package api

// The Virtualization tab: LXC containers and KVM virtual machines through Incus, per
// machine. Three page states — ready, repairable, installable, or unavailable with the
// reason — and every action lands on the machine that was asked. Long work (install, create,
// image downloads, publish) runs as a followed task; consoles are terminal sessions like
// any other, so they reattach and work through the hub's proxy.

import (
	"context"
	"encoding/json"
	"fmt"
	"io"
	"log"
	"net/http"
	"net/url"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"regexp"
	"strings"
	"time"

	"github.com/coder/websocket"

	"hamlab/internal/incus"
	"hamlab/internal/priv"
	"hamlab/internal/sensors"
)

func readBody(r *http.Request, v any, max int64) error {
	return json.NewDecoder(io.LimitReader(r.Body, max)).Decode(v)
}

// virtOverview is the page: the machine's state, and when Incus answers, everything on it.
func (s *Server) virtOverview(w http.ResponseWriter, r *http.Request) {
	st := s.virt.Detect(r.Context())
	out := map[string]any{"status": st}
	if st.State == "ready" {
		ctx, cancel := context.WithTimeout(r.Context(), 40*time.Second)
		defer cancel()
		inst, err := s.virt.Instances(ctx)
		if err != nil {
			out["error"] = err.Error()
		}
		out["instances"] = inst
		imgs, _ := s.virt.Images(ctx)
		out["images"] = imgs
		out["pools"] = s.virt.Pools(ctx)
		out["networks"] = s.virt.Networks(ctx)
	}
	isos := s.virt.Library(s.virt.ISOsDir())
	if inst, ok := out["instances"].([]incus.Instance); ok {
		users := s.isoUsers(inst)
		for i := range isos {
			isos[i].AttachedTo = users[isos[i].Name]
		}
	}
	out["library"] = map[string]any{"images": s.virt.Library(s.virt.ImagesDir()), "isos": isos}
	jsonOK(w, 200, out)
}

func (s *Server) virtInstall(w http.ResponseWriter, r *http.Request) {
	var o incus.InstallOpts
	if err := readBody(r, &o, 16<<10); err != nil {
		jsonErr(w, 400, "bad request")
		return
	}
	st := s.virt.Detect(r.Context())
	if st.State != "installable" && st.State != "repair" {
		jsonErr(w, 409, "nothing to install here: "+st.State)
		return
	}
	if err := s.virt.EnsureDirs(); err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	script, lay, err := s.virt.InstallScript(st, o)
	if err != nil {
		jsonErr(w, 400, err.Error())
		return
	}
	if err := s.virt.SaveLayout(lay); err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	// kept beside the layout, so what was run is on record
	_ = os.WriteFile(filepath.Join(s.virt.Dir(), "install.sh"), []byte(script), 0o700)
	t, err := s.tasks.Start("virt:install", "install Incus", s.virt.ShellCmd(r.Context(), script))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: install started as task %s — %s pool, %s (from %s)", t.ID, lay.Driver, lay.Subnet, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtReady(w http.ResponseWriter, r *http.Request) bool {
	if st := s.virt.Detect(r.Context()); st.State != "ready" {
		jsonErr(w, 409, "Incus isn't ready on this machine")
		return false
	}
	return true
}

// ---- images ----

func (s *Server) virtRemoteImages(w http.ResponseWriter, r *http.Request) {
	if !s.virtReady(w, r) {
		return
	}
	list, err := s.virt.Remote(r.Context(), r.URL.Query().Get("refresh") == "1")
	if err != nil {
		jsonErr(w, 502, err.Error())
		return
	}
	if t := r.URL.Query().Get("type"); t == "container" || t == "virtual-machine" {
		var f []incus.Image
		for _, im := range list {
			if im.Type == t {
				f = append(f, im)
			}
		}
		list = f
	}
	if list == nil {
		list = []incus.Image{}
	}
	jsonOK(w, 200, map[string]any{"images": list})
}

