/*
 *    Copyright (c) 2024 Project CHIP Authors
 *    All rights reserved.
 *
 *    Licensed under the Apache License, Version 2.0 (the "License");
 *    you may not use this file except in compliance with the License.
 *    You may obtain a copy of the License at
 *
 *        http://www.apache.org/licenses/LICENSE-2.0
 *
 *    Unless required by applicable law or agreed to in writing, software
 *    distributed under the License is distributed on an "AS IS" BASIS,
 *    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *    See the License for the specific language governing permissions and
 *    limitations under the License.
 */
#pragma once

#include <lib/core/CHIPEncoding.h>
#include <lib/core/CHIPError.h>
#include <stddef.h>
#include <stdint.h>

namespace chip {
namespace DeviceLayer {
namespace Silabs {
namespace Provision {
namespace Encoding {

struct Buffer
{
    Buffer(uint8_t * ptr, size_t size, bool at_end = false) { Init(ptr, size, at_end); }

    void Init(uint8_t * ptr, size_t size, bool at_end = false)
    {
        this->begin = ptr;
        this->end   = ptr + size;
        this->in    = at_end ? end : begin;
        this->out   = ptr;
    }

    void Clear() { this->in = this->out = this->begin; }
    size_t Limit() { return (this->end > this->begin) ? (this->end - this->begin) : 0; }
    size_t Size() { return (this->in > this->begin) ? (this->in - this->begin) : 0; }
    size_t Offset() { return (this->out > this->begin) ? (this->out - this->begin) : 0; }
    size_t Left() { return this->Size() - this->Offset(); }
    size_t Spare() { return this->Limit() - this->Size(); }

    CHIP_ERROR Add(uint8_t in);
    CHIP_ERROR Add(uint16_t in);
    CHIP_ERROR Add(uint32_t in);
    CHIP_ERROR Add(int32_t in);
    CHIP_ERROR Add(const uint8_t * in, size_t size);
    CHIP_ERROR Add(Buffer & from, size_t size);
    CHIP_ERROR Get(uint8_t & out);
    CHIP_ERROR Get(uint16_t & out);
    CHIP_ERROR Get(uint32_t & out);
    CHIP_ERROR Get(uint8_t * out, size_t size);
    CHIP_ERROR Get(Buffer & into, size_t size);

    uint8_t * begin = nullptr;
    uint8_t * end   = nullptr;
    uint8_t * in    = nullptr;
    uint8_t * out   = nullptr;
};

//------------------------------------------------------------------------------
// Version 1
//------------------------------------------------------------------------------
#ifdef SILABS_PROVISION_PROTOCOL_V1

namespace Version1 {

enum Types : uint8_t
{
    Type_None   = 0x00,
    Type_Int8u  = 0x01,
    Type_Int16u = 0x02,
    Type_Int32u = 0x03,
    Type_Array  = 0x04,
};

CHIP_ERROR Encode(Buffer & arg, uint8_t in);
CHIP_ERROR Encode(Buffer & arg, uint16_t in);
CHIP_ERROR Encode(Buffer & arg, int32_t in);
CHIP_ERROR Encode(Buffer & arg, uint32_t in);
CHIP_ERROR Encode(Buffer & arg, const uint8_t * in, size_t size);
CHIP_ERROR Encode(Buffer & arg, const char * in);

CHIP_ERROR Decode(Buffer & arg, uint8_t & out);
CHIP_ERROR Decode(Buffer & arg, uint16_t & out);
CHIP_ERROR Decode(Buffer & arg, uint32_t & out);
CHIP_ERROR Decode(Buffer & arg, uint8_t * out, size_t limit, size_t & size);
CHIP_ERROR Decode(Buffer & arg, char * out, size_t limit, size_t & size);

namespace Legacy {
CHIP_ERROR DecodeInt8u(Encoding::Buffer & in, uint8_t & out);
CHIP_ERROR DecodeInt16u(Encoding::Buffer & in, uint16_t & out);
CHIP_ERROR DecodeInt32u(Encoding::Buffer & in, uint32_t & out);
} // namespace Legacy

} // namespace Version1

#endif // SILABS_PROVISION_PROTOCOL_V1

//------------------------------------------------------------------------------
// Version 2
//------------------------------------------------------------------------------

namespace Version2 {

enum Types : uint8_t
{
    Type_Binary = 0x00,
    Type_Int8u  = 0x01,
    Type_Int16u = 0x02,
    Type_Int32u = 0x03,
    Type_Int64u = 0x04,
    Type_String = 0x08,
    Type_Int8s  = 0x09,
    Type_Int16s = 0x0a,
    Type_Int32s = 0x0b,
    Type_Int64s = 0x0c,
};

union Value
{
    uint8_t u8;
    uint16_t u16;
    uint32_t u32;
    uint32_t u64;
    uint8_t * b;
};

struct Argument : public Buffer
{
    enum States : uint8_t
    {
        State_Flags = 1,
        State_Size  = 3,
        State_Data  = 4,
        State_Ready = 5,
    };

    Argument(uint8_t * ptr, size_t size) : Buffer(ptr, size) { Reset(); }

    void Reset()
    {
        this->Clear();
        this->state        = State_Flags;
        this->id           = 0;
        this->type         = 0;
        this->size         = 0;
        this->size_len     = 0;
        this->encoded_size = 0;
        this->is_null      = false;
        this->is_binary    = false;
        this->is_known     = false;
        this->feedback     = false;
        this->offset       = 0;
        memset(&this->value, 0x00, sizeof(Value));
    }

    States state        = State_Flags;
    uint16_t id         = 0;
    uint8_t type        = 0;
    size_t size         = 0;
    uint8_t size_len    = 0;
    size_t encoded_size = 0;
    bool is_null        = false;
    bool is_binary      = false;
    bool is_known       = false;
    bool feedback       = false;
    size_t offset       = 0;
    Value value;
};

CHIP_ERROR Encode(uint16_t id, uint8_t * value, Buffer & out);
CHIP_ERROR Encode(uint16_t id, uint16_t * value, Buffer & out);
CHIP_ERROR Encode(uint16_t id, uint32_t * value, Buffer & out);
CHIP_ERROR Encode(uint16_t id, const uint8_t * value, size_t size, Buffer & out);
CHIP_ERROR Decode(Buffer & in, Argument & arg);
CHIP_ERROR Find(Buffer & in, uint16_t id, Argument & arg);

} // namespace Version2

} // namespace Encoding
} // namespace Provision
} // namespace Silabs
} // namespace DeviceLayer
} // namespace chip