package models

import (
	"bytes"
	"math/rand"
	"net"
	"strings"
	"time"

	"golang.org/x/crypto/bcrypt"
)

const (
	// NODE_SERVER_NAME - the default server name
	NODE_SERVER_NAME = "netmaker"
	// TEN_YEARS_IN_SECONDS - ten years in seconds
	TEN_YEARS_IN_SECONDS = 300000000
	// MAX_NAME_LENGTH - max name length of node
	MAX_NAME_LENGTH = 62
	// == ACTIONS == (can only be set by server)
	// NODE_UPDATE_KEY - action to update key
	NODE_UPDATE_KEY = "updatekey"
	// NODE_DELETE - delete node action
	NODE_DELETE = "delete"
	// NODE_IS_PENDING - node pending status
	NODE_IS_PENDING = "pending"
	// NODE_NOOP - node no op action
	NODE_NOOP = "noop"
	// NODE_FORCE_UPDATE - indicates a node should pull all changes
	NODE_FORCE_UPDATE = "force"
	// FIREWALL_IPTABLES - indicates that iptables is the firewall in use
	FIREWALL_IPTABLES = "iptables"
	// FIREWALL_NFTABLES - indicates nftables is in use (Linux only)
	FIREWALL_NFTABLES = "nftables"
	// FIREWALL_NONE - indicates that no supported firewall in use
	FIREWALL_NONE = "none"
)

var seededRand *rand.Rand = rand.New(
	rand.NewSource(time.Now().UnixNano()))

// NodeCheckin - struct for node checkins with server
type NodeCheckin struct {
	Version   string
	Connected string
}

