package crypto

import (
	"encoding/hex"
	"strings"
	"testing"
)

func TestPeerIDIsHex(t *testing.T) {
	id := newTestIdentity(t)
	peerID := string(id.PeerID())

	if len(peerID) != 64 {
		t.Fatalf("PeerID length = %d, want 64", len(peerID))
	}
	if strings.ToLower(peerID) != peerID {
		t.Fatal("PeerID is not lowercase")
	}
	if _, err := hex.DecodeString(peerID); err != nil {
		t.Fatalf("PeerID is not valid hex: %v", err)
	}
}

func TestSignVerifyHex(t *testing.T) {
	id := newTestIdentity(t)
	msg := []byte("test message")

	sig := id.Sign(msg)
	if err := Verify(string(id.PeerID()), msg, sig); err != nil {
		t.Fatalf("Verify failed: %v", err)
	}
}

func TestSignalingBoxRoundTrip(t *testing.T) {
	alice := newTestIdentity(t)
	bob := newTestIdentity(t)

	plaintext := []byte(`{"kind":"offer","sdp":"v=0..."}`)

	sealed := SignalingBox(plaintext, bob.CurvePublicKey(), alice.CurvePrivateKey())
	got, err := SignalingOpen(sealed, alice.CurvePublicKey(), bob.CurvePrivateKey())
	if err != nil {
		t.Fatalf("SignalingOpen failed: %v", err)
	}
	if string(got) != string(plaintext) {
		t.Fatalf("got %q, want %q", got, plaintext)
	}
}

func TestSignalingBoxTamperedFails(t *testing.T) {
	alice := newTestIdentity(t)
	bob := newTestIdentity(t)

	sealed := SignalingBox([]byte("hello"), bob.CurvePublicKey(), alice.CurvePrivateKey())

	// wrong sender public key
	carol := newTestIdentity(t)
	if _, err := SignalingOpen(sealed, carol.CurvePublicKey(), bob.CurvePrivateKey()); err == nil {
		t.Fatal("expected error with wrong sender key, got nil")
	}
}

func TestExportImportRoundtrip(t *testing.T) {
	id := newTestIdentity(t)
	passphrase := "correct horse battery staple"

	blob, err := ExportIdentity(id, passphrase)
	if err != nil {
		t.Fatalf("ExportIdentity: %v", err)
	}

	// Exported blob must contain the public peer ID in plaintext.
	if !strings.Contains(string(blob), string(id.PeerID())) {
		t.Fatal("exported blob does not contain peer ID")
	}

	imported, err := ImportIdentity(blob, passphrase)
	if err != nil {
		t.Fatalf("ImportIdentity: %v", err)
	}

	if imported.PeerID() != id.PeerID() {
		t.Fatalf("peer ID mismatch: got %s, want %s", imported.PeerID(), id.PeerID())
	}
	if imported.Alias != id.Alias {
		t.Fatalf("alias mismatch: got %q, want %q", imported.Alias, id.Alias)
	}
}

func TestImportWrongPassphraseFails(t *testing.T) {
	id := newTestIdentity(t)
	blob, err := ExportIdentity(id, "correct")
	if err != nil {
		t.Fatalf("ExportIdentity: %v", err)
	}
	if _, err := ImportIdentity(blob, "wrong"); err == nil {
		t.Fatal("expected error with wrong passphrase, got nil")
	}
}

// newTestIdentity creates a fresh in-memory identity for testing.
func newTestIdentity(t *testing.T) *Identity {
	t.Helper()
	id, err := LoadOrCreate(t.TempDir(), "test")
	if err != nil {
		t.Fatalf("LoadOrCreate: %v", err)
	}
	return id
}