/*
 *  Copyright (c) 2017, The OpenThread Authors.
 *  All rights reserved.
 *
 *  Redistribution and use in source and binary forms, with or without
 *  modification, are permitted provided that the following conditions are met:
 *  1. Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *  3. Neither the name of the copyright holder nor the
 *     names of its contributors may be used to endorse or promote products
 *     derived from this software without specific prior written permission.
 *
 *  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 *  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 *  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 *  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 *  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 *  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 *  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 *  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 *  POSSIBILITY OF SUCH DAMAGE.
 */

#include <ctype.h>

#include "common/code_utils.hpp"
#include "common/instance.hpp"
#include "ncp/spinel_decoder.hpp"

#include "test_util.h"

namespace ot {
namespace Ncp {

enum
{
    kTestBufferSize = 800,
};

// Dump the buffer content to screen.
void DumpBuffer(const char *aTextMessage, uint8_t *aBuffer, uint16_t aBufferLength)
{
    enum
    {
        kBytesPerLine = 32, // Number of bytes per line.
    };

    char     charBuff[kBytesPerLine + 1];
    uint16_t counter;
    uint8_t  byte;

    printf("\n%s - len = %u\n    ", aTextMessage, aBufferLength);

    counter = 0;

    while (aBufferLength--)
    {
        byte = *aBuffer++;
        printf("%02X ", byte);
        charBuff[counter] = isprint(byte) ? static_cast<char>(byte) : '.';
        counter++;

        if (counter == kBytesPerLine)
        {
            charBuff[counter] = 0;
            printf("    %s\n    ", charBuff);
            counter = 0;
        }
    }

    charBuff[counter] = 0;

    while (counter++ < kBytesPerLine)
    {
        printf("   ");
    }

    printf("    %s\n", charBuff);
}

void TestSpinelDecoder(void)
{
    uint8_t       buffer[kTestBufferSize];
    SpinelDecoder decoder;

    spinel_ssize_t frameLen;

    const bool     kBool_1 = true;
    const bool     kBool_2 = false;
    const uint8_t  kUint8  = 0x42;
    const int8_t   kInt8   = -73;
    const uint16_t kUint16 = 0xabcd;
    const int16_t  kInt16  = -567;
    const uint32_t kUint32 = 0xdeadbeef;
    const int32_t  kInt32  = -123455678L;
    const uint64_t kUint64 = 0xfe10dc32ba549876ULL;
    const int64_t  kInt64  = -9197712039090021561LL;

    const unsigned int kUint_1 = 9;
    const unsigned int kUint_2 = 0xa3;
    const unsigned int kUint_3 = 0x8765;
    const unsigned int kUint_4 = SPINEL_MAX_UINT_PACKED - 1;

    const spinel_ipv6addr_t kIp6Addr = {
        {0x6B, 0x41, 0x65, 0x73, 0x42, 0x68, 0x61, 0x76, 0x54, 0x61, 0x72, 0x7A, 0x49, 0x69, 0x61, 0x4E}};

    const spinel_eui48_t kEui48 = {
        {4, 8, 15, 16, 23, 42} // "Lost" EUI48!
    };

    const spinel_eui64_t kEui64 = {
        {2, 3, 5, 7, 11, 13, 17, 19}, // "Prime" EUI64!
    };

    const char kString_1[] = "OpenThread";
    const char kString_2[] = "";

    const uint16_t kData[] = {10, 20, 3, 15, 1000, 60, 16}; // ... then comes 17,18,19,20  :)

    bool                     b_1, b_2;
    uint8_t                  u8;
    int8_t                   i8;
    uint16_t                 u16;
    int16_t                  i16;
    uint32_t                 u32;
    int32_t                  i32;
    uint64_t                 u64;
    int64_t                  i64;
    unsigned int             u_1, u_2, u_3, u_4;
    const spinel_ipv6addr_t *ip6Addr;
    const spinel_eui48_t *   eui48;
    const spinel_eui64_t *   eui64;
    const char *             utf_1;
    const char *             utf_2;
    const uint8_t *          dataPtr_1;
    const uint8_t *          dataPtr_2;
    uint16_t                 dataLen_1;
    uint16_t                 dataLen_2;

    memset(buffer, 0, sizeof(buffer));