// Node - struct for node model
type Node struct {
	ID                      string               `json:"id,omitempty" bson:"id,omitempty" yaml:"id,omitempty" validate:"required,min=5,id_unique"`
	Address                 string               `json:"address" bson:"address" yaml:"address" validate:"omitempty,ipv4"`
	Address6                string               `json:"address6" bson:"address6" yaml:"address6" validate:"omitempty,ipv6"`
	LocalAddress            string               `json:"localaddress" bson:"localaddress" yaml:"localaddress" validate:"omitempty"`
	Name                    string               `json:"name" bson:"name" yaml:"name" validate:"omitempty,max=62,in_charset"`
	NetworkSettings         Network              `json:"networksettings" bson:"networksettings" yaml:"networksettings" validate:"-"`
	ListenPort              int32                `json:"listenport" bson:"listenport" yaml:"listenport" validate:"omitempty,numeric,min=1024,max=65535"`
	LocalListenPort         int32                `json:"locallistenport" bson:"locallistenport" yaml:"locallistenport" validate:"numeric,min=0,max=65535"`
	PublicKey               string               `json:"publickey" bson:"publickey" yaml:"publickey" validate:"required,base64"`
	Endpoint                string               `json:"endpoint" bson:"endpoint" yaml:"endpoint" validate:"required,ip"`
	PostUp                  string               `json:"postup" bson:"postup" yaml:"postup"`
	PostDown                string               `json:"postdown" bson:"postdown" yaml:"postdown"`
	AllowedIPs              []string             `json:"allowedips" bson:"allowedips" yaml:"allowedips"`
	PersistentKeepalive     int32                `json:"persistentkeepalive" bson:"persistentkeepalive" yaml:"persistentkeepalive" validate:"omitempty,numeric,max=1000"`
	IsHub                   string               `json:"ishub" bson:"ishub" yaml:"ishub" validate:"checkyesorno"`
	AccessKey               string               `json:"accesskey" bson:"accesskey" yaml:"accesskey"`
	Interface               string               `json:"interface" bson:"interface" yaml:"interface"`
	LastModified            int64                `json:"lastmodified" bson:"lastmodified" yaml:"lastmodified"`
	ExpirationDateTime      int64                `json:"expdatetime" bson:"expdatetime" yaml:"expdatetime"`
	LastPeerUpdate          int64                `json:"lastpeerupdate" bson:"lastpeerupdate" yaml:"lastpeerupdate"`
	LastCheckIn             int64                `json:"lastcheckin" bson:"lastcheckin" yaml:"lastcheckin"`
	MacAddress              string               `json:"macaddress" bson:"macaddress" yaml:"macaddress"`
	Password                string               `json:"password" bson:"password" yaml:"password" validate:"required,min=6"`
	Network                 string               `json:"network" bson:"network" yaml:"network" validate:"network_exists"`
	IsRelayed               string               `json:"isrelayed" bson:"isrelayed" yaml:"isrelayed"`
	IsPending               string               `json:"ispending" bson:"ispending" yaml:"ispending"`
	IsRelay                 string               `json:"isrelay" bson:"isrelay" yaml:"isrelay" validate:"checkyesorno"`
	IsDocker                string               `json:"isdocker" bson:"isdocker" yaml:"isdocker" validate:"checkyesorno"`
	IsK8S                   string               `json:"isk8s" bson:"isk8s" yaml:"isk8s" validate:"checkyesorno"`
	IsEgressGateway         string               `json:"isegressgateway" bson:"isegressgateway" yaml:"isegressgateway" validate:"checkyesorno"`
	IsIngressGateway        string               `json:"isingressgateway" bson:"isingressgateway" yaml:"isingressgateway" validate:"checkyesorno"`
	EgressGatewayRanges     []string             `json:"egressgatewayranges" bson:"egressgatewayranges" yaml:"egressgatewayranges"`
	EgressGatewayNatEnabled string               `json:"egressgatewaynatenabled" bson:"egressgatewaynatenabled" yaml:"egressgatewaynatenabled"`
	EgressGatewayRequest    EgressGatewayRequest `json:"egressgatewayrequest" bson:"egressgatewayrequest" yaml:"egressgatewayrequest"`
	RelayAddrs              []string             `json:"relayaddrs" bson:"relayaddrs" yaml:"relayaddrs"`
	IngressGatewayRange     string               `json:"ingressgatewayrange" bson:"ingressgatewayrange" yaml:"ingressgatewayrange"`
	IngressGatewayRange6    string               `json:"ingressgatewayrange6" bson:"ingressgatewayrange6" yaml:"ingressgatewayrange6"`
	// IsStatic - refers to if the Endpoint is set manually or dynamically
	IsStatic        string      `json:"isstatic" bson:"isstatic" yaml:"isstatic" validate:"checkyesorno"`
	UDPHolePunch    string      `json:"udpholepunch" bson:"udpholepunch" yaml:"udpholepunch" validate:"checkyesorno"`
	DNSOn           string      `json:"dnson" bson:"dnson" yaml:"dnson" validate:"checkyesorno"`
	IsServer        string      `json:"isserver" bson:"isserver" yaml:"isserver" validate:"checkyesorno"`
	Action          string      `json:"action" bson:"action" yaml:"action"`
	IsLocal         string      `json:"islocal" bson:"islocal" yaml:"islocal" validate:"checkyesorno"`
	LocalRange      string      `json:"localrange" bson:"localrange" yaml:"localrange"`
	IPForwarding    string      `json:"ipforwarding" bson:"ipforwarding" yaml:"ipforwarding" validate:"checkyesorno"`
	OS              string      `json:"os" bson:"os" yaml:"os"`
	MTU             int32       `json:"mtu" bson:"mtu" yaml:"mtu"`
	Version         string      `json:"version" bson:"version" yaml:"version"`
	Server          string      `json:"server" bson:"server" yaml:"server"`
	TrafficKeys     TrafficKeys `json:"traffickeys" bson:"traffickeys" yaml:"traffickeys"`
	FirewallInUse   string      `json:"firewallinuse" bson:"firewallinuse" yaml:"firewallinuse"`
	InternetGateway string      `json:"internetgateway" bson:"internetgateway" yaml:"internetgateway"`
	Connected       string      `json:"connected" bson:"connected" yaml:"connected" validate:"checkyesorno"`
	// == PRO ==
	DefaultACL string `json:"defaultacl,omitempty" bson:"defaultacl,omitempty" yaml:"defaultacl,omitempty" validate:"checkyesornoorunset"`
	OwnerID    string `json:"ownerid,omitempty" bson:"ownerid,omitempty" yaml:"ownerid,omitempty"`
}

