package controller

import (
	"context"
	"fmt"
	"log"
	"time"

	"github.com/go-playground/validator/v10"
	"github.com/gravitl/netmaker/functions"
	"github.com/gravitl/netmaker/models"
	"github.com/gravitl/netmaker/mongoconn"
	"github.com/gravitl/netmaker/servercfg"
	"github.com/gravitl/netmaker/serverctl"
	"go.mongodb.org/mongo-driver/bson"
	"go.mongodb.org/mongo-driver/mongo/options"
	"golang.org/x/crypto/bcrypt"
)

func GetPeersList(networkName string) ([]models.PeersResponse, error) {

	var peers []models.PeersResponse

	//Connection mongoDB with mongoconn class
	collection := mongoconn.Client.Database("netmaker").Collection("nodes")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	//Get all nodes in the relevant network which are NOT in pending state
	filter := bson.M{"network": networkName, "ispending": false}
	cur, err := collection.Find(ctx, filter)

	if err != nil {
		return peers, err
	}

	// Close the cursor once finished and cancel if it takes too long
	defer cancel()

	for cur.Next(context.TODO()) {

		var peer models.PeersResponse
		err := cur.Decode(&peer)
		if err != nil {
			log.Fatal(err)
		}

		// add the node to our node array
		//maybe better to just return this? But then that's just GetNodes...
		peers = append(peers, peer)
	}

	//Uh oh, fatal error! This needs some better error handling
	//TODO: needs appropriate error handling so the server doesnt shut down.
	if err := cur.Err(); err != nil {
		log.Fatal(err)
	}

	return peers, err
}


func GetExtPeersList(networkName string, macaddress string) ([]models.ExtPeersResponse, error) {

        var peers []models.ExtPeersResponse

        //Connection mongoDB with mongoconn class
        collection := mongoconn.Client.Database("netmaker").Collection("extclients")

        ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

        //Get all nodes in the relevant network which are NOT in pending state
	filter := bson.M{"network": networkName, "ingressgatewayid": macaddress}
        cur, err := collection.Find(ctx, filter)

        if err != nil {
                return peers, err
        }

        // Close the cursor once finished and cancel if it takes too long
        defer cancel()

        for cur.Next(context.TODO()) {

                var peer models.ExtPeersResponse
                err := cur.Decode(&peer)
                if err != nil {
                        log.Fatal(err)
                }

                // add the node to our node array
                //maybe better to just return this? But then that's just GetNodes...
                peers = append(peers, peer)
        }

        //Uh oh, fatal error! This needs some better error handling
        //TODO: needs appropriate error handling so the server doesnt shut down.
        if err := cur.Err(); err != nil {
                log.Fatal(err)
        }

        return peers, err
}


func ValidateNodeCreate(networkName string, node models.Node) error {
	v := validator.New()
	_ = v.RegisterValidation("macaddress_unique", func(fl validator.FieldLevel) bool {
		var isFieldUnique bool = functions.IsFieldUnique(networkName, "macaddress", node.MacAddress)
		return isFieldUnique
	})
	_ = v.RegisterValidation("network_exists", func(fl validator.FieldLevel) bool {
		_, err := node.GetNetwork()
		return err == nil
	})
        _ = v.RegisterValidation("in_charset", func(fl validator.FieldLevel) bool {
                isgood := functions.NameInNodeCharSet(node.Name)
                return isgood
        })
	err := v.Struct(node)

	if err != nil {
		for _, e := range err.(validator.ValidationErrors) {
			fmt.Println(e)
		}
	}
	return err
}

func ValidateNodeUpdate(networkName string, node models.NodeUpdate) error {
	v := validator.New()
	_ = v.RegisterValidation("network_exists", func(fl validator.FieldLevel) bool {
		_, err := node.GetNetwork()
		return err == nil
	})
        _ = v.RegisterValidation("in_charset", func(fl validator.FieldLevel) bool {
                isgood := functions.NameInNodeCharSet(node.Name)
                return isgood
        })
	err := v.Struct(node)
	if err != nil {
		for _, e := range err.(validator.ValidationErrors) {
			fmt.Println(e)
		}
	}
	return err
}

