package appbackup

import "testing"

// R-203 — the ONE drive-kind rule. Table-driven over BOTH drive kinds on purpose: this defect
// survived because it is invisible on the kind that already worked, so a test that only covers the
// enrolled drive proves nothing about the fix.

func TestNamespaceRootFor_BothDriveKinds(t *testing.T) {
	const sys = "/mnt/sys_drive"
	cases := []struct {
		name, drive, want string
	}{
		// Scenario B — the enrolled drive must be BYTE-IDENTICAL to pre-R-203 behaviour. The
		// in-guest mount already IS the namespace root; appending felhom-data here would recreate
		// the .../felhom-data/felhom-data/... double-nest NamespaceRoot's comment exists to prevent.
		{"enrolled usb", "/mnt/felhom-usb", "/mnt/felhom-usb"},
		{"enrolled hdd", "/mnt/felhom-drives/hdd_1", "/mnt/felhom-drives/hdd_1"},
		{"enrolled nvme", "/mnt/felhom-drives/nvme-1tb", "/mnt/felhom-drives/nvme-1tb"},
		// Scenario A — the system-data fallback gains the segment. This is the case that was wrong.
		{"system drive", "/mnt/sys_drive", "/mnt/sys_drive/felhom-data"},
		// A trailing slash is the same drive. Before R-203 the backup package's copy of this rule
		// compared WITHOUT Clean while the stacks package's copy compared WITH it — so a config value
		// with a trailing slash would have flipped the mode in one package and not the other.
		{"system drive, trailing slash", "/mnt/sys_drive/", "/mnt/sys_drive/felhom-data"},
	}
	for _, tc := range cases {
		t.Run(tc.name, func(t *testing.T) {
			if got := NamespaceRootFor(tc.drive, sys); got != tc.want {
				t.Fatalf("NamespaceRootFor(%q, %q) = %q, want %q", tc.drive, sys, got, tc.want)
			}
		})
	}
}

// The rule must survive a trailing slash on the SYSTEM path too — it comes from config.
func TestIsEnrolledDrive_CleansBothSides(t *testing.T) {
	if IsEnrolledDrive("/mnt/sys_drive", "/mnt/sys_drive/") {
		t.Error("a trailing slash on the system path must not make the system drive look enrolled")
	}
	if IsEnrolledDrive("/mnt/sys_drive/", "/mnt/sys_drive") {
		t.Error("a trailing slash on the drive path must not make the system drive look enrolled")
	}
	if !IsEnrolledDrive("/mnt/felhom-usb", "/mnt/sys_drive") {
		t.Error("an enrolled drive must report enrolled")
	}
}

// The consequence the whole item is about: the directory an app binds and the directory the capture
// set looks in must be the SAME on both drive kinds.
//
// RED-PROOF: replace `UserdataDir(NamespaceRootFor(drive, sys))` with `UserdataDir(drive)` — the
// pre-R-203 call — and the system-drive row FAILS with the two paths differing by exactly
// `/felhom-data`. That is production behaviour up to v0.196.0.
func TestAppBindAndCaptureRootAgree(t *testing.T) {
	const sys = "/mnt/sys_drive"
	for _, drive := range []string{"/mnt/felhom-usb", "/mnt/felhom-drives/hdd_1", "/mnt/sys_drive"} {
		nsRoot := NamespaceRootFor(drive, sys)
		appBind := UserdataDir(nsRoot)   // what the deploy sets as ${USERDATA_PATH}
		captureRoot := UserdataDir(nsRoot) // what the capture set resolves RootUserdata against
		if appBind != captureRoot {
			t.Fatalf("drive %q: the app binds %q while the backup captures %q", drive, appBind, captureRoot)
		}
		// And it must be the canonical location — the one EnsureUserdataSkeleton creates.
		if drive == sys && appBind != "/mnt/sys_drive/felhom-data/userdata" {
			t.Fatalf("system drive resolved to %q, want the canonical /mnt/sys_drive/felhom-data/userdata", appBind)
		}
	}
}