package main

import (
	"context"
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"
)

// fake is a machine for a test: a tree standing in for /etc, /proc and /var/lib, and a runner
// answering from a table.
type fake struct {
	t       *testing.T
	root    string
	answers map[string]string
	zfs     bool
}

func newFake(t *testing.T) *fake {
	t.Helper()
	return &fake{t: t, root: t.TempDir(), answers: map[string]string{}}
}

func (f *fake) file(path, text string) {
	f.t.Helper()
	p := filepath.Join(f.root, path)
	if err := os.MkdirAll(filepath.Dir(p), 0o755); err != nil {
		f.t.Fatal(err)
	}
	if err := os.WriteFile(p, []byte(text), 0o644); err != nil {
		f.t.Fatal(err)
	}
}

func (f *fake) machine() *Machine {
	return &Machine{
		Root: f.root,
		Run: func(_ context.Context, name string, args ...string) (string, error) {
			line := strings.TrimSpace(name + " " + strings.Join(args, " "))
			if name == "systemctl" {
				if err := systemctlRefuses(args); err != nil {
					return "", err
				}
			}
			if out, ok := f.answers[line]; ok {
				return out, nil
			}
			return "", fmt.Errorf("%s: not found", line)
		},
		LookPath: func(n string) bool { return n == "zfs" && f.zfs },
	}
}

// systemctlRefuses is what systemctl itself does with an argument that starts with a dash before
// "--": it reads it as an option, so the root mount's unit -.mount is refused. The message is the
// one systemctl gave on the desktop (novox/hq issue 374); a fake that took -.mount as a unit name
// agreed with the mistake.
func systemctlRefuses(args []string) error {
	for i := 0; i < len(args); i++ {
		a := args[i]
		switch {
		case a == "--":
			return nil
		case a == "-p":
			i++ // its value is the property list
		case strings.HasPrefix(a, "--"):
		case strings.HasPrefix(a, "-") && len(a) > 1:
			return fmt.Errorf("exit status 1: systemctl: invalid option -- '%c'\nHint: to specify units starting with a dash, use \"--\":\n      systemctl [OPTIONS…] COMMAND -- %s …", a[1], a)
		}
	}
	return nil
}

func TestRedactOptions(t *testing.T) {
	cases := []struct{ in, want string }{
		{"", ""},
		{"defaults,_netdev", "defaults,_netdev"},
		{"username=root,password=hunter2,iocharset=utf8", "username=root,password=(redacted),iocharset=utf8"},
		{"user=a,pass=x,PASSWD=y", "user=a,pass=(redacted),PASSWD=(redacted)"},
		{"credentials=/etc/samba/creds,sec=ntlmssp", "credentials=/etc/samba/creds,sec=ntlmssp"},
		{"password=", "password=(redacted)"},
		{"password2=z,passwordless", "password2=(redacted),passwordless"},
	}
	for _, c := range cases {
		if got := RedactOptions(c.in); got != c.want {
			t.Errorf("RedactOptions(%q) = %q, want %q", c.in, got, c.want)
		}
	}
}

const sampleFstab = `# /etc/fstab
UUID=aaaa	/         	ext4      	rw,relatime	0 1
UUID=bbbb	none	swap	defaults	0 0
192.0.2.10:/storage/media  /storage/media  nfs  defaults,_netdev  0 0
//192.0.2.20/Share  /mnt/my\040share  cifs  username=root,password=s3cret,iocharset=utf8  0 0
192.0.2.10:/backup  /mnt/backup  nfs4  nofail,x-systemd.automount  0 0
`

func TestParseFstab(t *testing.T) {
	got := ParseFstab(sampleFstab)
	if len(got) != 5 {
		t.Fatalf("got %d entries, want 5: %+v", len(got), got)
	}
	cases := []struct {
		i       int
		point   string
		network bool
		line    int
	}{
		{0, "/", false, 2}, {2, "/storage/media", true, 4}, {3, "/mnt/my share", true, 5}, {4, "/mnt/backup", true, 6},
	}
	for _, c := range cases {
		e := got[c.i]
		if e.Mountpoint != c.point || e.Network != c.network || e.Line != c.line {
			t.Errorf("entry %d = %+v, want point %q network %v line %d", c.i, e, c.point, c.network, c.line)
		}
	}
	if strings.Contains(got[3].Options, "s3cret") {
		t.Errorf("a password was answered: %q", got[3].Options)
	}
}