func UpdateNode(nodechange models.NodeUpdate, node models.Node) (models.Node, error) {
	//Question: Is there a better way  of doing  this than a bunch of "if" statements? probably...
	//Eventually, lets have a better way to check if any of the fields are filled out...
	queryMac := node.MacAddress
	queryNetwork := node.Network
	notifynetwork := false

	if nodechange.Address != "" {
		node.Address = nodechange.Address
		notifynetwork = true
	}
	if nodechange.Address6 != "" {
		node.Address6 = nodechange.Address6
		notifynetwork = true
	}
	if nodechange.Name != "" {
		node.Name = nodechange.Name
	}
	if nodechange.LocalAddress != "" {
		node.LocalAddress = nodechange.LocalAddress
	}
	if nodechange.ListenPort != 0 {
		node.ListenPort = nodechange.ListenPort
	}
	if nodechange.ExpirationDateTime != 0 {
		node.ExpirationDateTime = nodechange.ExpirationDateTime
	}
	if nodechange.PostDown != "" {
		node.PostDown = nodechange.PostDown
	}
	if nodechange.Interface != "" {
		node.Interface = nodechange.Interface
	}
	if nodechange.PostUp != "" {
		node.PostUp = nodechange.PostUp
	}
	if nodechange.AccessKey != "" {
		node.AccessKey = nodechange.AccessKey
	}
	if nodechange.Endpoint != "" {
		node.Endpoint = nodechange.Endpoint
		notifynetwork = true
	}
	if nodechange.SaveConfig != nil {
		node.SaveConfig = nodechange.SaveConfig
	}
	if nodechange.PersistentKeepalive != 0 {
		node.PersistentKeepalive = nodechange.PersistentKeepalive
	}
	if nodechange.Password != "" {
		err := bcrypt.CompareHashAndPassword([]byte(nodechange.Password), []byte(node.Password))
		if err != nil && nodechange.Password != node.Password {
			hash, err := bcrypt.GenerateFromPassword([]byte(nodechange.Password), 5)
			if err != nil {
				return node, err
			}
			nodechange.Password = string(hash)
			node.Password = nodechange.Password
		}
	}
	if nodechange.MacAddress != "" {
		node.MacAddress = nodechange.MacAddress
	}
	if nodechange.PublicKey != "" {
		node.PublicKey = nodechange.PublicKey
		node.KeyUpdateTimeStamp = time.Now().Unix()
		notifynetwork = true
	}

	//collection := mongoconn.ConnectDB()
	collection := mongoconn.Client.Database("netmaker").Collection("nodes")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	// Create filter
	filter := bson.M{"macaddress": queryMac, "network": queryNetwork}

	node.SetLastModified()

	// prepare update model.
	update := bson.D{
		{"$set", bson.D{
			{"address", node.Address},
			{"address6", node.Address6},
			{"name", node.Name},
			{"password", node.Password},
			{"listenport", node.ListenPort},
			{"publickey", node.PublicKey},
			{"keyupdatetimestamp", node.KeyUpdateTimeStamp},
			{"expdatetime", node.ExpirationDateTime},
			{"endpoint", node.Endpoint},
			{"postup", node.PostUp},
			{"postdown", node.PostDown},
			{"macaddress", node.MacAddress},
			{"localaddress", node.LocalAddress},
			{"persistentkeepalive", node.PersistentKeepalive},
			{"saveconfig", node.SaveConfig},
			{"accesskey", node.AccessKey},
			{"interface", node.Interface},
			{"lastmodified", node.LastModified},
		}},
	}
	var nodeupdate models.Node
	errN := collection.FindOneAndUpdate(ctx, filter, update).Decode(&nodeupdate)
	if errN != nil {
		return nodeupdate, errN
	}

