package langext

import (
	"git.blackforestbytes.com/BlackForestBytes/goext/tst"
	"strings"
	"testing"
)

func TestEncodeBase62Zero(t *testing.T) {
	tst.AssertEqual(t, EncodeBase62(0), "0")
}

func TestEncodeBase62Small(t *testing.T) {
	tst.AssertEqual(t, EncodeBase62(1), "1")
	tst.AssertEqual(t, EncodeBase62(9), "9")
	tst.AssertEqual(t, EncodeBase62(10), "A")
	tst.AssertEqual(t, EncodeBase62(35), "Z")
	tst.AssertEqual(t, EncodeBase62(36), "a")
	tst.AssertEqual(t, EncodeBase62(61), "z")
	tst.AssertEqual(t, EncodeBase62(62), "10")
}

func TestDecodeBase62Empty(t *testing.T) {
	_, err := DecodeBase62("")
	if err == nil {
		t.Errorf("expected error on empty input")
	}
}

func TestDecodeBase62Invalid(t *testing.T) {
	_, err := DecodeBase62("foo!bar")
	if err == nil {
		t.Errorf("expected error on invalid character")
	}
}

func TestDecodeBase62Basic(t *testing.T) {
	v, err := DecodeBase62("0")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	tst.AssertEqual(t, v, uint64(0))

	v, err = DecodeBase62("10")
	if err != nil {
		t.Fatalf("unexpected error: %v", err)
	}
	tst.AssertEqual(t, v, uint64(62))
}

func TestEncodeDecodeBase62RoundTrip(t *testing.T) {
	for _, n := range []uint64{0, 1, 61, 62, 100, 12345, 1<<32 - 1, 1 << 40} {
		s := EncodeBase62(n)
		v, err := DecodeBase62(s)
		if err != nil {
			t.Errorf("decode error for %d (encoded %q): %v", n, s, err)
			continue
		}
		tst.AssertEqual(t, v, n)
	}
}

func TestRandBase62Length(t *testing.T) {
	for _, l := range []int{0, 1, 8, 32, 64} {
		s := RandBase62(l)
		tst.AssertEqual(t, len(s), l)
	}
}

func TestRandBase62Alphabet(t *testing.T) {
	const alphabet = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz"
	s := RandBase62(256)
	for _, r := range s {
		if !strings.ContainsRune(alphabet, r) {
			t.Errorf("character %q not in base62 alphabet", string(r))
		}
	}
}

func TestRandBase62Distinct(t *testing.T) {
	a := RandBase62(32)
	b := RandBase62(32)
	if a == b {
		t.Errorf("two base62 random strings of length 32 should not be equal")
	}
}