package storage

import (
	"context"
	"os"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
)

// --- Unit rendering: the exact, locked SPIKE option sets + the +100000 recipe -----------------------

func TestNetworkMount_NFSUnitRendering(t *testing.T) {
	spec := NetworkMountSpec{
		Name: "media", Protocol: ProtocolNFS, Server: "192.168.0.180", Export: "/srv/nas-sim/media",
		MappedUID: 1000, MappedGID: 1000,
	}
	if err := ValidateNetworkMountSpec(spec); err != nil {
		t.Fatalf("valid NFS spec rejected: %v", err)
	}
	mu := renderNetworkMountUnit(spec)

	wantOpts := "Options=vers=4.1,soft,timeo=50,retrans=2,noatime,_netdev"
	for _, want := range []string{
		netUnitMarker,
		"What=192.168.0.180:/srv/nas-sim/media",
		"Where=/mnt/felhom-drives/media",
		"Type=nfs4",
		wantOpts,
	} {
		if !strings.Contains(mu, want) {
			t.Errorf("NFS .mount missing %q:\n%s", want, mu)
		}
	}
	// soft is the failure-isolation knob; a default hard mount wedges — it must NEVER appear.
	if strings.Contains(mu, "hard") {
		t.Errorf("NFS mount must not be hard:\n%s", mu)
	}
	// NFS uid mapping is the EXPORT's job (anonuid=101000) — the client mount carries no uid/gid.
	if strings.Contains(mu, "uid=") || strings.Contains(mu, "anonuid") {
		t.Errorf("NFS client mount must not carry uid options (server-side squash):\n%s", mu)
	}

	au := renderNetworkAutomountUnit(spec)
	for _, want := range []string{
		netUnitMarker,
		"Where=/mnt/felhom-drives/media",
		"[Automount]",
		"TimeoutIdleSec=60",
		"WantedBy=multi-user.target",
	} {
		if !strings.Contains(au, want) {
			t.Errorf("NFS .automount missing %q:\n%s", want, au)
		}
	}
}

// TestNetworkMount_SMBUnitRendering_Plus100000 is the headline +100000 companion: a container uid/gid of
// 1000 MUST render the SMB client mount with uid=101000/gid=101000 (host = container+100000). A naive
// +0 implementation (uid=1000) would FAIL here — and lands as nobody:nogroup in the guest (not writable).
func TestNetworkMount_SMBUnitRendering_Plus100000(t *testing.T) {
	spec := NetworkMountSpec{
		Name: "media", Protocol: ProtocolSMB, Server: "nas.local", Export: "media",
		MappedUID: 1000, MappedGID: 1000, CredsRef: "/var/lib/felhom-agent/smb-creds/media.cred",
	}
	if err := ValidateNetworkMountSpec(spec); err != nil {
		t.Fatalf("valid SMB spec rejected: %v", err)
	}
	mu := renderNetworkMountUnit(spec)

	wantOpts := "Options=vers=3.0,credentials=/var/lib/felhom-agent/smb-creds/media.cred,uid=101000,gid=101000,forceuid,forcegid,file_mode=0664,dir_mode=0775,_netdev"
	for _, want := range []string{
		netUnitMarker,
		"What=//nas.local/media",
		"Where=/mnt/felhom-drives/media",
		"Type=cifs",
		wantOpts,
	} {
		if !strings.Contains(mu, want) {
			t.Errorf("SMB .mount missing %q:\n%s", want, mu)
		}
	}
	// THE companion red-proof: the +100000 offset must be applied; a +0 impl emits uid=1000.
	if strings.Contains(mu, "uid=1000,") || strings.Contains(mu, "gid=1000,") {
		t.Errorf("SMB mount used the raw container id, not +100000 (the documented non-writable trap):\n%s", mu)
	}
	// Modes must be PLAIN octal (0664/0775), never the setgid 2775 the drive userdata uses.
	if strings.Contains(mu, "2775") {
		t.Errorf("SMB dir_mode must be plain octal 0775, not setgid 2775:\n%s", mu)
	}
}

func TestNetworkMount_HostOffset(t *testing.T) {
	s := NetworkMountSpec{MappedUID: 1000, MappedGID: 1000}
	if s.HostUID() != 101000 || s.HostGID() != 101000 {
		t.Fatalf("HostUID/HostGID = %d/%d, want 101000/101000", s.HostUID(), s.HostGID())
	}
}

