DebTik/internal/dynamicrouting/manager.go

package dynamicrouting

import (
	"encoding/json"
	"fmt"
	"log"
	"os"
	"os/exec"
	"path/filepath"
	"strings"
	"sync"
	"time"
)

const (
	defaultConfigPath = "/etc/proxmox-router/routing/dynamic.json"
	frrConfigPath     = "/etc/frr/frr.conf"
)

type Manager struct {
	mu         sync.RWMutex
	configPath string
	config     DynamicConfig
}

func NewManager(configPath string) *Manager {
	if configPath == "" {
		configPath = defaultConfigPath
	}

	m := &Manager{
		configPath: configPath,
	}

	if err := m.load(); err != nil {
		log.Printf("[DynamicRouting] Config load warning: %v, initializing defaults", err)
		m.initDefaults()
		_ = m.save()
	}

	// Apply initial configuration to FRR
	if err := m.applyFRRConfig(); err != nil {
		log.Printf("[DynamicRouting] Initial FRR apply warning: %v", err)
	}

	return m
}

func (m *Manager) initDefaults() {
	m.config = DynamicConfig{
		BGPInstance: BGPInstance{
			Enabled:               false,
			AS:                    65001,
			RouterID:              "192.168.131.56",
			HoldTime:              180,
			KeepaliveTime:         60,
			RedistributeConnected: false,
			RedistributeStatic:    false,
			RedistributeOSPF:      false,
		},
		BGPPeers:    []BGPPeer{},
		BGPNetworks: []BGPNetwork{},
		OSPFInstance: OSPFInstance{
			Enabled:               false,
			RouterID:              "192.168.131.56",
			RedistributeConnected: false,
			RedistributeStatic:    false,
			RedistributeBGP:       false,
			DefaultMetric:         10,
		},
		OSPFAreas: []OSPFArea{
			{
				ID:       "area-backbone",
				Name:     "backbone",
				AreaID:   "0.0.0.0",
				AreaType: "default",
				Comment:  "Default OSPF Backbone Area",
			},
		},
		OSPFInterfaces: []OSPFInterface{},
	}
}

func (m *Manager) load() error {
	m.mu.Lock()
	defer m.mu.Unlock()

	data, err := os.ReadFile(m.configPath)
	if err != nil {
		return err
	}
	return json.Unmarshal(data, &m.config)
}

func (m *Manager) save() error {
	dir := filepath.Dir(m.configPath)
	if err := os.MkdirAll(dir, 0755); err != nil {
		return err
	}

	data, err := json.MarshalIndent(m.config, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(m.configPath, data, 0644)
}

// applyFRRConfig generates /etc/frr/frr.conf and reloads FRR daemons
func (m *Manager) applyFRRConfig() error {
	var sb strings.Builder

	sb.WriteString("frr version 10.3\n")
	sb.WriteString("frr defaults traditional\n")
	sb.WriteString("hostname WAN-Balancer\n")
	sb.WriteString("log syslog informational\n")
	sb.WriteString("service integrated-vtysh-config\n!\n")

	// 1. Interfaces section for OSPF (cost, timers, authentication)
	interfaceConfigs := make(map[string]bool)
	if m.config.OSPFInstance.Enabled {
		for _, iface := range m.config.OSPFInterfaces {
			if iface.Disabled || iface.Interface == "" || interfaceConfigs[iface.Interface] {
				continue
			}
			interfaceConfigs[iface.Interface] = true
			sb.WriteString(fmt.Sprintf("interface %s\n", iface.Interface))
			if iface.Cost > 0 {
				sb.WriteString(fmt.Sprintf(" ip ospf cost %d\n", iface.Cost))
			}
			if iface.Priority > 0 {
				sb.WriteString(fmt.Sprintf(" ip ospf priority %d\n", iface.Priority))
			}
			if iface.HelloInterval > 0 {
				sb.WriteString(fmt.Sprintf(" ip ospf hello-interval %d\n", iface.HelloInterval))
			}
			if iface.DeadInterval > 0 {
				sb.WriteString(fmt.Sprintf(" ip ospf dead-interval %d\n", iface.DeadInterval))
			}
			if iface.AuthType == "md5" && iface.AuthKey != "" {
				sb.WriteString(" ip ospf authentication message-digest\n")
				sb.WriteString(fmt.Sprintf(" ip ospf message-digest-key 1 md5 %s\n", iface.AuthKey))
			} else if iface.AuthType == "simple" && iface.AuthKey != "" {
				sb.WriteString(" ip ospf authentication\n")
				sb.WriteString(fmt.Sprintf(" ip ospf authentication-key %s\n", iface.AuthKey))
			}
			sb.WriteString("!\n")
		}
	}