// NodesArray - used for node sorting
type NodesArray []Node

// NodesArray.Len - gets length of node array
func (a NodesArray) Len() int { return len(a) }

// NodesArray.Less - gets returns lower rank of two node addresses
func (a NodesArray) Less(i, j int) bool { return isLess(a[i].Address, a[j].Address) }

// NodesArray.Swap - swaps two nodes in array
func (a NodesArray) Swap(i, j int) { a[i], a[j] = a[j], a[i] }

func isLess(ipA string, ipB string) bool {
	ipNetA := net.ParseIP(ipA)
	ipNetB := net.ParseIP(ipB)
	return bytes.Compare(ipNetA, ipNetB) < 0
}

// Node.PrimaryAddress - return ipv4 address if present, else return ipv6
func (node *Node) PrimaryAddress() string {
	if node.Address != "" {
		return node.Address
	}
	return node.Address6
}

// Node.SetDefaultConnected
func (node *Node) SetDefaultConnected() {
	if node.Connected == "" {
		node.Connected = "yes"
	}
	if node.IsServer == "yes" {
		node.Connected = "yes"
	}
}

// Node.SetDefaultMTU - sets default MTU of a node
func (node *Node) SetDefaultMTU() {
	if node.MTU == 0 {
		node.MTU = 1280
	}
}

// Node.SetDefaultNFTablesPresent - sets default for nftables check
func (node *Node) SetDefaultNFTablesPresent() {
	if node.FirewallInUse == "" {
		node.FirewallInUse = FIREWALL_IPTABLES // default to iptables
	}
}

// Node.SetDefaulIsPending - sets ispending default
func (node *Node) SetDefaulIsPending() {
	if node.IsPending == "" {
		node.IsPending = "no"
	}
}

// Node.SetDefaultIsRelayed - set default is relayed
func (node *Node) SetDefaultIsRelayed() {
	if node.IsRelayed == "" {
		node.IsRelayed = "no"
	}
}

// Node.SetDefaultIsRelayed - set default is relayed
func (node *Node) SetDefaultIsHub() {
	if node.IsHub == "" {
		node.IsHub = "no"
	}
}

// Node.SetDefaultIsRelay - set default isrelay
func (node *Node) SetDefaultIsRelay() {
	if node.IsRelay == "" {
		node.IsRelay = "no"
	}
}

// Node.SetDefaultIsDocker - set default isdocker
func (node *Node) SetDefaultIsDocker() {
	if node.IsDocker == "" {
		node.IsDocker = "no"
	}
}

// Node.SetDefaultIsK8S - set default isk8s
func (node *Node) SetDefaultIsK8S() {
	if node.IsK8S == "" {
		node.IsK8S = "no"
	}
}

// Node.SetDefaultEgressGateway - sets default egress gateway status
func (node *Node) SetDefaultEgressGateway() {
	if node.IsEgressGateway == "" {
		node.IsEgressGateway = "no"
	}
}

// Node.SetDefaultIngressGateway - sets default ingress gateway status
func (node *Node) SetDefaultIngressGateway() {
	if node.IsIngressGateway == "" {
		node.IsIngressGateway = "no"
	}
}

// Node.SetDefaultAction - sets default action status
func (node *Node) SetDefaultAction() {
	if node.Action == "" {
		node.Action = NODE_NOOP
	}
}

// Node.SetRoamingDefault - sets default roaming status
//func (node *Node) SetRoamingDefault() {
//	if node.Roaming == "" {
//		node.Roaming = "yes"
//	}
//}

// Node.SetIPForwardingDefault - set ip forwarding default
func (node *Node) SetIPForwardingDefault() {
	if node.IPForwarding == "" {
		node.IPForwarding = "yes"
	}
}

// Node.SetIsLocalDefault - set is local default
func (node *Node) SetIsLocalDefault() {
	if node.IsLocal == "" {
		node.IsLocal = "no"
	}
}

// Node.SetDNSOnDefault - sets dns on default
func (node *Node) SetDNSOnDefault() {
	if node.DNSOn == "" {
		node.DNSOn = "yes"
	}
}

