package pubsub

import (
	"context"
	"encoding/json"
	"errors"
	"oc-discovery/daemons"
	"oc-discovery/daemons/dht"
	"oc-discovery/models"

	"cloud.o-forge.io/core/oc-lib/models/peer"
	"cloud.o-forge.io/core/oc-lib/models/resources"
	"cloud.o-forge.io/core/oc-lib/tools"
)

func (ps *PubSubService) handleEvent(ctx context.Context, topicName string, evt models.Event) error {
	action := ps.getTopicName(topicName)
	if err := ps.handleEventFromPartner(evt, action); err != nil {
		return err
	}
	if err := ps.handleEventSearch(ctx, evt, action); err != nil {
		return err
	}
	return nil
}

func (ps *PubSubService) handleEventFromPartner(evt models.Event, action tools.PubSubAction) error {
	if !(action == tools.PB_CREATE || action == tools.PB_UPDATE || action == tools.PB_DELETE) {
		return nil
	}
	resource, err := resources.ToResource(int(evt.DataType), evt.Payload)
	if err != nil {
		return err
	}
	b, err := json.Marshal(resource)
	if err != nil {
		return err
	}
	switch action {
	case tools.PB_CREATE:
	case tools.PB_UPDATE:
		tools.NewNATSCaller().SetNATSPub(tools.CREATE_RESOURCE, tools.NATSResponse{
			FromApp:  "oc-discovery",
			Datatype: tools.DataType(evt.DataType),
			Method:   int(tools.CREATE_RESOURCE),
			Payload:  b,
		})
	case tools.PB_DELETE:
		tools.NewNATSCaller().SetNATSPub(tools.REMOVE_RESOURCE, tools.NATSResponse{
			FromApp:  "oc-discovery",
			Datatype: tools.DataType(evt.DataType),
			Method:   int(tools.REMOVE_RESOURCE),
			Payload:  b,
		})
	default:
		return errors.New("no action authorized available : " + action.String())
	}
	return nil
}

func (ps *PubSubService) handleEventSearch( // only : on partner followings. 3 canals for every partner.
	ctx context.Context,
	evt models.Event,
	action tools.PubSubAction,
) error {
	if !(action == tools.PB_SEARCH_RESPONSE || action == tools.PB_SEARCH) {
		return nil
	}
	if p, err := dht.GetDHTService().GetPeer(ctx, evt.From); err == nil {
		if err := daemons.VerifyPeer([]*peer.Peer{p}, evt); err != nil {
			return err
		}
		switch action {
		case tools.PB_SEARCH_RESPONSE:
			if err := ps.retrieveResponse(ctx, p, evt); err != nil {
				return err
			}
		case tools.PB_SEARCH: // when someone ask for search.
			if p, err := dht.GetDHTService().GetPeer(ctx, evt.From); err == nil {
				if err := ps.sendResponse(ctx, p, evt); err != nil {
					return err
				}
			}
		default:
			return nil
		}
	}
	return nil
}