package com.metaweb.gridworks.model.recon;

import java.io.InputStream;
import java.io.Serializable;
import java.io.StringWriter;
import java.net.URL;
import java.net.URLConnection;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import java.util.Properties;
import java.util.Set;

import org.apache.commons.lang.StringUtils;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import org.json.JSONWriter;

import com.metaweb.gridworks.model.Cell;
import com.metaweb.gridworks.model.Project;
import com.metaweb.gridworks.model.Recon;
import com.metaweb.gridworks.model.ReconCandidate;
import com.metaweb.gridworks.model.Row;
import com.metaweb.gridworks.model.Recon.Judgment;
import com.metaweb.gridworks.protograph.FreebaseProperty;
import com.metaweb.gridworks.util.ParsingUtilities;

public class HeuristicReconConfig extends ReconConfig {
	private static final long serialVersionUID = 423145327938373362L;
	
	static public class ColumnDetail implements Serializable {
		private static final long serialVersionUID = -8996704822460155543L;
		
		final public String columnName;
		final public FreebaseProperty property;
		
		public ColumnDetail(String columnName, FreebaseProperty property) {
			this.columnName = columnName;
			this.property = property;
		}
	}
	
    static public ReconConfig reconstruct(JSONObject obj) throws Exception {
    	List<ColumnDetail> columnDetails = null;
    	if (obj.has("columnDetails")) {
	    	JSONArray columnDetailsA = obj.getJSONArray("columnDetails");
	    	int l = columnDetailsA.length();
	    	
	    	columnDetails = new ArrayList<ColumnDetail>(l);
	    	for (int i = 0; i < l; i++) {
	    		JSONObject o = columnDetailsA.getJSONObject(i);
	    		JSONObject p = o.getJSONObject("property");
	    		
	    		columnDetails.add(new ColumnDetail(
	    			o.getString("column"),
	    			new FreebaseProperty(
	    				p.getString("id"),
	    				p.getString("name")
	    			)
	    		));
	    	}
    	} else {
	    	columnDetails = new ArrayList<ColumnDetail>();
    	}
    	
		JSONObject t = obj.getJSONObject("type");
		
    	return new HeuristicReconConfig(
            obj.getString("service"),
            t.getString("id"),
            t.getString("name"),
            obj.getBoolean("autoMatch"),
            columnDetails
        );
    }
    
    static protected class HeuristicReconJob extends ReconJob {
    	String text;
    	
    	public int getKey() {
    		return text.hashCode();
    	}
    }
	
    final public String		service; // either "recon" or "relevance"
	final public String 	typeID;
    final public String 	typeName;
    final public boolean 	autoMatch;
    final public List<ColumnDetail> columnDetails;
    
    public HeuristicReconConfig(
    	String service,
		String typeID, 
		String typeName,
		boolean autoMatch,
		List<ColumnDetail> columnDetails
	) {
    	this.service = service;
        this.typeID = typeID;
        this.typeName = typeName;
        this.autoMatch = autoMatch;
        this.columnDetails = new ArrayList<ColumnDetail>();
    }

    public void write(JSONWriter writer, Properties options)
            throws JSONException {
        
        writer.object();
        writer.key("mode"); writer.value("heuristic"); 
        writer.key("service"); writer.value(service); 
        writer.key("type"); 
        	writer.object();
        	writer.key("id"); writer.value(typeID);
        	writer.key("name"); writer.value(typeName);
        	writer.endObject();
        writer.key("autoMatch"); writer.value(autoMatch);
        writer.key("columnDetails");
        	writer.array();
        	for (ColumnDetail c : columnDetails) {
        		writer.object();
        		writer.key("column"); writer.value(c.columnName);
        		writer.key("property"); c.property.write(writer, options);
        		writer.endObject();
        	}
        	writer.endArray();
        writer.endObject();
    }

	@Override
	public int getBatchSize() {
		return 10;
	}

	@Override
	public String getBriefDescription(Project project, String columnName) {
        return "Reconcile cells in column " + columnName + " to type " + typeID;
	}