	// 2. BGP Router Section
	if m.config.BGPInstance.Enabled && m.config.BGPInstance.AS > 0 {
		inst := m.config.BGPInstance
		sb.WriteString(fmt.Sprintf("router bgp %d\n", inst.AS))
		if inst.RouterID != "" {
			sb.WriteString(fmt.Sprintf(" bgp router-id %s\n", inst.RouterID))
		}
		keepalive := 60
		hold := 180
		if inst.KeepaliveTime > 0 {
			keepalive = inst.KeepaliveTime
		}
		if inst.HoldTime > 0 {
			hold = inst.HoldTime
		}
		sb.WriteString(fmt.Sprintf(" timers bgp %d %d\n", keepalive, hold))

		// Peers definition
		for _, peer := range m.config.BGPPeers {
			if peer.Disabled || peer.RemoteAddress == "" || peer.RemoteAS == 0 {
				continue
			}
			sb.WriteString(fmt.Sprintf(" neighbor %s remote-as %d\n", peer.RemoteAddress, peer.RemoteAS))
			if peer.Name != "" {
				sb.WriteString(fmt.Sprintf(" neighbor %s description \"%s\"\n", peer.RemoteAddress, peer.Name))
			}
			if peer.Multihop {
				sb.WriteString(fmt.Sprintf(" neighbor %s ebgp-multihop 255\n", peer.RemoteAddress))
			}
			if peer.Passive {
				sb.WriteString(fmt.Sprintf(" neighbor %s passive\n", peer.RemoteAddress))
			}
			if peer.Password != "" {
				sb.WriteString(fmt.Sprintf(" neighbor %s password %s\n", peer.RemoteAddress, peer.Password))
			}
			if peer.LocalAddress != "" {
				sb.WriteString(fmt.Sprintf(" neighbor %s update-source %s\n", peer.RemoteAddress, peer.LocalAddress))
			}
		}

		// Address Family IPv4 Unicast
		sb.WriteString(" address-family ipv4 unicast\n")
		// Advertised Networks
		for _, net := range m.config.BGPNetworks {
			if !net.Disabled && net.Network != "" {
				sb.WriteString(fmt.Sprintf("  network %s\n", net.Network))
			}
		}

		// Activate peers in IPv4 unicast
		for _, peer := range m.config.BGPPeers {
			if peer.Disabled || peer.RemoteAddress == "" || peer.RemoteAS == 0 {
				continue
			}
			sb.WriteString(fmt.Sprintf("  neighbor %s activate\n", peer.RemoteAddress))
			if peer.NexthopSelf {
				sb.WriteString(fmt.Sprintf("  neighbor %s next-hop-self\n", peer.RemoteAddress))
			}
		}

		// Redistribute
		if inst.RedistributeConnected {
			sb.WriteString("  redistribute connected\n")
		}
		if inst.RedistributeStatic {
			sb.WriteString("  redistribute static\n")
		}
		if inst.RedistributeOSPF {
			sb.WriteString("  redistribute ospf\n")
		}
		sb.WriteString(" exit-address-family\n!\n")
	}

	// 3. OSPF Router Section
	if m.config.OSPFInstance.Enabled {
		inst := m.config.OSPFInstance
		sb.WriteString("router ospf\n")
		if inst.RouterID != "" {
			sb.WriteString(fmt.Sprintf(" ospf router-id %s\n", inst.RouterID))
		}
		if inst.DefaultMetric > 0 {
			sb.WriteString(fmt.Sprintf(" default-metric %d\n", inst.DefaultMetric))
		}
		if inst.RedistributeConnected {
			sb.WriteString(" redistribute connected\n")
		}
		if inst.RedistributeStatic {
			sb.WriteString(" redistribute static\n")
		}
		if inst.RedistributeBGP {
			sb.WriteString(" redistribute bgp\n")
		}

		for _, iface := range m.config.OSPFInterfaces {
			if iface.Disabled || iface.Network == "" {
				continue
			}
			area := iface.Area
			if area == "" {
				area = "0.0.0.0"
			}
			sb.WriteString(fmt.Sprintf(" network %s area %s\n", iface.Network, area))
			if iface.Passive && iface.Interface != "" {
				sb.WriteString(fmt.Sprintf(" passive-interface %s\n", iface.Interface))
			}
		}
		sb.WriteString("!\n")
	}

	sb.WriteString("end\n")