func (s *Server) virtImageDownload(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Alias string `json:"alias"`
	}
	_ = readBody(r, &body, 4096)
	alias := strings.TrimSpace(body.Alias)
	if !incus.ValidImage(alias) || strings.Contains(alias, ":") {
		jsonErr(w, 400, "alias: like debian/13 or ubuntu/24.04/cloud")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	local := strings.ReplaceAll(alias, "/", "-")
	// copied into the local store under a flat alias, then exported to the library so the
	// file is Ham Lab's whether or not Incus keeps its cache
	script := `set -e; incus image copy "images:$1" local: --alias "$2"; cd "$3" && incus image export "$2" "$2" && echo "exported to $3/$2"`
	t, err := s.tasks.Start("virt:image", "download "+alias, s.virt.ShellCmd(r.Context(), script, alias, local, s.virt.ImagesDir()))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: image %s download as task %s (from %s)", alias, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtImageImport(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Path  string `json:"path"`
		Alias string `json:"alias"`
		Type  string `json:"type"` // container | virtual-machine
	}
	_ = readBody(r, &body, 8192)
	alias := strings.TrimSpace(body.Alias)
	if !incus.ValidImage(alias) || strings.Contains(alias, ":") {
		jsonErr(w, 400, "alias: letters, digits, dots, dashes")
		return
	}
	p := filepath.Clean(body.Path)
	st, err := os.Stat(p)
	if !filepath.IsAbs(p) || err != nil || !st.Mode().IsRegular() {
		jsonErr(w, 400, "path: a file on this machine")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	dest := filepath.Join(s.virt.ImagesDir(), filepath.Base(p))
	var script string
	if body.Type == "virtual-machine" {
		// a bare disk image needs the metadata Incus wants beside it; a small tarball Ham Lab writes
		script = `set -e; [ "$1" = "$2" ] || cp -n "$1" "$2"; META="$3/$4.metadata.tar.gz"; T=$(mktemp -d); printf 'architecture: %s\ncreation_date: %s\nproperties:\n  description: "%s"\n  os: custom\n' "$5" "$(date +%s)" "$4" > "$T/metadata.yaml"; tar -C "$T" -czf "$META" metadata.yaml; rm -rf "$T"; incus image import "$META" "$2" --alias "$4"; echo "imported $4 from $2"`
	} else {
		script = `set -e; [ "$1" = "$2" ] || cp -n "$1" "$2"; incus image import "$2" --alias "$4"; echo "imported $4 from $2"`
	}
	t, err := s.tasks.Start("virt:image", "import "+alias, s.virt.ShellCmd(r.Context(), script, p, dest, s.virt.ImagesDir(), alias, incus.IncusArch()))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: image import %s from %s as task %s (from %s)", alias, p, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtImagePublish(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Instance string `json:"instance"`
		Alias    string `json:"alias"`
	}
	_ = readBody(r, &body, 4096)
	alias := strings.TrimSpace(body.Alias)
	if !incus.ValidName(body.Instance) || !incus.ValidImage(alias) || strings.Contains(alias, ":") {
		jsonErr(w, 400, "an instance and an alias")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	script := `set -e; incus publish "$1" --alias "$2"; cd "$3" && incus image export "$2" "$2" && echo "exported to $3/$2"`
	t, err := s.tasks.Start("virt:image", "publish "+body.Instance+" as "+alias, s.virt.ShellCmd(r.Context(), script, body.Instance, alias, s.virt.ImagesDir()))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: publish %s as %s, task %s (from %s)", body.Instance, alias, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtImageDelete(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Ref string `json:"ref"`
	}
	_ = readBody(r, &body, 4096)
	if !incus.ValidImage(body.Ref) {
		jsonErr(w, 400, "bad image")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), 60*time.Second)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, "image", "delete", body.Ref).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: image %s deleted (from %s)", body.Ref, clientIP(r))
	w.WriteHeader(204)
}