	if nodechange.MacAddress != "" {
		queryMac = nodechange.MacAddress
	}
	returnnode, errN := GetNode(queryMac, queryNetwork)

	defer cancel()

	if notifynetwork {
		errN = SetNetworkNodesLastModified(queryNetwork)
	}
	if servercfg.IsDNSMode() {
		errN = SetDNS()
	}

	return returnnode, errN
}

func DeleteNode(macaddress string, network string) (bool, error) {

	deleted := false

	collection := mongoconn.Client.Database("netmaker").Collection("nodes")

	filter := bson.M{"macaddress": macaddress, "network": network}

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	result, err := collection.DeleteOne(ctx, filter)

	deletecount := result.DeletedCount

	if deletecount > 0 {
		deleted = true
	}

	defer cancel()

	err = SetNetworkNodesLastModified(network)
	fmt.Println("Deleted node " + macaddress + " from network " + network)
	if servercfg.IsDNSMode() {
		err = SetDNS()
	}

	return deleted, err
}

func DeleteIntClient(clientid string) (bool, error) {

        deleted := false

        collection := mongoconn.Client.Database("netmaker").Collection("intclients")

        filter := bson.M{"clientid": clientid}

        ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

        result, err := collection.DeleteOne(ctx, filter)

        deletecount := result.DeletedCount

        if deletecount > 0 {
                deleted = true
        }

        defer cancel()

	err = serverctl.ReconfigureServerWireGuard()

        return deleted, err
}

func GetNode(macaddress string, network string) (models.Node, error) {

	var node models.Node

	collection := mongoconn.Client.Database("netmaker").Collection("nodes")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	filter := bson.M{"macaddress": macaddress, "network": network}
	err := collection.FindOne(ctx, filter, options.FindOne().SetProjection(bson.M{"_id": 0})).Decode(&node)

	defer cancel()

	return node, err
}

func GetIntClient(clientid string) (models.IntClient, error) {

        var client models.IntClient

        collection := mongoconn.Client.Database("netmaker").Collection("intclients")

        ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

        filter := bson.M{"clientid": clientid}
        err := collection.FindOne(ctx, filter, options.FindOne().SetProjection(bson.M{"_id": 0})).Decode(&clientid)

        defer cancel()

        return client, err
}

func CreateNode(node models.Node, networkName string) (models.Node, error) {

	//encrypt that password so we never see it again
	hash, err := bcrypt.GenerateFromPassword([]byte(node.Password), 5)

	if err != nil {
		return node, err
	}
	//set password to encrypted password
	node.Password = string(hash)

	node.Network = networkName

	//node.SetDefaults()
	//Umm, why am I doing this again?
	//TODO: Why am I using a local function instead of the struct function? I really dont know.
	//I think I thought it didn't work but uhhh...idk
	node.SetDefaults()

	//Another DB call here...Inefficient
	//Anyways, this scrolls through all the IP Addresses in the network range and checks against nodes
	//until one is open and then returns it
	node.Address, err = functions.UniqueAddress(networkName)
	if err != nil {
		return node, err
	}

	node.Address6, err = functions.UniqueAddress6(networkName)

	if err != nil {
		return node, err
	}

	//IDK why these aren't a part of "set defaults. Pretty dumb.
	//TODO: This is dumb. Consolidate and fix.
	node.SetLastModified()
	node.SetDefaultName()
	node.SetLastCheckIn()
	node.SetLastPeerUpdate()
	node.KeyUpdateTimeStamp = time.Now().Unix()

	//Create a JWT for the node
	tokenString, _ := functions.CreateJWT(node.MacAddress, networkName)

	if tokenString == "" {
		//returnErrorResponse(w, r, errorResponse)
		return node, err
	}

