// Copyright (c) 2013-2016 The btcsuite developers
// Copyright (c) 2015-2020 The Decred developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.

package wire

import (
	"bytes"
	"errors"
	"io"
	"reflect"
	"testing"

	"github.com/davecgh/go-spew/spew"
	"github.com/decred/dcrd/chaincfg/chainhash"
)

// TestNotFound tests the MsgNotFound API.
func TestNotFound(t *testing.T) {
	pver := ProtocolVersion

	// Ensure the command is expected value.
	wantCmd := "notfound"
	msg := NewMsgNotFound()
	if cmd := msg.Command(); cmd != wantCmd {
		t.Errorf("NewMsgNotFound: wrong command - got %v want %v",
			cmd, wantCmd)
	}

	// Ensure max payload is expected value for latest protocol version.
	// Num inventory vectors (varInt) 3 bytes + max allowed inventory vectors.
	wantPayload := uint32(1800003)
	maxPayload := msg.MaxPayloadLength(pver)
	if maxPayload != wantPayload {
		t.Errorf("MaxPayloadLength: wrong max payload length for "+
			"protocol version %d - got %v, want %v", pver,
			maxPayload, wantPayload)
	}

	// Ensure max payload length is not more than MaxMessagePayload.
	if maxPayload > MaxMessagePayload {
		t.Fatalf("MaxPayloadLength: payload length (%v) for protocol "+
			"version %d exceeds MaxMessagePayload (%v).", maxPayload, pver,
			MaxMessagePayload)
	}

	// Ensure inventory vectors are added properly.
	hash := chainhash.Hash{}
	iv := NewInvVect(InvTypeBlock, &hash)
	err := msg.AddInvVect(iv)
	if err != nil {
		t.Errorf("AddInvVect: %v", err)
	}
	if msg.InvList[0] != iv {
		t.Errorf("AddInvVect: wrong invvect added - got %v, want %v",
			spew.Sprint(msg.InvList[0]), spew.Sprint(iv))
	}

	// Ensure adding more than the max allowed inventory vectors per
	// message returns an error.
	for i := 0; i < MaxInvPerMsg; i++ {
		err = msg.AddInvVect(iv)
	}
	if err == nil {
		t.Errorf("AddInvVect: expected error on too many inventory " +
			"vectors not received")
	}
}

// TestNotFoundWire tests the MsgNotFound wire encode and decode for various
// numbers of inventory vectors and protocol versions.
func TestNotFoundWire(t *testing.T) {
	// Block 203707 hash.
	hashStr := "3264bc2ac36a60840790ba1d475d01367e7c723da941069e9dc"
	blockHash, err := chainhash.NewHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewHashFromStr: %v", err)
	}

	// Transaction 1 of Block 203707 hash.
	hashStr = "d28a3dc7392bf00a9855ee93dd9a81eff82a2c4fe57fbd42cfe71b487accfaf0"
	txHash, err := chainhash.NewHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewHashFromStr: %v", err)
	}

	iv := NewInvVect(InvTypeBlock, blockHash)
	iv2 := NewInvVect(InvTypeTx, txHash)

	// Empty notfound message.
	NoInv := NewMsgNotFound()
	NoInvEncoded := []byte{
		0x00, // Varint for number of inventory vectors
	}

	// NotFound message with multiple inventory vectors.
	MultiInv := NewMsgNotFound()
	MultiInv.AddInvVect(iv)
	MultiInv.AddInvVect(iv2)
	MultiInvEncoded := []byte{
		0x02,                   // Varint for number of inv vectors
		0x02, 0x00, 0x00, 0x00, // InvTypeBlock
		0xdc, 0xe9, 0x69, 0x10, 0x94, 0xda, 0x23, 0xc7,
		0xe7, 0x67, 0x13, 0xd0, 0x75, 0xd4, 0xa1, 0x0b,
		0x79, 0x40, 0x08, 0xa6, 0x36, 0xac, 0xc2, 0x4b,
		0x26, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 203707 hash
		0x01, 0x00, 0x00, 0x00, // InvTypeTx
		0xf0, 0xfa, 0xcc, 0x7a, 0x48, 0x1b, 0xe7, 0xcf,
		0x42, 0xbd, 0x7f, 0xe5, 0x4f, 0x2c, 0x2a, 0xf8,
		0xef, 0x81, 0x9a, 0xdd, 0x93, 0xee, 0x55, 0x98,
		0x0a, 0xf0, 0x2b, 0x39, 0xc7, 0x3d, 0x8a, 0xd2, // Tx 1 of block 203707 hash
	}

	tests := []struct {
		in   *MsgNotFound // Message to encode
		out  *MsgNotFound // Expected decoded message
		buf  []byte       // Wire encoding
		pver uint32       // Protocol version for wire encoding
	}{
		// Latest protocol version with no inv vectors.
		{
			NoInv,
			NoInv,
			NoInvEncoded,
			ProtocolVersion,
		},

