package main

import (
	"bufio"
	"context"
	crypto_rand "crypto/rand"
	"crypto/sha256"
	"encoding/base64"
	"encoding/hex"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"time"

	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud"
	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud/request"
	"github.com/UpCloudLtd/upcloud-go-api/v8/upcloud/service"
	"github.com/spf13/cobra"
)

var provisionCmd = &cobra.Command{
	Use:   "provision",
	Short: "Create all infrastructure (servers, network, LB, firewall)",
	RunE: func(cmd *cobra.Command, args []string) error {
		token, _ := cmd.Root().PersistentFlags().GetString("token")
		zone, _ := cmd.Flags().GetString("zone")
		plan, _ := cmd.Flags().GetString("plan")
		sshKey, _ := cmd.Flags().GetString("ssh-key")
		s3Secret, _ := cmd.Flags().GetString("s3-secret")
		withScanner, _ := cmd.Flags().GetBool("with-scanner")
		return cmdProvision(token, zone, plan, sshKey, s3Secret, withScanner)
	},
}

func init() {
	provisionCmd.Flags().String("zone", "", "UpCloud zone (interactive picker if omitted)")
	provisionCmd.Flags().String("plan", "", "Server plan (interactive picker if omitted)")
	provisionCmd.Flags().String("ssh-key", "", "Path to SSH public key file (required)")
	provisionCmd.Flags().String("s3-secret", "", "S3 secret access key (for existing object storage)")
	provisionCmd.Flags().Bool("with-scanner", false, "Deploy vulnerability scanner alongside hold")
	_ = provisionCmd.MarkFlagRequired("ssh-key")
	rootCmd.AddCommand(provisionCmd)
}

func cmdProvision(token, zone, plan, sshKeyPath, s3Secret string, withScanner bool) error {
	cfg, err := loadConfig(zone, plan, sshKeyPath, s3Secret)
	if err != nil {
		return err
	}

	naming := cfg.Naming()

	svc, err := newService(token)
	if err != nil {
		return err
	}

	ctx, cancel := context.WithTimeout(context.Background(), 15*time.Minute)
	defer cancel()

	// Load existing state or start fresh
	state, err := loadState()
	if err != nil {
		state = &InfraState{}
	}

	// Use zone from state if not provided via flags
	if cfg.Zone == "" && state.Zone != "" {
		cfg.Zone = state.Zone
	}

	// Only need interactive picker if we still need to create resources
	needsServers := state.Appview.UUID == "" || state.Hold.UUID == ""
	if cfg.Zone == "" || (needsServers && cfg.Plan == "") {
		if err := resolveInteractive(ctx, svc, cfg); err != nil {
			return err
		}
	}

	if state.Zone == "" {
		state.Zone = cfg.Zone
	}
	state.ClientName = cfg.ClientName
	state.RepoBranch = cfg.RepoBranch

	// Scanner setup
	if withScanner {
		state.ScannerEnabled = true
		if state.ScannerSecret == "" {
			secret, err := generateScannerSecret()
			if err != nil {
				return fmt.Errorf("generate scanner secret: %w", err)
			}
			state.ScannerSecret = secret
			fmt.Printf("Generated scanner shared secret\n")
		}
		_ = saveState(state)
	}

	fmt.Printf("Provisioning %s infrastructure in zone %s...\n", naming.DisplayName(), cfg.Zone)
	if needsServers {
		fmt.Printf("Server plan: %s\n", cfg.Plan)
	}
	fmt.Println()

	// S3 secret key — from flag for existing storage, from API for new
	s3SecretKey := cfg.S3SecretKey

	// 1. Object storage
	if state.ObjectStorage.UUID != "" {
		fmt.Printf("Object storage: %s (exists)\n", state.ObjectStorage.UUID)
		// Refresh discoverable fields if missing (e.g. pre-seeded UUID only)
		if state.ObjectStorage.Endpoint == "" || state.ObjectStorage.Bucket == "" {
			fmt.Println("  Discovering endpoint, bucket, access key...")
			discovered, err := lookupObjectStorage(ctx, svc, state.ObjectStorage.UUID)
			if err != nil {
				return err
			}
			state.ObjectStorage.Endpoint = discovered.Endpoint
			state.ObjectStorage.Region = discovered.Region
			if discovered.Bucket != "" {
				state.ObjectStorage.Bucket = discovered.Bucket
			}
			if discovered.AccessKeyID != "" {
				state.ObjectStorage.AccessKeyID = discovered.AccessKeyID
			}
			_ = saveState(state)
		}
	} else {
		fmt.Println("Creating object storage...")
		objState, secretKey, err := provisionObjectStorage(ctx, svc, cfg.Zone, naming.S3Name())
		if err != nil {
			return fmt.Errorf("object storage: %w", err)
		}
		state.ObjectStorage = objState
		s3SecretKey = secretKey
		_ = saveState(state)
		fmt.Printf("  S3 Secret Key: %s\n", secretKey)
	}

	fmt.Printf("  Endpoint:   %s\n", state.ObjectStorage.Endpoint)
	fmt.Printf("  Region:     %s\n", state.ObjectStorage.Region)
	fmt.Printf("  Bucket:     %s\n", state.ObjectStorage.Bucket)
	fmt.Printf("  Access Key: %s\n\n", state.ObjectStorage.AccessKeyID)

	// Hold domain is zone-based (e.g. us-chi1.cove.seamark.dev)
	holdDomain := cfg.Zone + ".cove." + cfg.BaseDomain

