// Pogram to read the last occupancy level from the EVALUES file adn create the OCCEXC file, it also prints the energy and level.
// The files EVALUES and SUMMARY must be present in the directory
//
// example usage: java create_occexc hole_state particle_state hole_spin particle_spin
//
// hole_state must be zero or negative
// particle state must be zero or positive
// spin is either 1 or 2
//
// Luis Basurto, Sept. 2012
//
import java.io.*;
import java.util.Scanner;

public class create_occexc{
	static double eqv=27.2116;
	static String List1[]=new String[11];
 	static FileInputStream fstream;
        static DataInputStream in;
        static Scanner scan;
public static void main(String args[]){
	double[] energy,occ;
	int level;
	int[]rep,deg,spin;
	String filename;
	int i=0;
	int hole_state=0,particle_state=0;
	int hole_spin=0,particle_spin=0;
	int spins[] = {0,0};
	double last_energy=0.0;
	try{
	if(args.length != 4){
		System.out.println("Need to input hole_state particle_state hole_spin particle_spin. Example: java create_occexc -2 3 1 2");
		return;
	}
	File file1= new File("EVALUES");
	if(!file1.exists()){
		System.out.println("Error: File EVALUES not found");
		return;
	}
	File file2= new File("SUMMARY");
	if(!file2.exists()){
		System.out.println("Error: File SUMMARY not found");
		return;
	}
	filename="EVALUES";
	try{
		hole_state = Integer.parseInt(args[0]);
	}catch(NumberFormatException e){
		System.out.println("Error in first argument: "+e.getMessage()+" must be integer");
		return;
	}
	try{
		particle_state = Integer.parseInt(args[1]);
	}catch(NumberFormatException e){
		System.out.println("Error in second argument: "+e.getMessage()+" must be integer");
		return;
	}
	try{
		hole_spin = Integer.parseInt(args[2]);
	}catch(NumberFormatException e){
		System.out.println("Error in third argument: "+e.getMessage()+" must be integer");
		return;
	}
	try{
		particle_spin = Integer.parseInt(args[3]);
	}catch(NumberFormatException e){
		System.out.println("Error in fourth argument: "+e.getMessage()+" must be integer");
		return;
	}
        last_energy = get_energy();
	double fermi = get_fermi(filename);
	int states = count_states(filename);
	System.out.println("States:"+states);
	rep = new int[states];
	deg = new int[states];
	spin = new int[states];
	energy = new double[states];
	occ = new double[states];
	fstream = new FileInputStream(filename);
	in = new DataInputStream(fstream);
	scan = new Scanner(in);
	String temp= new String();
	temp=scan.next();
	while(temp.compareTo("OCCUPANCIES:")!=0)
		temp=scan.next();
	while(scan.hasNext()){
		read_line();
//   1  REP:  1  DEG:  1  SPIN:  1  ENERGY:   -345.602      OCC:    1.00000
		try{
			rep[i]=Integer.parseInt(List1[2]);
		}catch(NumberFormatException e){
			System.out.println("Error: "+e.getMessage()+" Assuming zero");
			rep[i]=0;
		}
		try{
			deg[i]=Integer.parseInt(List1[4]);
		}catch(NumberFormatException e){
			System.out.println("Error: "+e.getMessage()+" Assuming zero");
			deg[i]=0;
		}
		try{
			spin[i]=Integer.parseInt(List1[6]);
		}catch(NumberFormatException e){
			System.out.println("Error: "+e.getMessage()+" Assuming zero");
			spin[i]=0;
		}
		try{
			energy[i]=Double.parseDouble(List1[8]);
		}catch(NumberFormatException e){
			System.out.println("Error: "+e.getMessage()+" Assuming zero");
			energy[i]=0.0;
		}
		try{
			occ[i]=Double.parseDouble(List1[10]);
		}catch(NumberFormatException e){
			System.out.println("Error: "+e.getMessage()+" Assuming zero");
			occ[i]=0.0;
		}
		i++;
	}
	i=0;
	fstream.close();
	in.close();
	while((energy[i]-fermi)<=0.00001){
		if(spin[i]==1)
			spins[0]++;
		else
			spins[1]++;
		i++;
	}
	level=i;
	double gap=energy[level]-energy[level-1];
	System.out.println("Gap:"+gap+" au");
	System.out.println("Gap:"+(gap*eqv)+" eV");
	System.out.println("State:"+(level-1)+" eHOMO:"+energy[level-1]+" OCC:"+occ[level-1]);
	System.out.println("State:"+level+" eLUMO:"+energy[level]+" OCC:"+occ[level]);

