//===-- StringExtractor.h ---------------------------------------*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef utility_StringExtractor_h_
#define utility_StringExtractor_h_

// C Includes
// C++ Includes
#include <string>
#include <stdint.h>

// Other libraries and framework includes
// Project includes

class StringExtractor
{
public:

    enum {
        BigEndian = 0,
        LittleEndian = 1
    };
    //------------------------------------------------------------------
    // Constructors and Destructors
    //------------------------------------------------------------------
    StringExtractor();
    StringExtractor(const char *packet_cstr);
    StringExtractor(const StringExtractor& rhs);
    virtual ~StringExtractor();

    //------------------------------------------------------------------
    // Operators
    //------------------------------------------------------------------
    const StringExtractor&
    operator=(const StringExtractor& rhs);

    // Returns true if the file position is still valid for the data
    // contained in this string extractor object.
    bool
    IsGood() const
    {
        return m_index != UINT64_MAX;
    }

    uint64_t
    GetFilePos () const
    {
        return m_index;
    }

    void
    SetFilePos (uint32_t idx)
    {
        m_index = idx;
    }

    void
    Clear ()
    {
        m_packet.clear();
        m_index = 0;
    }

    void
    SkipSpaces ();

    std::string &
    GetStringRef ()
    {
        return m_packet;
    }

    const std::string &
    GetStringRef () const
    {
        return m_packet;
    }

    bool
    Empty()
    {
        return m_packet.empty();
    }

    size_t
    GetBytesLeft ()
    {
        if (m_index < m_packet.size())
            return m_packet.size() - m_index;
        return 0;
    }

    char
    GetChar (char fail_value = '\0');

    char
    PeekChar (char fail_value = '\0')
    {
        const char *cstr = Peek();
        if (cstr)
            return cstr[0];
        return fail_value;
    }

    int
    DecodeHexU8();

    uint8_t
    GetHexU8 (uint8_t fail_value = 0, bool set_eof_on_fail = true);

    bool
    GetNameColonValue (std::string &name, std::string &value);

    int32_t
    GetS32 (int32_t fail_value, int base = 0);

    uint32_t
    GetU32 (uint32_t fail_value, int base = 0);

    int64_t
    GetS64 (int64_t fail_value, int base = 0);
    
    uint64_t
    GetU64 (uint64_t fail_value, int base = 0);

    uint32_t
    GetHexMaxU32 (bool little_endian, uint32_t fail_value);

    uint64_t
    GetHexMaxU64 (bool little_endian, uint64_t fail_value);

    size_t
    GetHexBytes (void *dst, size_t dst_len, uint8_t fail_fill_value);

    size_t
    GetHexBytesAvail (void *dst, size_t dst_len);

    uint64_t
    GetHexWithFixedSize (uint32_t byte_size, bool little_endian, uint64_t fail_value);

    size_t
    GetHexByteString (std::string &str);

    size_t
    GetHexByteStringFixedLength (std::string &str, uint32_t nibble_length);

    size_t
    GetHexByteStringTerminatedBy (std::string &str,
                                  char terminator);
    
    const char *
    Peek ()
    {
        if (m_index < m_packet.size())
            return m_packet.c_str() + m_index;
        return nullptr;
    }

protected:
    //------------------------------------------------------------------
    // For StringExtractor only
    //------------------------------------------------------------------
    std::string m_packet;   // The string in which to extract data.
    uint64_t m_index;       // When extracting data from a packet, this index
                            // will march along as things get extracted. If set
                            // to UINT64_MAX the end of the packet data was
                            // reached when decoding information
};

#endif  // utility_StringExtractor_h_