//go:build linux

package apply

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

	"github.com/novox/mesh-host/internal/declaration"
	"github.com/novox/mesh-host/internal/store"
)

// The contract the controller needs (novox/hq ADR 0325, issue 567): what it cannot know is read here, and what it
// names is matched as it names it.

// accountsHere stands in for the machine's user database: name → uid, gid.
func accountsHere(t *testing.T, known map[string][2]int) {
	t.Helper()
	was := AccountIDs
	AccountIDs = func(_ context.Context, name string) (int, int, bool, error) {
		ids, ok := known[name]
		return ids[0], ids[1], ok, nil
	}
	t.Cleanup(func() { AccountIDs = was })
}

// A tool runner's account comes with its name alone: its uid is read here, and its entry kept with it.
func TestAToolRunnersAccountIsReadByName(t *testing.T) {
	dir := aclFolder(t)
	keeping(t, nil, nil)
	accountsHere(t, map[string][2]int{"nox": {runner, 1000}})
	lib := filepath.Join(dir, "books")
	if err := os.Mkdir(lib, 0o755); err != nil {
		t.Fatal(err)
	}
	a := `{"id":"importer.books","type":"access","path":"` + lib + `","mode":"read-write","users":[` +
		`{"identity":"nox","use":"read-write","from":"tool-runner"}]}`
	if _, _, err := applyAccesses(t, store.State{}, a); err != nil {
		t.Fatal(err)
	}
	if got := effectiveOn(t, lib, runner); got != 7 {
		t.Fatalf("the tool runner's account read by name may %s", permWords(got))
	}
	if rec, _ := keptRecord(lib); len(rec.Want) != 1 || rec.Want[0].UID != runner {
		t.Errorf("the uid read is not what is kept: %+v", rec.Want)
	}
}

// One that is not here, or is root's, refuses its access, naming why, and gives nothing an entry.
func TestAToolRunnersAccountThatIsNotHereOrIsRootsIsRefused(t *testing.T) {
	was := RootGroupIDs
	RootGroupIDs = func() map[int]string { return map[int]string{10: "wheel"} }
	defer func() { RootGroupIDs = was }()
	for name, says := range map[string]string{"ghost": "not on this machine", "root": "never root",
		"admin": "root group"} {
		dir := aclFolder(t)
		keeping(t, nil, nil)
		accountsHere(t, map[string][2]int{"root": {0, 0}, "admin": {1001, 10}})
		lib := filepath.Join(dir, "books")
		if err := os.Mkdir(lib, 0o755); err != nil {
			t.Fatal(err)
		}
		a := `{"id":"importer.books","type":"access","path":"` + lib + `","mode":"read-write","users":[` +
			`{"identity":"` + name + `","use":"read-write","from":"tool-runner"}]}`
		_, _, err := applyAccesses(t, store.State{}, a)
		if err == nil || !strings.Contains(err.Error(), says) {
			t.Errorf("%s: not refused saying %q: %v", name, says, err)
		}
		if n := len(readACLsOrNil(t, lib)); n > 3 {
			t.Errorf("%s: an entry was kept", name)
		}
	}
	// And only a tool runner's account may come without a number.
	if _, err := declaration.Parse([]byte(`{"declaration":1,"resources":[{"id":"m.a","type":"access","path":"/srv/x",` +
		`"mode":"read-write","users":[{"identity":"mesh-m","use":"read","from":"container"}]}]}`)); err == nil {
		t.Error("a container's identity without a uid was accepted")
	}
}

func readACLsOrNil(t *testing.T, path string) acl {
	a, _, _ := readACLs(t, path)
	return a
}

// The take act names its access by the declared resource id exactly, `/` and all; anything not declared is refused.
func TestTheTakeActMatchesTheDeclaredAccessId(t *testing.T) {
	dir := aclFolder(t)
	keeping(t, nil, nil)
	lib := filepath.Join(dir, "movies")
	if err := os.MkdirAll(filepath.Join(lib, "a film"), 0o755); err != nil {
		t.Fatal(err)
	}
	id := "radarr.access-services/media/movies"
	a := `{"id":"` + id + `","type":"access","path":"` + lib + `","mode":"read-write","users":[` +
		`{"identity":"mesh-radarr","uid":61001,"use":"read-write","from":"container"}]}`
	toUser(t)
	if _, _, err := TakeFolder(context.Background(), declare(t, a), "radarr.access-services/media", lib, "w", "op",
		noServices); err == nil {
		t.Fatal("an access not declared was taken")
	}
	toUser(t)
	done, _, err := TakeFolder(context.Background(), declare(t, a), id, lib, "w", "op", noServices)
	if err != nil {
		t.Fatalf("the declared id with a slash was refused: %v", err)
	}
	<-done
}

// The words a keep wait says of ACLs: only a ZFS dataset is one the take act lets carry them.
func TestAKeepWaitSaysWhetherTheTakeActCanAllowACLs(t *testing.T) {
	if aclWord("tank/media", "zfs") != ACLNeedsEnabling || aclWord("/dev/sdb1", "ext4") != ACLUnsupported ||
		aclWord("", "zfs") != ACLUnsupported {
		t.Fatal("the ACL words are not what the take act can do")
	}
	dir := aclFolder(t) // carries ACLs: the wait says nothing of them
	keeping(t, nil, nil)
	lib := filepath.Join(dir, "music")
	if err := os.MkdirAll(filepath.Join(lib, "album"), 0o755); err != nil {
		t.Fatal(err)
	}
	toUser(t)
	if v := AccessVerdict(context.Background(), lib, false, true); v.Kind != VerdictWaitKeep || v.ACL != "" {
		t.Fatalf("a folder whose filesystem allows ACLs is said %+v", v)
	}
}