package lib

import (
	"bytes"
	"testing"
)

func TestMintWireToken_roundtrip(t *testing.T) {
	l0 := []byte{0x11, 0x22, 0x33, 0x44}
	l1 := []byte{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88}
	agentID := make([]byte, 16)
	for i := range agentID {
		agentID[i] = byte(0x40 + i)
	}

	token, err := MintWireToken(l0, l1, agentID)
	if err != nil {
		t.Fatalf("MintWireToken: %v", err)
	}

	gotL0, gotL1, gotAgentID, err := ParseWireToken(token)
	if err != nil {
		t.Fatalf("ParseWireToken: %v", err)
	}
	if !bytes.Equal(gotL0, l0) {
		t.Fatalf("L0 mismatch")
	}
	if !bytes.Equal(gotL1, l1) {
		t.Fatalf("L1 mismatch")
	}
	if !bytes.Equal(gotAgentID, agentID) {
		t.Fatalf("agent_id mismatch")
	}
}

func TestCVT_tamper_detection(t *testing.T) {
	l0 := []byte{0x11, 0x22, 0x33, 0x44}
	l1 := []byte{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88}
	agentID := make([]byte, 16)

	token, _ := MintWireToken(l0, l1, agentID)

	// Flip a character in the middle
	tampered := token[:10] + "X" + token[11:]
	_, _, _, err := ParseWireToken(tampered)
	if err == nil {
		t.Fatal("expected error on tampered token")
	}
}

func TestCVT_unique(t *testing.T) {
	l0 := []byte{0x11, 0x22, 0x33, 0x44}
	l1 := []byte{0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88}
	agentID := make([]byte, 16)

	t1, _ := MintWireToken(l0, l1, agentID)
	t2, _ := MintWireToken(l0, l1, agentID)
	if t1 == t2 {
		t.Fatal("two tokens with same input should differ (random nonce)")
	}
}