package tendrils

import (
	"context"
	"encoding/json"
	"fmt"
	"net"
	"sort"
	"strings"
	"time"

	"github.com/fvbommel/sortorder"
	"go.jetify.com/typeid"
)

func newID(prefix string) string {
	tid, _ := typeid.WithPrefix(prefix)
	return tid.String()
}

type ArtNetUniverse int

func (u ArtNetUniverse) Net() int {
	return (int(u) >> 8) & 0x7f
}

func (u ArtNetUniverse) Subnet() int {
	return (int(u) >> 4) & 0x0f
}

func (u ArtNetUniverse) Universe() int {
	return int(u) & 0x0f
}

func (u ArtNetUniverse) String() string {
	return fmt.Sprintf("%d/%d/%d", u.Net(), u.Subnet(), u.Universe())
}

type ArtNetUniverseSet map[ArtNetUniverse]time.Time

func (s ArtNetUniverseSet) Add(u ArtNetUniverse) {
	s[u] = time.Now()
}

func (s ArtNetUniverseSet) Universes() []ArtNetUniverse {
	result := make([]ArtNetUniverse, 0, len(s))
	for u := range s {
		result = append(result, u)
	}
	sort.Slice(result, func(i, j int) bool { return result[i] < result[j] })
	return result
}

func (s ArtNetUniverseSet) Expire(maxAge time.Duration) {
	expireTime := time.Now().Add(-maxAge)
	for u, lastSeen := range s {
		if lastSeen.Before(expireTime) {
			delete(s, u)
		}
	}
}

func (s ArtNetUniverseSet) MarshalJSON() ([]byte, error) {
	return json.Marshal(s.Universes())
}

type SACNUniverse int

func (u SACNUniverse) String() string {
	return fmt.Sprintf("%d", u)
}

type SACNUniverseSet map[SACNUniverse]time.Time

func (s SACNUniverseSet) Add(u SACNUniverse) {
	s[u] = time.Now()
}

func (s SACNUniverseSet) Universes() []SACNUniverse {
	result := make([]SACNUniverse, 0, len(s))
	for u := range s {
		result = append(result, u)
	}
	sort.Slice(result, func(i, j int) bool { return result[i] < result[j] })
	return result
}

func (s SACNUniverseSet) Expire(maxAge time.Duration) {
	expireTime := time.Now().Add(-maxAge)
	for u, lastSeen := range s {
		if lastSeen.Before(expireTime) {
			delete(s, u)
		}
	}
}

func (s SACNUniverseSet) MarshalJSON() ([]byte, error) {
	return json.Marshal(s.Universes())
}

type MulticastGroupID int

const (
	MulticastUnknown MulticastGroupID = iota
	MulticastMDNS
	MulticastPTP
	MulticastPTPAnnounce
	MulticastPTPSync
	MulticastPTPDelay
	MulticastSAP
	MulticastShureSLP
	MulticastSSDP
	MulticastSLP
	MulticastAdminScopedBroadcast
)

type MulticastGroup struct {
	ID       MulticastGroupID
	SACNUniverse  SACNUniverse
	DanteFlow     int
	DanteAV       int
	RawIP         string
}

func (g MulticastGroup) String() string {
	switch g.ID {
	case MulticastMDNS:
		return "mdns"
	case MulticastPTP:
		return "ptp"
	case MulticastPTPAnnounce:
		return "ptp-announce"
	case MulticastPTPSync:
		return "ptp-sync"
	case MulticastPTPDelay:
		return "ptp-delay"
	case MulticastSAP:
		return "sap"
	case MulticastShureSLP:
		return "shure-slp"
	case MulticastSSDP:
		return "ssdp"
	case MulticastSLP:
		return "slp"
	case MulticastAdminScopedBroadcast:
		return "admin-scoped-broadcast"
	}
	if g.SACNUniverse > 0 {
		return fmt.Sprintf("sacn:%d", g.SACNUniverse)
	}
	if g.DanteFlow > 0 {
		return fmt.Sprintf("dante-mcast:%d", g.DanteFlow)
	}
	if g.DanteAV > 0 {
		return fmt.Sprintf("dante-av:%d", g.DanteAV)
	}
	return g.RawIP
}

func (g MulticastGroup) MarshalJSON() ([]byte, error) {
	return json.Marshal(g.String())
}

func (g MulticastGroup) IsDante() bool {
	return g.DanteFlow > 0 || g.DanteAV > 0
}

func (g MulticastGroup) IsSACN() bool {
	return g.SACNUniverse > 0
}

func ParseMulticastGroup(ip net.IP) MulticastGroup {
	ip4 := ip.To4()
	if ip4 == nil {
		return MulticastGroup{RawIP: ip.String()}
	}