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 1: Decoding simple types");

    frameLen = spinel_datatype_pack(
        buffer, sizeof(buffer),
        (SPINEL_DATATYPE_BOOL_S SPINEL_DATATYPE_BOOL_S SPINEL_DATATYPE_UINT8_S SPINEL_DATATYPE_INT8_S
             SPINEL_DATATYPE_UINT16_S SPINEL_DATATYPE_INT16_S SPINEL_DATATYPE_UINT32_S SPINEL_DATATYPE_INT32_S
                 SPINEL_DATATYPE_UINT64_S SPINEL_DATATYPE_INT64_S SPINEL_DATATYPE_UINT_PACKED_S
                     SPINEL_DATATYPE_UINT_PACKED_S SPINEL_DATATYPE_UINT_PACKED_S SPINEL_DATATYPE_UINT_PACKED_S
                         SPINEL_DATATYPE_IPv6ADDR_S SPINEL_DATATYPE_EUI48_S SPINEL_DATATYPE_EUI64_S
                             SPINEL_DATATYPE_UTF8_S SPINEL_DATATYPE_UTF8_S SPINEL_DATATYPE_DATA_WLEN_S
                                                                           SPINEL_DATATYPE_DATA_S),
        kBool_1, kBool_2, kUint8, kInt8, kUint16, kInt16, kUint32, kInt32, kUint64, kInt64, kUint_1, kUint_2, kUint_3,
        kUint_4, &kIp6Addr, &kEui48, &kEui64, kString_1, kString_2, kData, sizeof(kData), kData, sizeof(kData));

    DumpBuffer("Packed Spinel Frame", buffer, static_cast<uint16_t>(frameLen));

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    VerifyOrQuit(decoder.GetFrame() == &buffer[0], "GetFrame() failed.");
    VerifyOrQuit(decoder.GetLength() == frameLen, "GetLength() failed.");

    VerifyOrQuit(decoder.GetReadLength() == 0, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == frameLen, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == false, "IsAllRead() failed.");

    SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
    SuccessOrQuit(decoder.ReadBool(b_2), "ReadBool() failed.");
    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.ReadInt8(i8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    SuccessOrQuit(decoder.ReadInt16(i16), "ReadInt16() failed.");
    SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
    SuccessOrQuit(decoder.ReadInt32(i32), "ReadUint32() failed.");
    SuccessOrQuit(decoder.ReadUint64(u64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadInt64(i64), "ReadUint64() failed.");

    // Check the state
    VerifyOrQuit(decoder.GetReadLength() != 0, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == frameLen - decoder.GetReadLength(), "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == false, "IsAllRead() failed.");

    SuccessOrQuit(decoder.ReadUintPacked(u_1), "ReadUintPacked() failed.");

    SuccessOrQuit(decoder.ReadUintPacked(u_2), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_4), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");
    SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
    SuccessOrQuit(decoder.ReadEui64(eui64), "ReadEui64() failed.");
    SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
    SuccessOrQuit(decoder.ReadUtf8(utf_2), "ReadUtf8() failed.");
    SuccessOrQuit(decoder.ReadDataWithLen(dataPtr_1, dataLen_1), "ReadDataWithLen() failed.");
    SuccessOrQuit(decoder.ReadData(dataPtr_2, dataLen_2), "ReadData() failed.");

    VerifyOrQuit(decoder.GetReadLength() == frameLen, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == 0, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
    VerifyOrQuit(b_2 == kBool_2, "ReadBool() parse failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(i8 == kInt8, "ReadUint8() parse failed.");
    VerifyOrQuit(u16 == kUint16, "ReadUint16() parse failed.");
    VerifyOrQuit(i16 == kInt16, "ReadInt16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(i32 == kInt32, "ReadInt32() parse failed.");
    VerifyOrQuit(u64 == kUint64, "ReadUint64() parse failed.");
    VerifyOrQuit(i64 == kInt64, "ReadInt64() parse failed.");
    VerifyOrQuit(u_1 == kUint_1, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_2 == kUint_2, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_4 == kUint_4, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");
    VerifyOrQuit(memcmp(eui64, &kEui64, sizeof(spinel_eui64_t)) == 0, "ReadEui64() parse failed.");
    VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");
    VerifyOrQuit(memcmp(utf_2, kString_2, sizeof(kString_2)) == 0, "ReadUtf8() parse failed.");
    VerifyOrQuit(dataLen_1 == sizeof(kData), "ReadData() parse failed.");
    VerifyOrQuit(memcmp(dataPtr_1, &kData, sizeof(kData)) == 0, "ReadData() parse failed.");
    VerifyOrQuit(dataLen_2 == sizeof(kData), "ReadData() parse failed.");
    VerifyOrQuit(memcmp(dataPtr_2, &kData, sizeof(kData)) == 0, "ReadData() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 2: Test Reset(), SavePosition(), ResetToSaved()");