	if(occ[level]>0&&occ[level]<1.0)
		System.out.println("Warning: Metallic system!");
	}catch(IOException e){
	System.err.println("Error: "+e.getMessage());
	}
// Create File OCCEXC
// Introductory stuff
	try{
	FileWriter Outfile = new FileWriter("OCCEXC");
	PrintWriter out = new PrintWriter(Outfile);
	out.println("1");
	out.println(""+last_energy);
        if(hole_spin==1)
            out.println(""+hole_spin+" "+(spins[0]+hole_state)+"             Hole Spin, hole state");
        else
            out.println(""+hole_spin+" "+(spins[1]+hole_state)+"             Hole Spin, hole state");
        if(particle_spin==1)
            out.println(""+particle_spin+" "+(spins[0]+1+particle_state)+"             Particle Spin, particle state");
        else
            out.println(""+particle_spin+" "+(spins[1]+1+particle_state)+"             Particle Spin, particle state");
// Print states in the "before" moving the electron
	out.println(""+spins[0]);
	for(i=0;i<spins[0];i++){
		out.print("1 ");
		if((i+1) % 20 == 0)
			out.print("\n");
	}
	out.print("\n");
	if(spins[1]!=0){
		out.println(""+spins[1]);
		for(i=0;i<spins[1];i++){
			out.print("1 ");
			if( (i+1) % 20 == 0)
				out.print("\n");
		}
		out.print("\n");
	}
// Print states after electron has moved
	// Determine if system is spin polarized
	if(spins[1]!=0){
		if(hole_spin==1){
			if(particle_spin==1){
			// Electron jumps from spin 1 to spin 1
				// Print spin 1 info
				out.println(""+(spins[0]+1+particle_state));
				for(i=1;i<=spins[0];i++){
					if(i==spins[0]+hole_state)
						out.print("0 ");
					else
						out.print("1 ");
					if( i % 20 == 0)
						out.print("\n");
				}
				for(i=0;i<particle_state+1;i++){
					if(i==particle_state)
						out.print("1 ");
					else
						out.print("0 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
				// Print spin 2 info
				if(!(spins[0] % 20 == 0))
					out.print("\n");
				out.println(""+spins[1]);
				for(i=0;i<spins[1];i++){
					out.print("1 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
			}
			else{
			// Electron jumps from spin 1 to spin 2
				// Print spin 1 info
				out.println(""+spins[0]);
				for(i=1;i<=spins[0];i++){
					if(i==spins[0]+hole_state)
						out.print("0 ");
					else
						out.print("1 ");
					if( i % 20 == 0)
						out.print("\n");
				}
				// Print spin 2 info
				if(!(spins[0] % 20 == 0))
					out.print("\n");
				out.println(""+(spins[1]+1+particle_state));
				for(i=0;i<spins[1];i++){
					out.print("1 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
				for(i=0;i<particle_state+1;i++){
					if(i==particle_state)
						out.print("1 ");
					else
						out.print("0 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
			}
		}
		else{
			if(particle_spin==1){
			// Electron jumps from spin 2 to spin 1
				// Print spin 1 info
				out.println(""+(spins[0]+1+particle_state));
				for(i=0;i<spins[0];i++){
					out.print("1 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
				for(i=0;i<particle_state+1;i++){
					if(i==particle_state)
						out.print("1 ");
					else
						out.print("0 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
				// Print spin 2 info
				if(!(spins[0] % 20 == 0))
					out.print("\n");
				out.println(""+spins[1]);
				for(i=1;i<=spins[1];i++){
					if(i==spins[1]+hole_state)
						out.print("0 ");
					else
						out.print("1 ");
					if( i % 20 == 0)
						out.print("\n");
				}
			}
			else{
			// Electron jumps from spin 2 to spin 2
				// Print spin 1 info
				out.println(""+spins[0]);
				for(i=0;i<spins[0];i++){
					out.print("1 ");
					if((i+1) % 20 == 0)
						out.print("\n");
				}
				// Print spin 2 info
				if(!(spins[0] % 20 == 0))
					out.print("\n");
				out.println(""+(spins[1]+1+particle_state));
				for(i=1;i<=spins[1];i++){
					if(i==spins[1]+hole_state)
						out.print("0 ");
					else
						out.print("1 ");
					if( i % 20 == 0)
						out.print("\n");
				}
				for(i=0;i<particle_state+1;i++){
					if(i==particle_state)
						out.print("1 ");
					else
						out.print("0 ");
					if( (i+1) % 20 == 0)
						out.print("\n");
				}
			}	
		}
	}
	// Code for spin unpolarized system
	else{
		out.println(""+(spins[0]+1+particle_state));
		for(i=1;i<=spins[0];i++){
			if(i==spins[0]+hole_state)
				out.print("0 ");
			else
				out.print("1 ");
			if( i % 20 == 0)
				out.print("\n");
		}
		for(i=0;i<particle_state+1;i++){
			if(i==particle_state)
				out.print("1 ");
			else
				out.print("0 ");
			if( (i+1) % 20 == 0)
				out.print("\n");
		}
	}
// Done printing, close output to file
	Outfile.close();
	out.close();
	}catch(IOException e){
	System.err.println("Error: "+e.getMessage());
	}
} // End on main function

