package org.hathitrust.extractedfeatures;

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashMap;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * Servlet implementation class VolumeCheck
 */
@WebServlet("/VolumeCheck")
public class VolumeCheck extends HttpServlet {
	private static final long serialVersionUID = 1L;

	protected static int HASHMAP_INIT_SIZE = 13800000;
	protected static String DATA_DIR="D:/cygwin64/home/davidb/research/code-managed/hathitrust/wcsa/extracted-features-solr/trunk/solr-ingest";
	protected static HashMap<String,Boolean> id_check_ = null;
	
    
    public VolumeCheck() {
    	if (id_check_ == null) {
    		id_check_ = new HashMap<String,Boolean>(HASHMAP_INIT_SIZE);
    		storeIDs(DATA_DIR + "/full-listing.txt");
    	}
    }

    protected void storeIDs(String filename)
    {    	
    	try {
    		FileReader fr = new FileReader(filename);
    		BufferedReader br = new BufferedReader(fr);
    		
    		long line_num = 1;
    	    String line;
    	    System.err.println("Loading in volume IDS: " + filename);
    	    
    	    String opt_file_ext = ".json.bz2";
	    	
    	    while ((line = br.readLine()) != null) {
    	    	
    	    	String file_id = line.substring(line.lastIndexOf("/")+1);
    	    	String id = null;
    	    	if (file_id.endsWith(opt_file_ext)) {
    	    		id = file_id.substring(0,file_id.lastIndexOf(opt_file_ext));
    	    	}
    	    	else {
    	    		id = file_id;
    	    	}
    	    	
    	    	id = id.replaceAll("\\+", ":").replaceAll("=", "/");
    	    			 
    	    	id_check_.put(id, true);
    	    	
    	    	if ((line_num % 100000) == 0) {
    	    		System.err.println("sample id = " + id);
    	    		System.err.println("Passed line: " + line_num);
    	    	}
    	    	line_num++;
    	    	
    	    }
    	    
    	    br.close();
    	}
    	catch (Exception e) {
    		e.printStackTrace();
    	}
    	
    }
	/**
	 * @see Servlet#init(ServletConfig)
	 */
	public void init(ServletConfig config) throws ServletException {
		// currently everything we need to happen at start up can be done in the constructor
	}

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		PrintWriter pw = response.getWriter();
		
		String cgi_ids = request.getParameter("ids");
		String cgi_id = request.getParameter("id");
		
		if (cgi_ids != null) {
			response.setContentType("application/json");
	
			String[] ids = cgi_ids.split(",");
		    int ids_len = ids.length;
		    
		    pw.append("{");
			
		    for (int i=0; i<ids_len; i++) {
		    	String id = ids[i];
		    	
		    	Boolean exists = id_check_.get(id);
		    	boolean status = (exists != null) ? exists : false;
		    	
		    	if (i>0) {
		    		pw.append(",");
		    	}
		    	pw.append("\"" + id + "\":" + status );
		    }
		    pw.append("}");
			
		}
		else if (cgi_id != null) {
			response.setContentType("application/json");
			
			String id = cgi_id;
			Boolean exists = id_check_.get(id);
			boolean status = (exists != null) ? exists : false;
			pw.append("{'" + id + "':" + status + "}");
		}
		else {

			pw.append("General Info: Number of HTRC Volumes in check-list = " + id_check_.size());
						
		}
		//pw.close();
		
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}

}