#ifndef __REGISTER_HPP__
  #define __REGISTER_HPP__

#include <vector>
#include <cstdlib>
#include <cassert>
#include <string>
#include <stdint.h>

#include "SALConfig.hpp"

namespace sal
{

/**
 * \enum RegisterType
 * Lists the different register types. You need to expand this enumeration
 * to provide more detailed types for your concrete derived register classes
 * specific to a simulator.
 */
enum RegisterType
{
	RT_GP, //!< general purpose
	RT_PC, //!< program counter / instruction pointer
	RT_ST  //!< status register
};

/**
 * \class Register
 * Represents the basic generic register class. A set of registers is composed
 * of classes which had been derived from this class.
 */
class Register
{
	protected:
		RegisterType m_Type; //!< the type of this register
		regwidth_t m_Width; //!< the register width
		unsigned int m_Id; //!< the unique id of this register
		//! \c true if register has already been assigned, \c false otherwise
		bool m_Assigned;
		//! The index in it's register set if assigned (\c -1 otherwise)
		size_t m_Index;
		std::string m_Name; //!< The (optional) name, maybe empty
		friend class UniformRegisterSet;
	public:
		/**
		 * Creates a new register.
		 * @param id the unique id of this register (simulator specific)
		 * @param t the type of the register to be constructed
		 * @param w the width of the register in bits
		 */
		Register(unsigned int id, RegisterType t, regwidth_t w)
			: m_Type(t), m_Width(w), m_Id(id), m_Assigned(false),
			  m_Index(static_cast<size_t>(-1)) { }
		/**
		 * Returns the (fixed) type of this register.
		 * @return the type of this register
		 */
		RegisterType getType() const { return (m_Type); }
		/**
		 * Returns the (fixed) width of this register.
		 * @return the width in bits
		 */
		regwidth_t getWidth() const { return (m_Width); }
		/**
		 * Returns the data referenced by this register. In a concrete
		 * derived class this method has to be defined appropriately.
		 * @return the current data
		 */
		virtual regdata_t getData() /*!const*/ = 0;
		/**
		 * Sets new data to be stored in this register.
		 * @param data the data to be written to the register
		 */
		virtual void setData(regdata_t data) = 0;
		/**
		 * Sets the (optional) name of this register.
		 * @param name the textual register name, e.g. "EAX"
		 */
		void setName(const std::string& name) { m_Name = name; }
		/**
		 * Retrieves the register name.
		 * @return the textual register description
		 */
		const std::string& getName() const { return (m_Name); }
		/**
		 * Retrieves the unique index within it's assigned register set.
		 * If the register has not been assigned, \c (size_t)-1 will be
		 * returned.
		 * @return the register index or -1 if not assigned
		 * @see isAssigned()
		 */
		size_t getIndex() const { return (m_Index); }
		/**
		 * Checks whether this register has already been assigned. On
		 * creation the register isn't initially assigned.
		 * @return \c true if assigned, \c false otherwise
		 */
		bool isAssigned() const { return (m_Assigned); }
		/**
		 * Returns the unique id of this register.
		 * @return the unique id
		 */
		unsigned int getId() const { return (m_Id); }
};

