/*
 * Copyright 1993-2013 NVIDIA Corporation.  All rights reserved.
 *
 * Please refer to the NVIDIA end user license agreement (EULA) associated
 * with this source code for terms and conditions that govern your use of
 * this software. Any use, reproduction, disclosure, or distribution of
 * this software and related documentation outside the terms of the EULA
 * is strictly prohibited.
 *
 */

/*
 Simple parameter system
 sgreen@nvidia.com 4/2001
*/

#ifndef PARAM_H
#define PARAM_H

#include <string>
#include <vector>
#include <map>
#include <iostream>
#include <sstream>
#include <iomanip>

// base class for named parameter
class ParamBase
{
    public:
        ParamBase(const char *name) : m_name(name) { }
        virtual ~ParamBase() { }

        std::string &GetName()
        {
            return m_name;
        }

        virtual float GetFloatValue() = 0;
        virtual int GetIntValue() = 0;
        virtual std::string GetValueString() = 0;

        virtual void Reset() = 0;
        virtual void Increment() = 0;
        virtual void Decrement() = 0;

        virtual float GetPercentage() = 0;
        virtual void SetPercentage(float p) = 0;

        virtual void Write(std::ostream &stream) = 0;
        virtual void Read(std::istream &stream) = 0;

        virtual bool IsList() = 0;

    protected:
        std::string m_name;
};

// derived class for single-valued parameter
template<class T> class Param : public ParamBase
{
    public:
        Param(const char *name, T value = 0, T min = 0, T max = 10000, T step = 1, T *ptr = 0) :
            ParamBase(name),
            m_default(value),
            m_min(min),
            m_max(max),
            m_step(step),
            m_precision(3)
        {
            if (ptr)
            {
                m_ptr = ptr;
            }
            else
            {
                m_ptr = &m_value;
            }

            *m_ptr = value;
        }
        ~Param() { }

        T GetValue() const
        {
            return *m_ptr;
        }
        T SetValue(const T value)
        {
            *m_ptr = value;
        }

        float GetFloatValue()
        {
            return (float) *m_ptr;
        }
        int GetIntValue()
        {
            return (int) *m_ptr;
        }

        std::string GetValueString()
        {
            std::ostringstream ost;
            ost<<std::setprecision(m_precision)<<std::fixed;
            ost<<*m_ptr;
            return ost.str();
        }

        void SetPrecision(int x)
        {
            m_precision = x;
        }

        float GetPercentage()
        {
            return (*m_ptr - m_min) / (float)(m_max - m_min);
        }

        void SetPercentage(float p)
        {
            *m_ptr = (T)(m_min + p * (m_max - m_min));
        }

        void Reset()
        {
            *m_ptr = m_default;
        }

        void Increment()
        {
            *m_ptr += m_step;

            if (*m_ptr > m_max)
            {
                *m_ptr = m_max;
            }
        }

        void Decrement()
        {
            *m_ptr -= m_step;

            if (*m_ptr < m_min)
            {
                *m_ptr = m_min;
            }
        }

        void Write(std::ostream &stream)
        {
            stream << m_name << " " << *m_ptr << '\n';
        }
        void Read(std::istream &stream)
        {
            stream >> m_name >> *m_ptr;
        }

        bool IsList()
        {
            return false;
        }

    private:
        T m_value;
        T *m_ptr;         // pointer to value declared elsewhere
        T m_default, m_min, m_max, m_step;
        int m_precision;  // number of digits after decimal point in string output
};

const Param<int> dummy("error");

// list of parameters
class ParamList : public ParamBase
{
    public:
        ParamList(const char *name = "") :
            ParamBase(name)
        {
            active = true;
        }
        ~ParamList() { }

        float GetFloatValue()
        {
            return 0.0f;
        }
        int GetIntValue()
        {
            return 0;
        }

        void AddParam(ParamBase *param)
        {
            m_params.push_back(param);
            m_map[param->GetName()] = param;
            m_current = m_params.begin();
        }

        // look-up parameter based on name
        ParamBase *GetParam(char *name)
        {
            ParamBase *p = m_map[name];

            if (p)
            {
                return p;
            }
            else
            {
                return (ParamBase *) &dummy;
            }
        }

        ParamBase *GetParam(int i)
        {
            return m_params[i];
        }

        ParamBase *GetCurrent()
        {
            return *m_current;
        }

        int GetSize()
        {
            return (int)m_params.size();
        }

        std::string GetValueString()
        {
            return m_name;
        }

        // functions to traverse list
        void Reset()
        {
            m_current = m_params.begin();
        }

        void Increment()
        {
            m_current++;

            if (m_current == m_params.end())
            {
                m_current = m_params.begin();
            }
        }

        void Decrement()
        {
            if (m_current == m_params.begin())
            {
                m_current = m_params.end()-1;
            }
            else
            {
                m_current--;
            }

        }

        float GetPercentage()
        {
            return 0.0f;
        }
        void SetPercentage(float /*p*/) {}

        void Write(std::ostream &stream)
        {
            stream << m_name << '\n';

            for (std::vector<ParamBase *>::const_iterator p = m_params.begin(); p != m_params.end(); ++p)
            {
                (*p)->Write(stream);
            }
        }

        void Read(std::istream &stream)
        {
            stream >> m_name;

            for (std::vector<ParamBase *>::const_iterator p = m_params.begin(); p != m_params.end(); ++p)
            {
                (*p)->Read(stream);
            }
        }

        bool IsList()
        {
            return true;
        }

        void ResetAll()
        {
            for (std::vector<ParamBase *>::const_iterator p = m_params.begin(); p != m_params.end(); ++p)
            {
                (*p)->Reset();
            }
        }

    protected:
        bool active;
        std::vector<ParamBase *> m_params;
        std::map<std::string, ParamBase *> m_map;
        std::vector<ParamBase *>::const_iterator m_current;
};

#endif