#include <stdio.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <string>
#include <sstream>
#include <iostream>
#include <vector>
#include <syslog.h>
#include <pthread.h>
#include <unistd.h>


using namespace std;
typedef vector<char> wektor;


wektor str2vector(string s)
{
	wektor result_vector;
	for(int i=0; i<s.length();i++)
		result_vector.push_back(s[i]);
		
	return result_vector;
	
}

wektor cutvector(wektor str,int start_offset, int end_offset)
{

	wektor result_vector;
	for(int i=start_offset;i<=end_offset;i++)
			result_vector.push_back(str[i]);

	
		return result_vector;

}

wektor mergevector(wektor str1,wektor str2)
{

	wektor result_vector;

	for(int i=0;i<str1.size();i++)
		result_vector.push_back(str1[i]);
	
	for(int i=0;i<str2.size();i++)
		result_vector.push_back(str2[i]);

	return result_vector;

}

void revregx_error(wektor &regex)
{

fprintf(stdout,"Regex error : !!");			
for(int k=0;k<regex.size();k++)
	cout<<regex[k];
cout<<endl;

}

void print_vector(wektor &wektor,int s,int e)
{
int sf =s;
int ef = e;
for(int k=sf;k<ef;k++)
	cout<<wektor[k];
cout<<endl;
}

int char2hex(char hb,char lb) //set to 2 chars
{
	unsigned int value = 0;
	char ch = hb;
	int i=2;
		   
		while(i--) {
		if (ch >= '0' && ch <= '9')
			value = (value << 4) + (ch - '0');
		 else if (ch >= 'A' && ch <= 'F')
			value = (value << 4) + (ch - 'A' + 10);
         else if (ch >= 'a' && ch <= 'f')
			value = (value << 4) + (ch - 'a' + 10);	  
		else
            return value;    
	    ch = lb;
		}
	  
	return value;
	
}

int ishex(char val)
{
	
	if (val >= '0' && val <= '9')
		return 1;
	 else if (val >= 'A' && val <= 'F')
		return 1;
     else if (val >= 'a' && val <= 'f')
		return 1;
	else
        return 0;

}

wektor revregex_process_bracket(wektor str,int start_offset,int end_offset) //index: '[' ... ']' 
{
	wektor result_vector;
	//TODO hex support
	int bslash='\\';
	int word='w';
	int digit='d';
	int range='-';

	//flags
	char nnot=0;
	char wordf=0;
	char digitf=0;
	char rangeword=0;
	char rangedigit=0;
	
	//character pool
	char characters[255]={0,};
	int chari=0;
	char characterstmp[255]={0,};
	long character_class=0;
	
	//skip first bracket char
	int i=start_offset+1;
	int lend_offset=end_offset;
	int tmpj;
	
	if( str[i]=='^') //not flag
	{
		i++;nnot=1;
	}
	
	// DEBUG
	//fprintf(stdout,"Start off:%d  End off:%d\n",i,end_offset);
	//print_vector(str,i,end_offset);
	
	for(i;i<lend_offset;i++)
	{
		 		
			if( str[i]==bslash && i+1!=lend_offset ) //special chars - check if character class
			{
				if(str[i+1]=='c') 
					character_class|=1<<1;
				else if(str[i+1]=='s')
					character_class|=2<<1;
				else if(str[i+1]=='S')
					character_class|=1<<3;
				else if(str[i+1]=='d')
					character_class|=1<<4;
				else if(str[i+1]=='D')
					character_class|=1<<5;
				else if(str[i+1]=='w')
					character_class|=1<<6;
				else if(str[i+1]=='W')
					character_class|=1<<7;	
				else if(str[i+1]=='n')
					characters['\n']=1;
				else if(str[i+1]=='r')
					characters['\r']=1;
				else if(str[i+1]=='t')
					characters['\t']=1;
				else if(str[i+1]=='v')
					characters['\v']=1;
				else if(str[i+1]=='f')
					characters['\f']=1;
				else if(str[i+1]=='0')
					characters['\0']=1;
				else
					{
						//DEBUG
						//fprintf(stdout,"unknown char: %c !\n", str[i+1]); //DEBUG - ignore this char it probably was escaped
						characters[str[i+1]]=1;
					}
				i++;
				
			}
			else if( isalpha(str[i]) && (i+1)!=lend_offset && str[i+1]==range && (i+2)!=lend_offset && isalpha(str[i+2])) //check if rangeword
			{
					//DEBUG
					//fprintf(stdout,"rangew");
					
					//add chars from range to the pool
					tmpj=str[i];
					for(tmpj;tmpj<=str[i+2];tmpj++)
					{
						characters[tmpj]=1;
					}
					i+=3;
					rangeword=1;
					