// Node.SetIsServerDefault - sets node isserver default
func (node *Node) SetIsServerDefault() {
	if node.IsServer != "yes" {
		node.IsServer = "no"
	}
}

// Node.SetIsStaticDefault - set is static default
func (node *Node) SetIsStaticDefault() {
	if node.IsServer == "yes" {
		node.IsStatic = "yes"
	} else if node.IsStatic != "yes" {
		node.IsStatic = "no"
	}
}

// Node.SetLastModified - set last modified initial time
func (node *Node) SetLastModified() {
	node.LastModified = time.Now().Unix()
}

// Node.SetLastCheckIn - time.Now().Unix()
func (node *Node) SetLastCheckIn() {
	node.LastCheckIn = time.Now().Unix()
}

// Node.SetLastPeerUpdate - sets last peer update time
func (node *Node) SetLastPeerUpdate() {
	node.LastPeerUpdate = time.Now().Unix()
}

// Node.SetExpirationDateTime - sets node expiry time
func (node *Node) SetExpirationDateTime() {
	node.ExpirationDateTime = time.Now().Unix() + TEN_YEARS_IN_SECONDS
}

// Node.SetDefaultName - sets a random name to node
func (node *Node) SetDefaultName() {
	if node.Name == "" {
		node.Name = GenerateNodeName()
	}
}

// Node.Fill - fills other node data into calling node data if not set on calling node
func (newNode *Node) Fill(currentNode *Node) { // TODO add new field for nftables present
	newNode.ID = currentNode.ID