func TestIsNetwork(t *testing.T) {
	cases := []struct {
		typ, src string
		want     bool
	}{
		{"nfs", "h:/x", true}, {"cifs", "//h/s", true}, {"fuse.sshfs", "u@h:/x", true}, {"ext4", "/dev/sda1", false},
		{"fuseblk", "/dev/sda2", false}, {"fuse.rclone", "remote:", true}, {"fuse.portal", "portal", false},
	}
	for _, c := range cases {
		if got := IsNetwork(c.typ, c.src); got != c.want {
			t.Errorf("IsNetwork(%q, %q) = %v, want %v", c.typ, c.src, got, c.want)
		}
	}
}

const sampleMountinfo = `22 1 259:3 / / rw,relatime shared:1 - ext4 /dev/nvme0n1p3 rw
40 22 0:50 / /mnt/backup rw,relatime shared:30 - autofs systemd-1 rw,fd=50
61 40 0:60 / /mnt/backup rw,relatime shared:31 - nfs4 192.0.2.10:/backup rw,vers=4.2
70 22 0:70 / /mnt/my\040share rw - cifs //192.0.2.20/Share rw,username=root,password=leaked
`

func TestParseMountinfo(t *testing.T) {
	got := ParseMountinfo(sampleMountinfo)
	if got["/mnt/backup"].Type != "nfs4" {
		t.Errorf("the last mount at a point must win: %+v", got["/mnt/backup"])
	}
	share, ok := got["/mnt/my share"]
	if !ok {
		t.Fatalf("an escaped mount point was not decoded: %+v", got)
	}
	if strings.Contains(share.Options, "leaked") {
		t.Errorf("a password in mountinfo was answered: %q", share.Options)
	}
}

const sampleListUnits = `-.mount              loaded active mounted Root Mount
mnt-backup.automount loaded active waiting mnt-backup.automount
mnt-backup.mount     loaded active mounted /mnt/backup
mnt-my\x20share.mount loaded failed failed /mnt/my share
storage-media.mount  loaded failed failed /storage/media
dev-mqueue.mount     loaded active mounted POSIX Message Queue File System
`

var sampleShow = strings.Join([]string{
	"Id=-.mount\nWhere=/\nWhat=/dev/nvme0n1p3\nType=ext4\nOptions=rw\nResult=success\nActiveState=active\nSubState=mounted\nFragmentPath=/run/systemd/generator/-.mount\nSourcePath=/etc/fstab\nTimeoutUSec=1min 30s\nUnitFileState=generated",
	"Id=mnt-backup.automount\nWhere=/mnt/backup\nResult=success\nActiveState=active\nSubState=waiting\nFragmentPath=/run/systemd/generator/mnt-backup.automount\nSourcePath=/etc/fstab\nUnitFileState=generated",
	"Id=mnt-backup.mount\nWhere=/mnt/backup\nWhat=192.0.2.10:/backup\nType=nfs4\nOptions=rw,vers=4.2\nResult=success\nActiveState=active\nSubState=mounted\nFragmentPath=/run/systemd/generator/mnt-backup.mount\nSourcePath=/etc/fstab\nTimeoutUSec=1min 30s\nUnitFileState=generated",
	"Id=mnt-my\\x20share.mount\nWhere=/mnt/my share\nWhat=//192.0.2.20/Share\nType=cifs\nOptions=username=root,password=s3cret\nResult=exit-code\nActiveState=failed\nSubState=failed\nFragmentPath=/run/systemd/generator/mnt-my\\x20share.mount\nSourcePath=/etc/fstab\nUnitFileState=generated",
	"Id=storage-media.mount\nWhere=/storage/media\nWhat=192.0.2.10:/storage/media\nType=nfs\nOptions=defaults,_netdev\nResult=timeout\nActiveState=failed\nSubState=failed\nFragmentPath=/run/systemd/generator/storage-media.mount\nSourcePath=/etc/fstab\nTimeoutUSec=1min 30s\nUnitFileState=generated",
	"Id=dev-mqueue.mount\nWhere=/dev/mqueue\nWhat=mqueue\nType=mqueue\nActiveState=active\nSubState=mounted\nFragmentPath=/usr/lib/systemd/system/dev-mqueue.mount\nUnitFileState=static",
}, "\n\n") + "\n"