		// Latest protocol version with multiple inv vectors.
		{
			MultiInv,
			MultiInv,
			MultiInvEncoded,
			ProtocolVersion,
		},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode the message to wire format.
		var buf bytes.Buffer
		err := test.in.BtcEncode(&buf, test.pver)
		if err != nil {
			t.Errorf("BtcEncode #%d error %v", i, err)
			continue
		}
		if !bytes.Equal(buf.Bytes(), test.buf) {
			t.Errorf("BtcEncode #%d\n got: %s want: %s", i,
				spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
			continue
		}

		// Decode the message from wire format.
		var msg MsgNotFound
		rbuf := bytes.NewReader(test.buf)
		err = msg.BtcDecode(rbuf, test.pver)
		if err != nil {
			t.Errorf("BtcDecode #%d error %v", i, err)
			continue
		}
		if !reflect.DeepEqual(&msg, test.out) {
			t.Errorf("BtcDecode #%d\n got: %s want: %s", i,
				spew.Sdump(msg), spew.Sdump(test.out))
			continue
		}
	}
}

// TestNotFoundWireErrors performs negative tests against wire encode and decode
// of MsgNotFound to confirm error paths work correctly.
func TestNotFoundWireErrors(t *testing.T) {
	pver := ProtocolVersion

	// Block 203707 hash.
	hashStr := "3264bc2ac36a60840790ba1d475d01367e7c723da941069e9dc"
	blockHash, err := chainhash.NewHashFromStr(hashStr)
	if err != nil {
		t.Errorf("NewHashFromStr: %v", err)
	}

	iv := NewInvVect(InvTypeBlock, blockHash)

	// Base message used to induce errors.
	baseNotFound := NewMsgNotFound()
	baseNotFound.AddInvVect(iv)
	baseNotFoundEncoded := []byte{
		0x02,                   // Varint for number of inv vectors
		0x02, 0x00, 0x00, 0x00, // InvTypeBlock
		0xdc, 0xe9, 0x69, 0x10, 0x94, 0xda, 0x23, 0xc7,
		0xe7, 0x67, 0x13, 0xd0, 0x75, 0xd4, 0xa1, 0x0b,
		0x79, 0x40, 0x08, 0xa6, 0x36, 0xac, 0xc2, 0x4b,
		0x26, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // Block 203707 hash
	}

	// Message that forces an error by having more than the max allowed inv
	// vectors.
	maxNotFound := NewMsgNotFound()
	for i := 0; i < MaxInvPerMsg; i++ {
		maxNotFound.AddInvVect(iv)
	}
	maxNotFound.InvList = append(maxNotFound.InvList, iv)
	maxNotFoundEncoded := []byte{
		0xfd, 0x51, 0xc3, // Varint for number of inv vectors (50001)
	}

	tests := []struct {
		in       *MsgNotFound // Value to encode
		buf      []byte       // Wire encoding
		pver     uint32       // Protocol version for wire encoding
		max      int          // Max size of fixed buffer to induce errors
		writeErr error        // Expected write error
		readErr  error        // Expected read error
	}{
		// Force error in inventory vector count
		{baseNotFound, baseNotFoundEncoded, pver, 0, io.ErrShortWrite, io.EOF},
		// Force error in inventory list.
		{baseNotFound, baseNotFoundEncoded, pver, 1, io.ErrShortWrite, io.EOF},
		// Force error with greater than max inventory vectors.
		{maxNotFound, maxNotFoundEncoded, pver, 3, ErrTooManyVectors, ErrTooManyVectors},
	}

	t.Logf("Running %d tests", len(tests))
	for i, test := range tests {
		// Encode to wire format.
		w := newFixedWriter(test.max)
		err := test.in.BtcEncode(w, test.pver)
		if !errors.Is(err, test.writeErr) {
			t.Errorf("BtcEncode #%d wrong error got: %v, want: %v", i, err,
				test.writeErr)
			continue
		}

		// Decode from wire format.
		var msg MsgNotFound
		r := newFixedReader(test.max, test.buf)
		err = msg.BtcDecode(r, test.pver)
		if !errors.Is(err, test.readErr) {
			t.Errorf("BtcDecode #%d wrong error got: %v, want: %v", i, err,
				test.readErr)
			continue
		}
	}
}
