package com.example;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONArray;
import com.alibaba.fastjson.JSONObject;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;

public class NeteaseCommentCrawler {
    private static final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/120.0.0.0 Safari/537.36";

    public static JSONArray getHotComments(String songId) {
        String apiUrl = "https://music.163.com/api/v1/resource/comments/R_SO_4_" + songId
                + "?rid=R_SO_4_" + songId
                + "&offset=0&total=true&limit=20";

        try {
            System.out.println("正在请求网易云音乐评论接口...");

            URL url = new URL(apiUrl);
            HttpURLConnection conn = (HttpURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(15000);
            conn.setReadTimeout(15000);
            conn.setRequestProperty("User-Agent", USER_AGENT);
            conn.setRequestProperty("Referer", "https://music.163.com/song?id=" + songId);
            conn.setRequestProperty("Accept", "*/*");
            conn.setRequestProperty("Accept-Language", "zh-CN,zh;q=0.9,en;q=0.8");

            int statusCode = conn.getResponseCode();
            System.out.println("HTTP状态码：" + statusCode);

            if (statusCode != 200) {
                System.err.println("请求失败，HTTP状态码：" + statusCode);
                return new JSONArray();
            }

            String responseStr = readStream(conn.getInputStream());
            System.out.println("响应长度：" + responseStr.length() + " 字符");

            if (responseStr == null || responseStr.trim().isEmpty()) {
                System.err.println("响应内容为空");
                return new JSONArray();
            }

            JSONObject responseJson = JSON.parseObject(responseStr);

            if (responseJson == null) {
                System.err.println("JSON解析失败");
                return new JSONArray();
            }

            int code = responseJson.getIntValue("code");
            if (code != 200) {
                System.err.println("接口返回错误码：" + code + "，消息：" + responseJson.getString("message"));
                return new JSONArray();
            }

            JSONArray hotComments = responseJson.getJSONArray("hotComments");
            if (hotComments == null || hotComments.isEmpty()) {
                System.out.println("该歌曲暂无热门评论");
                return new JSONArray();
            }

            return hotComments;

        } catch (Exception e) {
            System.err.println("爬取失败：" + e.getMessage());
            e.printStackTrace();
        }
        return new JSONArray();
    }

    private static String readStream(InputStream is) throws IOException {
        BufferedReader reader = new BufferedReader(new InputStreamReader(is, StandardCharsets.UTF_8));
        StringBuilder sb = new StringBuilder();
        String line;
        while ((line = reader.readLine()) != null) {
            sb.append(line);
        }
        return sb.toString();
    }

    public static void printComments(JSONArray hotComments) {
        System.out.println("\n===== 网易云音乐热门评论 =====");
        System.out.println("共获取到 " + hotComments.size() + " 条热门评论\n");
        for (int i = 0; i < hotComments.size(); i++) {
            JSONObject comment = hotComments.getJSONObject(i);
            JSONObject user = comment.getJSONObject("user");
            String nickname = user.getString("nickname");
            String content = comment.getString("content").replace("\n", " ");
            int likedCount = comment.getInteger("likedCount");
            Long time = comment.getLong("time");
            String timeStr = formatTime(time);

            System.out.printf("%d. [%s]：%s（%d赞）%s%n",
                    i + 1, nickname, content, likedCount, timeStr);
        }
    }

    private static String formatTime(Long timestamp) {
        if (timestamp == null) return "";
        java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        return sdf.format(new java.util.Date(timestamp));
    }

    public static void saveToCSV(JSONArray hotComments) {
        String filePath = "netease_hot_comments.csv";
        try (FileWriter writer = new FileWriter(filePath, StandardCharsets.UTF_8)) {
            writer.write("序号,用户,评论,点赞数,时间\n");
            for (int i = 0; i < hotComments.size(); i++) {
                JSONObject comment = hotComments.getJSONObject(i);
                JSONObject user = comment.getJSONObject("user");
                String nickname = user.getString("nickname");
                String content = comment.getString("content").replace("\n", " ").replace(",", "，");
                int likedCount = comment.getInteger("likedCount");
                Long time = comment.getLong("time");
                String timeStr = formatTime(time);

                writer.write(String.format("%d,%s,%s,%d,%s%n",
                        i + 1, nickname, content, likedCount, timeStr));
            }
            System.out.println("\n评论已保存到 " + filePath);
        } catch (Exception e) {
            System.err.println("保存CSV失败：" + e.getMessage());
        }
    }

    public static void main(String[] args) {
        String songId = "186016";
        System.out.println("歌曲ID：" + songId + "（周杰伦 - 晴天）");
        System.out.println("================================");

        JSONArray hotComments = getHotComments(songId);
        if (!hotComments.isEmpty()) {
            printComments(hotComments);
            saveToCSV(hotComments);
        } else {
            System.out.println("未获取到评论，请检查：");
            System.out.println("  1. 歌曲ID是否正确");
            System.out.println("  2. 网络是否能访问 music.163.com");
        }
    }
}