func listFake(t *testing.T) *fake {
	f := newFake(t)
	f.file("/etc/fstab", sampleFstab)
	f.file("/proc/self/mountinfo", sampleMountinfo)
	f.answers["systemctl list-units --type=mount,automount --all --no-legend --plain --no-pager"] = sampleListUnits
	names := strings.Join(ParseListUnits(sampleListUnits), " ")
	f.answers["systemctl show -p "+ShowProperties+" --no-pager -- "+names] = sampleShow
	return f
}

func TestList(t *testing.T) {
	r := listFake(t).machine().List(false, "")
	said := strings.Join(r.Said, "\n")
	for _, want := range []string{
		"/storage/media (nfs from 192.0.2.10:/storage/media): failed, timeout; from /etc/fstab line 4, no automount, no nofail",
		"/mnt/my share (cifs from //192.0.2.20/Share): failed, exit-code; from /etc/fstab line 5, no automount, no nofail",
		"/mnt/backup (nfs4 from 192.0.2.10:/backup): mounted; from /etc/fstab line 6",
		"/ (ext4 from UUID=aaaa): mounted; from /etc/fstab line 2",
	} {
		if !strings.Contains(said, want) {
			t.Errorf("said lacks %q:\n%s", want, said)
		}
	}
	if strings.Contains(said, "mqueue") {
		t.Errorf("a kernel filesystem was said:\n%s", said)
	}
	for _, mt := range r.Mounts {
		if mt.Mountpoint == "/mnt/backup" && (mt.Automount == nil || mt.MountUnit == nil) {
			t.Errorf("/mnt/backup must carry both units: %+v", mt)
		}
		if mt.Mountpoint == "/storage/media" && mt.MountUnit.From != "generated from /etc/fstab" {
			t.Errorf("from = %q", mt.MountUnit.From)
		}
	}
	all, _ := json.Marshal(r)
	if strings.Contains(string(all), "s3cret") || strings.Contains(string(all), "leaked") {
		t.Errorf("a credential was answered: %s", all)
	}
}

// The desktop's own mount units, as its service manager listed them on 2026-10-11 (novox/hq issue
// 374): the root mount's unit is -.mount, and systemctl reads a name that starts with a dash as an
// option unless it comes after "--". Every mount then lost its unit state, not only the root's.
const desktopListUnits = `-.mount                   loaded active   mounted Root Mount
boot.mount                loaded active   mounted /boot
home.mount                loaded active   mounted /home
mnt-hdd_2tb.mount         loaded active   mounted /mnt/hdd_2tb
mnt-recalbox.automount    loaded active   waiting recalbox, mounted by the mesh at first use
mnt-recalbox.mount        loaded inactive dead    recalbox (//192.0.2.176/Share), mounted by the mesh
storage-media.automount   loaded active   waiting media, mounted by the mesh at first use
storage-media.mount       loaded inactive dead    media (192.0.2.10:/storage/media), mounted by the mesh
`

func TestListReadsTheRootMountsUnit(t *testing.T) {
	f := newFake(t)
	f.file("/etc/fstab", "UUID=aaaa / ext4 rw,relatime 0 1\n")
	f.file("/proc/self/mountinfo", "22 1 259:3 / / rw,relatime shared:1 - ext4 /dev/nvme0n1p3 rw\n")
	f.answers["systemctl list-units --type=mount,automount --all --no-legend --plain --no-pager"] = desktopListUnits
	names := strings.Join(ParseListUnits(desktopListUnits), " ")
	if !strings.HasPrefix(names, "-.mount ") {
		t.Fatalf("the root mount's unit was not listed: %q", names)
	}
	f.answers["systemctl show -p "+ShowProperties+" --no-pager -- "+names] =
		"Id=-.mount\nWhere=/\nWhat=/dev/nvme0n1p3\nType=ext4\nOptions=rw\nResult=success\nActiveState=active\nSubState=mounted\n" +
			"FragmentPath=/run/systemd/generator/-.mount\nSourcePath=/etc/fstab\nUnitFileState=generated\n\n" +
			"Id=storage-media.automount\nWhere=/storage/media\nResult=success\nActiveState=active\nSubState=waiting\n" +
			"FragmentPath=/etc/systemd/system/storage-media.automount\nUnitFileState=enabled\n"
	r := f.machine().List(false, "")
	if len(r.Notes) != 0 {
		t.Fatalf("the units' properties must be read, the root mount's included: %q", r.Notes)
	}
	got := map[string]Mount{}
	for _, mt := range r.Mounts {
		got[mt.Mountpoint] = mt
	}
	if root := got["/"]; root.MountUnit == nil || root.MountUnit.Unit != "-.mount" {
		t.Errorf("/ must carry its unit -.mount: %+v", root.MountUnit)
	}
	if media := got["/storage/media"]; media.Automount == nil {
		t.Errorf("/storage/media must carry its automount: %+v", media)
	}
}