	// Write frr.conf
	if err := os.WriteFile(frrConfigPath, []byte(sb.String()), 0640); err != nil {
		return fmt.Errorf("failed to write %s: %w", frrConfigPath, err)
	}

	// Change ownership to frr:frr
	_ = exec.Command("chown", "frr:frr", frrConfigPath).Run()

	// Reload FRR using vtysh or systemctl
	out, err := exec.Command("vtysh", "-f", frrConfigPath).CombinedOutput()
	if err != nil {
		log.Printf("[DynamicRouting] vtysh -f reload warning: %v, output: %s", err, string(out))
		// fallback to systemctl reload frr
		_ = exec.Command("systemctl", "reload", "frr").Run()
	}

	return nil
}

func vtyshExec(cmd string) ([]byte, error) {
	return exec.Command("vtysh", "-c", cmd).Output()
}

// -------------------------------------------------------------
// BGP API & Operations
// -------------------------------------------------------------

func (m *Manager) GetBGPInstance() BGPInstance {
	m.mu.RLock()
	defer m.mu.RUnlock()

	inst := m.config.BGPInstance
	// Check if BGP is currently running in FRR
	out, err := vtyshExec("show ip bgp summary json")
	if err == nil && len(out) > 5 && !strings.Contains(string(out), "warning") {
		inst.Running = true
	}
	return inst
}

func (m *Manager) UpdateBGPInstance(inst BGPInstance) error {
	m.mu.Lock()
	m.config.BGPInstance = inst
	_ = m.save()
	m.mu.Unlock()

	return m.applyFRRConfig()
}

func (m *Manager) ListBGPPeers() []BGPPeer {
	m.mu.RLock()
	defer m.mu.RUnlock()

	// Make a copy of configured peers
	peers := make([]BGPPeer, len(m.config.BGPPeers))
	copy(peers, m.config.BGPPeers)

	// Fetch live peer telemetry from vtysh
	out, err := vtyshExec("show ip bgp summary json")
	if err == nil {
		var summary struct {
			IPv4Unicast struct {
				Peers map[string]struct {
					RemoteAs   uint32 `json:"remoteAs"`
					State      string `json:"state"`
					PeerUptime string `json:"peerUptime"`
					PfxRcd     int    `json:"pfxRcd"`
					PfxSnt     int    `json:"pfxSnt"`
				} `json:"peers"`
			} `json:"ipv4Unicast"`
		}
		if err := json.Unmarshal(out, &summary); err == nil && summary.IPv4Unicast.Peers != nil {
			for i := range peers {
				if live, ok := summary.IPv4Unicast.Peers[peers[i].RemoteAddress]; ok {
					peers[i].State = live.State
					peers[i].Uptime = live.PeerUptime
					peers[i].PrefixReceived = live.PfxRcd
					peers[i].PrefixSent = live.PfxSnt
				} else if peers[i].Disabled {
					peers[i].State = "Disabled"
				} else {
					peers[i].State = "Idle"
				}
			}
		}
	}

	return peers
}

func (m *Manager) SaveBGPPeer(peer BGPPeer) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	if peer.ID == "" {
		peer.ID = fmt.Sprintf("bgp-peer-%d", time.Now().UnixNano())
	}

	found := false
	for i, p := range m.config.BGPPeers {
		if p.ID == peer.ID {
			m.config.BGPPeers[i] = peer
			found = true
			break
		}
	}
	if !found {
		m.config.BGPPeers = append(m.config.BGPPeers, peer)
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) DeleteBGPPeer(id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	newPeers := make([]BGPPeer, 0, len(m.config.BGPPeers))
	for _, p := range m.config.BGPPeers {
		if p.ID != id {
			newPeers = append(newPeers, p)
		}
	}
	m.config.BGPPeers = newPeers

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) SetBGPPeerState(id string, disabled bool) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	for i := range m.config.BGPPeers {
		if m.config.BGPPeers[i].ID == id {
			m.config.BGPPeers[i].Disabled = disabled
			break
		}
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) ListBGPNetworks() []BGPNetwork {
	m.mu.RLock()
	defer m.mu.RUnlock()
	return m.config.BGPNetworks
}

func (m *Manager) SaveBGPNetwork(net BGPNetwork) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	if net.ID == "" {
		net.ID = fmt.Sprintf("bgp-net-%d", time.Now().UnixNano())
	}

	found := false
	for i, n := range m.config.BGPNetworks {
		if n.ID == net.ID {
			m.config.BGPNetworks[i] = net
			found = true
			break
		}
	}
	if !found {
		m.config.BGPNetworks = append(m.config.BGPNetworks, net)
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) DeleteBGPNetwork(id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	newNets := make([]BGPNetwork, 0, len(m.config.BGPNetworks))
	for _, n := range m.config.BGPNetworks {
		if n.ID != id {
			newNets = append(newNets, n)
		}
	}
	m.config.BGPNetworks = newNets

