// License: AGPLv3 or later. https://www.gnu.org/licenses/licenses.html

#ifndef _CFC_H_
#define _CFC_H_

#include <vector>

#include "auxiliary.h"
#include "general_functions.h"

class Mint
{
    public:
        Mint() {};
        Mint(int Number, int Modulus);
        int getNumber() const;
        // standard function to be used for template codeword.
        // it just 'return getNumber();'
        int getSymbol() const;
        int operator-(const Mint mint2) const;
        static const int zeroSymbol = 0;
    private:
        int number;
        int modulus;
};

class Melt
{
    public:
        Melt() {};
        Melt(char Character);
        char getCharacter() const;
        // standard function to be used for template codeword.
        // it just 'return getCharacter();'
        char getSymbol() const;
        int operator-(const Melt melt2) const;
        static const char zeroSymbol = 'a';
    private:
        char character;
};

template<typename T>
class Codeword
{
    public:
        Codeword();
        Codeword(std::vector<T> &aTVector);
        Codeword(const Codeword<T> &aCodeword);
        void push_back(T symbol);
        std::vector<T> getCodeword() const;
        int getWeight() const;
        // return -1 if encounters error i.e.:
        // If size of own codeword and codeword passed as argument
        // mismatch However It Will Not Happen Within Runtime Of This
        // Program. This is just defensive programming.
        int Distance(const Codeword<T> &aCodeword) const;
        void Display() const;
        int size() const;
        T getSymbolByIndex(int index) const;
        //bool isZeroCodeword() const;
    private:
        void Weight();
        void incrementalWeight();
        //void calculateIfZeroCodeword();
        std::vector<T> codeword;
        int weight = 0;
        //bool isZerocodeword;
};

template<typename T>
class Codebook
{
    public:
        Codebook();
        Codebook(std::vector<T> &aTVector);
        Codebook(const Codebook<T> &aCodebook);
        void push_back(T codeword);
        std::vector<T> getCodebook() const;
        void Display() const;
        int getMinimumWeight() const;
        std::vector<std::vector<int>> getDistance() const;
        int getMinimumDistance() const;
    private:
        // this function simply calls other three private functions
        void doCalculations();
        void minimumWeight();
        void calcDistance();
        void minimumDistance();
        void doIncrementalCalculations();
        void minimumIncrementalWeight();
        void calcIncrementalDistance();
        void minimumIncrementalDistance();
        int minWeight = 0;
        std::vector<std::vector<int>> distance;
        int minDistance = 0;
        std::vector<T> codebook;
        inline void updateIfNewMinimumDistance(int aDistance);
};

class driver
{
    public:
        driver(processArguments &ProgArgs);
    private:
        template<typename U>
        void processMintOrMelt(U aMintOrMelt);
        void processMint(Codebook<Codeword<Mint>> &theCodebook);
        void processMelt(Codebook<Codeword<Melt>> &theCodebook);
        // placeholder functions which are never called and
        // will print error and quit if called
        void processMint(Codebook<Codeword<Melt>> &theCodebook);
        void processMelt(Codebook<Codeword<Mint>> &theCodebook);
        processArguments &ProgramArguments;
};


/******TEMPLATE CLASES AND FUNCTIONS DEFINITION STARTS FROM HERE******/


template<typename U>
void driver::processMintOrMelt(U aMintOrMelt)
{
    Codebook<Codeword<U>> theCodebook;
    Codeword<U> aCodeword;
    for (int i=0; i < 1 &&i < ProgramArguments.codebookSize(); i++)
    {
        for (int j=0; j < ProgramArguments.codewordLength(); j++)
        {
            aCodeword.push_back(aMintOrMelt);
        }
        theCodebook.push_back(aCodeword);
    }
    if (typeid(U) == typeid(Mint))
    {
        processMint(theCodebook);
    }
    else if (typeid(U) == typeid(Melt))
    {
        processMelt(theCodebook);
    }
}

template<typename T>
Codeword<T>::Codeword()
{
}

template<typename T>
Codeword<T>::Codeword(std::vector<T> &aTVector)
{
    for (T symbol: aTVector)
    {
        codeword.push_back(symbol);
    }
    Weight();
}

template<typename T>
Codeword<T>::Codeword(const Codeword<T> &aCodeword)
{
    codeword = aCodeword.getCodeword();
    weight = aCodeword.getWeight();
}

template<typename T>
void Codeword<T>::push_back(T symbol)
{
    codeword.push_back(symbol);
    incrementalWeight();
}

template<typename T>
std::vector<T> Codeword<T>::getCodeword() const
{
    return codeword;
}

template<typename T>
int Codeword<T>::getWeight() const
{
    return weight;
}

template<typename T>
int Codeword<T>::Distance(const Codeword<T> &aCodeword) const
{
    int distance = 0;
    if (codeword.size() != aCodeword.size())
    {
        cerr_only(
            "Internal",
            __FILE__,
            __func__,
            __LINE__,
            "For calculating Codeword Distance, no. of symbols in own"
            " codeword and codeword passed as argument mismatch. "
            "Though technically a possiblity, it should not happen "
            "within the run of this program."
        );
        distance = -1;
    }
    else
    {
        for (int i=0; i < size(); i++)
        {
            distance += codeword[i] - aCodeword.getSymbolByIndex(i);
        }
    }
    return distance;
}