	// connect db
	collection := mongoconn.Client.Database("netmaker").Collection("nodes")
	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	// insert our node to the node db.
	result, err := collection.InsertOne(ctx, node)
	_ = result

	defer cancel()

	if err != nil {
		return node, err
	}
	//return response for if node  is pending
	if !node.IsPending {

		functions.DecrimentKey(node.Network, node.AccessKey)

	}

	SetNetworkNodesLastModified(node.Network)
	if servercfg.IsDNSMode() {
		err = SetDNS()
	}
	return node, err
}

func NodeCheckIn(node models.Node, networkName string) (models.CheckInResponse, error) {

	var response models.CheckInResponse

	parentnetwork, err := functions.GetParentNetwork(networkName)
	if err != nil {
		err = fmt.Errorf("%w; Couldnt retrieve Network "+networkName+": ", err)
		return response, err
	}

	parentnode, err := functions.GetNodeByMacAddress(networkName, node.MacAddress)
	if err != nil {
		err = fmt.Errorf("%w; Couldnt Get Node "+node.MacAddress, err)
		return response, err
	}
	if parentnode.IsPending {
		err = fmt.Errorf("%w; Node checking in is still pending: "+node.MacAddress, err)
		response.IsPending = true
		return response, err
	}

	networklm := parentnetwork.NetworkLastModified
	peerslm := parentnetwork.NodesLastModified
	gkeyupdate := parentnetwork.KeyUpdateTimeStamp
	nkeyupdate := parentnode.KeyUpdateTimeStamp
	peerlistlm := parentnode.LastPeerUpdate
	parentnodelm := parentnode.LastModified
	parentnodelastcheckin := parentnode.LastCheckIn

	if parentnodelastcheckin < parentnodelm {
		response.NeedConfigUpdate = true
	}

	if parentnodelm < networklm {
		response.NeedConfigUpdate = true
	}
	if peerlistlm < peerslm {
		response.NeedPeerUpdate = true
	}
	if nkeyupdate < gkeyupdate {
		response.NeedKeyUpdate = true
	}
	if time.Now().Unix() > parentnode.ExpirationDateTime {
		response.NeedDelete = true
		_, err = DeleteNode(node.MacAddress, networkName)
	} else {
		err = TimestampNode(parentnode, true, false, false)

		if err != nil {
			err = fmt.Errorf("%w; Couldnt Timestamp Node: ", err)
			return response, err
		}
	}
	response.Success = true

	return response, err
}

func SetNetworkNodesLastModified(networkName string) error {

	timestamp := time.Now().Unix()

	collection := mongoconn.Client.Database("netmaker").Collection("networks")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	// Create filter
	filter := bson.M{"netid": networkName}

	// prepare update model.
	update := bson.D{
		{"$set", bson.D{
			{"nodeslastmodified", timestamp},
		}},
	}

	result := collection.FindOneAndUpdate(ctx, filter, update)

	defer cancel()

	if result.Err() != nil {
		return result.Err()
	}

	return nil
}

func TimestampNode(node models.Node, updatecheckin bool, updatepeers bool, updatelm bool) error {
	if updatelm {
		node.SetLastModified()
	}
	if updatecheckin {
		node.SetLastCheckIn()
	}
	if updatepeers {
		node.SetLastPeerUpdate()
	}

	collection := mongoconn.Client.Database("netmaker").Collection("nodes")

	ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)

	// Create filter
	filter := bson.M{"macaddress": node.MacAddress, "network": node.Network}

	// prepare update model.
	update := bson.D{
		{"$set", bson.D{
			{"lastmodified", node.LastModified},
			{"lastpeerupdate", node.LastPeerUpdate},
			{"lastcheckin", node.LastCheckIn},
		}},
	}

	var nodeupdate models.Node
	err := collection.FindOneAndUpdate(ctx, filter, update).Decode(&nodeupdate)
	defer cancel()

	return err
}