// ---- instances ----

func (s *Server) virtCreate(w http.ResponseWriter, r *http.Request) {
	var sp incus.CreateSpec
	if err := readBody(r, &sp, 512<<10); err != nil {
		jsonErr(w, 400, "bad request")
		return
	}
	st := s.virt.Detect(r.Context())
	if st.State != "ready" {
		jsonErr(w, 409, "Incus isn't ready on this machine")
		return
	}
	args, err := incus.CreateArgs(sp, st.KVM)
	if err != nil {
		jsonErr(w, 400, err.Error())
		return
	}
	if inst, err := s.virt.Instances(r.Context()); err == nil {
		for _, in := range inst {
			if in.Name == sp.Name {
				jsonErr(w, 409, "there is already an instance called "+sp.Name)
				return
			}
		}
	}
	kind := "container"
	if sp.VM {
		kind = "VM"
	}
	t, err := s.tasks.Start("virt:create", fmt.Sprintf("create %s %s", kind, sp.Name), s.virt.Cmd(r.Context(), args...))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: create %s %s from %s as task %s (from %s)", kind, sp.Name, sp.Image, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtInstance(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	if !incus.ValidName(name) {
		jsonErr(w, 400, "bad name")
		return
	}
	list, err := s.virt.Instances(r.Context())
	if err != nil {
		jsonErr(w, 502, err.Error())
		return
	}
	for _, in := range list {
		if in.Name == name {
			jsonOK(w, 200, in)
			return
		}
	}
	jsonErr(w, 404, "no such instance")
}

// virtAction is start / stop / restart / kill / delete, and the two consoles.
func (s *Server) virtAction(w http.ResponseWriter, r *http.Request) {
	name, action := r.PathValue("name"), r.PathValue("action")
	if !incus.ValidName(name) {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	var args []string
	switch action {
	case "start":
		args = []string{"start", name}
	case "stop":
		args = []string{"stop", name}
	case "restart":
		args = []string{"restart", name}
	case "kill":
		args = []string{"stop", "--force", name}
	case "delete":
		var body struct {
			Confirm string `json:"confirm"`
			Force   bool   `json:"force"`
		}
		_ = readBody(r, &body, 4096)
		if body.Confirm != name {
			jsonErr(w, 400, "type the instance's name to delete it")
			return
		}
		args = []string{"delete", name}
		if body.Force {
			args = []string{"delete", "--force", name}
		}
	case "console", "exec":
		s.virtTerminal(w, r, name, action)
		return
	default:
		jsonErr(w, 400, "unknown action")
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), 3*time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, args...).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: %s %s (from %s)", action, name, clientIP(r))
	w.WriteHeader(204)
}

// virtTerminal opens the serial console or a shell as a terminal session.
func (s *Server) virtTerminal(w http.ResponseWriter, r *http.Request, name, kind string) {
	var argv []string
	title := ""
	if kind == "console" {
		argv = s.virt.Argv(r.Context(), "console", name)
		title = "console " + name
	} else {
		argv = s.virt.Argv(r.Context(), "exec", name, "--", "sh", "-c", "if command -v bash >/dev/null 2>&1; then exec bash -l; else exec sh -l; fi")
		title = "sh " + name
	}
	sess, err := s.mgr.CreateCmd("", title, argv)
	if err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	log.Printf("virt: %s of %s as terminal %s (from %s)", kind, name, sess.ID, clientIP(r))
	jsonOK(w, 200, map[string]string{"id": sess.ID, "name": title})
}

func (s *Server) virtRename(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		Name string `json:"name"`
	}
	_ = readBody(r, &body, 4096)
	if !incus.ValidName(name) || !incus.ValidName(body.Name) {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, "rename", name, body.Name).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: renamed %s to %s (from %s)", name, body.Name, clientIP(r))
	w.WriteHeader(204)
}

// virtConfig sets limits, the snapshot schedule, or a description — the config keys the page
// edits, each validated for its shape. An empty value unsets the key.
func (s *Server) virtConfig(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body map[string]string
	if err := readBody(r, &body, 16<<10); err != nil || !incus.ValidName(name) {
		jsonErr(w, 400, "bad request")
		return
	}
	var set, unset []string
	desc, hasDesc := body["description"]
	delete(body, "description")
	if hasDesc && (len(desc) > 200 || strings.ContainsAny(desc, "\n\r")) {
		jsonErr(w, 400, "bad value for description")
		return
	}
	for k, v := range body {
		v = strings.TrimSpace(v)
		ok := false
		switch k {
		case "limits.cpu":
			ok = incus.ValidCPU(v)
		case "limits.memory":
			ok = incus.ValidSize(v)
		case "snapshots.schedule":
			ok = incus.ValidCron(v)
		case "snapshots.expiry":
			ok = incus.ValidExpiry(v)
		case "boot.autostart":
			ok = v == "" || v == "true" || v == "false"
		}
		if !ok {
			jsonErr(w, 400, "bad value for "+k)
			return
		}
		if v == "" {
			unset = append(unset, k)
		} else {
			set = append(set, k+"="+v)
		}
	}
	if !s.virtReady(w, r) {
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if len(set) > 0 {
		if out, err := s.virt.Cmd(ctx, append([]string{"config", "set", name}, set...)...).CombinedOutput(); err != nil {
			jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
			return
		}
	}
	for _, k := range unset {
		_, _ = s.virt.Cmd(ctx, "config", "unset", name, k).CombinedOutput() // unsetting what isn't set is fine
	}
	if hasDesc {
		// the description is a field of the instance, not a config key, so it goes in through the API
		patch, _ := json.Marshal(map[string]string{"description": strings.TrimSpace(desc)})
		if out, err := s.virt.Cmd(ctx, "query", "-X", "PATCH", "-d", string(patch), "/1.0/instances/"+name).CombinedOutput(); err != nil {
			jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
			return
		}
	}
	log.Printf("virt: config %s set %v unset %v (from %s)", name, set, unset, clientIP(r))
	w.WriteHeader(204)
}