template<typename T>
void Codeword<T>::Display() const
{
    for(T symbol: codeword)
    {
        std::cout << symbol.getSymbol() << " ";
    }
    std::cout << "   Weight: "  << weight << std::endl;
}

template<typename T>
int Codeword<T>::size() const
{
    return codeword.size();
}

template<typename T>
T Codeword<T>::getSymbolByIndex(int index) const
{
    if (codeword.size() > index)
    {
        return codeword[index];
    }
    else
    {
        cerr_only(
            "internal",
            __FILE__,
            __func__,
            __LINE__,
            "Index symbol requqested is greater than cointainer size "
            "An empty symbol of same type will be returned but this "
            "will therefore give garbage result."
        );
        T emptySymbol;
        return emptySymbol;
    }
}

template<typename T>
void Codeword<T>::Weight()
{
    weight = 0;
    for (T symbol: codeword)
    {
        if (symbol.getSymbol() != symbol.zeroSymbol)
        {
            weight++;
        }
    }
}

template<typename T>
void Codeword<T>::incrementalWeight()
{
    if (codeword[codeword.size()-1].getSymbol()
        != codeword[0].zeroSymbol)
    {
        weight++;
    }
}

template<typename T>
Codebook<T>::Codebook()
{
}

template<typename T>
Codebook<T>::Codebook(std::vector<T> &aTVector)
{
    for (T codeword: aTVector)
    {
        codebook.push_back(codeword);
    }
    doCalculations();
}

template<typename T>
Codebook<T>::Codebook(const Codebook<T> &aCodebook)
{
    minWeight = aCodebook.getMinimumWeight();
    distance = aCodebook.getDistance();
    minDistance = aCodebook.getMinimumDistance();
    codebook = aCodebook.getCodebook();
}

template<typename T>
void Codebook<T>::push_back(T codeword)
{
    codebook.push_back(codeword);
    doIncrementalCalculations();
}

template<typename T>
std::vector<T> Codebook<T>::getCodebook() const
{
    return codebook;
}

template<typename T>
void Codebook<T>::Display() const
{
    for (T codeword: codebook)
    {
        codeword.Display();
    }
    std::cout 
        << "Minimum Weight: " << minWeight << '\n'
        << "Minimum Distance: " << minDistance << '\n'
        << "Distances Table:" << std::endl;
    for (auto row: distance)
    {
        for (int eachDistance: row)
        {
            std::cout << eachDistance << " ";
        }
        std::cout << "\b\n";
    }
    std::cout << std::flush;
}

template<typename T>
int Codebook<T>::getMinimumWeight() const
{
    return minWeight;
}

template<typename T>
std::vector<std::vector<int>> Codebook<T>::getDistance() const
{
    return distance;
}

template<typename T>
int Codebook<T>::getMinimumDistance() const
{
    return minDistance;
}

template<typename T>
void Codebook<T>::doCalculations()
{
    minimumWeight();
    calcDistance();
    minimumDistance();
}

template<typename T>
void Codebook<T>::minimumWeight()
{
    for (T codeword: codebook)
    {
        int weight = codeword.getWeight();
        if (weight < minWeight or minWeight == 0)
        {
            minWeight = weight;
        }
    }
}

template<typename T>
void Codebook<T>::calcDistance()
{
    int i = 0;
    for (T codeword: codebook)
    {
        distance.emplace_back();
        for(T otherCodeword: codebook)
        {
            int aDistance = codeword.Distance(otherCodeword);
            distance[i].push_back(aDistance);
        }
    }
}

template<typename T>
void Codebook<T>::minimumDistance()
{
    for (std::vector<int> distanceVector: distance)
    {
        for (int aDistance: distanceVector)
        {
            if ((aDistance < minDistance
                and aDistance != 0)
                or minDistance == 0)
            {
                minDistance = aDistance;
            }
        }
    }
}

template<typename T>
void Codebook<T>::doIncrementalCalculations()
{
    minimumIncrementalWeight();
    calcIncrementalDistance();
    minimumDistance();
}

template<typename T>
void Codebook<T>::minimumIncrementalWeight()
{
    int weight = codebook[codebook.size()-1].getWeight();
    if (weight < minWeight or minWeight == 0)
    {
        minWeight = weight;
    }
}

template<typename T>
void Codebook<T>::calcIncrementalDistance()
{
    int lastCodeword = codebook.size()-1;
    
    // Adding new column to table
    // previous codewords - new codeowrd
    for (int i=0; i < distance.size(); i++)
    {
        int aDistance = codebook[i].Distance(codebook[lastCodeword]);
        distance[i].push_back(aDistance);
    }
    
    // Adding new row to table
    // new codeword - all Codewords
    distance.emplace_back();
    for(T aCodeword: codebook)
    {
        int aDistance = codebook[lastCodeword].Distance(aCodeword);
        distance[distance.size()-1].push_back(aDistance);
    }
}

template<typename T>
void Codebook<T>::minimumIncrementalDistance()
{
    for (int aDistance: distance[distance.size()-1])
    {
        if (aDistance < minDistance or minDistance == 0)
        {
            minDistance = aDistance;
        }
    }
}

#endif