	// Build config template values
	vals := &ConfigValues{
		S3Endpoint:    state.ObjectStorage.Endpoint,
		S3Region:      state.ObjectStorage.Region,
		S3Bucket:      state.ObjectStorage.Bucket,
		S3AccessKey:   state.ObjectStorage.AccessKeyID,
		S3SecretKey:   s3SecretKey,
		Zone:          cfg.Zone,
		HoldDomain:    holdDomain,
		HoldDid:       "did:web:" + holdDomain,
		BasePath:      naming.BasePath(),
		ScannerSecret: state.ScannerSecret,
	}

	// 2. Private network
	if state.Network.UUID != "" {
		fmt.Printf("Network: %s (exists)\n", state.Network.UUID)
	} else {
		fmt.Println("Creating private network...")
		network, err := svc.CreateNetwork(ctx, &request.CreateNetworkRequest{
			Name: naming.NetworkName(),
			Zone: cfg.Zone,
			IPNetworks: upcloud.IPNetworkSlice{
				{
					Address:          privateNetworkCIDR,
					DHCP:             upcloud.True,
					DHCPDefaultRoute: upcloud.False,
					DHCPDns:          []string{"8.8.8.8", "1.1.1.1"},
					Family:           upcloud.IPAddressFamilyIPv4,
					Gateway:          "",
				},
			},
		})
		if err != nil {
			return fmt.Errorf("create network: %w", err)
		}
		state.Network = StateRef{UUID: network.UUID}
		_ = saveState(state)
		fmt.Printf("  Network: %s (%s)\n", network.UUID, privateNetworkCIDR)
	}

	// Find Debian template (needed for server creation)
	templateUUID, err := findDebianTemplate(ctx, svc)
	if err != nil {
		return err
	}

	// 3. Appview server
	appviewCreated := false
	if state.Appview.UUID != "" {
		fmt.Printf("Appview: %s (exists)\n", state.Appview.UUID)
		appviewScript, err := generateAppviewCloudInit(cfg, vals)
		if err != nil {
			return err
		}
		if err := syncCloudInit("appview", state.Appview.PublicIP, appviewScript); err != nil {
			return err
		}
		appviewConfigYAML, err := renderConfig(appviewConfigTmpl, vals)
		if err != nil {
			return fmt.Errorf("render appview config: %w", err)
		}
		if err := syncConfigKeys("appview", state.Appview.PublicIP, naming.AppviewConfigPath(), appviewConfigYAML); err != nil {
			return fmt.Errorf("appview config sync: %w", err)
		}
	} else {
		fmt.Println("Creating appview server...")
		appviewUserData, err := generateAppviewCloudInit(cfg, vals)
		if err != nil {
			return err
		}
		appview, err := createServer(ctx, svc, cfg, templateUUID, state.Network.UUID, naming.Appview(), appviewUserData)
		if err != nil {
			return fmt.Errorf("create appview: %w", err)
		}
		state.Appview = *appview
		_ = saveState(state)
		appviewCreated = true
		fmt.Printf("  Appview: %s (public: %s, private: %s)\n", appview.UUID, appview.PublicIP, appview.PrivateIP)
	}

	// 4. Hold server
	holdCreated := false
	if state.Hold.UUID != "" {
		fmt.Printf("Hold: %s (exists)\n", state.Hold.UUID)
		holdScript, err := generateHoldCloudInit(cfg, vals, state.ScannerEnabled)
		if err != nil {
			return err
		}
		if err := syncCloudInit("hold", state.Hold.PublicIP, holdScript); err != nil {
			return err
		}
		holdConfigYAML, err := renderConfig(holdConfigTmpl, vals)
		if err != nil {
			return fmt.Errorf("render hold config: %w", err)
		}
		if err := syncConfigKeys("hold", state.Hold.PublicIP, naming.HoldConfigPath(), holdConfigYAML); err != nil {
			return fmt.Errorf("hold config sync: %w", err)
		}
		if state.ScannerEnabled {
			scannerConfigYAML, err := renderConfig(scannerConfigTmpl, vals)
			if err != nil {
				return fmt.Errorf("render scanner config: %w", err)
			}
			if err := syncConfigKeys("scanner", state.Hold.PublicIP, naming.ScannerConfigPath(), scannerConfigYAML); err != nil {
				return fmt.Errorf("scanner config sync: %w", err)
			}
		}
	} else {
		fmt.Println("Creating hold server...")
		holdUserData, err := generateHoldCloudInit(cfg, vals, state.ScannerEnabled)
		if err != nil {
			return err
		}
		hold, err := createServer(ctx, svc, cfg, templateUUID, state.Network.UUID, naming.Hold(), holdUserData)
		if err != nil {
			return fmt.Errorf("create hold: %w", err)
		}
		state.Hold = *hold
		_ = saveState(state)
		holdCreated = true
		fmt.Printf("  Hold: %s (public: %s, private: %s)\n", hold.UUID, hold.PublicIP, hold.PrivateIP)
	}

	// 5. Firewall rules (idempotent — replaces all rules)
	fmt.Println("Configuring firewall rules...")
	for _, s := range []struct {
		name string
		uuid string
	}{
		{"appview", state.Appview.UUID},
		{"hold", state.Hold.UUID},
	} {
		if err := createFirewallRules(ctx, svc, s.uuid, privateNetworkCIDR); err != nil {
			return fmt.Errorf("firewall %s: %w", s.name, err)
		}
	}

	// 6. Load balancer
	if state.LB.UUID != "" {
		fmt.Printf("Load balancer: %s (exists)\n", state.LB.UUID)
	} else {
		fmt.Println("Creating load balancer (Essentials tier)...")
		lb, err := createLoadBalancer(ctx, svc, cfg, naming, state.Network.UUID, state.Appview.PrivateIP, state.Hold.PrivateIP, holdDomain)
		if err != nil {
			return fmt.Errorf("create LB: %w", err)
		}
		state.LB = StateRef{UUID: lb.UUID}
		_ = saveState(state)
	}

