package util;

import java.io.*;
import java.text.SimpleDateFormat;
import java.util.*;
import model.Article;

public class FileUtil {
    private static final String DATA_DIR = "data";
    
    static {
        File dir = new File(DATA_DIR);
        if (!dir.exists()) {
            dir.mkdirs();
        }
    }
    
    public static void saveArticle(Article article) throws IOException {
        String timestamp = new SimpleDateFormat("yyyyMMdd_HHmmss").format(new Date());
        String filename = DATA_DIR + "/" + article.getSource() + "_" + timestamp + ".txt";
        
        try (BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(new FileOutputStream(filename), "UTF-8"))) {
            writer.write("========================================\n");
            writer.write("来源：" + article.getSource() + "\n");
            writer.write("标题：" + article.getTitle() + "\n");
            writer.write("链接：" + article.getUrl() + "\n");
            writer.write("时间：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "\n");
            writer.write("========================================\n");
            writer.write("内容：\n");
            writer.write(article.getContent() != null ? article.getContent() : "无内容");
            writer.write("\n");
        }
    }
    
    public static void saveArticles(List<Article> articles, String filename) throws IOException {
        String filepath = DATA_DIR + "/" + filename;
        
        try (BufferedWriter writer = new BufferedWriter(
                new OutputStreamWriter(new FileOutputStream(filepath), "UTF-8"))) {
            writer.write("爬取结果汇总\n");
            writer.write("时间：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date()) + "\n");
            writer.write("数量：" + articles.size() + "\n");
            writer.write("========================================\n\n");
            
            for (int i = 0; i < articles.size(); i++) {
                Article article = articles.get(i);
                writer.write("【" + (i + 1) + "】\n");
                writer.write("来源：" + article.getSource() + "\n");
                writer.write("标题：" + article.getTitle() + "\n");
                writer.write("链接：" + article.getUrl() + "\n");
                writer.write("\n");
            }
        }
    }
    
    public static List<String> listSavedFiles() {
        File dir = new File(DATA_DIR);
        File[] files = dir.listFiles((d, name) -> name.endsWith(".txt"));
        
        List<String> result = new ArrayList<>();
        if (files != null) {
            for (File file : files) {
                result.add(file.getName());
            }
        }
        return result;
    }
}