#pragma once

#include <cstddef>
#include <string>

#include "dxbc_tag.h"

namespace dxvk {
  
  /**
   * \brief DXBC bytecode reader
   * 
   * Holds references to the shader byte code and
   * provides methods to read 
   */
  class DxbcReader {
    
  public:
    
    DxbcReader(const char* data, size_t size)
    : DxbcReader(data, size, 0) { }
    
    auto readu8 () { return this->readNum<uint8_t> (); }
    auto readu16() { return this->readNum<uint16_t>(); }
    auto readu32() { return this->readNum<uint32_t>(); }
    auto readu64() { return this->readNum<uint64_t>(); }
    
    auto readi8 () { return this->readNum<int8_t>  (); }
    auto readi16() { return this->readNum<int16_t> (); }
    auto readi32() { return this->readNum<int32_t> (); }
    auto readi64() { return this->readNum<int64_t> (); }
    
    auto readf32() { return this->readNum<float>   (); }
    auto readf64() { return this->readNum<double>  (); }
    
    template<typename T>
    auto readEnum() {
      using Tx = std::underlying_type_t<T>;
      return static_cast<T>(this->readNum<Tx>());
    }
    
    DxbcTag readTag();
    
    std::string readString();
    
    void read(void* dst, size_t n);
    
    void skip(size_t n);
    
    DxbcReader clone(size_t pos) const;
    
    DxbcReader resize(size_t size) const;
    
    bool eof() const {
      return m_pos >= m_size;
    }
    
  private:
    
    DxbcReader(const char* data, size_t size, size_t pos)
    : m_data(data), m_size(size), m_pos(pos) { }
    
    const char* m_data = nullptr;
    size_t      m_size = 0;
    size_t      m_pos  = 0;
    
    template<typename T>
    T readNum() {
      T result;
      this->read(&result, sizeof(result));
      return result;
    }
    
  };
  
}