	// Always reconcile forwarded headers rule (handles existing LBs)
	if err := ensureLBForwardedHeaders(ctx, svc, state.LB.UUID); err != nil {
		return fmt.Errorf("LB forwarded headers: %w", err)
	}

	// Ensure route-hold rule includes forwarded headers action
	if err := ensureLBHoldForwardedHeaders(ctx, svc, state.LB.UUID, holdDomain); err != nil {
		return fmt.Errorf("LB hold forwarded headers: %w", err)
	}

	// Always reconcile scanner block rule
	if err := ensureLBScannerBlock(ctx, svc, state.LB.UUID); err != nil {
		return fmt.Errorf("LB scanner block: %w", err)
	}

	// Always reconcile TLS certs (handles partial failures and re-runs)
	tlsDomains := []string{cfg.BaseDomain}
	tlsDomains = append(tlsDomains, cfg.RegistryDomains...)
	tlsDomains = append(tlsDomains, holdDomain)
	if err := ensureLBCertificates(ctx, svc, state.LB.UUID, tlsDomains); err != nil {
		return fmt.Errorf("LB certificates: %w", err)
	}

	// Fetch LB DNS name for output
	lbDNS := ""
	if state.LB.UUID != "" {
		lb, err := svc.GetLoadBalancer(ctx, &request.GetLoadBalancerRequest{UUID: state.LB.UUID})
		if err == nil {
			for _, n := range lb.Networks {
				if n.Type == upcloud.LoadBalancerNetworkTypePublic {
					lbDNS = n.DNSName
				}
			}
		}
	}

	// 7. Build locally and deploy binaries to new servers
	if appviewCreated || holdCreated {
		rootDir := projectRoot()

		if err := runGenerate(rootDir); err != nil {
			return fmt.Errorf("go generate: %w", err)
		}

		fmt.Println("\nBuilding locally (GOOS=linux GOARCH=amd64)...")
		if appviewCreated {
			outputPath := filepath.Join(rootDir, "bin", "atcr-appview")
			if err := buildLocal(rootDir, outputPath, "./cmd/appview"); err != nil {
				return fmt.Errorf("build appview: %w", err)
			}
		}
		if holdCreated {
			outputPath := filepath.Join(rootDir, "bin", "atcr-hold")
			if err := buildLocal(rootDir, outputPath, "./cmd/hold"); err != nil {
				return fmt.Errorf("build hold: %w", err)
			}
			if state.ScannerEnabled {
				outputPath := filepath.Join(rootDir, "bin", "atcr-scanner")
				if err := buildLocal(filepath.Join(rootDir, "scanner"), outputPath, "./cmd/scanner"); err != nil {
					return fmt.Errorf("build scanner: %w", err)
				}
			}
		}

		fmt.Println("\nWaiting for cloud-init to complete on new servers...")
		if appviewCreated {
			if err := waitForSetup(state.Appview.PublicIP, "appview"); err != nil {
				return err
			}
		}
		if holdCreated {
			if err := waitForSetup(state.Hold.PublicIP, "hold"); err != nil {
				return err
			}
		}

		fmt.Println("\nDeploying binaries...")
		if appviewCreated {
			localPath := filepath.Join(rootDir, "bin", "atcr-appview")
			remotePath := naming.InstallDir() + "/bin/" + naming.Appview()
			if err := scpFile(localPath, state.Appview.PublicIP, remotePath); err != nil {
				return fmt.Errorf("upload appview: %w", err)
			}
		}
		if holdCreated {
			localPath := filepath.Join(rootDir, "bin", "atcr-hold")
			remotePath := naming.InstallDir() + "/bin/" + naming.Hold()
			if err := scpFile(localPath, state.Hold.PublicIP, remotePath); err != nil {
				return fmt.Errorf("upload hold: %w", err)
			}
			if state.ScannerEnabled {
				scannerLocal := filepath.Join(rootDir, "bin", "atcr-scanner")
				scannerRemote := naming.InstallDir() + "/bin/" + naming.Scanner()
				if err := scpFile(scannerLocal, state.Hold.PublicIP, scannerRemote); err != nil {
					return fmt.Errorf("upload scanner: %w", err)
				}
			}
		}
	}

	fmt.Println("\n=== Provisioning Complete ===")
	fmt.Println()
	fmt.Println("DNS records needed:")
	if lbDNS != "" {
		fmt.Printf("  CNAME  %-24s → %s\n", cfg.BaseDomain, lbDNS)
		for _, rd := range cfg.RegistryDomains {
			fmt.Printf("  CNAME  %-24s → %s\n", rd, lbDNS)
		}
		fmt.Printf("  CNAME  %-24s → %s\n", holdDomain, lbDNS)
	} else {
		fmt.Println("  (LB DNS name not yet available — check 'status' in a few minutes)")
	}
	fmt.Println()
	fmt.Println("SSH access:")
	fmt.Printf("  ssh root@%s   # appview\n", state.Appview.PublicIP)
	fmt.Printf("  ssh root@%s   # hold\n", state.Hold.PublicIP)
	fmt.Println()
	fmt.Println("Next steps:")
	if appviewCreated || holdCreated {
		fmt.Println("  1. Edit configs if needed, then start services:")
	} else {
		fmt.Println("  1. Start services:")
	}
	if state.ScannerEnabled {
		fmt.Printf("     systemctl start %s / %s / %s\n", naming.Appview(), naming.Hold(), naming.Scanner())
	} else {
		fmt.Printf("     systemctl start %s / %s\n", naming.Appview(), naming.Hold())
	}
	fmt.Println("  2. Configure DNS records above")