	switch ip.String() {
	case "224.0.0.251":
		return MulticastGroup{ID: MulticastMDNS}
	case "224.0.1.129":
		return MulticastGroup{ID: MulticastPTP}
	case "224.0.1.130":
		return MulticastGroup{ID: MulticastPTPAnnounce}
	case "224.0.1.131":
		return MulticastGroup{ID: MulticastPTPSync}
	case "224.0.1.132":
		return MulticastGroup{ID: MulticastPTPDelay}
	case "224.2.127.254":
		return MulticastGroup{ID: MulticastSAP}
	case "239.255.254.253":
		return MulticastGroup{ID: MulticastShureSLP}
	case "239.255.255.250":
		return MulticastGroup{ID: MulticastSSDP}
	case "239.255.255.253":
		return MulticastGroup{ID: MulticastSLP}
	case "239.255.255.255":
		return MulticastGroup{ID: MulticastAdminScopedBroadcast}
	}

	if ip4[0] == 239 && ip4[1] == 255 {
		universe := int(ip4[2])*256 + int(ip4[3])
		if universe >= 1 && universe <= 63999 {
			return MulticastGroup{SACNUniverse: SACNUniverse(universe)}
		}
	}

	if ip4[0] == 239 && ip4[1] >= 69 && ip4[1] <= 71 {
		flowID := (int(ip4[1]-69) << 16) | (int(ip4[2]) << 8) | int(ip4[3])
		return MulticastGroup{DanteFlow: flowID}
	}

	if ip4[0] == 239 && ip4[1] == 253 {
		flowID := (int(ip4[2]) << 8) | int(ip4[3])
		return MulticastGroup{DanteAV: flowID}
	}

	return MulticastGroup{RawIP: ip.String()}
}

type MulticastMembership struct {
	Group    MulticastGroup
	LastSeen time.Time
}

type MulticastMembershipSet map[string]*MulticastMembership

func (s MulticastMembershipSet) Add(group MulticastGroup) {
	key := group.String()
	if m, exists := s[key]; exists {
		m.LastSeen = time.Now()
	} else {
		s[key] = &MulticastMembership{Group: group, LastSeen: time.Now()}
	}
}

func (s MulticastMembershipSet) Remove(group MulticastGroup) {
	delete(s, group.String())
}

func (s MulticastMembershipSet) Groups() []MulticastGroup {
	result := make([]MulticastGroup, 0, len(s))
	for _, m := range s {
		result = append(result, m.Group)
	}
	sort.Slice(result, func(i, j int) bool {
		return result[i].String() < result[j].String()
	})
	return result
}

func (s MulticastMembershipSet) SACNInputs() []SACNUniverse {
	var result []SACNUniverse
	for _, m := range s {
		if m.Group.IsSACN() {
			result = append(result, m.Group.SACNUniverse)
		}
	}
	sort.Slice(result, func(i, j int) bool { return result[i] < result[j] })
	return result
}

func (s MulticastMembershipSet) Expire(maxAge time.Duration) {
	expireTime := time.Now().Add(-maxAge)
	for key, m := range s {
		if m.LastSeen.Before(expireTime) {
			delete(s, key)
		}
	}
}

func (s MulticastMembershipSet) MarshalJSON() ([]byte, error) {
	return json.Marshal(s.Groups())
}

type MAC string

func (m MAC) Parse() net.HardwareAddr {
	mac, _ := net.ParseMAC(string(m))
	return mac
}

func MACFrom(mac net.HardwareAddr) MAC {
	if mac == nil {
		return ""
	}
	return MAC(mac.String())
}

type IPSet map[string]bool

func (s IPSet) MarshalJSON() ([]byte, error) {
	ips := make([]string, 0, len(s))
	for ip := range s {
		ips = append(ips, ip)
	}
	sort.Strings(ips)
	return json.Marshal(ips)
}

func (s IPSet) Add(ip net.IP) {
	s[ip.String()] = true
}

func (s IPSet) Has(ip string) bool {
	return s[ip]
}

func (s IPSet) Slice() []string {
	ips := make([]string, 0, len(s))
	for ip := range s {
		ips = append(ips, ip)
	}
	sort.Strings(ips)
	return ips
}

type NameSet map[string]bool

func sortNamesByLength(names []string) {
	sort.Slice(names, func(i, j int) bool {
		if len(names[i]) != len(names[j]) {
			return len(names[i]) < len(names[j])
		}
		return names[i] < names[j]
	})
}

func (s NameSet) MarshalJSON() ([]byte, error) {
	names := make([]string, 0, len(s))
	for name := range s {
		names = append(names, name)
	}
	sortNamesByLength(names)
	return json.Marshal(names)
}