func (s *Server) virtSnapshotCreate(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		Name string `json:"name"`
	}
	_ = readBody(r, &body, 4096)
	snap := strings.TrimSpace(body.Name)
	if snap == "" {
		snap = time.Now().Format("2006-01-02_15.04.05")
	}
	if !incus.ValidName(name) || !incus.ValidSnap(snap) {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), 5*time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, "snapshot", "create", name, snap).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: snapshot %s/%s (from %s)", name, snap, clientIP(r))
	jsonOK(w, 200, map[string]string{"name": snap})
}

func (s *Server) virtSnapshotAction(w http.ResponseWriter, r *http.Request) {
	name, snap, action := r.PathValue("name"), r.PathValue("snap"), r.PathValue("action")
	if !incus.ValidName(name) || !incus.ValidSnap(snap) {
		jsonErr(w, 400, "bad name")
		return
	}
	var args []string
	switch action {
	case "restore":
		args = []string{"snapshot", "restore", name, snap}
	case "delete":
		args = []string{"snapshot", "delete", name, snap}
	default:
		jsonErr(w, 400, "unknown action")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), 10*time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, args...).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: snapshot %s %s/%s (from %s)", action, name, snap, clientIP(r))
	w.WriteHeader(204)
}

// ---- the graphical console ----

// virtVGA bridges the browser to the VM's SPICE display: the browser's websocket on one side,
// Incus's display websocket (dialled over its unix socket) on the other, frames copied both
// ways. spice-html5 in the page speaks SPICE; Ham Lab only carries it.
func (s *Server) virtVGA(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	if !incus.ValidName(name) {
		jsonErr(w, 400, "bad name")
		return
	}
	// spice-html5 asks for the "binary" subprotocol and gives up unless the server agrees to it
	conn, err := websocket.Accept(w, r, &websocket.AcceptOptions{CompressionMode: websocket.CompressionDisabled, Subprotocols: []string{"binary"}})
	if err != nil {
		return
	}
	conn.SetReadLimit(64 << 20)
	ctx, cancel := context.WithCancel(r.Context())
	defer cancel()
	display, release, err := s.virt.VGAChannel(ctx, name)
	if err != nil {
		log.Printf("virt: vga %s refused: %v (from %s)", name, err, clientIP(r))
		conn.Close(websocket.StatusInternalError, truncate(err.Error(), 120))
		return
	}
	defer release()
	defer display.Close(websocket.StatusNormalClosure, "")
	go func() {
		defer cancel()
		for {
			_, data, err := display.Read(ctx)
			if err != nil {
				return
			}
			if err := conn.Write(ctx, websocket.MessageBinary, data); err != nil {
				return
			}
		}
	}()
	for {
		_, data, err := conn.Read(ctx)
		if err != nil {
			break
		}
		if err := display.Write(ctx, websocket.MessageBinary, data); err != nil {
			break
		}
	}
	cancel()
	conn.Close(websocket.StatusNormalClosure, "")
}

func truncate(s string, n int) string {
	if len(s) > n {
		return s[:n]
	}
	return s
}