	return nil
}

// provisionObjectStorage creates a new Managed Object Storage with a user, access key, and bucket.
// Returns the state and the secret key separately (only available at creation time).
func provisionObjectStorage(ctx context.Context, svc *service.Service, zone, s3Name string) (ObjectStorageState, string, error) {
	// Map compute zone to object storage region (e.g. us-chi1 → us-east-1)
	region := objectStorageRegion(zone)

	storage, err := svc.CreateManagedObjectStorage(ctx, &request.CreateManagedObjectStorageRequest{
		Name:             s3Name,
		Region:           region,
		ConfiguredStatus: upcloud.ManagedObjectStorageConfiguredStatusStarted,
		Networks: []upcloud.ManagedObjectStorageNetwork{
			{
				Family: upcloud.IPAddressFamilyIPv4,
				Name:   "public",
				Type:   "public",
			},
		},
	})
	if err != nil {
		return ObjectStorageState{}, "", fmt.Errorf("create storage: %w", err)
	}
	fmt.Printf("  Created: %s (region: %s)\n", storage.UUID, region)

	// Find endpoint
	var endpoint string
	for _, ep := range storage.Endpoints {
		if ep.DomainName != "" {
			endpoint = "https://" + ep.DomainName
			break
		}
	}

	// Create user
	_, err = svc.CreateManagedObjectStorageUser(ctx, &request.CreateManagedObjectStorageUserRequest{
		ServiceUUID: storage.UUID,
		Username:    s3Name,
	})
	if err != nil {
		return ObjectStorageState{}, "", fmt.Errorf("create user: %w", err)
	}

	// Attach admin policy
	err = svc.AttachManagedObjectStorageUserPolicy(ctx, &request.AttachManagedObjectStorageUserPolicyRequest{
		ServiceUUID: storage.UUID,
		Username:    s3Name,
		Name:        "admin",
	})
	if err != nil {
		return ObjectStorageState{}, "", fmt.Errorf("attach policy: %w", err)
	}

	// Create access key (secret is only returned here)
	accessKey, err := svc.CreateManagedObjectStorageUserAccessKey(ctx, &request.CreateManagedObjectStorageUserAccessKeyRequest{
		ServiceUUID: storage.UUID,
		Username:    s3Name,
	})
	if err != nil {
		return ObjectStorageState{}, "", fmt.Errorf("create access key: %w", err)
	}

	secretKey := ""
	if accessKey.SecretAccessKey != nil {
		secretKey = *accessKey.SecretAccessKey
	}

	// Create bucket
	_, err = svc.CreateManagedObjectStorageBucket(ctx, &request.CreateManagedObjectStorageBucketRequest{
		ServiceUUID: storage.UUID,
		Name:        s3Name,
	})
	if err != nil {
		return ObjectStorageState{}, "", fmt.Errorf("create bucket: %w", err)
	}

	return ObjectStorageState{
		UUID:        storage.UUID,
		Endpoint:    endpoint,
		Region:      region,
		Bucket:      s3Name,
		AccessKeyID: accessKey.AccessKeyID,
	}, secretKey, nil
}

// objectStorageRegion maps a compute zone to the nearest object storage region.
func objectStorageRegion(zone string) string {
	switch {
	case strings.HasPrefix(zone, "us-"):
		return "us-east-1"
	case strings.HasPrefix(zone, "de-"):
		return "europe-1"
	case strings.HasPrefix(zone, "fi-"):
		return "europe-1"
	case strings.HasPrefix(zone, "nl-"):
		return "europe-1"
	case strings.HasPrefix(zone, "es-"):
		return "europe-1"
	case strings.HasPrefix(zone, "pl-"):
		return "europe-1"
	case strings.HasPrefix(zone, "se-"):
		return "europe-1"
	case strings.HasPrefix(zone, "au-"):
		return "australia-1"
	case strings.HasPrefix(zone, "sg-"):
		return "singapore-1"
	default:
		return "us-east-1"
	}
}

func createServer(ctx context.Context, svc *service.Service, cfg *InfraConfig, templateUUID, networkUUID, title, userData string) (*ServerState, error) {
	storageTier := "maxiops"
	if strings.HasPrefix(strings.ToUpper(cfg.Plan), "DEV-") {
		storageTier = "standard"
	}

	// Look up the plan's storage size from the API instead of hardcoding.
	diskSize := 25 // fallback
	plans, err := svc.GetPlans(ctx)
	if err == nil {
		for _, p := range plans.Plans {
			if p.Name == cfg.Plan {
				diskSize = p.StorageSize
				break
			}
		}
	}

	details, err := svc.CreateServer(ctx, &request.CreateServerRequest{
		Zone:             cfg.Zone,
		Title:            title,
		Hostname:         title,
		Plan:             cfg.Plan,
		Metadata:         upcloud.True,
		UserData:         userData,
		Firewall:         "on",
		PasswordDelivery: "none",
		StorageDevices: request.CreateServerStorageDeviceSlice{
			{
				Action:  "clone",
				Storage: templateUUID,
				Title:   title + "-disk",
				Size:    diskSize,
				Tier:    storageTier,
			},
		},
		Networking: &request.CreateServerNetworking{
			Interfaces: request.CreateServerInterfaceSlice{
				{
					Index: 1,
					Type:  upcloud.IPAddressAccessPublic,
					IPAddresses: request.CreateServerIPAddressSlice{
						{Family: upcloud.IPAddressFamilyIPv4},
					},
				},
				{
					Index:   2,
					Type:    upcloud.IPAddressAccessPrivate,
					Network: networkUUID,
					IPAddresses: request.CreateServerIPAddressSlice{
						{Family: upcloud.IPAddressFamilyIPv4},
					},
				},
			},
		},
		LoginUser: &request.LoginUser{
			CreatePassword: "no",
			SSHKeys:        request.SSHKeySlice{cfg.SSHPublicKey},
		},
	})
	if err != nil {
		return nil, err
	}

