package vault

import (
	"bytes"
	"errors"
	"strings"
	"testing"
)

const master = "0123456789abcdef0123456789abcdef"

func must(t *testing.T, m, iss, sub string) *Cipher {
	t.Helper()
	c, err := New(m, iss, sub)
	if err != nil {
		t.Fatal(err)
	}
	return c
}

func TestRoundTrip(t *testing.T) {
	c := must(t, master, "https://a/", "alice")
	plain := []byte("---\ntitle: \"Secret\"\n---\n\ndear diary")
	sealed := c.Seal(plain, "page-1")
	if !IsSealed(sealed) || bytes.Contains(sealed, []byte("diary")) || bytes.Contains(sealed, []byte("Secret")) {
		t.Fatalf("not encrypted: %q", sealed)
	}
	got, err := c.Open(sealed, "page-1")
	if err != nil || !bytes.Equal(got, plain) {
		t.Fatalf("open: %q %v", got, err)
	}
	if bytes.Equal(sealed, c.Seal(plain, "page-1")) {
		t.Fatal("two seals of the same text must differ")
	}
}

func TestWrongKeyNameOrDamage(t *testing.T) {
	c := must(t, master, "https://a/", "alice")
	sealed := c.Seal([]byte("hello"), "p1")

	cases := map[string]*Cipher{
		"another person":     must(t, master, "https://a/", "bob"),
		"another issuer":     must(t, master, "https://b/", "alice"),
		"another master key": must(t, strings.Repeat("z", 40), "https://a/", "alice"),
	}
	for name, other := range cases {
		if _, err := other.Open(sealed, "p1"); !errors.Is(err, ErrWrongKey) {
			t.Errorf("%s: want ErrWrongKey, got %v", name, err)
		}
	}
	if _, err := c.Open(sealed, "p2"); !errors.Is(err, ErrWrongKey) {
		t.Errorf("a file moved to another page name opened: %v", err)
	}
	bad := append([]byte{}, sealed...)
	bad[len(bad)-1] ^= 1
	if _, err := c.Open(bad, "p1"); !errors.Is(err, ErrWrongKey) {
		t.Errorf("a damaged file opened: %v", err)
	}
	if _, err := c.Open([]byte("plain text"), "p1"); !errors.Is(err, ErrWrongKey) {
		t.Errorf("plain text opened: %v", err)
	}
}

func TestNewChecks(t *testing.T) {
	if _, err := New("short", "i", "s"); err == nil {
		t.Error("a short key was accepted")
	}
	if _, err := New(master, "i", ""); err == nil {
		t.Error("an empty user was accepted")
	}
}