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

import java.io.BufferedWriter;
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;

/** 结果表使用UTF-8，运行入口只需指定文件名和行。 */
public final class ResultWriter {
    private ResultWriter() {}

    public static void lines(String name, List<String> lines) {
        try (BufferedWriter writer =
                Files.newBufferedWriter(ProjectPaths.output(name), StandardCharsets.UTF_8)) {
            for (String line : lines) {
                writer.write(line);
                writer.newLine();
            }
        } catch (IOException e) {
            throw new UncheckedIOException("保存结果失败：" + name, e);
        }
    }

    public static void features(String prefix, TextFeatures.Result result) {
        List<String> vocab = new ArrayList<>();
        vocab.add("column\tfeature\tdf");
        for (int j = 0; j < result.vocabulary.size(); j++) {
            vocab.add(j + "\t" + result.vocabulary.get(j) + "\t" + result.documentFrequencies[j]);
        }
        lines(prefix + "_vocabulary.tsv", vocab);
        List<String> rows = new ArrayList<>();
        for (double[] vector : result.vectors) {
            StringBuilder line = new StringBuilder();
            for (int j = 0; j < vector.length; j++) {
                if (j > 0) {
                    line.append(',');
                }
                line.append(Double.toString(vector[j]));
            }
            rows.add(line.toString());
        }
        lines(prefix + "_vectors.csv", rows);
    }
}