	fmt.Printf("  Waiting for server %s to start...\n", details.UUID)
	details, err = svc.WaitForServerState(ctx, &request.WaitForServerStateRequest{
		UUID:         details.UUID,
		DesiredState: upcloud.ServerStateStarted,
	})
	if err != nil {
		return nil, fmt.Errorf("wait for server: %w", err)
	}

	s := &ServerState{UUID: details.UUID}
	for _, iface := range details.Networking.Interfaces {
		for _, addr := range iface.IPAddresses {
			if addr.Family == upcloud.IPAddressFamilyIPv4 {
				switch iface.Type {
				case upcloud.IPAddressAccessPublic:
					s.PublicIP = addr.Address
				case upcloud.IPAddressAccessPrivate:
					s.PrivateIP = addr.Address
				}
			}
		}
	}

	return s, nil
}

func createFirewallRules(ctx context.Context, svc *service.Service, serverUUID, privateCIDR string) error {
	networkBase := strings.TrimSuffix(privateCIDR, "/24")
	networkBase = strings.TrimSuffix(networkBase, ".0")

	return svc.CreateFirewallRules(ctx, &request.CreateFirewallRulesRequest{
		ServerUUID: serverUUID,
		FirewallRules: request.FirewallRuleSlice{
			{
				Direction:            upcloud.FirewallRuleDirectionIn,
				Action:               upcloud.FirewallRuleActionAccept,
				Family:               upcloud.IPAddressFamilyIPv4,
				Protocol:             upcloud.FirewallRuleProtocolTCP,
				DestinationPortStart: "22",
				DestinationPortEnd:   "22",
				Position:             1,
				Comment:              "Allow SSH",
			},
			{
				Direction:          upcloud.FirewallRuleDirectionIn,
				Action:             upcloud.FirewallRuleActionAccept,
				Family:             upcloud.IPAddressFamilyIPv4,
				SourceAddressStart: networkBase + ".0",
				SourceAddressEnd:   networkBase + ".255",
				Position:           2,
				Comment:            "Allow private network",
			},
			{
				Direction:          upcloud.FirewallRuleDirectionIn,
				Action:             upcloud.FirewallRuleActionAccept,
				Family:             upcloud.IPAddressFamilyIPv4,
				Protocol:           upcloud.FirewallRuleProtocolUDP,
				SourcePortStart:    "123",
				SourcePortEnd:      "123",
				Position:           3,
				Comment:            "Allow NTP replies",
			},
			{
				Direction: upcloud.FirewallRuleDirectionIn,
				Action:    upcloud.FirewallRuleActionDrop,
				Position:  4,
				Comment:   "Drop all other inbound",
			},
		},
	})
}

func createLoadBalancer(ctx context.Context, svc *service.Service, cfg *InfraConfig, naming Naming, networkUUID, appviewIP, holdIP, holdDomain string) (*upcloud.LoadBalancer, error) {
	lb, err := svc.CreateLoadBalancer(ctx, &request.CreateLoadBalancerRequest{
		Name:             naming.LBName(),
		Plan:             "essentials",
		Zone:             cfg.Zone,
		ConfiguredStatus: upcloud.LoadBalancerConfiguredStatusStarted,
		Networks: []request.LoadBalancerNetwork{
			{
				Name:   "public",
				Type:   upcloud.LoadBalancerNetworkTypePublic,
				Family: upcloud.LoadBalancerAddressFamilyIPv4,
			},
			{
				Name:   "private",
				Type:   upcloud.LoadBalancerNetworkTypePrivate,
				Family: upcloud.LoadBalancerAddressFamilyIPv4,
				UUID:   networkUUID,
			},
		},
		Frontends: []request.LoadBalancerFrontend{
			{
				Name:           "https",
				Mode:           upcloud.LoadBalancerModeHTTP,
				Port:           443,
				DefaultBackend: "appview",
				Networks: []upcloud.LoadBalancerFrontendNetwork{
					{Name: "public"},
				},
				Rules: []request.LoadBalancerFrontendRule{
					{
						Name:     "set-forwarded-headers",
						Priority: 1,
						Matchers: []upcloud.LoadBalancerMatcher{},
						Actions: []upcloud.LoadBalancerAction{
							request.NewLoadBalancerSetForwardedHeadersAction(),
						},
					},
					{
						Name:     "route-hold",
						Priority: 10,
						Matchers: []upcloud.LoadBalancerMatcher{
							{
								Type: upcloud.LoadBalancerMatcherTypeHost,
								Host: &upcloud.LoadBalancerMatcherHost{
									Value: holdDomain,
								},
							},
						},
						Actions: []upcloud.LoadBalancerAction{
							request.NewLoadBalancerSetForwardedHeadersAction(),
							{
								Type: upcloud.LoadBalancerActionTypeUseBackend,
								UseBackend: &upcloud.LoadBalancerActionUseBackend{
									Backend: "hold",
								},
							},
						},
					},
				},
			},
			{
				Name:           "http-redirect",
				Mode:           upcloud.LoadBalancerModeHTTP,
				Port:           80,
				DefaultBackend: "appview",
				Networks: []upcloud.LoadBalancerFrontendNetwork{
					{Name: "public"},
				},
				Rules: []request.LoadBalancerFrontendRule{
					{
						Name:     "redirect-https",
						Priority: 10,
						Matchers: []upcloud.LoadBalancerMatcher{
							{
								Type: upcloud.LoadBalancerMatcherTypeSrcPort,
								SrcPort: &upcloud.LoadBalancerMatcherInteger{
									Method: upcloud.LoadBalancerIntegerMatcherMethodEqual,
									Value:  80,
								},
							},
						},
						Actions: []upcloud.LoadBalancerAction{
							{
								Type: upcloud.LoadBalancerActionTypeHTTPRedirect,
								HTTPRedirect: &upcloud.LoadBalancerActionHTTPRedirect{
									Scheme: upcloud.LoadBalancerActionHTTPRedirectSchemeHTTPS,
								},
							},
						},
					},
				},
			},
		},
		Resolvers: []request.LoadBalancerResolver{},
		Backends: []request.LoadBalancerBackend{
			{
				Name: "appview",
				Members: []request.LoadBalancerBackendMember{
					{
						Name:        "appview-1",
						Type:        upcloud.LoadBalancerBackendMemberTypeStatic,
						IP:          appviewIP,
						Port:        5000,
						Weight:      100,
						MaxSessions: 1000,
						Enabled:     true,
					},
				},
				Properties: &upcloud.LoadBalancerBackendProperties{
					HealthCheckType: upcloud.LoadBalancerHealthCheckTypeHTTP,
					HealthCheckURL:  "/health",
				},
			},
			{
				Name: "hold",
				Members: []request.LoadBalancerBackendMember{
					{
						Name:        "hold-1",
						Type:        upcloud.LoadBalancerBackendMemberTypeStatic,
						IP:          holdIP,
						Port:        8080,
						Weight:      100,
						MaxSessions: 1000,
						Enabled:     true,
					},
				},
				Properties: &upcloud.LoadBalancerBackendProperties{
					HealthCheckType: upcloud.LoadBalancerHealthCheckTypeHTTP,
					HealthCheckURL:  "/xrpc/_health",
				},
			},
		},
	})
	if err != nil {
		return nil, err
	}

