#include <vector>
#include <iostream>
#include <fstream>
using namespace std;
struct recordLZW{
    unsigned short index;
    unsigned short prev_index;
    recordLZW(unsigned short index,unsigned short prev_index){
        this->index = index;
        this->prev_index = prev_index;
    }
    bool operator==(const recordLZW& r){
        return (index==r.index)&&(prev_index==r.prev_index);
    }
};
class LZW{
private:
    const char* txtfilename;
    const char* lzfilename;
    ifstream infile;
    ofstream outfile;
    vector<recordLZW> dictionary;
    int inDictionary(const recordLZW& r){
        for(unsigned int i = 0;i<dictionary.size();++i) if(dictionary[i] == r) return i;
        return -1;
    }
public:
    LZW(const char* txtfilename, const char* lzfilename){
        this->txtfilename = txtfilename;
        this->lzfilename = lzfilename;
        for(unsigned short i=0;i<256;++i) {
            recordLZW tmp(i,0);
            dictionary.push_back(tmp);
        }
    }
    void drawDictionary(){
        for(unsigned int i=256;i<dictionary.size();++i) cout<<i<<":"<<dictionary[i].prev_index<<"("<<(char)dictionary[i].prev_index<<")  "<<dictionary[i].index<<"("<<(char)dictionary[i].index<<")"<<endl;
    }
    char firstChar(unsigned short code){
        if(!dictionary[code].prev_index)
            return (char)dictionary[code].index;
        do{
            if(dictionary[code].prev_index<255) return (char)dictionary[code].prev_index;
            else code = dictionary[code].prev_index;
        }while(true);
    }
    void decompress(){
        infile.open(lzfilename,ifstream::binary);
        outfile.open(txtfilename,ofstream::binary);
        unsigned short current_code;
        unsigned short previous_code = 0;
        char* buffer = new char[65535];
        infile.read((char*)&previous_code,sizeof(unsigned short));
        outfile.put((char)previous_code);
        while(true){
            int bufsize = 0;
            if(infile.good()){
                infile.read((char*)&current_code,sizeof(unsigned short));
                if(infile.eof()) break;
                if(dictionary.size()>current_code){ //ячейка dictionary[current_code] заполнена
                    //выводим table[current_code]
                    int picode = current_code;
                    do{
                        buffer[bufsize++] = (char)dictionary[picode].index;
                        if(dictionary[picode].prev_index<256) {
                            if(dictionary[picode].prev_index>0)
                                buffer[bufsize++]=(char)dictionary[picode].prev_index;
                            break;
                        }
                        else picode = dictionary[picode].prev_index;
                    }while(true);
                    for(int i=bufsize-1;i>=0;--i){
                        outfile.put(buffer[i]);
                    }
                    //выволы
                    recordLZW tmp((unsigned short)firstChar(current_code), previous_code);
                    dictionary.push_back(tmp);
                    previous_code = current_code;
                }else{//если ячейки не существу
                    recordLZW tmp((unsigned short)firstChar(previous_code),previous_code);
                    dictionary.push_back(tmp);
                    int picode = dictionary.size() - 1;
                    do{
                        buffer[bufsize++] = (char)dictionary[picode].index;
                        if(dictionary[picode].prev_index<256) {
                            if(dictionary[picode].prev_index>0)
                                buffer[bufsize++]=(char)dictionary[picode].prev_index;
                            break;
                        }
                        else picode = dictionary[picode].prev_index;
                    }while(true);
                    for(int i=bufsize-1;i>=0;--i){
                        outfile.put(buffer[i]);
                    }
                }
            }else{
                break;
            }
        }
        delete[] buffer;
        //drawDictionary();
        infile.close();
        outfile.close();
    }
    void STUPIDdecompress(){
        infile.open(lzfilename,ifstream::binary);
        outfile.open(txtfilename,ofstream::binary);
        unsigned short current_code;
        char* buffer = new char[65535];
        unsigned short old_code = 0;
        while(true){
            infile.read((char*)&current_code, sizeof(unsigned short));
            int bufsize = 0;
            if(infile.good()){
                if(current_code<256){
                    recordLZW tmp(current_code,old_code);
                    cout<<current_code;
                    outfile.put((char)current_code);