// ---- ISOs ----

func (s *Server) isoPath(name string) (string, bool) {
	if !incus.ValidISOName(name) {
		return "", false
	}
	return filepath.Join(s.virt.ISOsDir(), name), true
}

// isoUsers says which instances have each ISO file attached, by its file name.
func (s *Server) isoUsers(list []incus.Instance) map[string][]string {
	out := map[string][]string{}
	dir := s.virt.ISOsDir() + "/"
	for _, in := range list {
		for _, d := range in.Devices {
			if d["type"] == "disk" && strings.HasPrefix(d["source"], dir) {
				n := strings.TrimPrefix(d["source"], dir)
				out[n] = append(out[n], in.Name)
			}
		}
	}
	return out
}

// userShell runs a small script as the daemon's own account — file work in Ham Lab's folder
// needs no root — with positional parameters.
func userShell(script string, params ...string) *exec.Cmd {
	return exec.Command("sh", append([]string{"-c", script, "hamlab"}, params...)...)
}

var urlRe = regexp.MustCompile(`^https?://[^\s"'<>]+$`)

func (s *Server) virtISOFetch(w http.ResponseWriter, r *http.Request) {
	var body struct {
		URL    string `json:"url"`
		SHA256 string `json:"sha256"`
		Name   string `json:"name"`
	}
	_ = readBody(r, &body, 8192)
	u := strings.TrimSpace(body.URL)
	if !urlRe.MatchString(u) {
		jsonErr(w, 400, "url: http or https")
		return
	}
	name := strings.TrimSpace(body.Name)
	if name == "" {
		if pu, err := url.Parse(u); err == nil {
			name = path.Base(pu.Path)
		}
	}
	dest, ok := s.isoPath(name)
	if !ok {
		jsonErr(w, 400, "name: a file name ending in .iso")
		return
	}
	sum := strings.ToLower(strings.TrimSpace(body.SHA256))
	if sum != "" && !regexp.MustCompile(`^[0-9a-f]{64}$`).MatchString(sum) {
		jsonErr(w, 400, "sha256: 64 hex digits")
		return
	}
	if _, err := os.Stat(dest); err == nil {
		jsonErr(w, 409, name+" is already in the library")
		return
	}
	if err := s.virt.EnsureDirs(); err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	script := `set -e; echo "fetching $1"; echo "  to $2"; curl -fL --retry 3 -sS -o "$2.part" "$1"; if [ -n "$3" ]; then echo "$3  $2.part" | sha256sum -c - || { rm -f "$2.part"; exit 1; }; fi; mv "$2.part" "$2"; ls -l "$2" | awk '{print "  " $5 " bytes"}'`
	t, err := s.tasks.Start("virt:iso", "fetch "+name, userShell(script, u, dest, sum))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: iso fetch %s as task %s (from %s)", u, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtISOImport(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Path string `json:"path"`
	}
	_ = readBody(r, &body, 8192)
	p := filepath.Clean(body.Path)
	st, err := os.Stat(p)
	if !filepath.IsAbs(p) || err != nil || !st.Mode().IsRegular() {
		jsonErr(w, 400, "path: a file on this machine")
		return
	}
	dest, ok := s.isoPath(filepath.Base(p))
	if !ok {
		jsonErr(w, 400, "the file has to be a .iso or .img")
		return
	}
	if _, err := os.Stat(dest); err == nil {
		jsonErr(w, 409, filepath.Base(p)+" is already in the library")
		return
	}
	if err := s.virt.EnsureDirs(); err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	script := `set -e; echo "copying $1"; echo "  to $2"; cp --reflink=auto "$1" "$2.part" && mv "$2.part" "$2"; ls -l "$2" | awk '{print "  " $5 " bytes"}'`
	cmd := userShell(script, p, dest)
	if f, err := os.Open(p); err != nil && priv.Available() { // readable only by root: copy as root and hand it over
		argv := priv.Wrap("sh", "-c", script+`; chown "$3" "$2"`, "hamlab", p, dest, s.user)
		cmd = exec.Command(argv[0], argv[1:]...)
	} else if err == nil {
		f.Close()
	}
	t, err := s.tasks.Start("virt:iso", "import "+filepath.Base(p), cmd)
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: iso import %s as task %s (from %s)", p, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtISODelete(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Name string `json:"name"`
	}
	_ = readBody(r, &body, 4096)
	p, ok := s.isoPath(body.Name)
	if !ok {
		jsonErr(w, 400, "bad name")
		return
	}
	if list, err := s.virt.Instances(r.Context()); err == nil {
		if users := s.isoUsers(list)[body.Name]; len(users) > 0 {
			jsonErr(w, 409, "attached to "+strings.Join(users, ", ")+" — detach it first")
			return
		}
	}
	if err := os.Remove(p); err != nil {
		jsonErr(w, 404, "no such ISO")
		return
	}
	log.Printf("virt: iso %s deleted (from %s)", body.Name, clientIP(r))
	w.WriteHeader(204)
}