	return lb, nil
}

// ensureLBCertificates reconciles TLS certificate bundles on the load balancer.
// It skips domains that already have a TLS config attached and creates missing ones.
func ensureLBCertificates(ctx context.Context, svc *service.Service, lbUUID string, tlsDomains []string) error {
	lb, err := svc.GetLoadBalancer(ctx, &request.GetLoadBalancerRequest{UUID: lbUUID})
	if err != nil {
		return fmt.Errorf("get load balancer: %w", err)
	}

	// Build set of existing TLS config names on the "https" frontend
	existing := make(map[string]bool)
	for _, fe := range lb.Frontends {
		if fe.Name == "https" {
			for _, tc := range fe.TLSConfigs {
				existing[tc.Name] = true
			}
		}
	}

	for _, domain := range tlsDomains {
		certName := "tls-" + strings.ReplaceAll(domain, ".", "-")
		if existing[certName] {
			fmt.Printf("  TLS certificate: %s (exists)\n", domain)
			continue
		}

		bundle, err := svc.CreateLoadBalancerCertificateBundle(ctx, &request.CreateLoadBalancerCertificateBundleRequest{
			Type:      upcloud.LoadBalancerCertificateBundleTypeDynamic,
			Name:      certName,
			KeyType:   "ecdsa",
			Hostnames: []string{domain},
		})
		if err != nil {
			return fmt.Errorf("create TLS cert for %s: %w", domain, err)
		}

		_, err = svc.CreateLoadBalancerFrontendTLSConfig(ctx, &request.CreateLoadBalancerFrontendTLSConfigRequest{
			ServiceUUID:  lbUUID,
			FrontendName: "https",
			Config: request.LoadBalancerFrontendTLSConfig{
				Name:                  certName,
				CertificateBundleUUID: bundle.UUID,
			},
		})
		if err != nil {
			return fmt.Errorf("attach TLS cert %s to frontend: %w", domain, err)
		}
		fmt.Printf("  TLS certificate: %s\n", domain)
	}

	return nil
}

// ensureLBForwardedHeaders ensures the "https" frontend has a set_forwarded_headers rule.
// This makes the LB set X-Forwarded-For, X-Forwarded-Proto, and X-Forwarded-Port headers,
// overwriting any pre-existing values (prevents spoofing).
func ensureLBForwardedHeaders(ctx context.Context, svc *service.Service, lbUUID string) error {
	rules, err := svc.GetLoadBalancerFrontendRules(ctx, &request.GetLoadBalancerFrontendRulesRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
	})
	if err != nil {
		return fmt.Errorf("get frontend rules: %w", err)
	}

	for _, r := range rules {
		if r.Name == "set-forwarded-headers" {
			// Verify it has the set_forwarded_headers action
			for _, a := range r.Actions {
				if a.SetForwardedHeaders != nil {
					fmt.Println("  Forwarded headers rule: exists and valid")
					return nil
				}
			}
			// Rule exists but is misconfigured — delete and recreate
			fmt.Println("  Forwarded headers rule: exists but misconfigured, recreating")
			if err := svc.DeleteLoadBalancerFrontendRule(ctx, &request.DeleteLoadBalancerFrontendRuleRequest{
				ServiceUUID:  lbUUID,
				FrontendName: "https",
				Name:         r.Name,
			}); err != nil {
				return fmt.Errorf("delete misconfigured forwarded headers rule: %w", err)
			}
			break
		}
	}