// The desktop's recalbox share as it stood on 2026-10-11 (novox/hq issue 437): its automount armed
// (active, waiting), its mount unit inactive, and in mountinfo only the autofs line the armed automount
// leaves at the point, with the superblock options the desktop showed. Nothing is mounted there, so it
// must be said as waiting for its first use, never as mounted. /mnt/backup in TestList keeps the other
// half: an nfs4 line over the autofs line is mounted.
func TestListSaysAnArmedAutomountIsNotMounted(t *testing.T) {
	f := newFake(t)
	f.file("/etc/fstab", "//192.0.2.176/Share /mnt/recalbox cifs username=root,password=s3cret,iocharset=utf8,sec=ntlmssp 0 0\n")
	f.file("/proc/self/mountinfo", "22 1 259:3 / / rw,relatime shared:1 - ext4 /dev/nvme0n1p3 rw\n"+
		"40 22 0:50 / /mnt/recalbox rw,relatime shared:30 - autofs systemd-1 rw,fd=116,pgrp=1,timeout=600,minproto=5,maxproto=5,direct,pipe_ino=68285996\n")
	f.answers["systemctl list-units --type=mount,automount --all --no-legend --plain --no-pager"] = desktopListUnits
	names := strings.Join(ParseListUnits(desktopListUnits), " ")
	f.answers["systemctl show -p "+ShowProperties+" --no-pager -- "+names] =
		"Id=mnt-recalbox.automount\nWhere=/mnt/recalbox\nResult=success\nActiveState=active\nSubState=waiting\n" +
			"FragmentPath=/etc/systemd/system/mnt-recalbox.automount\nUnitFileState=enabled\n\n" +
			"Id=mnt-recalbox.mount\nWhere=/mnt/recalbox\nWhat=//192.0.2.176/Share\nType=cifs\n" +
			"Options=credentials=/var/lib/mounts/smb-recalbox.credentials,iocharset=utf8,_netdev,nofail,uid=1000,gid=1000\n" +
			"Result=success\nActiveState=inactive\nSubState=dead\nFragmentPath=/etc/systemd/system/mnt-recalbox.mount\n" +
			"TimeoutUSec=10s\nUnitFileState=enabled-runtime\n"
	r := f.machine().List(false, "recalbox")
	if len(r.Said) != 1 {
		t.Fatalf("said %q, want one line for /mnt/recalbox", r.Said)
	}
	want := "/mnt/recalbox (cifs from //192.0.2.176/Share): not mounted, waits for its first use (automount waiting); from /etc/fstab line 1, no nofail"
	if r.Said[0] != want {
		t.Errorf("said %q,\nwant  %q", r.Said[0], want)
	}
}

func TestListNarrowed(t *testing.T) {
	m := listFake(t).machine()
	if r := m.List(true, ""); len(r.Mounts) != 3 {
		t.Errorf("network only: got %d mounts, want 3: %v", len(r.Mounts), r.Said)
	}
	if r := m.List(false, "192.0.2.20"); len(r.Mounts) != 1 || r.Mounts[0].Mountpoint != "/mnt/my share" {
		t.Errorf("match on source: %v", r.Said)
	}
}

func TestListWithoutFstabSaysSo(t *testing.T) {
	f := newFake(t)
	f.file("/proc/self/mountinfo", sampleMountinfo)
	r := f.machine().List(false, "")
	notes := strings.Join(r.Notes, "\n")
	if !strings.Contains(notes, "/etc/fstab: not present") || !strings.Contains(notes, "units were not read") {
		t.Errorf("a file or command that could not be read must be said: %q", notes)
	}
}