func (s NameSet) Add(name string) {
	s[name] = true
}

func (s NameSet) Has(name string) bool {
	return s[name]
}

type InterfaceMap map[string]*Interface

func (m InterfaceMap) MarshalJSON() ([]byte, error) {
	keys := make([]string, 0, len(m))
	for k := range m {
		keys = append(keys, k)
	}
	sort.Slice(keys, func(i, j int) bool {
		return sortorder.NaturalLess(keys[i], keys[j])
	})
	ifaces := make([]*Interface, 0, len(m))
	for _, k := range keys {
		ifaces = append(ifaces, m[k])
	}
	return json.Marshal(ifaces)
}

type Interface struct {
	Name  string          `json:"name,omitempty"`
	MAC   MAC             `json:"mac"`
	IPs   IPSet           `json:"ips"`
	Stats *InterfaceStats `json:"stats,omitempty"`
}

type InterfaceStats struct {
	Speed       uint64    `json:"speed,omitempty"`
	InErrors    uint64    `json:"in_errors,omitempty"`
	OutErrors   uint64    `json:"out_errors,omitempty"`
	InPktsRate  float64   `json:"in_pkts_rate,omitempty"`
	OutPktsRate float64   `json:"out_pkts_rate,omitempty"`
	InBytesRate float64   `json:"in_bytes_rate,omitempty"`
	OutBytesRate float64  `json:"out_bytes_rate,omitempty"`
	PoE         *PoEStats `json:"poe,omitempty"`
}

type PoEStats struct {
	Power    float64 `json:"power"`
	MaxPower float64 `json:"max_power"`
}

type PoEBudget struct {
	Power    float64 `json:"power"`
	MaxPower float64 `json:"max_power"`
}

type Node struct {
	ID                 string                 `json:"id"`
	Names              NameSet                `json:"names"`
	Interfaces         InterfaceMap           `json:"interfaces"`
	MACTable           map[string]string      `json:"-"`
	PoEBudget          *PoEBudget             `json:"poe_budget,omitempty"`
	IsDanteClockMaster bool                   `json:"is_dante_clock_master,omitempty"`
	DanteTxChannels    string                 `json:"dante_tx_channels,omitempty"`
	MulticastGroups    MulticastMembershipSet `json:"multicast_groups,omitempty"`
	ArtNetInputs       ArtNetUniverseSet      `json:"artnet_inputs,omitempty"`
	ArtNetOutputs      ArtNetUniverseSet      `json:"artnet_outputs,omitempty"`
	SACNOutputs        SACNUniverseSet        `json:"sacn_outputs,omitempty"`
	DanteTx            []*DantePeer           `json:"dante_tx,omitempty"`
	DanteRx            []*DantePeer           `json:"dante_rx,omitempty"`
	Unreachable        bool                   `json:"unreachable,omitempty"`
	pollTrigger        chan struct{}
	cancelFunc         context.CancelFunc
	danteLastSeen      time.Time
}

func (n *Node) MACTableSize() int {
	return len(n.MACTable)
}

func (n *Node) SACNInputs() []SACNUniverse {
	if n.MulticastGroups == nil {
		return nil
	}
	return n.MulticastGroups.SACNInputs()
}

func (n *Node) MarshalJSON() ([]byte, error) {
	type nodeJSON struct {
		ID                 string                 `json:"id"`
		Names              NameSet                `json:"names"`
		Interfaces         InterfaceMap           `json:"interfaces"`
		MACTableSize       int                    `json:"mac_table_size,omitempty"`
		PoEBudget          *PoEBudget             `json:"poe_budget,omitempty"`
		IsDanteClockMaster bool                   `json:"is_dante_clock_master,omitempty"`
		DanteTxChannels    string                 `json:"dante_tx_channels,omitempty"`
		MulticastGroups    MulticastMembershipSet `json:"multicast_groups,omitempty"`
		ArtNetInputs       ArtNetUniverseSet      `json:"artnet_inputs,omitempty"`
		ArtNetOutputs      ArtNetUniverseSet      `json:"artnet_outputs,omitempty"`
		SACNInputs         []SACNUniverse         `json:"sacn_inputs,omitempty"`
		SACNOutputs        SACNUniverseSet        `json:"sacn_outputs,omitempty"`
		DanteTx            []*DantePeer           `json:"dante_tx,omitempty"`
		DanteRx            []*DantePeer           `json:"dante_rx,omitempty"`
		Unreachable        bool                   `json:"unreachable,omitempty"`
	}
	return json.Marshal(nodeJSON{
		ID:                 n.ID,
		Names:              n.Names,
		Interfaces:         n.Interfaces,
		MACTableSize:       n.MACTableSize(),
		PoEBudget:          n.PoEBudget,
		IsDanteClockMaster: n.IsDanteClockMaster,
		DanteTxChannels:    n.DanteTxChannels,
		MulticastGroups:    n.MulticastGroups,
		ArtNetInputs:       n.ArtNetInputs,
		ArtNetOutputs:      n.ArtNetOutputs,
		SACNInputs:         n.SACNInputs(),
		SACNOutputs:        n.SACNOutputs,
		DanteTx:            n.DanteTx,
		DanteRx:            n.DanteRx,
		Unreachable:        n.Unreachable,
	})
}