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) GetBGPRoutes() []BGPRoute {
	var routes []BGPRoute

	out, err := vtyshExec("show ip bgp json")
	if err != nil {
		return routes
	}

	var parsed struct {
		Routes map[string][]struct {
			Metric   int    `json:"metric"`
			Weight   int    `json:"weight"`
			Path     string `json:"path"`
			Origin   string `json:"origin"`
			Nexthops []struct {
				IP   string `json:"ip"`
				Used bool   `json:"used"`
			} `json:"nexthops"`
		} `json:"routes"`
	}

	if err := json.Unmarshal(out, &parsed); err == nil && parsed.Routes != nil {
		for prefix, items := range parsed.Routes {
			for _, item := range items {
				nh := ""
				if len(item.Nexthops) > 0 {
					nh = item.Nexthops[0].IP
				}
				routes = append(routes, BGPRoute{
					Prefix:  prefix,
					NextHop: nh,
					Metric:  item.Metric,
					Weight:  item.Weight,
					Path:    item.Path,
					Origin:  item.Origin,
					Best:    true,
				})
			}
		}
	}

	return routes
}

// -------------------------------------------------------------
// OSPF API & Operations
// -------------------------------------------------------------

func (m *Manager) GetOSPFInstance() OSPFInstance {
	m.mu.RLock()
	defer m.mu.RUnlock()

	inst := m.config.OSPFInstance
	out, err := vtyshExec("show ip ospf json")
	if err == nil && len(out) > 5 && !strings.Contains(string(out), "warning") {
		inst.Running = true
	}
	return inst
}

func (m *Manager) UpdateOSPFInstance(inst OSPFInstance) error {
	m.mu.Lock()
	m.config.OSPFInstance = inst
	_ = m.save()
	m.mu.Unlock()

	return m.applyFRRConfig()
}

func (m *Manager) ListOSPFAreas() []OSPFArea {
	m.mu.RLock()
	defer m.mu.RUnlock()
	return m.config.OSPFAreas
}

func (m *Manager) SaveOSPFArea(area OSPFArea) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	if area.ID == "" {
		area.ID = fmt.Sprintf("area-%d", time.Now().UnixNano())
	}

	found := false
	for i, a := range m.config.OSPFAreas {
		if a.ID == area.ID {
			m.config.OSPFAreas[i] = area
			found = true
			break
		}
	}
	if !found {
		m.config.OSPFAreas = append(m.config.OSPFAreas, area)
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) DeleteOSPFArea(id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	newAreas := make([]OSPFArea, 0, len(m.config.OSPFAreas))
	for _, a := range m.config.OSPFAreas {
		if a.ID != id {
			newAreas = append(newAreas, a)
		}
	}
	m.config.OSPFAreas = newAreas

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) ListOSPFInterfaces() []OSPFInterface {
	m.mu.RLock()
	defer m.mu.RUnlock()
	return m.config.OSPFInterfaces
}

func (m *Manager) SaveOSPFInterface(iface OSPFInterface) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	if iface.ID == "" {
		iface.ID = fmt.Sprintf("ospf-iface-%d", time.Now().UnixNano())
	}
	if iface.Cost <= 0 {
		iface.Cost = 10
	}
	if iface.Priority <= 0 {
		iface.Priority = 1
	}
	if iface.HelloInterval <= 0 {
		iface.HelloInterval = 10
	}
	if iface.DeadInterval <= 0 {
		iface.DeadInterval = 40
	}

	found := false
	for i, item := range m.config.OSPFInterfaces {
		if item.ID == iface.ID {
			m.config.OSPFInterfaces[i] = iface
			found = true
			break
		}
	}
	if !found {
		m.config.OSPFInterfaces = append(m.config.OSPFInterfaces, iface)
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) DeleteOSPFInterface(id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	newInterfaces := make([]OSPFInterface, 0, len(m.config.OSPFInterfaces))
	for _, item := range m.config.OSPFInterfaces {
		if item.ID != id {
			newInterfaces = append(newInterfaces, item)
		}
	}
	m.config.OSPFInterfaces = newInterfaces