			}
			else if( isdigit(str[i]) && (i+1)!=lend_offset && str[i+1]==range && (i+2)!=lend_offset && isdigit(str[i+2])) //check if rangedigit
			{
					//DEBUG
					//fprintf(stdout,"ranged");
					
					tmpj=str[i];
					for(tmpj;tmpj<=str[i+2];tmpj++)
					{
						characters[tmpj]=1;
					}
					i+=3;
					rangedigit=1;
					
			} 
			else if(str[i]=='.')
				character_class|=1<<8;
			else if(str[i]=='|') //TODO: implement this
				character_class|=1<<9;
			else
			{
				//printf ("# [ char %c ]\n",str[i]);
				characters[str[i]]=1;
			} 
				
	}

	char endmetachar=str[end_offset+1]; //TODO: should be ok unless one creates "[a-z]", which is invalid regex!
	int finsize=0;
	//srand (time(NULL) );
	
	// fill character pool
	if(character_class & 1<<1) 
	{
		
	}
	else if(character_class & 1<<2) 
	{
		
	}
	else if(character_class & 1<<3) 
	{

	}
	else if(character_class & 1<<4) 
	{
		int j='0';
		for(j;j<='9';j++)
		{
			characters[j]=1;
		}
		
	}
	else if(character_class & 1<<5) 
	{
		
		
		
	}
	else if(character_class & 1<<6) 
	{
		int j='a';
		for(j;j<='z';j++)
		{
			characters[j]=1;
		}
		
		j='A';
		for(j;j<='Z';j++)
		{
			characters[j]=1;
		}
			
	}
	else if(character_class & 1<<7) 
	{
		
	}
	else if(character_class & 1<<8) 
	{
		/*
		int j=0;
		for(j;j<255;j++)
		{
			characters[j]=1;
		}
		
		characters['\n']=0;
		*/
	}
	else if(character_class & 1<<9) 
	{

	}
	
	// simple support - TODO to extend
	if(endmetachar=='*')
		finsize=rand()%10;
	else if(endmetachar =='+')
		finsize=1+rand()%9;
		

	// DEBUG f
	//fprintf(stdout,"\n###\n");
		
	
	//TODO to be corrected
	i=0;
	for(i;i<255;i++)
	{
		if(nnot==0 && characters[i])
		{
			if((i =='[') || (i==']'))
				continue;

			characterstmp[chari]=i;
			chari++;
			//fprintf(stdout,"%c",i);
		}
		else if(nnot && characters[i]==0)
		{
			if((i =='[') || (i==']'))
				continue;
			characterstmp[chari]=i;
			chari++;
			
		}
	}
	
	if(chari)
	{
	int tmp;
	i=0;

		for(i;i<finsize;i++)
		{
			tmp=rand()%chari;
			result_vector.push_back(characterstmp[tmp]);
		}
	
	}

	return result_vector;
}

wektor fill_specialchars(wektor str,int start_offset,int end_offset)
{
	
	int bslash='\\';
	int word='w';
	int digit='d';
	int dot='.';
	int newline='n';
	int creturn='r';
	int tab='t';
	
	wektor result_vector;

	int i=start_offset;
	
	for(i;i<=end_offset;i++)
	{
			if(str[i]==bslash && i+1<=end_offset && str[i+1]==word  && ( i == start_offset ||  str[i-1] != bslash ) )
			{
					result_vector.push_back(97+rand()%25);	
					i++;
					if(i+1<=end_offset && (str[i+1]=='+' || str[i+1]=='*') )
						i+=2;	
					
			}
			else if(str[i]==bslash && i+1<=end_offset && str[i+1]==digit && ( i == start_offset ||  str[i-1] != bslash ) )
			{
					result_vector.push_back(48+rand()%10);
					i++;
					
					if(i+1<=end_offset && (str[i+1]=='+' || str[i+1]=='*') )
						i=i+2;	
				
			}
			else if(str[i]==bslash && i+1<=end_offset && str[i+1]==newline && ( i == start_offset ||  str[i-1] != bslash ) )
			{
					result_vector.push_back('\n');
					i++;	
			}
			else if(str[i]==bslash && i+1<=end_offset && str[i+1]==creturn && ( i == start_offset ||  str[i-1] != bslash ) )
			{
					result_vector.push_back('\r');
					i++;	
			}
			else if(str[i]==bslash && i+1<=end_offset && str[i+1]==tab && ( i == start_offset ||  str[i-1] != bslash ) )
			{
					result_vector.push_back('\t');
					i++;	
			}
			else if(str[i]==dot && i+1<=end_offset && ( i == start_offset || str[i-1] != bslash ) )
			{
					result_vector.push_back(97+rand()%25);	
					if(i<=end_offset && (str[i+1]=='+' || str[i+1]=='*') )
						i++;	
			}
			else
				result_vector.push_back(str[i]);