    // `ResetToSaved()` should fail if there is no saved position
    VerifyOrQuit(decoder.ResetToSaved() == OT_ERROR_INVALID_STATE, "ResetToSaved() did not fail");

    decoder.Reset();

    VerifyOrQuit(decoder.GetFrame() == &buffer[0], "GetFrame() failed.");
    VerifyOrQuit(decoder.GetLength() == frameLen, "GetLength() failed.");
    VerifyOrQuit(decoder.GetReadLength() == 0, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == frameLen, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == false, "IsAllRead() failed.");

    SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
    SuccessOrQuit(decoder.ReadBool(b_2), "ReadBool() failed.");
    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.ReadInt8(i8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    SuccessOrQuit(decoder.ReadInt16(i16), "ReadInt16() failed.");
    SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
    SuccessOrQuit(decoder.ReadInt32(i32), "ReadUint32() failed.");

    // `ResetToSaved()` should fail if there is no saved position
    VerifyOrQuit(decoder.ResetToSaved() == OT_ERROR_INVALID_STATE, "ResetToSaved() did not fail");

    // Save position
    decoder.SavePosition();

    SuccessOrQuit(decoder.ReadUint64(u64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadInt64(i64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_1), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_2), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_4), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");

    VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
    VerifyOrQuit(b_2 == kBool_2, "ReadBool() parse failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(i8 == kInt8, "ReadUint8() parse failed.");
    VerifyOrQuit(u16 == kUint16, "ReadUint16() parse failed.");
    VerifyOrQuit(i16 == kInt16, "ReadInt16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(i32 == kInt32, "ReadUint32() parse failed.");
    VerifyOrQuit(u64 == kUint64, "ReadUint64() parse failed.");
    VerifyOrQuit(i64 == kInt64, "ReadInt64() parse failed.");
    VerifyOrQuit(u_1 == kUint_1, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_2 == kUint_2, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_4 == kUint_4, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");

    SuccessOrQuit(decoder.ResetToSaved(), "ResetToSaved() failed");

    SuccessOrQuit(decoder.ReadUint64(u64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadInt64(i64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_1), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_2), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_4), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");

    VerifyOrQuit(u64 == kUint64, "ReadUint64() parse failed.");
    VerifyOrQuit(i64 == kInt64, "ReadInt64() parse failed.");
    VerifyOrQuit(u_1 == kUint_1, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_2 == kUint_2, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_4 == kUint_4, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");

    // Go back to save position again.
    SuccessOrQuit(decoder.ResetToSaved(), "ResetToSaved() failed");

    SuccessOrQuit(decoder.ReadUint64(u64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadInt64(i64), "ReadUint64() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_1), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_2), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadUintPacked(u_4), "ReadUintPacked() failed.");
    SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");

    VerifyOrQuit(u64 == kUint64, "ReadUint64() parse failed.");
    VerifyOrQuit(i64 == kInt64, "ReadInt64() parse failed.");
    VerifyOrQuit(u_1 == kUint_1, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_2 == kUint_2, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(u_4 == kUint_4, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");

    // Ensure saved position is cleared when decoder is reset or re-initialized.

    decoder.Reset();

    // `ResetToSaved()` should fail if there is no saved position
    VerifyOrQuit(decoder.ResetToSaved() == OT_ERROR_INVALID_STATE, "ResetToSaved() did not fail");

    decoder.SavePosition();
    SuccessOrQuit(decoder.ResetToSaved(), "ResetToSaved() failed");

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));
    VerifyOrQuit(decoder.ResetToSaved() == OT_ERROR_INVALID_STATE, "ResetToSaved() did not fail");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 3: Test decoding a single simple struct.");

    frameLen = spinel_datatype_pack(buffer, sizeof(buffer),
                                    (SPINEL_DATATYPE_UINT8_S SPINEL_DATATYPE_STRUCT_S(
                                        SPINEL_DATATYPE_UINT32_S SPINEL_DATATYPE_EUI48_S SPINEL_DATATYPE_UINT_PACKED_S)
                                         SPINEL_DATATYPE_INT16_S

                                     ),
                                    kUint8, kUint32, &kEui48, kUint_3, kInt16);

    DumpBuffer("Packed Spinel Frame (single struct)", buffer, static_cast<uint16_t>(frameLen));

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
        SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
        SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadInt16(i16), "ReadInt16() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(i16 == kInt16, "ReadInt16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 4: Test partial struct read");

    // Re-use same frame as the previous test.

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
        // Skip the remaining fields in the struct
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadInt16(i16), "ReadInt16() failed.");

    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(i16 == kInt16, "ReadInt16() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 5: Test `GetRemainingLengthInStruct()` and `IsAllReadInStruct`() in and out of an struct");

    // Re-use same frame as the previous test.

