package logic

import (
	"errors"
	"fmt"
	"net"

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

var (
	IPv4Network = "0.0.0.0/0"
	IPv6Network = "::/0"
)

// GetNetworkIngresses - gets the gateways of a network
func GetNetworkIngresses(network string) ([]models.Node, error) {
	var ingresses []models.Node
	netNodes, err := logic.GetNetworkNodes(network)
	if err != nil {
		return []models.Node{}, err
	}
	for i := range netNodes {
		if netNodes[i].IsIngressGateway {
			ingresses = append(ingresses, netNodes[i])
		}
	}
	return ingresses, nil
}

func GetTagMapWithNodes() (tagNodesMap map[models.TagID][]models.Node) {
	tagNodesMap = make(map[models.TagID][]models.Node)
	nodes, _ := logic.GetAllNodes()
	for _, nodeI := range nodes {
		if nodeI.Tags == nil {
			continue
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Lock()
		}
		for nodeTagID := range nodeI.Tags {
			tagNodesMap[nodeTagID] = append(tagNodesMap[nodeTagID], nodeI)
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Unlock()
		}

	}
	return
}

func GetTagMapWithNodesByNetwork(netID models.NetworkID, withStaticNodes bool) (tagNodesMap map[models.TagID][]models.Node) {
	tagNodesMap = make(map[models.TagID][]models.Node)
	nodes, _ := logic.GetNetworkNodes(netID.String())
	for _, nodeI := range nodes {
		tagNodesMap[models.TagID(nodeI.ID.String())] = []models.Node{
			nodeI,
		}
		if nodeI.Tags == nil {
			continue
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Lock()
		}
		for nodeTagID := range nodeI.Tags {
			if nodeTagID == models.TagID(nodeI.ID.String()) {
				continue
			}
			tagNodesMap[nodeTagID] = append(tagNodesMap[nodeTagID], nodeI)
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Unlock()
		}
	}
	tagNodesMap["*"] = nodes
	if !withStaticNodes {
		return
	}
	return AddTagMapWithStaticNodes(netID, tagNodesMap)
}

func AddTagMapWithStaticNodes(netID models.NetworkID,
	tagNodesMap map[models.TagID][]models.Node) map[models.TagID][]models.Node {
	extclients, err := logic.GetNetworkExtClients(netID.String())
	if err != nil {
		return tagNodesMap
	}
	for _, extclient := range extclients {
		if extclient.RemoteAccessClientID != "" {
			continue
		}
		tagNodesMap[models.TagID(extclient.ClientID)] = []models.Node{
			{
				IsStatic:   true,
				StaticNode: extclient,
			},
		}
		if extclient.Tags == nil {
			continue
		}

		if extclient.Mutex != nil {
			extclient.Mutex.Lock()
		}
		for tagID := range extclient.Tags {
			if tagID == models.TagID(extclient.ClientID) {
				continue
			}
			tagNodesMap[tagID] = append(tagNodesMap[tagID], extclient.ConvertToStaticNode())
			tagNodesMap["*"] = append(tagNodesMap["*"], extclient.ConvertToStaticNode())
		}
		if extclient.Mutex != nil {
			extclient.Mutex.Unlock()
		}
	}
	return tagNodesMap
}

func AddTagMapWithStaticNodesWithUsers(netID models.NetworkID,
	tagNodesMap map[models.TagID][]models.Node) map[models.TagID][]models.Node {
	extclients, err := logic.GetNetworkExtClients(netID.String())
	if err != nil {
		return tagNodesMap
	}
	for _, extclient := range extclients {
		tagNodesMap[models.TagID(extclient.ClientID)] = []models.Node{
			{
				IsStatic:   true,
				StaticNode: extclient,
			},
		}
		if extclient.Tags == nil {
			continue
		}
		if extclient.Mutex != nil {
			extclient.Mutex.Lock()
		}
		for tagID := range extclient.Tags {
			tagNodesMap[tagID] = append(tagNodesMap[tagID], extclient.ConvertToStaticNode())
		}
		if extclient.Mutex != nil {
			extclient.Mutex.Unlock()
		}

