package mq

import (
	"encoding/json"
	"errors"
	"fmt"
	"sync"
	"time"

	"github.com/google/uuid"
	"github.com/gravitl/netmaker/logger"
	"github.com/gravitl/netmaker/logic"
	"github.com/gravitl/netmaker/models"
	"github.com/gravitl/netmaker/servercfg"
	"golang.org/x/exp/slog"
)

// PublishPeerUpdate --- determines and publishes a peer update to all the hosts
func PublishPeerUpdate(replacePeers bool) error {
	if !servercfg.IsMessageQueueBackend() {
		return nil
	}

	if logic.GetManageDNS() {
		sendDNSSync()
	}

	hosts, err := logic.GetAllHosts()
	if err != nil {
		logger.Log(1, "err getting all hosts", err.Error())
		return err
	}
	allNodes, err := logic.GetAllNodes()
	if err != nil {
		return err
	}

	for _, host := range hosts {
		host := host
		time.Sleep(5 * time.Millisecond)
		go func(host models.Host) {
			if err = PublishSingleHostPeerUpdate(&host, allNodes, nil, nil, replacePeers, nil); err != nil {
				id := host.Name
				if host.ID != uuid.Nil {
					id = host.ID.String()
				}
				slog.Error("failed to publish peer update to host", id, ": ", err)
			}
		}(host)
	}

	return nil
}

// PublishDeletedNodePeerUpdate --- determines and publishes a peer update
// to all the hosts with a deleted node to account for
func PublishDeletedNodePeerUpdate(delNode *models.Node) error {
	if !servercfg.IsMessageQueueBackend() {
		return nil
	}

	hosts, err := logic.GetAllHosts()
	if err != nil {
		logger.Log(1, "err getting all hosts", err.Error())
		return err
	}
	allNodes, err := logic.GetAllNodes()
	if err != nil {
		return err
	}
	for _, host := range hosts {
		host := host
		if err = PublishSingleHostPeerUpdate(&host, allNodes, delNode, nil, false, nil); err != nil {
			logger.Log(1, "failed to publish peer update to host", host.ID.String(), ": ", err.Error())
		}
	}
	return err
}

// PublishDeletedClientPeerUpdate --- determines and publishes a peer update
// to all the hosts with a deleted ext client to account for
func PublishDeletedClientPeerUpdate(delClient *models.ExtClient) error {
	if !servercfg.IsMessageQueueBackend() {
		return nil
	}

	hosts, err := logic.GetAllHosts()
	if err != nil {
		logger.Log(1, "err getting all hosts", err.Error())
		return err
	}
	nodes, err := logic.GetAllNodes()
	if err != nil {
		return err
	}
	for _, host := range hosts {
		host := host
		if host.OS != models.OS_Types.IoT {
			if err = PublishSingleHostPeerUpdate(&host, nodes, nil, []models.ExtClient{*delClient}, false, nil); err != nil {
				logger.Log(1, "failed to publish peer update to host", host.ID.String(), ": ", err.Error())
			}
		}
	}
	return err
}

// PublishSingleHostPeerUpdate --- determines and publishes a peer update to one host
func PublishSingleHostPeerUpdate(host *models.Host, allNodes []models.Node, deletedNode *models.Node, deletedClients []models.ExtClient, replacePeers bool, wg *sync.WaitGroup) error {
	if wg != nil {
		defer wg.Done()
	}
	peerUpdate, err := logic.GetPeerUpdateForHost("", host, allNodes, deletedNode, deletedClients)
	if err != nil {
		return err
	}
	peerUpdate.OldPeerUpdateFields = models.OldPeerUpdateFields{
		NodePeers:         peerUpdate.NodePeers,
		OldPeers:          peerUpdate.Peers,
		EndpointDetection: peerUpdate.ServerConfig.EndpointDetection,
	}
	peerUpdate.ReplacePeers = replacePeers
	data, err := json.Marshal(&peerUpdate)
	if err != nil {
		return err
	}
	return publish(host, fmt.Sprintf("peers/host/%s/%s", host.ID.String(), servercfg.GetServer()), data)
}

// NodeUpdate -- publishes a node update
func NodeUpdate(node *models.Node) error {
	host, err := logic.GetHost(node.HostID.String())
	if err != nil {
		return nil
	}
	if !servercfg.IsMessageQueueBackend() {
		return nil
	}
	logger.Log(3, "publishing node update to "+node.ID.String())