// --- Validation -------------------------------------------------------------------------------------

func TestValidateNetworkMountSpec(t *testing.T) {
	base := NetworkMountSpec{Name: "media", Protocol: ProtocolNFS, Server: "10.0.0.5", Export: "/srv/media", MappedUID: 1000, MappedGID: 1000}
	good := func(mut func(*NetworkMountSpec)) NetworkMountSpec { s := base; mut(&s); return s }

	bad := []struct {
		name string
		spec NetworkMountSpec
	}{
		{"empty name", good(func(s *NetworkMountSpec) { s.Name = "" })},
		{"name traversal", good(func(s *NetworkMountSpec) { s.Name = ".." })},
		{"name with slash", good(func(s *NetworkMountSpec) { s.Name = "a/b" })},
		{"name with space", good(func(s *NetworkMountSpec) { s.Name = "a b" })},
		{"bad protocol", good(func(s *NetworkMountSpec) { s.Protocol = "afp" })},
		{"server metachar", good(func(s *NetworkMountSpec) { s.Server = "a;rm -rf" })},
		{"empty server", good(func(s *NetworkMountSpec) { s.Server = "" })},
		{"nfs relative export", good(func(s *NetworkMountSpec) { s.Export = "srv/media" })},
		{"nfs export traversal", good(func(s *NetworkMountSpec) { s.Export = "/srv/../etc" })},
		{"uid out of range", good(func(s *NetworkMountSpec) { s.MappedUID = 70000 })},
		{"negative gid", good(func(s *NetworkMountSpec) { s.MappedGID = -1 })},
		{"smb without creds", good(func(s *NetworkMountSpec) { s.Protocol = ProtocolSMB; s.Export = "media"; s.CredsRef = "" })},
		{"smb bad share name", good(func(s *NetworkMountSpec) { s.Protocol = ProtocolSMB; s.Export = "a/b"; s.CredsRef = "/x/y.cred" })},
	}
	for _, c := range bad {
		if err := ValidateNetworkMountSpec(c.spec); err == nil {
			t.Errorf("%s: expected rejection, got nil", c.name)
		}
	}

	// Good specs.
	if err := ValidateNetworkMountSpec(base); err != nil {
		t.Errorf("valid NFS spec rejected: %v", err)
	}
	smb := good(func(s *NetworkMountSpec) { s.Protocol = ProtocolSMB; s.Export = "media"; s.CredsRef = "/var/lib/felhom-agent/smb-creds/media.cred" })
	if err := ValidateNetworkMountSpec(smb); err != nil {
		t.Errorf("valid SMB spec rejected: %v", err)
	}
}

// --- Role gate: bulk-userdata namespace only --------------------------------------------------------

func TestNetworkMountRole(t *testing.T) {
	userdata := []string{"/mnt/felhom-drives/media", "/mnt/felhom-drives/photos", NetworkMountRoot}
	for _, p := range userdata {
		if NetworkMountRole(p) != RoleUserData {
			t.Errorf("%s should be user-data", p)
		}
	}
	system := []string{"/etc/passwd", "/srv/system/x", "/mnt/felhom-drivesX/y", "/var/lib/felhom-agent"}
	for _, p := range system {
		if NetworkMountRole(p) != RoleSystem {
			t.Errorf("%s should be system (refused)", p)
		}
	}
}

// --- Liveness parse + health ------------------------------------------------------------------------

func TestParseNetworkMountUnit_RoundTrip(t *testing.T) {
	nfs := NetworkMountSpec{Name: "media", Protocol: ProtocolNFS, Server: "10.0.0.5", Export: "/srv/media", MappedUID: 1000, MappedGID: 1000}
	proto, server, export, where, ok := parseNetworkMountUnit(renderNetworkMountUnit(nfs))
	if !ok || proto != "nfs" || server != "10.0.0.5" || export != "/srv/media" || where != "/mnt/felhom-drives/media" {
		t.Errorf("NFS parse = %q %q %q %q ok=%v", proto, server, export, where, ok)
	}
	smb := NetworkMountSpec{Name: "vids", Protocol: ProtocolSMB, Server: "nas", Export: "vids", MappedUID: 1000, MappedGID: 1000, CredsRef: "/x/y.cred"}
	proto, server, export, where, ok = parseNetworkMountUnit(renderNetworkMountUnit(smb))
	if !ok || proto != "smb" || server != "nas" || export != "vids" || where != "/mnt/felhom-drives/vids" {
		t.Errorf("SMB parse = %q %q %q %q ok=%v", proto, server, export, where, ok)
	}
	// A non-network unit (a drive by-uuid .mount) must NOT parse as a network mount.
	drive := renderMountUnit(MountSpec{Name: "usb", UUID: "0fc63daf-8483-4772-8e79-3d69d8477de4", Where: "/mnt/felhom-usb", FSType: "ext4"})
	if _, _, _, _, ok := parseNetworkMountUnit(drive); ok {
		t.Errorf("a drive by-uuid unit must not parse as a network mount")
	}
}

