package files

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

	"github.com/pkg/sftp"
	"github.com/profullstack/agentbbs/internal/store"
)

func newTestService(t *testing.T) (*Service, store.Store, store.User) {
	t.Helper()
	dir := t.TempDir()
	st, err := store.Open(filepath.Join(dir, "test.db"))
	if err != nil {
		t.Fatalf("store.Open: %v", err)
	}
	t.Cleanup(func() { _ = st.Close() })
	svc, err := New(st, Config{Root: filepath.Join(dir, "files"), DefaultQuota: 1 << 20})
	if err != nil {
		t.Fatalf("New: %v", err)
	}
	u, err := st.EnsureUser("alice", "member", "SHA256:alicekey")
	if err != nil {
		t.Fatalf("EnsureUser: %v", err)
	}
	return svc, st, u
}

func TestResolveConfinement(t *testing.T) {
	svc, _, u := newTestService(t)
	sess, err := svc.newSession(u)
	if err != nil {
		t.Fatal(err)
	}
	priv := svc.privRoot(u.Name)
	pub := svc.pubRoot()

	// These must never resolve to a path outside their area root. Some are
	// expected to error outright; for the rest, assert containment.
	escapes := []string{
		"/me/../../../etc/passwd",
		"/me/../../etc",
		"/me/sub/../../../../etc/shadow",
		"/public/../me/secret",
		"/public/../../etc",
		"/../etc/passwd",
		"/me/./../../public/../../root",
	}
	for _, p := range escapes {
		res, err := sess.resolve(p)
		if err != nil {
			continue // rejected outright — fine
		}
		if res.root {
			continue // collapsed to the synthetic root — fine
		}
		ok := within(priv, res.real) || within(pub, res.real)
		if !ok {
			t.Errorf("resolve(%q) escaped: %q (priv=%q pub=%q)", p, res.real, priv, pub)
		}
	}
}

func TestResolveAreas(t *testing.T) {
	svc, _, u := newTestService(t)
	sess, _ := svc.newSession(u)

	root, _ := sess.resolve("/")
	if !root.root {
		t.Error("/ should be the synthetic root")
	}
	me, err := sess.resolve("/me/notes.txt")
	if err != nil || me.area != areaMe || !me.writable {
		t.Errorf("/me should be writable me-area: %+v err=%v", me, err)
	}
	if !within(svc.privRoot(u.Name), me.real) {
		t.Errorf("/me path %q not under priv root", me.real)
	}
	pub, err := sess.resolve("/public/shared.txt")
	if err != nil || pub.area != areaPublic {
		t.Errorf("/public should be public area: %+v err=%v", pub, err)
	}
	if _, err := sess.resolve("/etc/passwd"); err == nil {
		t.Error("unknown top-level area should be rejected")
	}
}

func TestSymlinkEscapeBlocked(t *testing.T) {
	svc, _, u := newTestService(t)
	sess, _ := svc.newSession(u)
	priv := svc.privRoot(u.Name)

	// Plant a symlink inside the workspace pointing at the system root.
	link := filepath.Join(priv, "escape")
	if err := os.Symlink("/etc", link); err != nil {
		t.Skipf("symlink unsupported: %v", err)
	}
	if _, err := sess.resolve("/me/escape/passwd"); err == nil {
		t.Error("path through an escaping symlink must be rejected")
	}
}

func TestPublicWriteACL(t *testing.T) {
	svc, st, u := newTestService(t)

	// Default: members may write to the public area.
	sess, _ := svc.newSession(u)
	r := sftp.NewRequest("Mkdir", "/public/uploads")
	if err := sess.Filecmd(r); err != nil {
		t.Fatalf("public mkdir should succeed by default: %v", err)
	}

	// Turn public write off → writes denied, reads still fine.
	if err := svc.SetPublicWrite(false); err != nil {
		t.Fatal(err)
	}
	_ = st
	sess2, _ := svc.newSession(u)
	if err := sess2.Filecmd(sftp.NewRequest("Mkdir", "/public/more")); err != sftp.ErrSSHFxPermissionDenied {
		t.Errorf("public write should be denied when off, got %v", err)
	}
	res, err := sess2.resolve("/public/uploads")
	if err != nil || res.writable {
		t.Errorf("public should resolve read-only when write is off: %+v err=%v", res, err)
	}
}

func TestQuotaEnforced(t *testing.T) {
	svc, _, u := newTestService(t)
	sess, _ := svc.newSession(u)
	sess.quota = 100 // tiny

	f, err := os.Create(filepath.Join(svc.privRoot(u.Name), "big"))
	if err != nil {
		t.Fatal(err)
	}
	defer f.Close()
	w := &quotaWriter{f: f, sess: sess}

	if _, err := w.WriteAt(make([]byte, 80), 0); err != nil {
		t.Fatalf("write within quota failed: %v", err)
	}
	if _, err := w.WriteAt(make([]byte, 80), 80); err != sftp.ErrSSHFxFailure {
		t.Errorf("write over quota should fail, got %v", err)
	}
}

func TestUsage(t *testing.T) {
	svc, _, u := newTestService(t)
	if err := svc.ensureWorkspace(u.Name); err != nil {
		t.Fatal(err)
	}
	want := []byte(strings.Repeat("x", 512))
	if err := os.WriteFile(filepath.Join(svc.privRoot(u.Name), "a.txt"), want, 0o644); err != nil {
		t.Fatal(err)
	}
	usage, err := svc.Usage(u)
	if err != nil {
		t.Fatal(err)
	}
	if usage.Bytes != 512 {
		t.Errorf("usage = %d, want 512", usage.Bytes)
	}
	if usage.Quota != 1<<20 {
		t.Errorf("quota = %d, want default", usage.Quota)
	}
}

func TestRevokeBlocksAndQuotaOverride(t *testing.T) {
	svc, st, u := newTestService(t)
	if err := st.SetFilesQuota(u.ID, 4096); err != nil {
		t.Fatal(err)
	}
	if got := svc.quotaFor(u.ID); got != 4096 {
		t.Errorf("quotaFor = %d, want 4096 override", got)
	}
	if err := st.SetFilesRevoked(u.ID, true); err != nil {
		t.Fatal(err)
	}
	fa, err := st.FilesAccess(u.ID)
	if err != nil || !fa.Revoked {
		t.Errorf("FilesAccess revoked = %+v err=%v", fa, err)
	}
}