	//if len(node.NetworkSettings.AccessKeys) > 0 {
	//node.NetworkSettings.AccessKeys = []models.AccessKey{} // not to be sent (don't need to spread access keys around the network; we need to know how to reach other nodes, not become them)
	//}

	data, err := json.Marshal(node)
	if err != nil {
		logger.Log(2, "error marshalling node update ", err.Error())
		return err
	}
	if err = publish(host, fmt.Sprintf("node/update/%s/%s", node.Network, node.ID), data); err != nil {
		logger.Log(2, "error publishing node update to peer ", node.ID.String(), err.Error())
		return err
	}

	return nil
}

// HostUpdate -- publishes a host update to clients
func HostUpdate(hostUpdate *models.HostUpdate) error {
	if !servercfg.IsMessageQueueBackend() {
		return nil
	}
	logger.Log(3, "publishing host update to "+hostUpdate.Host.ID.String())

	data, err := json.Marshal(hostUpdate)
	if err != nil {
		logger.Log(2, "error marshalling node update ", err.Error())
		return err
	}
	if err = publish(&hostUpdate.Host, fmt.Sprintf("host/update/%s/%s", hostUpdate.Host.ID.String(), servercfg.GetServer()), data); err != nil {
		logger.Log(2, "error publishing host update to", hostUpdate.Host.ID.String(), err.Error())
		return err
	}

	return nil
}

// ServerStartNotify - notifies all non server nodes to pull changes after a restart
func ServerStartNotify() error {
	nodes, err := logic.GetAllNodes()
	if err != nil {
		return err
	}
	for i := range nodes {
		nodes[i].Action = models.NODE_FORCE_UPDATE
		if err = NodeUpdate(&nodes[i]); err != nil {
			logger.Log(1, "error when notifying node", nodes[i].ID.String(), "of a server startup")
		}
	}
	return nil
}

// PublishMqUpdatesForDeletedNode - published all the required updates for deleted node
func PublishMqUpdatesForDeletedNode(node models.Node, sendNodeUpdate bool, gwClients []models.ExtClient) {
	// notify of peer change
	node.PendingDelete = true
	node.Action = models.NODE_DELETE
	if sendNodeUpdate {
		if err := NodeUpdate(&node); err != nil {
			slog.Error("error publishing node update to node", "node", node.ID, "error", err)
		}
	}
	if err := PublishDeletedNodePeerUpdate(&node); err != nil {
		logger.Log(1, "error publishing peer update ", err.Error())
	}
	if servercfg.IsDNSMode() {
		logic.SetDNS()
	}

}

func PushMetricsToExporter(metrics models.Metrics) error {
	logger.Log(2, "----> Pushing metrics to exporter")
	data, err := json.Marshal(metrics)
	if err != nil {
		return errors.New("failed to marshal metrics: " + err.Error())
	}
	if mqclient == nil || !mqclient.IsConnectionOpen() {
		return errors.New("cannot publish ... mqclient not connected")
	}
	if token := mqclient.Publish("metrics_exporter", 0, true, data); !token.WaitTimeout(MQ_TIMEOUT*time.Second) || token.Error() != nil {
		var err error
		if token.Error() == nil {
			err = errors.New("connection timeout")
		} else {
			err = token.Error()
		}
		return err
	}
	return nil
}

// sendPeers - retrieve networks, send peer ports to all peers
func sendPeers() {
	peer_force_send++
	if peer_force_send == 5 {
		servercfg.SetHost()
		peer_force_send = 0
		err := logic.TimerCheckpoint() // run telemetry & log dumps if 24 hours has passed..
		if err != nil {
			logger.Log(3, "error occurred on timer,", err.Error())
		}
	}
}

func SendDNSSyncByNetwork(network string) error {

	k, err := logic.GetDNS(network)
	if err == nil && len(k) > 0 {
		err = PushSyncDNS(k)
		if err != nil {
			slog.Warn("error publishing dns entry data for network ", network, err.Error())
		}
	}

	return err
}

func sendDNSSync() error {

	networks, err := logic.GetNetworks()
	if err == nil && len(networks) > 0 {
		for _, v := range networks {
			k, err := logic.GetDNS(v.NetID)
			if err == nil && len(k) > 0 {
				err = PushSyncDNS(k)
				if err != nil {
					slog.Warn("error publishing dns entry data for network ", v.NetID, err.Error())
				}
			}
		}
		return nil
	}
	return err
}

func PushSyncDNS(dnsEntries []models.DNSEntry) error {
	logger.Log(2, "----> Pushing Sync DNS")
	data, err := json.Marshal(dnsEntries)
	if err != nil {
		return errors.New("failed to marshal DNS entries: " + err.Error())
	}
	if mqclient == nil || !mqclient.IsConnectionOpen() {
		return errors.New("cannot publish ... mqclient not connected")
	}
	if token := mqclient.Publish(fmt.Sprintf("host/dns/sync/%s", dnsEntries[0].Network), 0, true, data); !token.WaitTimeout(MQ_TIMEOUT*time.Second) || token.Error() != nil {
		var err error
		if token.Error() == nil {
			err = errors.New("connection timeout")
		} else {
			err = token.Error()
		}
		return err
	}
	return nil
}