	if newNode.Address == "" {
		newNode.Address = currentNode.Address
	}
	if newNode.Address6 == "" {
		newNode.Address6 = currentNode.Address6
	}
	if newNode.LocalAddress == "" {
		newNode.LocalAddress = currentNode.LocalAddress
	}
	if newNode.Name == "" {
		newNode.Name = currentNode.Name
	}
	if newNode.ListenPort == 0 {
		newNode.ListenPort = currentNode.ListenPort
	}
	if newNode.LocalListenPort == 0 {
		newNode.LocalListenPort = currentNode.LocalListenPort
	}
	if newNode.PublicKey == "" {
		newNode.PublicKey = currentNode.PublicKey
	}
	if newNode.Endpoint == "" {
		newNode.Endpoint = currentNode.Endpoint
	}
	if newNode.PostUp == "" {
		newNode.PostUp = currentNode.PostUp
	}
	if newNode.PostDown == "" {
		newNode.PostDown = currentNode.PostDown
	}
	if newNode.AllowedIPs == nil {
		newNode.AllowedIPs = currentNode.AllowedIPs
	}
	if newNode.PersistentKeepalive < 0 {
		newNode.PersistentKeepalive = currentNode.PersistentKeepalive
	}
	if newNode.AccessKey == "" {
		newNode.AccessKey = currentNode.AccessKey
	}
	if newNode.Interface == "" {
		newNode.Interface = currentNode.Interface
	}
	if newNode.LastModified == 0 {
		newNode.LastModified = currentNode.LastModified
	}
	if newNode.ExpirationDateTime == 0 {
		newNode.ExpirationDateTime = currentNode.ExpirationDateTime
	}
	if newNode.LastPeerUpdate == 0 {
		newNode.LastPeerUpdate = currentNode.LastPeerUpdate
	}
	if newNode.LastCheckIn == 0 {
		newNode.LastCheckIn = currentNode.LastCheckIn
	}
	if newNode.MacAddress == "" {
		newNode.MacAddress = currentNode.MacAddress
	}
	if newNode.Password != "" {
		err := bcrypt.CompareHashAndPassword([]byte(newNode.Password), []byte(currentNode.Password))
		if err != nil && currentNode.Password != newNode.Password {
			hash, err := bcrypt.GenerateFromPassword([]byte(newNode.Password), 5)
			if err == nil {
				newNode.Password = string(hash)
			}
		}
	} else {
		newNode.Password = currentNode.Password
	}
	if newNode.Network == "" {
		newNode.Network = currentNode.Network
	}
	if newNode.IsPending == "" {
		newNode.IsPending = currentNode.IsPending
	}
	if newNode.IsEgressGateway == "" {
		newNode.IsEgressGateway = currentNode.IsEgressGateway
	}
	if newNode.IsIngressGateway == "" {
		newNode.IsIngressGateway = currentNode.IsIngressGateway
	}
	if newNode.EgressGatewayRanges == nil {
		newNode.EgressGatewayRanges = currentNode.EgressGatewayRanges
	}
	if newNode.IngressGatewayRange == "" {
		newNode.IngressGatewayRange = currentNode.IngressGatewayRange
	}
	if newNode.IngressGatewayRange6 == "" {
		newNode.IngressGatewayRange6 = currentNode.IngressGatewayRange6
	}
	if newNode.IsStatic == "" {
		newNode.IsStatic = currentNode.IsStatic
	}
	if newNode.UDPHolePunch == "" {
		newNode.UDPHolePunch = currentNode.UDPHolePunch
	}
	if newNode.DNSOn == "" {
		newNode.DNSOn = currentNode.DNSOn
	}
	if newNode.IsLocal == "" {
		newNode.IsLocal = currentNode.IsLocal
	}
	if newNode.IPForwarding == "" {
		newNode.IPForwarding = currentNode.IPForwarding
	}
	if newNode.Action == "" {
		newNode.Action = currentNode.Action
	}
	if newNode.IsServer == "" {
		newNode.IsServer = currentNode.IsServer
	}
	if newNode.IsServer == "yes" {
		newNode.IsStatic = "yes"
		newNode.Connected = "yes"
	}
	if newNode.MTU == 0 {
		newNode.MTU = currentNode.MTU
	}
	if newNode.OS == "" {
		newNode.OS = currentNode.OS
	}
	if newNode.RelayAddrs == nil {
		newNode.RelayAddrs = currentNode.RelayAddrs
	}
	if newNode.IsRelay == "" {
		newNode.IsRelay = currentNode.IsRelay
	}
	if newNode.IsRelayed == "" {
		newNode.IsRelayed = currentNode.IsRelayed
	}
	if newNode.IsDocker == "" {
		newNode.IsDocker = currentNode.IsDocker
	}
	if newNode.IsK8S == "" {
		newNode.IsK8S = currentNode.IsK8S
	}
	if newNode.Version == "" {
		newNode.Version = currentNode.Version
	}
	if newNode.IsHub == "" {
		newNode.IsHub = currentNode.IsHub
	}
	if newNode.Server == "" {
		newNode.Server = currentNode.Server
	}
	if newNode.Connected == "" {
		newNode.Connected = currentNode.Connected
	}
	if newNode.DefaultACL == "" {
		newNode.DefaultACL = currentNode.DefaultACL
	}

	newNode.TrafficKeys = currentNode.TrafficKeys
}

// StringWithCharset - returns random string inside defined charset
func StringWithCharset(length int, charset string) string {
	b := make([]byte, length)
	for i := range b {
		b[i] = charset[seededRand.Intn(len(charset))]
	}
	return string(b)
}

// IsIpv4Net - check for valid IPv4 address
// Note: We dont handle IPv6 AT ALL!!!!! This definitely is needed at some point
// But for iteration 1, lets just stick to IPv4. Keep it simple stupid.
func IsIpv4Net(host string) bool {
	return net.ParseIP(host) != nil
}

// Node.NameInNodeCharset - returns if name is in charset below or not
func (node *Node) NameInNodeCharSet() bool {

	charset := "abcdefghijklmnopqrstuvwxyz1234567890-"

	for _, char := range node.Name {
		if !strings.Contains(charset, strings.ToLower(string(char))) {
			return false
		}
	}
	return true
}

// == PRO ==

// Node.DoesACLAllow - checks if default ACL on node is "yes"
func (node *Node) DoesACLAllow() bool {
	return node.DefaultACL == "yes"
}

// Node.DoesACLDeny - checks if default ACL on node is "no"
func (node *Node) DoesACLDeny() bool {
	return node.DefaultACL == "no"
}