package edu.vt.marian.server;

import java.io.*;
import java.net.*;
import java.lang.*;
import java.util.*;

import edu.vt.marian.common.*;

/**
	class name:  match
	class description: this class parses the query strings and provides information
						for query.
	uses the services of class(es): 
	designer(s): Jianxin Zhao (jxzhao@csgrad.cs.vt.edu)
	implementator(s): Jian Zeng (jizeng@vt.edu)
	finished time:
	known bugs: 
	JDK version: 1.1.7A
	side effects:
*/

public class match
{	

	/** expected parser number
	*/
	private final static int num_parsers = 17;

	/** the string with exact searching conditions?
	*/
	private Vector exact_strings;

	/** the string with inexact searching conditions?
	*/
	private Vector inexact_strings;

	/** define all kind of searching flags
	*/
	private final static int exact_match_flag = 0x40000000;

	// used in VTLS collection
	private final static int cover_title_flag = 0x1;
	private final static int cover_subject_flag = 0x2;
	private final static int cover_notes_flag = 0x4;
	private final static int cover_personal_author_flag = 0x8;
	private final static int cover_corporate_author_flag = 0x10;
	private final static int cover_conference_author_flag = 0x20;
	private final static int cover_subject_entry_flag = 0x40;
	private final static int cover_date_flag = 0x0 ; //may be changed later.

	// used in NLM collection
	private final static int cover_address = 0x80;
	private final static int cover_contact_person = 0x100;
	private final static int cover_cross_reference = 0x200;
	private final static int cover_description = 0x400;
	private final static int cover_keywords = 0x800;
	private final static int cover_mesh_headings = 0x1000;
	private final static int cover_name = 0x2000;
	private final static int cover_notes = 0x4000;
	private final static int cover_sponsoring_agency = 0x8000;
	private final static int cover_type = 0x10000;


	/** define returned constants
	*/
	public final static int SUCCESS = 0;
	
	/** data from coverage string pair is null
	*/
	public final static int NULL_DATA = 1;

	
	/** define return value for method get_inexact_parser_flag and
	get_exact_parser_flag
	*/
	public final static int INVALID_PARSER_FLAG = -1;
	
	/** define debug object
	*/
	private Debug debug;

	/**
		method description: this constructor will create a match object with empty
			exact and inexact string.
		uses the services of class(es): Debug
		input parameter(s): 
			debug -- used for debugging.
		output parameter(s): none
		return value: none
		synchronization consideration: none
	*/      
	public match(Debug debug)
	{
		int i;
		String temp = null;

		this.debug = debug;
		exact_strings = new Vector();
		inexact_strings = new Vector();

		for (i = 0; i < num_parsers; i++)
		{
			// create an empty string, and add it to exact_strings
			temp = new String("");
			exact_strings.addElement(temp);

			// create an empty string, and add it to inexact_strings
			temp = new String("");
			inexact_strings.addElement(temp);
		}

		return;	
	}


	/**
		method description: this method will return the number of parsers
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the number of parsers
		synchronization consideration: none
	*/      
	public int get_number_parsers()
	{

		return num_parsers;

	}


	/**
		method description: this method constructs exact or inexact string from the converage string pair.
		uses the services of class(es): 
		input parameter(s): 
			csp --- this coverage string pair
		output parameter(s): none
		return value: 
			SUCCESS -- execute correctly
			NULL_DATA -- data from coverage string pair is null
		synchronization consideration: this is a synchronized method because writing to the 	
			  exact and inexact string
	*/      
	public synchronized int add(coverage_string_pair csp)
	{
		String data = null;
		int coverage;
		int i;
		int exponent = 1; //this varaible is used to calculte 2^i.
		String s = null;  //to store the ith element of vector

		// get data from csp
		data = csp.get_data();

		if ((data == null) || (data.equals("")))
		{
			debug.dumpTrace("In class match, method add, data from the " +
				             "coverage string pair is null or empty.");
			return NULL_DATA;
		}

		coverage = csp.get_coverage();

		if ( (coverage & exact_match_flag) != 0)
		{

			//deal with exact strings
			for (i = 0; i < num_parsers; i++)
			{
				if ( (coverage & exponent) != 0)
				{
					// coverage & 2^i = 1
					s = (String) exact_strings.elementAt(i);
					s = s + data + " ";
					exact_strings.setElementAt(s, i);
				}
				exponent = exponent << 1;
			}
		}
		else
		{
			// for inexact_strings