func TestNetworkHealth(t *testing.T) {
	cases := []struct {
		reachable, mounted bool
		want               string
	}{
		{true, true, NetHealthOK},
		{true, false, NetHealthIdle},
		{false, true, NetHealthUnreachable},
		{false, false, NetHealthUnreachable},
	}
	for _, c := range cases {
		if got := networkHealth(c.reachable, c.mounted); got != c.want {
			t.Errorf("networkHealth(%v,%v)=%q want %q", c.reachable, c.mounted, got, c.want)
		}
	}
}

func TestIsNetworkMounted(t *testing.T) {
	for _, fs := range []string{"nfs", "nfs4", "cifs"} {
		if !isNetworkMounted(fs) {
			t.Errorf("%s should count as mounted", fs)
		}
	}
	for _, fs := range []string{"autofs", "", "ext4", "tmpfs"} {
		if isNetworkMounted(fs) {
			t.Errorf("%s must NOT count as a real network mount (idle automount = autofs)", fs)
		}
	}
}

// --- Scenario D: the drive machinery ignores a NAS mount (guard + companion red-proof) --------------

// TestNetMount_DriveMachineryGuard proves parseFelhomMountUnit (the host-reboot drive re-assert's
// classifier) REFUSES a network unit, so a NAS mount never enters the drive lifecycle. The companion
// red-proof: the SAME unit content WITHOUT the network marker but WITH a by-uuid What parses as a drive
// — i.e. it is the netUnitMarker guard (not luck) that keeps the NAS out of the drive machinery.
func TestNetMount_DriveMachineryGuard(t *testing.T) {
	// A real network .mount unit: parseFelhomMountUnit must reject it.
	netUnit := renderNetworkMountUnit(NetworkMountSpec{
		Name: "media", Protocol: ProtocolNFS, Server: "10.0.0.5", Export: "/srv/media", MappedUID: 1000, MappedGID: 1000,
	})
	if _, ok := parseFelhomMountUnit(netUnit); ok {
		t.Fatalf("a NAS network unit must NOT be classified as a drive by parseFelhomMountUnit:\n%s", netUnit)
	}

	// Contrived worst case: a unit carrying the network marker AND a by-uuid What (the shape that WOULD
	// otherwise parse as a drive). The guard must still refuse it.
	contrived := "# " + netUnitMarker + "\n[Unit]\nDescription=Felhom storage mount x\n[Mount]\n" +
		"What=" + byUUIDDir + "/0fc63daf-8483-4772-8e79-3d69d8477de4\nWhere=/mnt/felhom-drives/x\nType=nfs4\n"
	if _, ok := parseFelhomMountUnit(contrived); ok {
		t.Fatalf("the netUnitMarker guard must refuse a by-uuid-shaped network unit")
	}

	// COMPANION RED-PROOF: identical content but with the drive marker instead of the network marker
	// DOES parse as a drive — confirming the guard is the discriminator, not an accident of shape.
	driveShaped := strings.Replace(contrived, "# "+netUnitMarker, "# "+felhomUnitMarker, 1)
	if spec, ok := parseFelhomMountUnit(driveShaped); !ok || spec.UUID == "" {
		t.Fatalf("control: a by-uuid unit with ONLY the drive marker should parse as a drive (ok=%v uuid=%q)", ok, spec.UUID)
	}
}

