package mobile

import (
	"encoding/hex"
	"testing"
)

// TestDeriveParityWithWeb pins the Go wallet derivation to the TypeScript one
// (web/src/wallet/derive.ts). The canonical BIP39 test mnemonic must derive to this
// exact Ed25519 sign_pub — the same value the uniweb client showed for this phrase.
// If this fails, web and mobile would derive different identities from the same seed
// and the "same account on both devices" guarantee breaks.
func TestDeriveParityWithWeb(t *testing.T) {
	const mnemonic = "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about"
	const wantSignPub = "34302746268e7370d35940e1bcef8c0b1c13a857ea6209e6ecc6e9b3af06b3c8"

	id, err := deriveIdentity(mnemonic)
	if err != nil {
		t.Fatalf("deriveIdentity: %v", err)
	}
	if got := hex.EncodeToString(id.SignPub); got != wantSignPub {
		t.Fatalf("sign_pub mismatch:\n got  %s\n want %s", got, wantSignPub)
	}
	if len(id.SignPriv) != 64 || len(id.KexPub) != 32 || len(id.KexPriv) != 32 {
		t.Fatalf("bad key lengths: signPriv=%d kexPub=%d kexPriv=%d",
			len(id.SignPriv), len(id.KexPub), len(id.KexPriv))
	}
	// sign_priv is Go's ed25519 layout: seed || pub, so its tail must equal sign_pub.
	if got := hex.EncodeToString(id.SignPriv[32:]); got != wantSignPub {
		t.Fatalf("sign_priv tail != sign_pub:\n got  %s\n want %s", got, wantSignPub)
	}
}

// TestMnemonicRoundTrip checks a freshly generated phrase validates and derives.
func TestMnemonicRoundTrip(t *testing.T) {
	m, err := NewMnemonic()
	if err != nil {
		t.Fatalf("NewMnemonic: %v", err)
	}
	if !ValidateMnemonic(m) {
		t.Fatalf("generated mnemonic failed validation: %q", m)
	}
	if _, err := deriveIdentity(m); err != nil {
		t.Fatalf("deriveIdentity(fresh): %v", err)
	}
	if ValidateMnemonic("not a real mnemonic at all please") {
		t.Fatal("garbage phrase validated as a mnemonic")
	}
}