func (s *Server) virtISORename(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Name string `json:"name"`
		To   string `json:"to"`
	}
	_ = readBody(r, &body, 4096)
	from, ok1 := s.isoPath(body.Name)
	to, ok2 := s.isoPath(body.To)
	if !ok1 || !ok2 {
		jsonErr(w, 400, "bad name")
		return
	}
	if list, err := s.virt.Instances(r.Context()); err == nil {
		if users := s.isoUsers(list)[body.Name]; len(users) > 0 {
			jsonErr(w, 409, "attached to "+strings.Join(users, ", ")+" — detach it first")
			return
		}
	}
	if _, err := os.Stat(to); err == nil {
		jsonErr(w, 409, body.To+" already exists")
		return
	}
	if err := os.Rename(from, to); err != nil {
		jsonErr(w, 404, "no such ISO")
		return
	}
	w.WriteHeader(204)
}

func (s *Server) instanceByName(ctx context.Context, name string) (*incus.Instance, error) {
	list, err := s.virt.Instances(ctx)
	if err != nil {
		return nil, err
	}
	for i := range list {
		if list[i].Name == name {
			return &list[i], nil
		}
	}
	return nil, fmt.Errorf("no instance called %s", name)
}

// virtISOAttach puts an ISO in a VM's drive — live or stopped, Incus takes either — as a ROM
// device, first in the boot order when asked.
func (s *Server) virtISOAttach(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		ISO       string `json:"iso"`
		BootFirst bool   `json:"boot_first"`
	}
	_ = readBody(r, &body, 4096)
	p, ok := s.isoPath(body.ISO)
	if !incus.ValidName(name) || !ok {
		jsonErr(w, 400, "bad name")
		return
	}
	if _, err := os.Stat(p); err != nil {
		jsonErr(w, 404, "no such ISO in the library")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	in, err := s.instanceByName(r.Context(), name)
	if err != nil {
		jsonErr(w, 404, err.Error())
		return
	}
	if in.Type != "virtual-machine" {
		jsonErr(w, 409, "only a virtual machine takes an ISO")
		return
	}
	dev := ""
	for i := 0; i < 10; i++ {
		if _, taken := in.Devices[fmt.Sprintf("iso%d", i)]; !taken {
			dev = fmt.Sprintf("iso%d", i)
			break
		}
	}
	if dev == "" {
		jsonErr(w, 409, "ten ISOs are already attached")
		return
	}
	args := []string{"config", "device", "add", name, dev, "disk", "source=" + p}
	if body.BootFirst {
		args = append(args, "boot.priority=10")
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, args...).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: %s attached to %s as %s (from %s)", body.ISO, name, dev, clientIP(r))
	jsonOK(w, 200, map[string]string{"device": dev})
}

func (s *Server) virtISODetach(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		Device string `json:"device"`
	}
	_ = readBody(r, &body, 4096)
	if !incus.ValidName(name) || !incus.ValidDevice(body.Device) {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	in, err := s.instanceByName(r.Context(), name)
	if err != nil {
		jsonErr(w, 404, err.Error())
		return
	}
	d, ok := in.Devices[body.Device]
	if !ok || d["type"] != "disk" || !strings.HasPrefix(d["source"], s.virt.ISOsDir()+"/") {
		jsonErr(w, 409, body.Device+" isn't an ISO from the library")
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, "config", "device", "remove", name, body.Device).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: %s detached from %s (from %s)", body.Device, name, clientIP(r))
	w.WriteHeader(204)
}