	@Override
	public ReconJob createJob(Project project, int rowIndex, Row row,
			String columnName, Cell cell) {
		
		HeuristicReconJob job = new HeuristicReconJob();
		
		job.text = cell.value.toString();
		
		return job;
	}
	
	@Override
	public List<Recon> batchRecon(List<ReconJob> jobs) {
		if ("relevance".equals(service)) {
			return batchReconUsingRelevance(jobs);
		} else {
			return batchReconUsingReconService(jobs);
		}
	}
	
	protected List<Recon> batchReconUsingRelevance(List<ReconJob> jobs) {
		List<Recon> recons = new ArrayList<Recon>(jobs.size());
		
		try {
			StringWriter stringWriter = new StringWriter();
			JSONWriter jsonWriter = new JSONWriter(stringWriter);
			
			jsonWriter.object();
			for (int i = 0; i < jobs.size(); i++) {
				HeuristicReconJob job = (HeuristicReconJob) jobs.get(i);
				
				jsonWriter.key("q" + i + ":search");
				
				jsonWriter.object();
					jsonWriter.key("query"); jsonWriter.value(job.text);
					jsonWriter.key("limit"); jsonWriter.value(3);
					jsonWriter.key("type"); jsonWriter.value(typeID);
					jsonWriter.key("type_strict"); jsonWriter.value("should");
					jsonWriter.key("type_exclude"); jsonWriter.value("/common/image");
					jsonWriter.key("domain_exclude"); jsonWriter.value("/freebase");
				jsonWriter.endObject();
			}
			jsonWriter.endObject();
			
			StringBuffer sb = new StringBuffer();
			sb.append("http://api.freebase.com/api/service/search?indent=1&queries=");
			sb.append(ParsingUtilities.encode(stringWriter.toString()));
			
			URL url = new URL(sb.toString());
			URLConnection connection = url.openConnection();
			connection.setConnectTimeout(5000);
			connection.connect();
			
			InputStream is = connection.getInputStream();
			try {
				String s = ParsingUtilities.inputStreamToString(is);
				JSONObject o = ParsingUtilities.evaluateJsonStringToObject(s);
				
				for (int i = 0; i < jobs.size(); i++) {
					HeuristicReconJob job = (HeuristicReconJob) jobs.get(i);
					
					String text = job.text;
					String key = "q" + i + ":search";
					if (!o.has(key)) {
						continue;
					}
					
					Recon recon = null;
					
					JSONObject o2 = o.getJSONObject(key);
					if (o2.has("result")) {
						JSONArray results = o2.getJSONArray("result");
						
						recon = createReconFromRelevanceResults(text, results);
					} else {
						recon = new Recon();
					}
					
					recons.add(recon);
				}
			} finally {
				is.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		System.gc();
		
		return recons;
	}

	protected Recon createReconFromRelevanceResults(String text, JSONArray results) {
		Recon recon = new Recon();
		try {
			int length = results.length();
			int count = 0;
			for (int i = 0; i < length && count < 3; i++) {
				JSONObject result = results.getJSONObject(i);
				if (!result.has("name")) {
					continue;
				}
				
				JSONArray types = result.getJSONArray("type");
				String[] typeIDs = new String[types.length()];
				for (int j = 0; j < typeIDs.length; j++) {
					typeIDs[j] = types.getJSONObject(j).getString("id");
				}
				
				double score = result.getDouble("relevance:score");
				ReconCandidate candidate = new ReconCandidate(
					result.getString("id"),
					result.getString("guid"),
					result.getString("name"),
					typeIDs,
					score
				);
				