	_, err = svc.CreateLoadBalancerFrontendRule(ctx, &request.CreateLoadBalancerFrontendRuleRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
		Rule: request.LoadBalancerFrontendRule{
			Name:     "set-forwarded-headers",
			Priority: 1,
			Matchers: []upcloud.LoadBalancerMatcher{},
			Actions: []upcloud.LoadBalancerAction{
				request.NewLoadBalancerSetForwardedHeadersAction(),
			},
		},
	})
	if err != nil {
		return fmt.Errorf("create forwarded headers rule: %w", err)
	}
	fmt.Println("  Forwarded headers rule: created")

	return nil
}

// ensureLBHoldForwardedHeaders ensures the "route-hold" rule includes a
// set_forwarded_headers action alongside use_backend. Without this, the LB
// doesn't set X-Forwarded-For on hold-routed traffic.
func ensureLBHoldForwardedHeaders(ctx context.Context, svc *service.Service, lbUUID, holdDomain string) error {
	rules, err := svc.GetLoadBalancerFrontendRules(ctx, &request.GetLoadBalancerFrontendRulesRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
	})
	if err != nil {
		return fmt.Errorf("get frontend rules: %w", err)
	}

	for _, r := range rules {
		if r.Name == "route-hold" {
			hasForwarded := false
			for _, a := range r.Actions {
				if a.SetForwardedHeaders != nil {
					hasForwarded = true
					break
				}
			}
			if hasForwarded {
				fmt.Println("  Route-hold forwarded headers: exists")
				return nil
			}
			// Delete and recreate with both actions
			fmt.Println("  Route-hold forwarded headers: missing, recreating rule")
			if err := svc.DeleteLoadBalancerFrontendRule(ctx, &request.DeleteLoadBalancerFrontendRuleRequest{
				ServiceUUID:  lbUUID,
				FrontendName: "https",
				Name:         r.Name,
			}); err != nil {
				return fmt.Errorf("delete route-hold rule: %w", err)
			}
			break
		}
	}

	_, err = svc.CreateLoadBalancerFrontendRule(ctx, &request.CreateLoadBalancerFrontendRuleRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
		Rule: request.LoadBalancerFrontendRule{
			Name:     "route-hold",
			Priority: 10,
			Matchers: []upcloud.LoadBalancerMatcher{
				{
					Type: upcloud.LoadBalancerMatcherTypeHost,
					Host: &upcloud.LoadBalancerMatcherHost{
						Value: holdDomain,
					},
				},
			},
			Actions: []upcloud.LoadBalancerAction{
				request.NewLoadBalancerSetForwardedHeadersAction(),
				{
					Type: upcloud.LoadBalancerActionTypeUseBackend,
					UseBackend: &upcloud.LoadBalancerActionUseBackend{
						Backend: "hold",
					},
				},
			},
		},
	})
	if err != nil {
		return fmt.Errorf("create route-hold rule: %w", err)
	}
	fmt.Println("  Route-hold forwarded headers: created")

	return nil
}

// ensureLBScannerBlock ensures the "https" frontend has a rule that returns 403
// for common scanner paths (.php, .asp, .aspx, .jsp, .cgi, .env).
func ensureLBScannerBlock(ctx context.Context, svc *service.Service, lbUUID string) error {
	rules, err := svc.GetLoadBalancerFrontendRules(ctx, &request.GetLoadBalancerFrontendRulesRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
	})
	if err != nil {
		return fmt.Errorf("get frontend rules: %w", err)
	}

	for _, r := range rules {
		if r.Name == "block-scanners" {
			for _, a := range r.Actions {
				if a.HTTPReturn != nil {
					fmt.Println("  Scanner block rule: exists and valid")
					return nil
				}
			}
			fmt.Println("  Scanner block rule: exists but misconfigured, recreating")
			if err := svc.DeleteLoadBalancerFrontendRule(ctx, &request.DeleteLoadBalancerFrontendRuleRequest{
				ServiceUUID:  lbUUID,
				FrontendName: "https",
				Name:         r.Name,
			}); err != nil {
				return fmt.Errorf("delete misconfigured scanner block rule: %w", err)
			}
			break
		}
	}

	ignoreCase := true
	_, err = svc.CreateLoadBalancerFrontendRule(ctx, &request.CreateLoadBalancerFrontendRuleRequest{
		ServiceUUID:  lbUUID,
		FrontendName: "https",
		Rule: request.LoadBalancerFrontendRule{
			Name:     "block-scanners",
			Priority: 2,
			Matchers: []upcloud.LoadBalancerMatcher{
				request.NewLoadBalancerPathMatcher(
					upcloud.LoadBalancerStringMatcherMethodRegexp,
					`\.(php|asp|aspx|jsp|cgi|env)$`,
					&ignoreCase,
				),
			},
			Actions: []upcloud.LoadBalancerAction{
				{
					Type: upcloud.LoadBalancerActionTypeHTTPReturn,
					HTTPReturn: &upcloud.LoadBalancerActionHTTPReturn{
						Status:      403,
						ContentType: "text/plain",
						Payload:     base64.StdEncoding.EncodeToString([]byte("Forbidden")),
					},
				},
			},
		},
	})
	if err != nil {
		return fmt.Errorf("create scanner block rule: %w", err)
	}
	fmt.Println("  Scanner block rule: created")

	return nil
}

// lookupObjectStorage discovers details of an existing Managed Object Storage.
func lookupObjectStorage(ctx context.Context, svc *service.Service, uuid string) (ObjectStorageState, error) {
	storage, err := svc.GetManagedObjectStorage(ctx, &request.GetManagedObjectStorageRequest{
		UUID: uuid,
	})
	if err != nil {
		return ObjectStorageState{}, fmt.Errorf("get object storage %s: %w", uuid, err)
	}

	var endpoint string
	for _, ep := range storage.Endpoints {
		if ep.DomainName != "" {
			endpoint = "https://" + ep.DomainName
			break
		}
	}

	var bucket string
	buckets, err := svc.GetManagedObjectStorageBucketMetrics(ctx, &request.GetManagedObjectStorageBucketMetricsRequest{
		ServiceUUID: uuid,
	})
	if err == nil {
		for _, b := range buckets {
			if !b.Deleted {
				bucket = b.Name
				break
			}
		}
	}