// Function to scan a line of elements	
	static void read_line(){
		for(int i=0;i<11;i++){
			List1[i]=scan.next();
		}
	}
	static int count_states(String filename){
	int i=0;
	try{
	fstream = new FileInputStream(filename);
	in = new DataInputStream(fstream);
	scan = new Scanner(in);
	String temp= new String();
	temp=scan.next();
	while(temp.compareTo("OCCUPANCIES:")!=0)
		temp=scan.next();
	while(scan.hasNextLine()){
		temp=scan.nextLine();
		i++;
	}
	in.close();
	fstream.close();
	}catch(IOException e){
	System.err.println("Error:"+e.getMessage());
	}
	return i-1;
	}
// Function to get the Fermi level from the EVALUES file
	static double get_fermi(String filename){
	Double fermi_level=0.0;
	try{
	fstream = new FileInputStream(filename);
	in = new DataInputStream(fstream);
	scan = new Scanner(in);

	String temp= new String();
	temp=scan.next();
	while(temp.compareTo("FERMI")!=0)
		temp=scan.next();
	while(temp.compareTo("LEVEL:")!=0)
		temp=scan.next();
        temp=scan.next();
	System.out.println("Fermi Level:"+temp+" au");
	fermi_level=Double.parseDouble(temp);
	System.out.println("Fermi Level:"+(fermi_level*eqv)+" eV");
	in.close();
	fstream.close();
	}catch(IOException e){
	 System.err.println("Error:"+e.getMessage());
	}
	return fermi_level;
	}
// Function to read the final energy from the SUMMARY file
	static double get_energy(){
	double answer = 0.0;
	String list[] = new String[5];
	try{
	fstream = new FileInputStream("SUMMARY");
	in = new DataInputStream(fstream);
	scan = new Scanner(in);
	while(scan.hasNext())
		for(int i=0;i<5;i++)
			list[i]=scan.next();
	in.close();
	fstream.close();
	System.out.println("Final energy:"+list[2]);
	answer=Double.parseDouble(list[2]);

	} catch(IOException e){
	 System.err.println("Error:"+e.getMessage());
	}
	return answer;
	}
}