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) SetOSPFInterfaceState(id string, disabled bool) error {
	m.mu.Lock()
	defer m.mu.Unlock()

	for i := range m.config.OSPFInterfaces {
		if m.config.OSPFInterfaces[i].ID == id {
			m.config.OSPFInterfaces[i].Disabled = disabled
			break
		}
	}

	if err := m.save(); err != nil {
		return err
	}
	return m.applyFRRConfig()
}

func (m *Manager) GetOSPFNeighbors() []OSPFNeighbor {
	var neighbors []OSPFNeighbor

	out, err := vtyshExec("show ip ospf neighbor json")
	if err != nil {
		return neighbors
	}

	var parsed struct {
		Neighbors map[string][]struct {
			NbrState  string `json:"nbrState"`
			Address   string `json:"address"`
			IfaceName string `json:"ifaceName"`
			Area      string `json:"area"`
			DeadTime  string `json:"deadTime"`
		} `json:"neighbors"`
	}

	if err := json.Unmarshal(out, &parsed); err == nil && parsed.Neighbors != nil {
		for nbrID, entries := range parsed.Neighbors {
			for _, entry := range entries {
				neighbors = append(neighbors, OSPFNeighbor{
					NeighborID: nbrID,
					Address:    entry.Address,
					Interface:  entry.IfaceName,
					Area:       entry.Area,
					State:      entry.NbrState,
					DeadTimer:  entry.DeadTime,
				})
			}
		}
	}

	return neighbors
}

func (m *Manager) GetOSPFRoutes() []OSPFRoute {
	var routes []OSPFRoute

	out, err := vtyshExec("show ip ospf route json")
	if err != nil {
		return routes
	}

	var parsed map[string]struct {
		RouteType string `json:"routeType"`
		Cost      int    `json:"cost"`
		Area      string `json:"area"`
		Nexthops  []struct {
			IP                 string `json:"ip"`
			DirectlyAttachedTo string `json:"directlyAttachedTo"`
		} `json:"nexthops"`
	}

	if err := json.Unmarshal(out, &parsed); err == nil {
		for prefix, r := range parsed {
			nh := ""
			dev := ""
			if len(r.Nexthops) > 0 {
				nh = strings.TrimSpace(r.Nexthops[0].IP)
				dev = r.Nexthops[0].DirectlyAttachedTo
			}
			routes = append(routes, OSPFRoute{
				Prefix:    prefix,
				RouteType: r.RouteType,
				Cost:      r.Cost,
				Area:      r.Area,
				NextHop:   nh,
				Interface: dev,
			})
		}
	}

	return routes
}

// -------------------------------------------------------------
// Summary Telemetry
// -------------------------------------------------------------

func (m *Manager) GetSummary() DynamicRoutingSummary {
	m.mu.RLock()
	defer m.mu.RUnlock()

	summary := DynamicRoutingSummary{
		BGPEnabled:  m.config.BGPInstance.Enabled,
		OSPFEnabled: m.config.OSPFInstance.Enabled,
	}

	// Check BGP status
	if summary.BGPEnabled {
		out, err := vtyshExec("show ip bgp summary json")
		if err == nil && len(out) > 5 && !strings.Contains(string(out), "warning") {
			summary.BGPRunning = true
			var bgpParsed struct {
				IPv4Unicast struct {
					PeerCount int `json:"peerCount"`
					Peers     map[string]struct {
						State string `json:"state"`
					} `json:"peers"`
				} `json:"ipv4Unicast"`
			}
			if err := json.Unmarshal(out, &bgpParsed); err == nil {
				summary.BGPPeerCount = len(m.config.BGPPeers)
				for _, p := range bgpParsed.IPv4Unicast.Peers {
					if p.State == "Established" {
						summary.BGPEstablishedCount++
					}
				}
			}
		}
	}

	// Check OSPF status
	if summary.OSPFEnabled {
		out, err := vtyshExec("show ip ospf json")
		if err == nil && len(out) > 5 && !strings.Contains(string(out), "warning") {
			summary.OSPFRunning = true
		}
		nbrs := m.GetOSPFNeighbors()
		summary.OSPFNeighborCount = len(nbrs)
		for _, n := range nbrs {
			if strings.HasPrefix(n.State, "Full") {
				summary.OSPFAdjacentCount++
			}
		}
	}

	return summary
}