dienste mit Namen bis 50 Zeichen')
        # Use normalized validated values, never the original loosely typed input.
        normalized=dict(s.data)
        if any(isinstance(v,float) and not math.isfinite(v) for v in normalized.values()):
            raise serializers.ValidationError('Messwerte müssen endlich sein')
        data['payload']={key:value for key,value in normalized.items() if key in data['payload']}
        return data
class Batch(serializers.Serializer):
    events=Envelope(many=True,allow_empty=False,max_length=500)
class ConfigurationSerializer(serializers.Serializer):
    retention_days=serializers.IntegerField(min_value=7,max_value=3650)
    heartbeat_timeout=serializers.IntegerField(min_value=30,max_value=3600)
    cpu_warning=serializers.IntegerField(min_value=1,max_value=100)
    ram_warning=serializers.IntegerField(min_value=1,max_value=100)
    disk_warning=serializers.IntegerField(min_value=1,max_value=100)