                    if(old_code){
                        dictionary.push_back(tmp);
                        cout<<" Добавляем 1 "<<dictionary.size()-1<<"  "<<dictionary[dictionary.size() - 1].prev_index<<","<<dictionary[dictionary.size() - 1].index<<endl;
                    }
                }else{
                    cout<<"Нужен "<<current_code<<" имеется "<<dictionary.size()-1<<endl;
                    if(dictionary.size()>current_code){
                        //outfile.put((char)dictionary[current_code].prev_index);
                        //outfile.put((char)dictionary[current_code].index);
                        int picode = current_code;
                        cout<<"Record: "<<current_code<<" - "<<dictionary[current_code].prev_index<<","<<dictionary[current_code].index<<endl;
                        bufsize=0;
                        do{
                            buffer[bufsize++] = (char)dictionary[picode].index;
                            if(dictionary[picode].prev_index<256) {
                                buffer[bufsize++]=(char)dictionary[picode].prev_index;
                                break;
                            }
                            else picode = dictionary[picode].prev_index;
                        }while(true);
                        for(int i=bufsize-1;i>=0;--i){
                            outfile.put(buffer[i]);
                        }
                    }else{
                        //oldcode first char
                        char fch = firstChar(old_code);
                        //cout<<"FC "<<fch<<endl;
                        recordLZW tmp(fch,old_code);
                        dictionary.push_back(tmp);
                        cout<<"Добавляем 2 "<<dictionary.size()-1<<"   "<<dictionary[dictionary.size() - 1].prev_index<<","<<dictionary[dictionary.size() - 1].index<<endl;
                        if(old_code>255) { // Дописать алгоритм распаковки буфера на лету
                            int picode = old_code;
                            bufsize=0;
                            do{
                                buffer[bufsize++] = (char)dictionary[picode].index;
                                if(dictionary[picode].prev_index<256) {
                                    buffer[bufsize++]=(char)dictionary[picode].prev_index;
                                    break;
                                }
                                else picode = dictionary[picode].prev_index;
                            }while(true);
                            for(int i=bufsize-1;i>=0;--i){
                                outfile.put(buffer[i]);
                            }
                        }else{
                            outfile.put((char)old_code);
                        }
                        outfile.put(fch);
                    }
                    //continue;//FIX IT
                }
                old_code = current_code;
            }else break;
        }
        delete[] buffer;
        drawDictionary();
        infile.close();
        outfile.close();
    }
    void compress(){
        infile.open(txtfilename,ifstream::binary);
        outfile.open(lzfilename,ofstream::binary);
        unsigned char buffer;
        unsigned short prefix = 0;
        while(true){
            infile.read((char*)&buffer,1);
            if(infile.good()) {
                recordLZW tmp(static_cast<unsigned short>(buffer),prefix);
                int find_index = inDictionary(tmp);
                cout<<"Структура :"<<tmp.prev_index<<"("<<(char)tmp.prev_index<<")  "<<tmp.index<<"("<<(char)tmp.index<<")";
                if(find_index>=0) {
                    cout<<"        [найдена]"<<endl;
                    prefix = (unsigned short)find_index;
                    //if(prefix>255){
                        //outfile.write((char*)&prefix,sizeof(prefix));
                        //prefix = buffer;
                        //cout<<prefix<<" "<<sizeof(prefix)<<endl;
                    //}
                }
                else{
                    dictionary.push_back(tmp);
                    //if(prefix<=255) //FIX IT исправлено для абракадабры, для других может не работать. лишний 00 01
                        outfile.write((char*)&prefix,sizeof(unsigned short));
                    //cout<<prefix<<endl;
                    cout<<"        [добавлена]"<<endl;
                    prefix = buffer;
                }
            }else{
                if(prefix) outfile.write((char*)&prefix,sizeof(unsigned short));
                break;
            }
        }
        cout<<endl<<dictionary.size() - 256;
        cout<<endl;
        infile.close();
        outfile.close();
        drawDictionary();
    }
};