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    VerifyOrQuit(decoder.GetFrame() == &buffer[0], "GetFrame() failed.");
    VerifyOrQuit(decoder.GetLength() == frameLen, "GetLength() failed.");

    VerifyOrQuit(decoder.GetReadLength() == 0, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == frameLen, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == false, "IsAllRead() failed.");

    // When not in an struct,  `etRemainingLengthInStruct()` should consider the whole frame.
    VerifyOrQuit(decoder.GetRemainingLengthInStruct() == frameLen, "GetRemLengthInStruct() failed.");
    VerifyOrQuit(decoder.IsAllReadInStruct() == false, "IsAllReadInStruct() failed.");

    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        VerifyOrQuit(decoder.IsAllReadInStruct() == false, "IsAllReadInStruct() failed.");

        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
        SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
        SuccessOrQuit(decoder.ReadUintPacked(u_3), "ReadUintPacked() failed.");

        VerifyOrQuit(decoder.IsAllReadInStruct() == true, "IsAllReadInStruct() failed.");
        VerifyOrQuit(decoder.GetRemainingLengthInStruct() == 0, "GetRemLengthInStruct() failed.");

        // Try reading beyond end of the struct and ensure it fails.
        VerifyOrQuit(decoder.ReadUint8(u8) == OT_ERROR_PARSE, "ReadUint8() did not fail.");

        // `ReadData()` at end of struct should still succeed but return zero as the data length.
        SuccessOrQuit(decoder.ReadData(dataPtr_1, dataLen_1), "ReadData() failed.");
        VerifyOrQuit(dataLen_1 == 0, "ReadData() parse value failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");

    VerifyOrQuit(decoder.IsAllReadInStruct() == false, "IsAllReadInStruct() failed.");
    SuccessOrQuit(decoder.ReadInt16(i16), "ReadInt16() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(decoder.GetRemainingLengthInStruct() == 0, "GetRemLengthInStruct() failed.");
    VerifyOrQuit(decoder.IsAllReadInStruct() == true, "IsAllReadInStruct() failed.");

    // `ReadData()` at end of frame should still succeed but return zero as the data length.
    SuccessOrQuit(decoder.ReadData(dataPtr_1, dataLen_1), "ReadData() failed.");
    VerifyOrQuit(dataLen_1 == 0, "ReadData() parse value failed.");

    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(i16 == kInt16, "ReadInt16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(u_3 == kUint_3, "ReadUintPacked() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 6: Test multiple nested structs");

    frameLen = spinel_datatype_pack(
        buffer, sizeof(buffer),
        (SPINEL_DATATYPE_STRUCT_S(SPINEL_DATATYPE_UINT8_S SPINEL_DATATYPE_UTF8_S SPINEL_DATATYPE_STRUCT_S(
            SPINEL_DATATYPE_BOOL_S SPINEL_DATATYPE_IPv6ADDR_S) SPINEL_DATATYPE_UINT16_S)
             SPINEL_DATATYPE_EUI48_S SPINEL_DATATYPE_STRUCT_S(SPINEL_DATATYPE_UINT32_S) SPINEL_DATATYPE_INT32_S),
        kUint8, kString_1, kBool_1, &kIp6Addr, kUint16, &kEui48, kUint32, kInt32);

    DumpBuffer("Packed Spinel Frame (multiple struct)", buffer, static_cast<uint16_t>(frameLen));

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
        SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
        SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
        {
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
            SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");
        }
        SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
        SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadInt32(i32), "WriteUint32() failed.");

    VerifyOrQuit(decoder.GetReadLength() == frameLen, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == 0, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(u16 == kUint16, "ReadUint16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(i32 == kInt32, "ReadUint32() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");
    VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 7: Test `SavePosition()`, `ResetToSaved()` for nested structs");

    // Re-use same frame as the previous test.

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");

        decoder.SavePosition();

        SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
        SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
        {
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
        }

        // Verify the read content so far.

        VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
        VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
        VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");

        // Do not close the inner struct and jump to previously saved position and re-read the content.

        SuccessOrQuit(decoder.ResetToSaved(), "ResetToSaved() failed.");

        SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
        SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
        {
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
            SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");
        }
        SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
        SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadInt32(i32), "WriteUint32() failed.");

    VerifyOrQuit(decoder.GetReadLength() == frameLen, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == 0, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(u16 == kUint16, "ReadUint16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(i32 == kInt32, "ReadUint32() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");
    VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 8: Test saving position at start of an open struct");

    // Re-use same frame as the previous test.