			
	}
	
	return result_vector;
}

wektor escape_hex(wektor str,int start_offset,int end_offset)
{

	wektor result_vector;
	int bslash='\\';
	
	int i=start_offset;
	
	for(i;i<=end_offset;i++)
	{
		if(str[i]==bslash && ( i == start_offset ||  str[i-1] != bslash )){
			
		 	if(str[i+1]=='x' && i+2!=end_offset+1 && ishex(str[i+2]) && i+3!=end_offset+1 && ishex(str[i+3]))
				{
					result_vector.push_back(char2hex(str[i+2],str[i+3]));
					i+=3;
				}

		}
		else
			result_vector.push_back(str[i]);
			
				
	}
	
	return result_vector;
	
}


wektor revregexn(wektor str)
{

	//defines
	char lnaw='(';
	char rnaw=')';
	char lbrak='[';
	char rbrak=']';
	char bslash='\\';
	bool isinbracketi=false;
	bool isinbracketj=false;
	bool isescapedi=false;
	bool isescapedj=false;

	std::vector<char> result_vector=str;
	std::vector<char> tmp;

	repeat_remove:
	tmp.clear();
	isinbracketi=false;
	isescapedi = false;

	//cout<<"start1: \n";
	//print_vector(result_vector,0,result_vector.size());

	for(int i=0;i<result_vector.size();i++) // remove parenthises
	{
		if(result_vector[i]==lbrak && i-1>=0 && result_vector[i-1]!=bslash )
		isinbracketi=true;
		if(result_vector[i]==rbrak && result_vector[i-1]!=bslash )
		isinbracketi=false;

		if(result_vector[i]==bslash)
			isescapedi = !isescapedi;
		else
			isescapedi = false;
		

		if( result_vector[i]==lnaw && !isinbracketi &&  (i==0 || result_vector[i-1]!=bslash ) && !isescapedi )
		{

			isinbracketj=false;
			isescapedj = isescapedi;

			for(int j=i;j<result_vector.size();)
			{


				if(result_vector[j]==lbrak && j-1>=0 && result_vector[j-1]!=bslash)
					isinbracketj=true;
				if(result_vector[j]==rbrak && result_vector[j-1]!=bslash)
					isinbracketj=false;

				if(result_vector[j]==bslash)
					isescapedj = !isescapedj;
				else
					isescapedj = false;


				if(result_vector[j]==rnaw && !isinbracketi && !isinbracketj && !isescapedj ){
					
					tmp=mergevector(tmp,cutvector(result_vector,0,i-1));
					tmp=mergevector(tmp,cutvector(result_vector,i+1,j-1));
					tmp=mergevector(tmp,cutvector(result_vector,j+1,result_vector.size()-1));
					result_vector=tmp;
					goto repeat_remove;
					}

				j++;

				/*
				if(j==result_vector.size())
				{

				if(configuration->getConfigValue(OPT_DEBUG))
				revregx_error(result_vector);

				}
				*/
				
			}

		}
		else if(result_vector[i]==rnaw && i>0 && result_vector[i-1]!=bslash && !isinbracketi)
		{	
			/*
			if(configuration->getConfigValue(OPT_DEBUG))
			revregx_error(result_vector);
			*/
		}


	}


	repeat_remove2:
	tmp.clear();
	isescapedi = false;
	//cout<<"start2: \n";
	//print_vector(result_vector,0,result_vector.size());
	wektor tmpwekt;
	for(int i=0;i<result_vector.size();i++) // remove brackets
	{

		if(result_vector[i]==bslash)
			isescapedi = !isescapedi;
		else
			isescapedi = false;

		if(result_vector[i]==lbrak && ( (i == 0 ) || result_vector[i-1]!=bslash) && !isescapedi) 
		{

		isescapedj = isescapedi;

			for(int j=i;j<result_vector.size();)
			{

				if(result_vector[j]==bslash)
					isescapedj = !isescapedj;
				else
					isescapedj = false;

				if(result_vector[j]==rbrak && !isescapedj){
					//cout<<i<<" "<<j<<endl;
					tmpwekt=revregex_process_bracket(result_vector,i,j);
					tmp=mergevector(tmp,cutvector(result_vector,0,i-1));
					tmp=mergevector(tmp,tmpwekt);
					tmp=mergevector(tmp,cutvector(result_vector,j+2,result_vector.size()-1));
					result_vector=tmp;
					goto repeat_remove2;
					}

				j++;

				/*
				if(j==result_vector.size())
				{
				revregx_error(result_vector);
				}
				*/
				
			}
		}
	}	

	
	return result_vector;
}




std::vector<char> process_signature(std::string str)
{
	
	std::vector<char> result_vector;

	   try {

	result_vector=revregexn(str2vector(str));
    result_vector=fill_specialchars(result_vector,0,result_vector.size()-1);
    result_vector=escape_hex(result_vector,0,result_vector.size()-1);
    		} 
       catch(...){
       	cout<<"Fatal error occured while processing signatures. Plz. open a github ticker for following regex:"<<endl;
       	cout<<str<<endl;
       	exit(1);
       }

	return result_vector;
	
}