package com.jeeww.lucene.demo;

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE
 * file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file
 * to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the
 * License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by
 * applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language
 * governing permissions and limitations under the License.
 */

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.lucene.analysis.core.WhitespaceAnalyzer;
import org.apache.lucene.document.Document;
import org.apache.lucene.facet.FacetField;
import org.apache.lucene.facet.FacetResult;
import org.apache.lucene.facet.Facets;
import org.apache.lucene.facet.FacetsCollector;
import org.apache.lucene.facet.FacetsConfig;
import org.apache.lucene.facet.taxonomy.FastTaxonomyFacetCounts;
import org.apache.lucene.facet.taxonomy.TaxonomyReader;
import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyReader;
import org.apache.lucene.facet.taxonomy.directory.DirectoryTaxonomyWriter;
import org.apache.lucene.index.DirectoryReader;
import org.apache.lucene.index.IndexWriter;
import org.apache.lucene.index.IndexWriterConfig;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.MatchAllDocsQuery;
import org.apache.lucene.store.Directory;
import org.apache.lucene.store.RAMDirectory;

/** Demonstrates indexing categories into different indexed fields. */
public class MultiCategoryListsFacetsExample {

    private final Directory indexDir = new RAMDirectory();
    private final Directory taxoDir = new RAMDirectory();
    private final FacetsConfig config = new FacetsConfig();

    /** Creates a new instance and populates the catetory list params mapping. */
    public MultiCategoryListsFacetsExample() {
        config.setIndexFieldName("Author", "author");
        config.setIndexFieldName("Publish Date", "pubdate");
        config.setHierarchical("Publish Date", true);
    }

    /** Build the example index. */
    private void index() throws IOException {
        IndexWriter indexWriter = new IndexWriter(indexDir, new IndexWriterConfig(FacetExamples.EXAMPLES_VER,
                new WhitespaceAnalyzer(FacetExamples.EXAMPLES_VER)));

        // Writes facet ords to a separate directory from the main index
        DirectoryTaxonomyWriter taxoWriter = new DirectoryTaxonomyWriter(taxoDir);

        Document doc = new Document();
        doc.add(new FacetField("Author", "Bob"));
        doc.add(new FacetField("Publish Date", "2010", "10", "15"));
        indexWriter.addDocument(config.build(taxoWriter, doc));

        doc = new Document();
        doc.add(new FacetField("Author", "Lisa"));
        doc.add(new FacetField("Publish Date", "2010", "10", "20"));
        indexWriter.addDocument(config.build(taxoWriter, doc));

        doc = new Document();
        doc.add(new FacetField("Author", "Lisa"));
        doc.add(new FacetField("Publish Date", "2012", "1", "1"));
        indexWriter.addDocument(config.build(taxoWriter, doc));

        doc = new Document();
        doc.add(new FacetField("Author", "Susan"));
        doc.add(new FacetField("Publish Date", "2012", "1", "7"));
        indexWriter.addDocument(config.build(taxoWriter, doc));

        doc = new Document();
        doc.add(new FacetField("Author", "Frank"));
        doc.add(new FacetField("Publish Date", "1999", "5", "5"));
        indexWriter.addDocument(config.build(taxoWriter, doc));

        indexWriter.close();
        taxoWriter.close();
    }

    /** User runs a query and counts facets. */
    private List<FacetResult> search() throws IOException {
        DirectoryReader indexReader = DirectoryReader.open(indexDir);
        IndexSearcher searcher = new IndexSearcher(indexReader);
        TaxonomyReader taxoReader = new DirectoryTaxonomyReader(taxoDir);

        FacetsCollector fc = new FacetsCollector();

        // MatchAllDocsQuery is for "browsing" (counts facets
        // for all non-deleted docs in the index); normally
        // you'd use a "normal" query:
        FacetsCollector.search(searcher, new MatchAllDocsQuery(), 10, fc);

        // Retrieve results
        List<FacetResult> results = new ArrayList<FacetResult>();

        // Count both "Publish Date" and "Author" dimensions
        Facets author = new FastTaxonomyFacetCounts("author", taxoReader, config, fc);
        results.add(author.getTopChildren(10, "Author"));

        Facets pubDate = new FastTaxonomyFacetCounts("pubdate", taxoReader, config, fc);
        results.add(pubDate.getTopChildren(10, "Publish Date"));

        indexReader.close();
        taxoReader.close();

        return results;
    }

    /** Runs the search example. */
    public List<FacetResult> runSearch() throws IOException {
        index();
        return search();
    }

    /** Runs the search example and prints the results. */
    public static void main(String[] args) throws Exception {
        System.out.println("Facet counting over multiple category lists example:");
        System.out.println("-----------------------");
        List<FacetResult> results = new MultiCategoryListsFacetsExample().runSearch();
        System.out.println("Author: " + results.get(0));
        System.out.println("Publish Date: " + results.get(1));
    }
}