type DantePeer struct {
	Node     *Node             `json:"node"`
	Channels []string          `json:"channels,omitempty"`
	Status   map[string]string `json:"status,omitempty"`
}

func (p *DantePeer) MarshalJSON() ([]byte, error) {
	type peerJSON struct {
		Node     *Node             `json:"node"`
		Channels []string          `json:"channels,omitempty"`
		Status   map[string]string `json:"status,omitempty"`
	}
	nodeRef := &Node{
		ID:         p.Node.ID,
		Names:      p.Node.Names,
		Interfaces: p.Node.Interfaces,
	}
	return json.Marshal(peerJSON{
		Node:     nodeRef,
		Channels: p.Channels,
		Status:   p.Status,
	})
}

func (n *Node) WithInterface(ifaceKey string) *Node {
	if ifaceKey == "" {
		return n
	}
	iface, exists := n.Interfaces[ifaceKey]
	if !exists {
		return n
	}
	return &Node{
		ID:                 n.ID,
		Names:              n.Names,
		Interfaces:         InterfaceMap{ifaceKey: iface},
		MACTable:           n.MACTable,
		PoEBudget:          n.PoEBudget,
		IsDanteClockMaster: n.IsDanteClockMaster,
		DanteTxChannels:    n.DanteTxChannels,
	}
}

func (i *Interface) String() string {
	var parts []string
	parts = append(parts, string(i.MAC))
	if i.Name != "" {
		parts = append(parts, fmt.Sprintf("(%s)", i.Name))
	}
	if len(i.IPs) > 0 {
		parts = append(parts, fmt.Sprintf("%v", i.IPs.Slice()))
	}
	if i.Stats != nil {
		parts = append(parts, i.Stats.String())
	}

	result := parts[0]
	for _, p := range parts[1:] {
		result += " " + p
	}
	return result
}

func (s *InterfaceStats) String() string {
	var parts []string

	if s.Speed > 0 {
		if s.Speed >= 1000000000 {
			parts = append(parts, fmt.Sprintf("%dG", s.Speed/1000000000))
		} else if s.Speed >= 1000000 {
			parts = append(parts, fmt.Sprintf("%dM", s.Speed/1000000))
		} else {
			parts = append(parts, fmt.Sprintf("%d", s.Speed))
		}
	}

	if s.InErrors > 0 || s.OutErrors > 0 {
		parts = append(parts, fmt.Sprintf("err:%d/%d", s.InErrors, s.OutErrors))
	}

	if s.InBytesRate > 0 || s.OutBytesRate > 0 {
		parts = append(parts, fmt.Sprintf("%.0f/%.0fB/s", s.InBytesRate, s.OutBytesRate))
	}

	if s.PoE != nil {
		if s.PoE.MaxPower > 0 {
			parts = append(parts, fmt.Sprintf("poe:%.1f/%.1fW", s.PoE.Power, s.PoE.MaxPower))
		} else {
			parts = append(parts, fmt.Sprintf("poe:%.1fW", s.PoE.Power))
		}
	}

	return "[" + strings.Join(parts, " ") + "]"
}

func (n *Node) String() string {
	name := n.DisplayName()
	if name == "" {
		name = "??"
	}

	var parts []string
	parts = append(parts, name)

	if n.PoEBudget != nil {
		parts = append(parts, fmt.Sprintf("[poe:%.0f/%.0fW]", n.PoEBudget.Power, n.PoEBudget.MaxPower))
	}

	var ifaces []string
	for _, iface := range n.Interfaces {
		ifaces = append(ifaces, iface.String())
	}
	sort.Slice(ifaces, func(i, j int) bool { return sortorder.NaturalLess(ifaces[i], ifaces[j]) })

	parts = append(parts, fmt.Sprintf("{%v}", ifaces))

	return strings.Join(parts, " ")
}

func (n *Node) DisplayName() string {
	if len(n.Names) > 0 {
		var names []string
		for name := range n.Names {
			names = append(names, name)
		}
		sortNamesByLength(names)
		return strings.Join(names, "/")
	}
	for _, iface := range n.Interfaces {
		for ip := range iface.IPs {
			return ip
		}
	}
	for _, iface := range n.Interfaces {
		if iface.MAC != "" {
			return string(iface.MAC)
		}
	}
	return ""
}

func (n *Node) FirstMAC() string {
	for _, iface := range n.Interfaces {
		if iface.MAC != "" {
			return string(iface.MAC)
		}
	}
	return ""
}

func (n *Node) FirstIP() string {
	for _, iface := range n.Interfaces {
		for ip := range iface.IPs {
			return ip
		}
	}
	return ""
}