	var accessKeyID string
	users, err := svc.GetManagedObjectStorageUsers(ctx, &request.GetManagedObjectStorageUsersRequest{
		ServiceUUID: uuid,
	})
	if err == nil {
		for _, u := range users {
			for _, k := range u.AccessKeys {
				if k.Status == "Active" {
					accessKeyID = k.AccessKeyID
					break
				}
			}
			if accessKeyID != "" {
				break
			}
		}
	}

	return ObjectStorageState{
		UUID:        uuid,
		Endpoint:    endpoint,
		Region:      storage.Region,
		Bucket:      bucket,
		AccessKeyID: accessKeyID,
	}, nil
}

func findDebianTemplate(ctx context.Context, svc *service.Service) (string, error) {
	storages, err := svc.GetStorages(ctx, &request.GetStoragesRequest{
		Type: "template",
	})
	if err != nil {
		return "", fmt.Errorf("list templates: %w", err)
	}

	var debian13, debian12 string
	for _, s := range storages.Storages {
		title := strings.ToLower(s.Title)
		if strings.Contains(title, "debian") {
			if strings.Contains(title, "13") || strings.Contains(title, "trixie") {
				debian13 = s.UUID
			} else if strings.Contains(title, "12") || strings.Contains(title, "bookworm") {
				debian12 = s.UUID
			}
		}
	}

	if debian13 != "" {
		return debian13, nil
	}
	if debian12 != "" {
		fmt.Println("  Debian 13 not available, using Debian 12")
		return debian12, nil
	}

	return "", fmt.Errorf("no Debian template found — check UpCloud template list")
}

const cloudInitPath = "/var/lib/cloud/instance/scripts/part-001"

// syncCloudInit compares a locally-generated cloud-init script against what's
// on the server. If they differ (or the remote is missing), it prompts the
// user and re-runs the script over SSH.
func syncCloudInit(name, ip, localScript string) error {
	// Fetch the remote script
	remoteScript, err := runSSH(ip, fmt.Sprintf("cat %s 2>/dev/null || echo '__MISSING__'", cloudInitPath), false)
	if err != nil {
		fmt.Printf("  cloud-init: could not reach %s (%v)\n", name, err)
		return nil
	}
	remoteScript = strings.TrimSpace(remoteScript)

	if remoteScript == "__MISSING__" {
		fmt.Printf("  cloud-init: not found on %s (server may need initial setup)\n", name)
	} else {
		localHash := fmt.Sprintf("%x", sha256.Sum256([]byte(strings.TrimSpace(localScript))))
		remoteHash := fmt.Sprintf("%x", sha256.Sum256([]byte(remoteScript)))
		if localHash == remoteHash {
			fmt.Printf("  cloud-init: up to date\n")
			return nil
		}
		fmt.Printf("  cloud-init: differs from local\n")
	}

	fmt.Printf("  Re-run cloud-init on %s? [Y/n] ", name)
	scanner := bufio.NewScanner(os.Stdin)
	scanner.Scan()
	answer := strings.TrimSpace(strings.ToLower(scanner.Text()))
	if answer != "" && answer != "y" && answer != "yes" {
		fmt.Printf("  Skipped\n")
		// Still update the remote reference so next provision sees an accurate diff
		if err := writeRemoteCloudInit(ip, localScript); err != nil {
			fmt.Printf("  WARNING: could not update remote cloud-init reference: %v\n", err)
		}
		return nil
	}

	// Write the reference file first so next provision can detect real diffs,
	// regardless of whether the script execution succeeds or fails.
	if err := writeRemoteCloudInit(ip, localScript); err != nil {
		fmt.Printf("  WARNING: could not update remote cloud-init reference: %v\n", err)
	}

	fmt.Printf("  Running cloud-init on %s (%s)... (this may take several minutes)\n", name, ip)
	output, err := runSSH(ip, localScript, true)
	if err != nil {
		fmt.Printf("  ERROR: %v\n", err)
		fmt.Printf("  Output:\n%s\n", output)
		return fmt.Errorf("cloud-init %s failed", name)
	}

	fmt.Printf("  %s: cloud-init complete\n", name)
	return nil
}

// generateScannerSecret generates a random 32-byte hex-encoded shared secret
// for authenticating scanner-to-hold WebSocket connections.
func generateScannerSecret() (string, error) {
	b := make([]byte, 32)
	if _, err := crypto_rand.Read(b); err != nil {
		return "", err
	}
	return hex.EncodeToString(b), nil
}

// writeRemoteCloudInit writes the local cloud-init script to the remote server
// so that subsequent provision runs can accurately detect real changes.
// Uses base64 encoding to avoid heredoc nesting issues (the cloud-init script
// itself contains heredocs like CFGEOF and SVCEOF).
func writeRemoteCloudInit(ip, script string) error {
	encoded := base64.StdEncoding.EncodeToString([]byte(script))
	cmd := fmt.Sprintf("mkdir -p $(dirname %s) && echo '%s' | base64 -d > %s", cloudInitPath, encoded, cloudInitPath)
	_, err := runSSH(ip, cmd, false)
	return err
}

// waitForSetup polls SSH availability on a newly created server, then waits
// for cloud-init to complete before returning.
func waitForSetup(ip, name string) error {
	fmt.Printf("  %s (%s): waiting for SSH...\n", name, ip)
	for i := 0; i < 30; i++ {
		_, err := runSSH(ip, "echo ssh_ready", false)
		if err == nil {
			break
		}
		if i == 29 {
			return fmt.Errorf("SSH not available after 5 minutes on %s (%s)", name, ip)
		}
		time.Sleep(10 * time.Second)
	}

	fmt.Printf("  %s: waiting for cloud-init...\n", name)
	_, err := runSSH(ip, "cloud-init status --wait 2>/dev/null || true", false)
	if err != nil {
		return fmt.Errorf("cloud-init wait on %s: %w", name, err)
	}
	fmt.Printf("  %s: ready\n", name)
	return nil
}