// --- SudoHostOps command sequence (Linux only — the unit filename embeds an escaped '-' = backslash) -

func TestEnsureNetworkMount_Commands(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("systemd-escaped unit filename contains a backslash; staging is exercised on the Linux build server")
	}
	ctx := context.Background()
	stage, unitDir := t.TempDir(), t.TempDir()
	rr := &recordingRunner{}
	ops := NewSudoHostOps(SudoHostOpsConfig{
		Runner: rr, Bins: Binaries{}.withDefaults(), UnitDir: unitDir, StageDir: stage, Logger: quietLogger(),
	})
	spec := NetworkMountSpec{Name: "media", Protocol: ProtocolNFS, Server: "10.0.0.5", Export: "/srv/media", MappedUID: 1000, MappedGID: 1000}
	if err := ops.EnsureNetworkMount(ctx, spec); err != nil {
		t.Fatalf("EnsureNetworkMount: %v", err)
	}
	// Expect: mkdir, install(.mount), install(.automount), daemon-reload, enable --now <automount>.
	var sawMkdir, sawEnableAutomount, sawReload bool
	installs := 0
	for _, c := range rr.calls {
		joined := strings.Join(c, " ")
		switch {
		case strings.Contains(joined, "mkdir") && strings.Contains(joined, "/mnt/felhom-drives/media"):
			sawMkdir = true
		case strings.Contains(joined, "install"):
			installs++
		case strings.Contains(joined, "daemon-reload"):
			sawReload = true
		case strings.Contains(joined, "enable") && strings.Contains(joined, "--now") && strings.Contains(joined, ".automount"):
			sawEnableAutomount = true
		}
	}
	if !sawMkdir || installs != 2 || !sawReload || !sawEnableAutomount {
		t.Fatalf("unexpected command sequence (mkdir=%v installs=%d reload=%v enableAutomount=%v): %v",
			sawMkdir, installs, sawReload, sawEnableAutomount, rr.calls)
	}
	// The .automount is enabled; the .mount is NOT (automount triggers it).
	for _, c := range rr.calls {
		joined := strings.Join(c, " ")
		if strings.Contains(joined, "enable") && strings.Contains(joined, ".mount") && !strings.Contains(joined, ".automount") {
			t.Errorf("the .mount unit must NOT be enabled (automount drives it): %v", c)
		}
	}

	// Staged units carry the right bodies.
	autoName := "mnt-felhom\\x2ddrives-media.automount"
	body, err := os.ReadFile(filepath.Join(stage, autoName))
	if err != nil {
		t.Fatalf("staged automount not written: %v", err)
	}
	if !strings.Contains(string(body), "[Automount]") {
		t.Errorf("staged automount missing [Automount]:\n%s", body)
	}
}

func TestEnsureNetworkMount_RejectsBadSpec(t *testing.T) {
	ops := NewSudoHostOps(SudoHostOpsConfig{Runner: &recordingRunner{}, Bins: Binaries{}.withDefaults(), UnitDir: t.TempDir(), StageDir: t.TempDir(), Logger: quietLogger()})
	rr := ops.runner.(*recordingRunner)
	if err := ops.EnsureNetworkMount(context.Background(), NetworkMountSpec{Name: "..", Protocol: ProtocolNFS, Server: "x", Export: "/y"}); err == nil {
		t.Fatal("a bad spec must be refused")
	}
	if len(rr.calls) != 0 {
		t.Fatalf("a refused spec must construct ZERO commands, got: %v", rr.calls)
	}
}

func TestRemoveNetworkMount_Commands(t *testing.T) {
	if runtime.GOOS == "windows" {
		t.Skip("systemd-escaped unit filename contains a backslash; exercised on the Linux build server")
	}
	ctx := context.Background()
	rr := &recordingRunner{}
	ops := NewSudoHostOps(SudoHostOpsConfig{Runner: rr, Bins: Binaries{}.withDefaults(), UnitDir: t.TempDir(), StageDir: t.TempDir(), Logger: quietLogger()})
	if err := ops.RemoveNetworkMount(ctx, "media"); err != nil {
		t.Fatalf("RemoveNetworkMount: %v", err)
	}
	var stopAuto, disableAuto, rmCount, reload bool
	rms := 0
	for _, c := range rr.calls {
		j := strings.Join(c, " ")
		switch {
		case strings.Contains(j, "stop") && strings.Contains(j, ".automount"):
			stopAuto = true
		case strings.Contains(j, "disable") && strings.Contains(j, ".automount"):
			disableAuto = true
		case strings.Contains(j, "rm"):
			rms++
		case strings.Contains(j, "daemon-reload"):
			reload = true
		}
	}
	rmCount = rms == 2
	if !stopAuto || !disableAuto || !rmCount || !reload {
		t.Fatalf("unexpected remove sequence (stopAuto=%v disableAuto=%v rm=%d reload=%v): %v", stopAuto, disableAuto, rms, reload, rr.calls)
	}
}