package rootstate

import "testing"

func TestPersistentMountLineage(t *testing.T) {
	base := "10 1 8:1 / / rw - ext4 /dev/root rw\n"
	bound := base + "20 10 8:1 /opt /opt rw - ext4 /dev/root rw\n"
	got, err := persistentMountLineage(bound, 20)
	if err != nil || got != "/opt\t/opt\n/\t/\n" {
		t.Fatal(got, err)
	}
	renumbered := "110 1 8:7 / / rw - ext4 /dev/other rw\n120 110 8:7 /opt /opt rw - ext4 /dev/other rw\n"
	again, err := persistentMountLineage(renumbered, 120)
	if err != nil || again != got {
		t.Fatal(again, err)
	}
	stacked, err := persistentMountLineage(bound+"30 20 8:1 /opt /opt rw - ext4 /dev/root rw\n", 30)
	if err != nil || stacked == got {
		t.Fatal(stacked, err)
	}
	for _, malformed := range []string{
		"20 99 8:1 /opt /opt rw - ext4 /dev/root rw\n",
		"20 20 8:1 / / rw - ext4 /dev/root rw\n",
	} {
		if _, err := persistentMountLineage(malformed, 20); err == nil {
			t.Fatal("invalid ancestry accepted", malformed)
		}
	}
}

func TestPersistentMountSubstitutionWithRecycledNumbers(t *testing.T) {
	before := FileIdentity{Boot: "boot", Filesystem: "fs", Handle: "handle", Inode: 2, Mount: 3, MountUnique: 3, NamespaceUnique: 1, MountNamespace: "mnt:[1]", MountRoot: "/opt", MountPoint: "/opt", MountLineage: "/opt\t/opt\n/\t/\n"}
	after := before
	after.MountLineage = "/opt\t/opt\n" + before.MountLineage
	if before.Same(after) {
		t.Fatal("stacked mount accepted with recycled mount and namespace numbers")
	}
	after = before
	after.Mount++
	if !before.Same(after) {
		t.Fatal("recyclable mount number established identity")
	}
	after.MountUnique++
	if before.Same(after) {
		t.Fatal("replacement mount accepted within the same boot and namespace")
	}
	after.NamespaceUnique++
	if !before.Same(after) {
		t.Fatal("recreated unchanged topology refused")
	}
	after.Boot = "reboot"
	after.Device++
	if !before.Same(after) {
		t.Fatal("reboot refused")
	}
	for _, missing := range []string{"mount", "namespace"} {
		bad := before
		if missing == "mount" {
			bad.MountUnique = 0
		} else {
			bad.NamespaceUnique = 0
		}
		if before.Same(bad) || bad.Same(bad) {
			t.Fatal("lineage without unique boot evidence accepted", missing)
		}
	}
}

func TestPersistentMountPrivateParent(t *testing.T) {
	before := FileIdentity{Boot: "boot", Filesystem: "fs", Handle: "handle", Inode: 2, Mount: 3, MountUnique: 3, NamespaceUnique: 1, MountNamespace: "private", MountRoot: "/data/raw", MountPoint: "/data/view", MountLineage: "/data/raw\t/data/view\n/data\t/data\n/\t/\n"}
	after := before
	after.MountNamespace = "host"
	after.NamespaceUnique++
	after.MountUnique++
	after.MountLineage = "/data/raw\t/data/view\n/\t/\n"
	if !before.Same(after) {
		t.Fatal("private parent mount hid the unchanged child mount")
	}
	sameNamespace := before
	sameNamespace.MountNamespace = after.MountNamespace
	sameNamespace.NamespaceUnique = after.NamespaceUnique
	sameNamespace.MountUnique = after.MountUnique
	if sameNamespace.Same(after) {
		t.Fatal("removed ancestor mount accepted within the same boot and namespace")
	}
	if after.Same(before) {
		t.Fatal("added ancestor mount accepted")
	}
	substituted := before
	substituted.MountLineage = "/data/raw\t/data/view\n/other\t/data\n/\t/\n"
	if before.Same(substituted) {
		t.Fatal("substituted ancestor mount accepted")
	}
	after.MountLineage = "/data/raw\t/data/view\n" + after.MountLineage
	if before.Same(after) {
		t.Fatal("substitution at recorded mountpoint accepted")
	}
}

func TestPersistentMountPrivateParentWithOffset(t *testing.T) {
	before := FileIdentity{Boot: "boot", Filesystem: "fs", Handle: "handle", Inode: 2, Mount: 3, MountUnique: 3, NamespaceUnique: 1, MountNamespace: "private", MountRoot: "/disk/tmp/fixture/raw", MountPoint: "/tmp/fixture/view", MountLineage: "/disk/tmp/fixture/raw\t/tmp/fixture/view\n/disk/tmp/fixture\t/tmp/fixture\n/disk/tmp\t/tmp\n/\t/\n"}
	after := before
	after.MountNamespace = "host"
	after.NamespaceUnique++
	after.MountUnique++
	after.MountLineage = "/disk/tmp/fixture/raw\t/tmp/fixture/view\n/disk/tmp\t/tmp\n/\t/\n"
	if !before.Same(after) {
		t.Fatal("private self-bind beneath an offset bind refused")
	}
	for _, row := range []string{"/disk/other\t/tmp/fixture", "/tmp/fixture\t/tmp/fixture", "/disk/tmp/fixture\t/elsewhere", "@root:unknown\t/tmp/fixture"} {
		bad := before
		bad.MountLineage = "/disk/tmp/fixture/raw\t/tmp/fixture/view\n" + row + "\n/disk/tmp\t/tmp\n/\t/\n"
		if bad.Same(after) {
			t.Fatal("unproven parent accepted", row)
		}
	}
}