func (s *Server) virtFromISO(w http.ResponseWriter, r *http.Request) {
	var sp incus.FromISOSpec
	if err := readBody(r, &sp, 16<<10); err != nil {
		jsonErr(w, 400, "bad request")
		return
	}
	st := s.virt.Detect(r.Context())
	if st.State != "ready" {
		jsonErr(w, 409, "Incus isn't ready on this machine")
		return
	}
	script, params, err := incus.FromISOScript(sp, st.KVM)
	if err != nil {
		jsonErr(w, 400, err.Error())
		return
	}
	p, _ := s.isoPath(sp.ISO)
	if _, err := os.Stat(p); err != nil {
		jsonErr(w, 404, "no such ISO in the library")
		return
	}
	params[1] = p
	if _, err := s.instanceByName(r.Context(), sp.Name); err == nil {
		jsonErr(w, 409, "there is already an instance called "+sp.Name)
		return
	}
	t, err := s.tasks.Start("virt:create", "create VM "+sp.Name+" from "+sp.ISO, s.virt.ShellCmd(r.Context(), script, params...))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: VM %s from %s as task %s (from %s)", sp.Name, sp.ISO, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

// ---- mounts: disk devices other than root ----

func (s *Server) virtMountAdd(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		Device   string `json:"device"`
		Source   string `json:"source"`
		Path     string `json:"path"`
		ReadOnly bool   `json:"readonly"`
		Shift    bool   `json:"shift"`
	}
	_ = readBody(r, &body, 8192)
	src, dst := filepath.Clean(body.Source), filepath.Clean(body.Path)
	dev := strings.TrimSpace(body.Device)
	if dev == "" {
		dev = "mnt-" + sensors.Seg(filepath.Base(src))
	}
	switch {
	case !incus.ValidName(name):
		jsonErr(w, 400, "bad name")
		return
	case !incus.ValidDevice(dev):
		jsonErr(w, 400, "device: letters, digits, dashes")
		return
	case !filepath.IsAbs(src) || !filepath.IsAbs(dst) || dst == "/":
		jsonErr(w, 400, "source and path: absolute paths; path not /")
		return
	}
	if _, err := os.Stat(src); err != nil && os.IsNotExist(err) {
		jsonErr(w, 404, src+" doesn't exist on this machine")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	in, err := s.instanceByName(r.Context(), name)
	if err != nil {
		jsonErr(w, 404, err.Error())
		return
	}
	if _, taken := in.Devices[dev]; taken {
		jsonErr(w, 409, "there is already a device called "+dev)
		return
	}
	args := []string{"config", "device", "add", name, dev, "disk", "source=" + src, "path=" + dst}
	if body.ReadOnly {
		args = append(args, "readonly=true")
	}
	if body.Shift && in.Type == "container" {
		args = append(args, "shift=true")
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, args...).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: %s: mounted %s at %s as %s (from %s)", name, src, dst, dev, clientIP(r))
	jsonOK(w, 200, map[string]string{"device": dev})
}

func (s *Server) virtMountRemove(w http.ResponseWriter, r *http.Request) {
	name := r.PathValue("name")
	var body struct {
		Device string `json:"device"`
	}
	_ = readBody(r, &body, 4096)
	if !incus.ValidName(name) || !incus.ValidDevice(body.Device) || body.Device == "root" {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	in, err := s.instanceByName(r.Context(), name)
	if err != nil {
		jsonErr(w, 404, err.Error())
		return
	}
	if d, ok := in.Devices[body.Device]; !ok || d["type"] != "disk" {
		jsonErr(w, 409, body.Device+" isn't a disk device of "+name)
		return
	}
	ctx, cancel := context.WithTimeout(r.Context(), time.Minute)
	defer cancel()
	if out, err := s.virt.Cmd(ctx, "config", "device", "remove", name, body.Device).CombinedOutput(); err != nil {
		jsonErr(w, 409, strings.TrimPrefix(strings.TrimSpace(string(out)), "Error: "))
		return
	}
	log.Printf("virt: %s: device %s removed (from %s)", name, body.Device, clientIP(r))
	w.WriteHeader(204)
}

