//NAME:Caleb Bird
//ID: 1289680
//??References??

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.*;
import java.util.*;

public class TabRndListGen {
    public static void main(String[] args) {
	try{
	    if (args.length != 3){
		System.out.println("Usage: TabRndListGen <inputFilename> <outputCount> <outputFilename>");
	    }
	    else{
		String inputFilename = args[0];
		int outputCount  = Integer.parseInt(args[1]);
		String outputFilename = args[2];
		
		BufferedReader buf = new BufferedReader(new FileReader(inputFilename));
		FileWriter fw = new FileWriter(outputFilename);
		//FileWriter fw = new FileWriter("hathiRndIDList.txt");
		//BufferedReader buf = new BufferedReader(new FileReader("hathiDocIDList.txt"));

		ArrayList<String> list = new ArrayList<String>();
	
		String line = null;
		String[] item;

		//Add items to Array
		while ((line = buf.readLine()) != null) {
			//Split line by tab
			item = line.split("\t", -1);
			//Add first element (ID)
		    list.add(item[0]);	    
		}
		//randomize list
		Collections.shuffle(list);
		
		int countMatchingCrit = 0;
		int j = 0;
	    ArrayList<String> subList = new ArrayList<String>();
		//Download meta record, check if numpages >=10 
		while(countMatchingCrit < outputCount){
			System.out.println("Processing item: " + j);
			String idCurr = list.get(j);
			//run download script
			String cmd = "./download_metadata_temp.sh " + idCurr;
			Process p = Runtime.getRuntime().exec(cmd);
			/*BufferedReader br = new BufferedReader(new InputStreamReader(p.getInputStream()));
                while(br.ready())
                {
                        System.out.println(br.readLine());
                }*/
			p.waitFor();
			int exitStatus = p.exitValue();
			if(exitStatus == 0){
				//Extract numpages 
				int numpages = getNumPages(idCurr);
				if(numpages >= 10){
					System.out.println("Successful items: " + countMatchingCrit);
					countMatchingCrit++;
					subList.add(idCurr);						
				}
			}
			else{
				System.err.println("failed to run:" + cmd);
				System.exit(exitStatus);
			}
			j++;
			if(j >= list.size()){break;}
		}
		

		//Write these to new file
		for(int i =0; i < subList.size(); i++){
		    fw.write(subList.get(i) + '\n');
		}
			
		buf.close();
		fw.close();
	    }
	}catch(Exception e){
	    e.printStackTrace();
	}
    }
    private static int getNumPages(String id){
    	String numpages = null;
		try{
				//Variables
				String inputFilename = "metadata_temp.xml";
				FileReader fileReader = new FileReader(inputFilename);
				BufferedReader buf = new BufferedReader(fileReader);
				String line = null;
				String[] item;

				//Splits into each record
				while ((line = buf.readLine()) != null) {					
					/*
					if(line.contains("<id>")){
						//Isoclate and store the id from the line
						idLine = line.substring(line.indexOf(">")+1, line.indexOf("</"));
						id  = idLine.substring(idLine.lastIndexOf("meta/")+5);
						
					}
					*/	
					if(line.contains("<htd:numpages>")){
						//Iscolate and store the page number
						numpages = line.substring(line.indexOf(">")+1, line.lastIndexOf("<"));
										
					}											
				}
				buf.close();
				//Check if there are more than 10 pages
	
		}catch(Exception e){
			e.printStackTrace();
		}
		return Integer.parseInt(numpages);
    }
}
// Returns 42474

//REFERNECES
//https://stackoverflow.com/questions/12892665/how-to-capture-the-exit-status-of-a-shell-command-in-java
//https://www.javatpoint.com/java-filewriter-class
//https://docs.oracle.com/javase/8/docs/api/index.html?java/io/FileWriter.html
//https://www.geeksforgeeks.org/randomly-select-items-from-a-list-in-java/
//https://codereview.stackexchange.com/questions/146551/picking-10-distinct-words-randomly-from-list-of-unique-words
//http://www.linuxforums.org/forum/programming-scripting/65117-c-c-system-function-analog-java.html

//USE RUN-LIST.txt (modify file it reads using $1 (terminal entry variable (filename))