package util

import (
	"bytes"
	"crypto/rand"
	"testing"
)

func TestMacaroon(t *testing.T) {
	var (
		key          = randBytes(t)
		incorrectKey = randBytes(t)
		input        = randBytes(t)
		m            = NewMacaroon(key, input)
	)

	// Test incorrect key.
	decoded, err := m.Decode(incorrectKey)
	if err == nil {
		t.Errorf("m.Decode should have failed")
	}
	if decoded != nil {
		t.Errorf("decoded value should be nil when decode fails")
	}

	// Test correct key.
	if decoded, err = m.Decode(key); err != nil {
		t.Errorf("m.Decode should have succeeded")
	}
	if !bytes.Equal(decoded, input) {
		t.Errorf("decoded value should equal input")
	}
}

func TestBadMacaroon(t *testing.T) {
	var (
		key   = []byte{0xd4, 0x4f, 0x6b, 0x5c, 0xf2, 0x5f, 0xc4, 0x3, 0x68, 0x34, 0x15, 0xc6, 0x26, 0xc5, 0x1, 0x8a}
		tests = []Macaroon{
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r-",   // valid
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r",    // truncated
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r=",   // truncated content but valid base64
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r--",  // extended
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r-A=", // extended content but valid base64
			"AAA_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_2m4r-",   // modified data
			"Hkd_PqB1ekct6eH1rTntfJYFgYpGFQpM7z0Ur8cuAcVQscWa-FNV4_kTfC_XXXX-",   // modified HMAC
			"", // zero value
		}
	)
	// Test data above was generated by:
	//{
	//	key := randBytes(t)
	//	t.Logf("key=%#v\ntests = []Macaroon{\n\t%q, // valid\n}", key, NewMacaroon(key, randBytes(t)))
	//}

	// Make sure that "valid" is indeed valid!
	if data, err := tests[0].Decode(key); err != nil || data == nil {
		t.Fatalf("Bad test data: Got (%v, %v), want (<non-empty>, nil)", data, err)
	}
	// And all others are not:
	for idx, test := range tests[1:] {
		if _, err := test.Decode(key); err == nil {
			t.Errorf("Should have failed to decode invalid macaroon #%d", idx)
		}
	}
}

func randBytes(t *testing.T) []byte {
	b := make([]byte, 16)
	if _, err := rand.Read(b); err != nil {
		t.Fatalf("bytes creation failed: %v", err)
	}
	return b
}