package cn.edu.bjut.textmining.chapter5.support;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.UncheckedIOException;
import java.nio.charset.StandardCharsets;
import java.nio.file.Files;
import java.util.ArrayList;
import java.util.List;
import java.util.TreeSet;

/** 九篇标题和同一个词表，所有小样本实验保持一致。 */
public final class SampleNews {
    public static List<TNewsCorpusLoader.NewsRecord> load() {
        List<TNewsCorpusLoader.NewsRecord> result = new ArrayList<>();
        try (BufferedReader reader =
                Files.newBufferedReader(
                        ProjectPaths.data("news_sample.tsv"), StandardCharsets.UTF_8)) {
            reader.readLine();
            String line;
            while ((line = reader.readLine()) != null) {
                String[] fields = line.split("\t", 4);
                result.add(
                        new TNewsCorpusLoader.NewsRecord(
                                fields[2], fields[3], Integer.parseInt(fields[1])));
            }
        } catch (IOException e) {
            throw new UncheckedIOException("读取九条新闻失败", e);
        }
        if (result.size() != 9) {
            throw new IllegalStateException("样本清单应包含9篇新闻");
        }
        return result;
    }

    public static double[][] vectors() {
        return TNewsSmallVectorizer.tfIdf(TNewsCorpusLoader.titles(load()));
    }

    public static String[] goldLabels() {
        List<TNewsCorpusLoader.NewsRecord> records = load();
        String[] result = new String[records.size()];
        for (int i = 0; i < result.length; i++) {
            result[i] = records.get(i).getLabel();
        }
        return result;
    }

    public static void printClusters(int[] labels) {
        List<TNewsCorpusLoader.NewsRecord> records = load();
        for (int cluster : new TreeSet<Integer>(asList(labels))) {
            System.out.println("簇 " + (cluster + 1) + ":");
            for (int i = 0; i < labels.length; i++) {
                if (labels[i] == cluster) {
                    System.out.println("  N" + (i + 1) + " " + records.get(i).getTitle());
                }
            }
        }
    }

    private static List<Integer> asList(int[] values) {
        List<Integer> result = new ArrayList<>();
        for (int value : values) {
            result.add(value);
        }
        return result;
    }
}