				// best match
				if (i == 0) {
					recon.setFeature(Recon.Feature_nameMatch, text.equalsIgnoreCase(candidate.topicName));
					recon.setFeature(Recon.Feature_nameLevenshtein, StringUtils.getLevenshteinDistance(text, candidate.topicName));
					recon.setFeature(Recon.Feature_nameWordDistance, wordDistance(text, candidate.topicName));
					
					recon.setFeature(Recon.Feature_typeMatch, false);
					for (String typeID : candidate.typeIDs) {
						if (typeID.equals(typeID)) {
							recon.setFeature(Recon.Feature_typeMatch, true);
	                        if (autoMatch && score >= 100) {
	                            recon.match = candidate;
	                            recon.judgment = Judgment.Matched;
	                        }
							break;
						}
					}
				}
				
				recon.addCandidate(candidate);
				count++;
			}
		} catch (JSONException e) {
			e.printStackTrace();
		}
		return recon;
	}
	
	protected List<Recon> batchReconUsingReconService(List<ReconJob> jobs) {
		List<Recon> recons = new ArrayList<Recon>(jobs.size());
		
		try {
			StringWriter stringWriter = new StringWriter();
			JSONWriter jsonWriter = new JSONWriter(stringWriter);
			
			jsonWriter.object();
			for (int i = 0; i < jobs.size(); i++) {
				HeuristicReconJob job = (HeuristicReconJob) jobs.get(i);
				
				jsonWriter.key("q" + i + ":search");
				
				jsonWriter.object();
					jsonWriter.key("query"); jsonWriter.value(job.text);
					jsonWriter.key("limit"); jsonWriter.value(3);
					jsonWriter.key("type"); jsonWriter.value(typeID);
					jsonWriter.key("type_strict"); jsonWriter.value("should");
					jsonWriter.key("type_exclude"); jsonWriter.value("/common/image");
					jsonWriter.key("domain_exclude"); jsonWriter.value("/freebase");
				jsonWriter.endObject();
			}
			jsonWriter.endObject();
			
			StringBuffer sb = new StringBuffer();
			sb.append("http://api.freebase.com/api/service/search?indent=1&queries=");
			sb.append(ParsingUtilities.encode(stringWriter.toString()));
			
			URL url = new URL(sb.toString());
			URLConnection connection = url.openConnection();
			connection.setConnectTimeout(5000);
			connection.connect();
			
			InputStream is = connection.getInputStream();
			try {
				String s = ParsingUtilities.inputStreamToString(is);
				JSONObject o = ParsingUtilities.evaluateJsonStringToObject(s);
				
				for (int i = 0; i < jobs.size(); i++) {
					HeuristicReconJob job = (HeuristicReconJob) jobs.get(i);
					
					String text = job.text;
					String key = "q" + i + ":search";
					if (!o.has(key)) {
						continue;
					}
					
					Recon recon = null;
					
					JSONObject o2 = o.getJSONObject(key);
					if (o2.has("result")) {
						JSONArray results = o2.getJSONArray("result");
						
						recon = createReconFromRelevanceResults(text, results);
					} else {
						recon = new Recon();
					}
					
					recons.add(recon);
				}
			} finally {
				is.close();
			}
		} catch (Exception e) {
			e.printStackTrace();
		}
		
		System.gc();
		
		return recons;
	}

	
	static protected double wordDistance(String s1, String s2) {
		Set<String> words1 = breakWords(s1);
		Set<String> words2 = breakWords(s2);
		return words1.size() >= words2.size() ? wordDistance(words1, words2) : wordDistance(words2, words1);
	}
	
	static protected double wordDistance(Set<String> longWords, Set<String> shortWords) {
		double common = 0;
		for (String word : shortWords) {
			if (longWords.contains(word)) {
				common++;
			}
		}
		return common / longWords.size();
	}
	
	static protected Set<String> s_stopWords;
	static {
		s_stopWords = new HashSet<String>();
		s_stopWords.add("the");
		s_stopWords.add("a");
		s_stopWords.add("and");
		s_stopWords.add("of");
		s_stopWords.add("on");
		s_stopWords.add("in");
		s_stopWords.add("at");
		s_stopWords.add("by");
	}
	
	static protected Set<String> breakWords(String s) {
		String[] words = s.toLowerCase().split("\\s+");
		
		Set<String> set = new HashSet<String>(words.length);
		for (String word : words) {
			if (!s_stopWords.contains(word)) {
				set.add(word);
			}
		}
		return set;
	}
}