	}
	return tagNodesMap
}

func GetNodeIDsWithTag(tagID models.TagID) (ids []string) {

	tag, err := GetTag(tagID)
	if err != nil {
		return
	}
	nodes, _ := logic.GetNetworkNodes(tag.Network.String())
	for _, nodeI := range nodes {
		if nodeI.Tags == nil {
			continue
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Lock()
		}
		if _, ok := nodeI.Tags[tagID]; ok {
			ids = append(ids, nodeI.ID.String())
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Unlock()
		}
	}
	return
}

func GetNodesWithTag(tagID models.TagID) map[string]models.Node {
	nMap := make(map[string]models.Node)
	tag, err := GetTag(tagID)
	if err != nil {
		return nMap
	}
	nodes, _ := logic.GetNetworkNodes(tag.Network.String())
	for _, nodeI := range nodes {
		if nodeI.Tags == nil {
			continue
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Lock()
		}
		if _, ok := nodeI.Tags[tagID]; ok {
			nMap[nodeI.ID.String()] = nodeI
		}
		if nodeI.Mutex != nil {
			nodeI.Mutex.Unlock()
		}
	}
	return AddStaticNodesWithTag(tag, nMap)
}

func AddStaticNodesWithTag(tag models.Tag, nMap map[string]models.Node) map[string]models.Node {
	extclients, err := logic.GetNetworkExtClients(tag.Network.String())
	if err != nil {
		return nMap
	}
	for _, extclient := range extclients {
		if extclient.RemoteAccessClientID != "" {
			continue
		}
		if extclient.Mutex != nil {
			extclient.Mutex.Lock()
		}
		if _, ok := extclient.Tags[tag.ID]; ok {
			nMap[extclient.ClientID] = extclient.ConvertToStaticNode()
		}
		if extclient.Mutex != nil {
			extclient.Mutex.Unlock()
		}
	}
	return nMap
}

func GetStaticNodeWithTag(tagID models.TagID) map[string]models.Node {
	nMap := make(map[string]models.Node)
	tag, err := GetTag(tagID)
	if err != nil {
		return nMap
	}
	extclients, err := logic.GetNetworkExtClients(tag.Network.String())
	if err != nil {
		return nMap
	}
	for _, extclient := range extclients {
		nMap[extclient.ClientID] = extclient.ConvertToStaticNode()
	}
	return nMap
}

func ValidateInetGwReq(inetNode models.Node, req models.InetNodeReq, update bool) error {
	inetHost, err := logic.GetHost(inetNode.HostID.String())
	if err != nil {
		return err
	}
	if inetHost.FirewallInUse == models.FIREWALL_NONE {
		return errors.New("iptables or nftables needs to be installed")
	}
	if inetNode.InternetGwID != "" {
		return fmt.Errorf("node %s is using a internet gateway already", inetHost.Name)
	}
	if inetNode.IsRelayed {
		return fmt.Errorf("node %s is being relayed", inetHost.Name)
	}

	for _, clientNodeID := range req.InetNodeClientIDs {
		clientNode, err := logic.GetNodeByID(clientNodeID)
		if err != nil {
			return err
		}
		if clientNode.IsFailOver {
			return errors.New("failover node cannot be set to use internet gateway")
		}
		clientHost, err := logic.GetHost(clientNode.HostID.String())
		if err != nil {
			return err
		}
		if clientHost.IsDefault {
			return errors.New("default host cannot be set to use internet gateway")
		}
		if clientHost.OS != models.OS_Types.Linux && clientHost.OS != models.OS_Types.Windows {
			return errors.New("can only attach linux or windows machine to a internet gateway")
		}
		if clientNode.IsInternetGateway {
			return fmt.Errorf("node %s acting as internet gateway cannot use another internet gateway", clientHost.Name)
		}
		if update {
			if clientNode.InternetGwID != "" && clientNode.InternetGwID != inetNode.ID.String() {
				return fmt.Errorf("node %s is already using a internet gateway", clientHost.Name)
			}
		} else {
			if clientNode.InternetGwID != "" {
				return fmt.Errorf("node %s is already using a internet gateway", clientHost.Name)
			}
		}
		if clientNode.FailedOverBy != uuid.Nil {
			ResetFailedOverPeer(&clientNode)
		}