/**
 * \class UniformRegisterSet
 * Represents a (type-uniform) set of registers, e.g. all general purpose
 * registers. The granularity of the register type is determined by the
 * enumeration \c RegisterType. (All registers within this set must be of the
 * same register type.) The capacity of the set is managed automatically.
 */
class UniformRegisterSet
{
	private:
		std::vector< Register* > m_Regs; //!< the unique set of registers
		RegisterType m_Type; //!< the overall type of this container (set)
		void m_add(Register* preg);
		friend class RegisterManager;
	public:
		/**
		 * The iterator of this class used to loop through the list of
		 * added registers. To retrieve an iterator to the first element, call
		 * begin(). end() returns the iterator, pointing after the last element.
		 * (This behaviour equals the STL iterator in C++.)
		 */
		typedef std::vector< Register* >::iterator iterator;
		/**
		 * Returns an iterator to the beginning of the internal data structure.
		 * \code
		 * [1|2| ... |n]
		 *  ^
		 * \endcode
		 */
		iterator begin() { return (m_Regs.begin()); }
		/**
		 * Returns an iterator to the end of the interal data structure.
		 * \code
		 * [1|2| ... |n]X
		 *              ^
		 * \endcode
		 */
		iterator end() { return (m_Regs.end()); }
		/**
		 * Constructs a new register set with type \a containerType.
		 * @param containerType the type of registers which should be stored
		 *        in this set
		 */
		UniformRegisterSet(RegisterType containerType)
			: m_Type(containerType) { }
		/**
		 * Returns the type of this set.
		 * @return the type
		 */
		RegisterType getType() const { return (m_Type); }
		/**
		 * Gets the number of registers of this set.
		 * @return the number of registers
		 */
		size_t count() const { return (m_Regs.size()); }
		/**
		 * Retrieves the \a i-th register within this set.
		 * @return a pointer to the \a i-th register; if \a i is invalid, an
		 *         assertion is thrown
		 */
		Register* getRegister(size_t i);
		/**
		 * Retrieves the first register within this set (syntactical sugar).
		 * @return a pointer to the first register (if existing -- otherwise an
		 *         assertion is thrown)
		 */
		virtual Register* first() { return (getRegister(0)); }
};

/**
 * \class RegisterManager
 * Represents a complete set of (inhomogeneous) registers specific to a concrete
 * architecture, e.g. x86 or ARM.
 */
class RegisterManager
{
	protected:
		std::vector< Register* > m_Registers;
		//!< the managed set of homogeneous sets
		std::vector< UniformRegisterSet* > m_Subsets;
	public:
		/**
		 * The iterator of this class used to loop through the list of
		 * added registers. To retrieve an iterator to the first element, call
		 * begin(). end() returns the iterator, pointing after the last element.
		 * (This behaviour equals the STL iterator in C++.)
		 */
		typedef std::vector< Register* >::iterator iterator;
		/**
		 * Returns an iterator to the beginning of the internal data structure.
		 * \code
		 * [1|2| ... |n]
		 *  ^
		 * \endcode
		 */
		iterator begin() { return (m_Registers.begin()); }
		/**
		 * Returns an iterator to the end of the interal data structure.
		 * \code
		 * [1|2| ... |n]X
		 *              ^
		 * \endcode
		 */
		iterator end() { return (m_Registers.end()); }

		RegisterManager() { }
		~RegisterManager() { clear(); }
		/**
		 * Retrieves the total number of registers over all homogeneous sets.
		 * @return the total register count
		 */
		virtual size_t count() const;
		/**
		 * Retrieves the number of managed homogeneous register sets.
		 * @return the number of sets
		 */
		virtual size_t subsetCount() const { return (m_Subsets.size()); }
		/**
		 * Gets the \a i-th register set.
		 * @param i the index of the set to be returned
		 * @return a reference to the uniform register set
		 * @see subsetCount()
		 */
		virtual UniformRegisterSet& getSet(size_t i);
		/**
		 * Returns the set with register type \a t. The set can be used to
		 * loop over all registers of type \a t.
		 * @param t the type to check for
		 * @return a pointer to the retrieved register set (if found), NULL
		 *         otherwise
		 */
		virtual UniformRegisterSet* getSetOfType(RegisterType t);
		/**
		 * Adds a new register to this set. The register object needs to be
		 * typed (see Register::getType).
		 * @param reg a pointer to the register object to be added
		 * @see getType()
		 */
		void add(Register* reg);
		/**
		 * Retrieves the \a i-th register.
		 * @return a pointer to the \a i-th register; if \a i is invalid, an
		 *         assertion is thrown
		 */
		Register* getRegister(size_t i);
		/**
		 * Removes all registers and sets from the RegisterManager.
		 */
		virtual void clear();
		/**
		 * Returns the current instruction pointer.
		 * @return the current eip
		 */
		virtual address_t getInstructionPointer() = 0;
		/**
		 * Retruns the top address of the stack.
		 * @return the starting address of the stack
		 */
		virtual address_t getStackPointer() = 0;
		/**
		 * Retrieves the base ptr (holding the address of the
		 * current stack frame).
		 * @return the base pointer
		 */
		virtual address_t getBasePointer() = 0;
};

} // end-of-namespace: sal

#endif /* __REGISTER_HPP__ */