			//deal with inexact strings
			for (i = 0; i < num_parsers; i++)
			{
				if ( (coverage & exponent) != 0)
				{
					s = (String) inexact_strings.elementAt(i);
					s = s + data + " ";
					inexact_strings.setElementAt(s, i);
				}
				exponent = exponent << 1;
			}
		}

		return SUCCESS;
	}


	/**
		method description: this method will return the an element (string) from the inexact string
		uses the services of class(es): 
		input parameter(s): 
			parser_index --- the index of the parser
		output parameter(s): none
		return value: 
			the element of the inexact string which locates at parser_index.
		synchronization consideration: none
	*/      
	public String get_inexact_string(int parser_index)
	{

		if ((parser_index >= 0) && (parser_index < num_parsers))
		{
			String s = (String) inexact_strings.elementAt(parser_index);
			return s;
		}

		// parser_index is out of range.
		debug.dumpTrace("In class match, method get_inexact_string, " +
			             "parser index out of range.");
		return null;

	}



	/**
		method description: this method will return the an element (string) from the exact string
		uses the services of class(es): 
		input parameter(s): 
			parser_index --- the index of the parser
		output parameter(s): none
		return value: 
			the element of the exact string which locates at parser_index.
		synchronization consideration: none
	*/      
	public String get_exact_string(int parser_index)
	{

		if ((parser_index >= 0) && (parser_index < num_parsers))
		{
			String s = (String) exact_strings.elementAt(parser_index);
			return s;
		}

		// parser_index out of range
		debug.dumpTrace("In class match, method get_exact_string, " +
				             "parser index out of range.");
		return null;
	}


	/**
		method description: this method will return the inexact parser flag.
		uses the services of class(es): 
		input parameter(s): 
			parser_index --- the index of the parser
		output parameter(s): none
		return value: 
			correct- the inexact parser flag according to the parser index
			INVALID_PARSER_FLAG - parser_index is invalid
		synchronization consideration: none
	*/      
	public int get_inexact_parser_flag(int parser_index)
	{

		if ((parser_index >= 0) && (parser_index < num_parsers))
		{
			int i;
			int exponent = 1;

			for (i = 0; i < parser_index; i++)
			{
				exponent = exponent << 1;
			}

			return exponent;
		}

		// parser_index out of range
		debug.dumpTrace("In class match, method get_inexact_parser_flag, " +
				             "parser index out of range.");
			return INVALID_PARSER_FLAG;
	}


	/**
		method description: this method will return the exact parser flag.
		uses the services of class(es): 
		input parameter(s): 
			parser_index --- the index of the parser
		output parameter(s): none
		return value: 
			correct -- the exact parser flag according to the parser index
			INVALID_PARSER_FLAG -- parser_index is invalid
		synchronization consideration: none
	*/      
	public int get_exact_parser_flag(int parser_index)
	{

		if ((parser_index >= 0) && (parser_index < num_parsers))
		{
			int i;
			int exponent = 1;

			for (i = 0; i < parser_index; i++)
			{
				exponent = exponent << 1;
			}

			return (exponent | exact_match_flag);
		}

		// parser_index out of range		
		debug.dumpTrace("In class match, method get_exact_parser_flag, " +
			             "parser index out of range.");
		return INVALID_PARSER_FLAG;

	}


	/**
		method description: this method will return the value of the cover title flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover title flag
		synchronization consideration: none
	*/      
	public int get_cover_title_flag()
	{

		return cover_title_flag;

	}


	/**
		method description: this method will return the value of the cover subject flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover subject flag
		synchronization consideration: none
	*/      
	public int get_cover_subject_flag()
	{

		return cover_subject_flag;

	}


	/**
		method description: this method will return the value of the cover notes flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover notes flag
		synchronization consideration: none
	*/      
	public int get_cover_notes_flag()
	{

		return cover_notes_flag;

	}


	/**
		method description: this method will return the value of the cover personal author flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover personal author flag
		synchronization consideration: none
	*/      
	public int get_cover_personal_author_flag()
	{

		return cover_personal_author_flag;

	}


	/**
		method description: this method will return the value of the cover corporate author flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover corporate author flag
		synchronization consideration: none
	*/      
	public int get_cover_corporate_author_flag()
	{

		return cover_corporate_author_flag;

	}


	/**
		method description: this method will return the value of the cover conference author flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover conference author flag
		synchronization consideration: none
	*/      
	public int get_cover_conference_author_flag()
	{

		return cover_conference_author_flag;

	}


	/**
		method description: this method will return the value of the cover subject entry flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the cover subject entry flag
		synchronization consideration: none
	*/      
	public int get_cover_subject_entry_flag()
	{

		return cover_subject_entry_flag;

	}


	/**
		method description: this method will return the value of the date flag
		uses the services of class(es): 
		input parameter(s): none
		output parameter(s): none
		return value: 
			the value of the date flag
		synchronization consideration: none
	*/      
	public int get_date_flag()
	{

		return cover_date_flag;

	}

}