		if clientNode.IsRelayed && clientNode.RelayedBy != inetNode.ID.String() {
			return fmt.Errorf("node %s is being relayed", clientHost.Name)
		}

		for _, nodeID := range clientHost.Nodes {
			node, err := logic.GetNodeByID(nodeID)
			if err != nil {
				continue
			}
			if node.InternetGwID != "" && node.InternetGwID != inetNode.ID.String() {
				return errors.New("nodes on same host cannot use different internet gateway")
			}

		}
	}
	return nil
}

// SetInternetGw - sets the node as internet gw based on flag bool
func SetInternetGw(node *models.Node, req models.InetNodeReq) {
	node.IsInternetGateway = true
	node.InetNodeReq = req
	for _, clientNodeID := range req.InetNodeClientIDs {
		clientNode, err := logic.GetNodeByID(clientNodeID)
		if err != nil {
			continue
		}
		clientNode.InternetGwID = node.ID.String()
		logic.UpsertNode(&clientNode)
	}

}

func UnsetInternetGw(node *models.Node) {
	nodes, err := logic.GetNetworkNodes(node.Network)
	if err != nil {
		slog.Error("failed to get network nodes", "network", node.Network, "error", err)
		return
	}
	for _, clientNode := range nodes {
		if node.ID.String() == clientNode.InternetGwID {
			clientNode.InternetGwID = ""
			logic.UpsertNode(&clientNode)
		}

	}
	node.IsInternetGateway = false
	node.InetNodeReq = models.InetNodeReq{}

}

func SetDefaultGwForRelayedUpdate(relayed, relay models.Node, peerUpdate models.HostPeerUpdate) models.HostPeerUpdate {
	if relay.InternetGwID != "" {
		relayedHost, err := logic.GetHost(relayed.HostID.String())
		if err != nil {
			return peerUpdate
		}
		peerUpdate.ChangeDefaultGw = true
		peerUpdate.DefaultGwIp = relay.Address.IP
		if peerUpdate.DefaultGwIp == nil || relayedHost.EndpointIP == nil {
			peerUpdate.DefaultGwIp = relay.Address6.IP
		}

	}
	return peerUpdate
}

func SetDefaultGw(node models.Node, peerUpdate models.HostPeerUpdate) models.HostPeerUpdate {
	if node.InternetGwID != "" {

		inetNode, err := logic.GetNodeByID(node.InternetGwID)
		if err != nil {
			return peerUpdate
		}
		host, err := logic.GetHost(node.HostID.String())
		if err != nil {
			return peerUpdate
		}

		peerUpdate.ChangeDefaultGw = true
		peerUpdate.DefaultGwIp = inetNode.Address.IP
		if peerUpdate.DefaultGwIp == nil || host.EndpointIP == nil {
			peerUpdate.DefaultGwIp = inetNode.Address6.IP
		}
	}
	return peerUpdate
}

// GetAllowedIpForInetNodeClient - get inet cidr for node using a inet gw
func GetAllowedIpForInetNodeClient(node, peer *models.Node) []net.IPNet {
	var allowedips = []net.IPNet{}

	if peer.Address.IP != nil {
		_, ipnet, _ := net.ParseCIDR(IPv4Network)
		allowedips = append(allowedips, *ipnet)
	}

	if peer.Address6.IP != nil {
		_, ipnet, _ := net.ParseCIDR(IPv6Network)
		allowedips = append(allowedips, *ipnet)
	}

	return allowedips
}