package chapter7;

import org.apache.lucene.analysis.SimpleAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.Term;
import org.apache.lucene.search.FieldDoc;
import org.apache.lucene.search.Hits;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.Sort;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TermQuery;
import org.apache.lucene.search.TopFieldDocs;
import org.apache.lucene.store.RAMDirectory;

import java.io.IOException;

// 測試自定義排序的實現，基本過程是使用IndexWriter創建內存索引，使用自定義的排序類
// 構造Sort對象，得到的檢索結果，使用search方法分別獲得Hits對象和TopFieldDocs對象，
// 進行簡單排序測試和詳細結果的輸出。
public class SortExtendTest {

	private RAMDirectory directory;
	private IndexSearcher searcher;
	private Query query;

	//建立測試環境
	protected void setUp() throws Exception {
		directory = new RAMDirectory();
		// 創建索引
		IndexWriter writer = new IndexWriter(directory,new SimpleAnalyzer(), true);
		// 添加文檔
		addWare(writer, "蘋果", "fruit", 2.5F, 2.0F,3.0F);   
		addWare(writer, "桔子", "fruit", 2.0F, 2.0F,3.0F);   
		addWare(writer, "香蕉", "fruit", 3.0F, 3.0F,3.0F);
		addWare(writer, "菠蘿", "fruit", 4.5F, 5.0F,6.0F);

		writer.close();
	
		searcher = new IndexSearcher(directory);            // 創建檢索器
		query = new TermQuery(new Term("type", "fruit"));   // 創建Query查詢對象
	}
	/*================================================================
	 * 根據參數指定的索引器和參數，創建文檔對象并添加到索引器對應的索引中
	 *================================================================*/
	private void addWare(IndexWriter writer, String name, String type, float last,float stat,float next) 
	 throws IOException {
		Document document = new Document(); // 創建文檔對象
		// 創建域對象
	    Field fieldContent = new Field("name"   , name, Field.Store.YES, Field.Index.TOKENIZED);
	    Field fieldNumber  = new Field("type"   , type , Field.Store.YES, Field.Index.TOKENIZED);
	    Field fieldOrder   = new Field("prices" , last + "," + stat +"," + next , 
	    		                        Field.Store.YES, Field.Index.UN_TOKENIZED);
	
	    document.add(fieldContent);         // 添加創建的名字域到當前文檔
	    document.add(fieldNumber);          // 添加創建的文本域到當前文檔
	    document.add(fieldOrder);           // 添加創建的文本域到當前文檔
	
	    writer.addDocument(document);       // 完成的文檔添加到索引	
	}
	/*================================================================
	 * 測試自定義排序,簡單利用結果的Hits對象，獲取排序最大、最小結果
	 *================================================================*/
	public void simplesorttest() throws Exception {
		//使用SortExtendSearch構造一個SortField,作為域排序對象的參數
		Sort sort = new Sort(new SortField("prices",new SortExtendSearch()));

		Hits hits = searcher.search(query, sort); // 按照自定義匹配檢索
	
		int ihitsmax = hits.length() - 1;                  // 最大長度
		
		System.out.println("===========簡單自定義排序測試===================");
		System.out.println("匹配文檔數目 ：" + hits.length());
		System.out.println("價格最平穩  ：" +  hits.doc(0).get("name") + hits.doc(0).get("prices") );
		System.out.println("價格波動大  ：" +  hits.doc(ihitsmax).get("name") + hits.doc(ihitsmax).get("prices") );
		System.out.println("");
	}

	/*================================================================
	 * 測試自定義排序,利用TopFieldDocs 進一步訪問相關信息
	 *================================================================*/
	public void detailsorttest() throws Exception {
		Sort sort = new Sort(new SortField("prices",                // 排序對象域
				 			 new SortExtendSearch(0, 0 , 0))); 
		TopFieldDocs docs = searcher.search(query, null, 5, sort);  // 搜索索引，獲得TopFieldDocs集合

		System.out.println("===========詳細自定義排序測試===================");
		System.out.println( "匹配文檔個數 ：" + docs.totalHits );
		System.out.println( "評分文檔個數 ：" + docs.scoreDocs.length );

		displayDocs(sort, docs); // 顯示相關信息
	}

	/*================================================================
	 * 利用ScoreDoc對象顯示有關排序的信息
	 *================================================================*/
	private void displayDocs(Sort sort, TopFieldDocs docs) throws IOException {
		System.out.println("排序字段 : " + sort);                  // 輸出排序字段
		ScoreDoc[] scoreDocs = docs.scoreDocs;                   // 獲取scoreDoc數組
		for (int i = 0; i < scoreDocs.length; i++) {             // 循環處理每一個結果
			FieldDoc fieldDoc = (FieldDoc) scoreDocs[i];         // 獲得FieldDoc對象
			Float prices = (Float) fieldDoc.fields[0];           // 獲取價格波動數值
			Document document = searcher.doc(fieldDoc.doc);      // 取得文檔句柄
			System.out.println(" " + document.get("name") + " @ ("
								+ document.get("prices") + ") -> " + prices);
		}
	}
	
	public static void main(String[] args) throws IOException{

		try{
			SortExtendTest test = new SortExtendTest();   // 排序測試對象初始化
			test.setUp();                                 // 初始化自定義文檔
			test.simplesorttest();                        // 簡單自定義排序測試
			test.detailsorttest();                        // 詳細自定義排序測試

		} catch (Exception e){
			;
		}
	}
}