// Copyright 2016 The Vanadium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package ble

import (
	"math/rand"
	"reflect"
	"testing"

	"v.io/v23/discovery"
	idiscovery "v.io/x/ref/lib/discovery"
)

func TestEncode(t *testing.T) {
	rand := rand.New(rand.NewSource(0))
	randBytes := func(n int) []byte {
		p := make([]byte, rand.Intn(n))
		rand.Read(p)
		return p
	}
	randString := func(n int) string {
		return string(randBytes(n))
	}

	for i := 0; i < 10; i++ {
		encodedAdinfos := make(map[discovery.AdId][]byte)
		expectedAdinfos := make(map[discovery.AdId]idiscovery.AdInfo)

		for j, n := 0, rand.Intn(maxNumPackedServices); j < n; j++ {
			adinfo := idiscovery.AdInfo{}

			// Populate adinfo manually to test large payloads. testing.quick.Value()
			// fills only with small values.
			copy(adinfo.Ad.Id[:], randBytes(32))
			adinfo.Ad.InterfaceName = randString(128)
			adinfo.Ad.Addresses = make([]string, rand.Intn(3)+1)
			for i, _ := range adinfo.Ad.Addresses {
				adinfo.Ad.Addresses[i] = randString(128)
			}

			if n := rand.Intn(5); n > 0 {
				adinfo.Ad.Attributes = make(discovery.Attributes, n)
				for i := 0; i < n; i++ {
					adinfo.Ad.Attributes[randString(16)] = randString(256)
				}
			}
			if n := rand.Intn(5); n > 0 {
				adinfo.Ad.Attachments = make(discovery.Attachments, n)
				for i := 0; i < n; i++ {
					adinfo.Ad.Attachments[randString(16)] = randBytes(256)
				}
			}

			adinfo.EncryptionAlgorithm = idiscovery.EncryptionAlgorithm(rand.Intn(3))
			if adinfo.EncryptionAlgorithm != idiscovery.NoEncryption {
				adinfo.EncryptionKeys = make([]idiscovery.EncryptionKey, rand.Intn(3)+1)
				for i, _ := range adinfo.EncryptionKeys {
					adinfo.EncryptionKeys[i] = randBytes(128)
				}
			}

			copy(adinfo.Hash[:], randBytes(16))
			adinfo.TimestampNs = rand.Int63()

			adinfo.DirAddrs = make([]string, rand.Intn(3)+1)
			for i, _ := range adinfo.DirAddrs {
				adinfo.DirAddrs[i] = randString(128)
			}

			encoded, err := encodeAdInfo(&adinfo)
			if err != nil {
				t.Errorf("encode failed: %v", err)
				continue
			}
			encodedAdinfos[adinfo.Ad.Id] = encoded

			if len(adinfo.Ad.Attachments) > 0 {
				adinfo.Status = idiscovery.AdPartiallyReady
			} else {
				adinfo.DirAddrs = nil
				adinfo.Status = idiscovery.AdReady
			}
			adinfo.Ad.Attachments = nil
			expectedAdinfos[adinfo.Ad.Id] = adinfo
		}

		cs := packToCharacteristics(encodedAdinfos)
		unpacked := unpackFromCharacteristics(cs)

		for _, encoded := range unpacked {
			adinfo, err := decodeAdInfo(encoded)
			if err != nil {
				t.Errorf("decode failed: %v", err)
				continue
			}

			if !reflect.DeepEqual(*adinfo, expectedAdinfos[adinfo.Ad.Id]) {
				t.Errorf("decoded to %#v, but want %#v", *adinfo, expectedAdinfos[adinfo.Ad.Id])
			}
		}
	}
}