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
        SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
        SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
        {
            // Save position at start of the struct
            decoder.SavePosition();
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");

            // Verify the read content so far.

            VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
            VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");
            VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");

            // Do not close the struct and jump to the previously saved position and re-read the content.

            SuccessOrQuit(decoder.ResetToSaved(), "ResetToSaved() failed.");
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");
            SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");
        }
        SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
        SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadEui48(eui48), "ReadEui48() failed.");
    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint32(u32), "ReadUint32() failed.");
    }
    SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
    SuccessOrQuit(decoder.ReadInt32(i32), "WriteUint32() failed.");

    VerifyOrQuit(decoder.GetReadLength() == frameLen, "GetReadLength() failed.");
    VerifyOrQuit(decoder.GetRemainingLength() == 0, "GetRemainingLength() failed.");
    VerifyOrQuit(decoder.IsAllRead() == true, "IsAllRead() failed.");

    VerifyOrQuit(b_1 == kBool_1, "ReadBool() parse failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(u16 == kUint16, "ReadUint16() parse failed.");
    VerifyOrQuit(u32 == kUint32, "ReadUint32() parse failed.");
    VerifyOrQuit(i32 == kInt32, "ReadUint32() parse failed.");
    VerifyOrQuit(memcmp(ip6Addr, &kIp6Addr, sizeof(spinel_ipv6addr_t)) == 0, "ReadIp6Address() parse failed.");
    VerifyOrQuit(memcmp(eui48, &kEui48, sizeof(spinel_eui48_t)) == 0, "ReadEui48() parse failed.");
    VerifyOrQuit(memcmp(utf_1, kString_1, sizeof(kString_1)) == 0, "ReadUtf8() parse failed.");

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 9: Test `ResetToSaved()` failure case (jumping back to a saved position closed struct).");

    // Re-use same frame as the previous test.

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
    {
        SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
        SuccessOrQuit(decoder.ReadUtf8(utf_1), "ReadUtf8() failed.");
        SuccessOrQuit(decoder.OpenStruct(), "OpenStruct() failed.");
        {
            SuccessOrQuit(decoder.ReadBool(b_1), "ReadBool() failed.");

            decoder.SavePosition();

            SuccessOrQuit(decoder.ReadIp6Address(ip6Addr), "ReadIp6Addr() failed.");
        }
        SuccessOrQuit(decoder.CloseStruct(), "CloseStruct() failed.");
        SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");

        // `ResetToSaved()` should fail sicne the enclosing struct for the saved position is closed.
        VerifyOrQuit(decoder.ResetToSaved() == OT_ERROR_INVALID_STATE, "ResetToSaved() did not fail.");
    }

    printf(" -- PASS\n");

    printf("\n- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -");
    printf("\nTest 10: Testing error cases and failures. (e.g., wrong struct length).");

    frameLen = spinel_datatype_pack(buffer, sizeof(buffer),
                                    (SPINEL_DATATYPE_UINT8_S SPINEL_DATATYPE_UINT16_S // Treat this as struct length
                                                             SPINEL_DATATYPE_BOOL_S),
                                    kUint8, 10, kBool_1);

    DumpBuffer("Packed Spinel Frame (incorrect format)", buffer, static_cast<uint16_t>(frameLen));

    decoder.Init(buffer, static_cast<uint16_t>(frameLen));

    decoder.SavePosition();

    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");

    // `OpenStruct()` should fail, since it expects a length 10 but there are not enough
    // bytes in the frame.
    VerifyOrQuit(decoder.OpenStruct() == OT_ERROR_PARSE, "OpenStruct() did not fail.");

    decoder.ResetToSaved();

    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    VerifyOrQuit(u8 == kUint8, "ReadUint8() parse failed.");
    VerifyOrQuit(decoder.ReadDataWithLen(dataPtr_1, dataLen_1) == OT_ERROR_PARSE, "ReadDataWithLen() did not fail.");

    decoder.ResetToSaved();
    SuccessOrQuit(decoder.ReadUint8(u8), "ReadUint8() failed.");
    SuccessOrQuit(decoder.ReadUint16(u16), "ReadUint16() failed.");
    SuccessOrQuit(decoder.ReadBool(b_1), "ReadUint16() failed.");

    // Try reading beyond end of frame.
    VerifyOrQuit(decoder.ReadUint8(u8) == OT_ERROR_PARSE, "ReadUint8() did not fail");

    printf(" -- PASS\n");
}

} // namespace Ncp
} // namespace ot

#ifdef ENABLE_TEST_MAIN
int main(void)
{
    ot::Ncp::TestSpinelDecoder();
    printf("\nAll tests passed.\n");
    return 0;
}
#endif