package multibase

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

func TestMap(t *testing.T) {
	for s, e := range Encodings {
		s2 := EncodingToStr[e]
		if s != s2 {
			t.Errorf("round trip failed on encoding map: %s != %s", s, s2)
		}
	}
	for e, s := range EncodingToStr {
		e2 := Encodings[s]
		if e != e2 {
			t.Errorf("round trip failed on encoding map: '%c' != '%c'", e, e2)
		}
	}
}

var sampleBytes = []byte("Decentralize everything!!!")
var encodedSamples = map[Encoding]string{
	Identity:          string(0x00) + "Decentralize everything!!!",
	Base2:             "00100010001100101011000110110010101101110011101000111001001100001011011000110100101111010011001010010000001100101011101100110010101110010011110010111010001101000011010010110111001100111001000010010000100100001",
	Base16:            "f446563656e7472616c697a652065766572797468696e67212121",
	Base16Upper:       "F446563656E7472616C697A652065766572797468696E67212121",
	Base32:            "birswgzloorzgc3djpjssazlwmvzhs5dinfxgoijbee",
	Base32Upper:       "BIRSWGZLOORZGC3DJPJSSAZLWMVZHS5DINFXGOIJBEE",
	Base32pad:         "cirswgzloorzgc3djpjssazlwmvzhs5dinfxgoijbee======",
	Base32padUpper:    "CIRSWGZLOORZGC3DJPJSSAZLWMVZHS5DINFXGOIJBEE======",
	Base32hex:         "v8him6pbeehp62r39f9ii0pbmclp7it38d5n6e89144",
	Base32hexUpper:    "V8HIM6PBEEHP62R39F9II0PBMCLP7IT38D5N6E89144",
	Base32hexPad:      "t8him6pbeehp62r39f9ii0pbmclp7it38d5n6e89144======",
	Base32hexPadUpper: "T8HIM6PBEEHP62R39F9II0PBMCLP7IT38D5N6E89144======",
	Base58BTC:         "z36UQrhJq9fNDS7DiAHM9YXqDHMPfr4EMArvt",
	Base64:            "mRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchISE",
	Base64url:         "uRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchISE",
	Base64pad:         "MRGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchISE=",
	Base64urlPad:      "URGVjZW50cmFsaXplIGV2ZXJ5dGhpbmchISE=",
}

func testEncode(t *testing.T, encoding Encoding, bytes []byte, expected string) {
	actual, err := Encode(encoding, bytes)
	if err != nil {
		t.Error(err)
		return
	}
	if actual != expected {
		t.Errorf("encoding failed for %c (%d), expected: %s, got: %s", encoding, encoding, expected, actual)
	}
}

func testDecode(t *testing.T, expectedEncoding Encoding, expectedBytes []byte, data string) {
	actualEncoding, actualBytes, err := Decode(data)
	if err != nil {
		t.Error(err)
		return
	}
	if actualEncoding != expectedEncoding {
		t.Errorf("wrong encoding code, expected: %c (%d), got %c (%d)", expectedEncoding, expectedEncoding, actualEncoding, actualEncoding)
	}
	if !bytes.Equal(actualBytes, expectedBytes) {
		t.Errorf("decoding failed for %c (%d), expected: %v, got %v", actualEncoding, actualEncoding, expectedBytes, actualBytes)
	}
}

func TestEncode(t *testing.T) {
	for encoding, data := range encodedSamples {
		testEncode(t, encoding, sampleBytes, data)
	}
}

func TestDecode(t *testing.T) {
	for encoding, data := range encodedSamples {
		testDecode(t, encoding, sampleBytes, data)
	}
}

func TestRoundTrip(t *testing.T) {
	buf := make([]byte, 17)
	rand.Read(buf)

	baseList := []Encoding{Identity, Base16, Base32, Base32hex, Base32pad, Base32hexPad, Base58BTC, Base58Flickr, Base64pad, Base64urlPad}

	for _, base := range baseList {
		enc, err := Encode(base, buf)
		if err != nil {
			t.Fatal(err)
		}

		e, out, err := Decode(enc)
		if err != nil {
			t.Fatal(err)
		}

		if e != base {
			t.Fatal("got wrong encoding out")
		}

		if !bytes.Equal(buf, out) {
			t.Fatal("input wasnt the same as output", buf, out)
		}
	}

	_, _, err := Decode("")
	if err == nil {
		t.Fatal("shouldnt be able to decode empty string")
	}
}

func BenchmarkRoundTrip(b *testing.B) {
	buf := make([]byte, 32)
	rand.Read(buf)
	b.ResetTimer()

	bases := map[string]Encoding{
		"Identity":          Identity,
		"Base2":             Base2,
		"Base16":            Base16,
		"Base16Upper":       Base16Upper,
		"Base32":            Base32,
		"Base32Upper":       Base32Upper,
		"Base32pad":         Base32pad,
		"Base32padUpper":    Base32padUpper,
		"Base32hex":         Base32hex,
		"Base32hexUpper":    Base32hexUpper,
		"Base32hexPad":      Base32hexPad,
		"Base32hexPadUpper": Base32hexPadUpper,
		"Base58Flickr":      Base58Flickr,
		"Base58BTC":         Base58BTC,
		"Base64":            Base64,
		"Base64url":         Base64url,
		"Base64pad":         Base64pad,
		"Base64urlPad":      Base64urlPad,
	}

	for name, base := range bases {
		b.Run(name, func(b *testing.B) {
			for i := 0; i < b.N; i++ {
				enc, err := Encode(base, buf)
				if err != nil {
					b.Fatal(err)
				}

				e, out, err := Decode(enc)
				if err != nil {
					b.Fatal(err)
				}

				if e != base {
					b.Fatal("got wrong encoding out")
				}

				if !bytes.Equal(buf, out) {
					b.Fatal("input wasnt the same as output", buf, out)
				}
			}
		})
	}
}