// ---- exports ----

func (s *Server) virtExports(w http.ResponseWriter, r *http.Request) {
	c := s.virt.ExportConfig()
	out := map[string]any{"config": c, "cron": c.CronExpr(), "last": s.virt.LastExportRun(), "files": s.virt.ExportFiles(), "dir": s.virt.ExportsDir(), "cron_file": incus.CronFile}
	if c.Enabled {
		out["next"] = c.NextRun(time.Now())
	}
	jsonOK(w, 200, out)
}

func (s *Server) virtExportsPut(w http.ResponseWriter, r *http.Request) {
	var c incus.ExportConfig
	if err := readBody(r, &c, 16<<10); err != nil {
		jsonErr(w, 400, "bad request")
		return
	}
	if err := s.virt.SaveExportConfig(c); err != nil {
		jsonErr(w, 400, err.Error())
		return
	}
	exe, err := os.Executable()
	if err == nil {
		exe, _ = filepath.EvalSymlinks(exe)
	}
	if c.Enabled {
		err = s.storage.WriteRootFile(r.Context(), incus.CronFile, c.CronText(s.user, exe, s.cfg.Path()))
	} else {
		err = s.storage.RemoveRootFile(r.Context(), incus.CronFile)
	}
	if err != nil {
		jsonErr(w, 500, "schedule saved, but the cron file could not be written: "+err.Error())
		return
	}
	log.Printf("virt: exports %v at %02d:%02d keep %d (from %s)", c.Enabled, c.Hour, c.Minute, c.Keep, clientIP(r))
	w.WriteHeader(204)
}

func (s *Server) virtExportsRun(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Instance string `json:"instance"`
	}
	_ = readBody(r, &body, 4096)
	if body.Instance != "" && !incus.ValidName(body.Instance) {
		jsonErr(w, 400, "bad name")
		return
	}
	if !s.virtReady(w, r) {
		return
	}
	exe, err := os.Executable()
	if err != nil {
		jsonErr(w, 500, err.Error())
		return
	}
	args := []string{"-config", s.cfg.Path(), "virt-export"}
	title := "export every instance"
	if body.Instance != "" {
		args = append(args, body.Instance)
		title = "export " + body.Instance
	}
	t, err := s.tasks.Start("virt:export", title, exec.Command(exe, args...))
	if err != nil {
		jsonErr(w, 409, err.Error())
		return
	}
	log.Printf("virt: %s as task %s (from %s)", title, t.ID, clientIP(r))
	jsonOK(w, 202, t.Snapshot(false))
}

func (s *Server) virtExportDelete(w http.ResponseWriter, r *http.Request) {
	var body struct {
		Instance string `json:"instance"`
		Name     string `json:"name"`
	}
	_ = readBody(r, &body, 4096)
	if !incus.ValidName(body.Instance) || body.Name != filepath.Base(body.Name) || !strings.HasSuffix(body.Name, ".tar.gz") {
		jsonErr(w, 400, "bad name")
		return
	}
	if err := os.Remove(filepath.Join(s.virt.ExportsDir(), body.Instance, body.Name)); err != nil {
		jsonErr(w, 404, "no such export")
		return
	}
	log.Printf("virt: export %s/%s deleted (from %s)", body.Instance, body.Name, clientIP(r))
	w.WriteHeader(204)
}

// virtSSHKeys is the daemon account's public keys, for a cloud-init that lets him straight in.
func (s *Server) virtSSHKeys(w http.ResponseWriter, _ *http.Request) {
	home, _ := os.UserHomeDir()
	seen := map[string]bool{}
	keys := []string{}
	add := func(line string) {
		f := strings.Fields(line)
		if len(f) < 2 || !strings.HasPrefix(f[0], "ssh-") && !strings.HasPrefix(f[0], "ecdsa-") && !strings.HasPrefix(f[0], "sk-") {
			return
		}
		k := f[0] + " " + f[1]
		if seen[k] {
			return
		}
		seen[k] = true
		keys = append(keys, strings.TrimSpace(line))
	}
	if b, err := os.ReadFile(filepath.Join(home, ".ssh", "authorized_keys")); err == nil {
		for _, l := range strings.Split(string(b), "\n") {
			add(l)
		}
	}
	pubs, _ := filepath.Glob(filepath.Join(home, ".ssh", "*.pub"))
	for _, p := range pubs {
		if b, err := os.ReadFile(p); err == nil {
			add(string(b))
		}
	}
	jsonOK(w, 200, map[string]any{"keys": keys, "user": s.user})
}