package java01;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLEncoder;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class JobCrawler {
    private static final String USER_AGENT = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.124 Safari/537.36";
    
    public List<Job> crawlJobs(String keyword, int pageCount) {
        List<Job> jobs = new ArrayList<>();
        
        try {
            for (int page = 1; page <= pageCount; page++) {
                String encodedKeyword = URLEncoder.encode(keyword, "UTF-8");
                String url = String.format("https://sou.zhaopin.com/?jl=489&kw=%s&p=%d", encodedKeyword, page);
                System.out.println("爬取页面: " + url);
                
                // 发送HTTP请求
                String html = sendHttpRequest(url);
                
                // 解析HTML，提取职位信息
                List<Job> pageJobs = extractJobsFromHtml(html);
                jobs.addAll(pageJobs);
                
                // 添加延迟，避免被反爬虫
                Thread.sleep(2000);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        
        return jobs;
    }
    
    private String sendHttpRequest(String urlString) throws Exception {
        URL url = new URL(urlString);
        HttpURLConnection conn = (HttpURLConnection) url.openConnection();
        conn.setRequestMethod("GET");
        conn.setRequestProperty("User-Agent", USER_AGENT);
        conn.setConnectTimeout(10000);
        conn.setReadTimeout(10000);
        
        BufferedReader in = new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
        StringBuilder response = new StringBuilder();
        String inputLine;
        
        while ((inputLine = in.readLine()) != null) {
            response.append(inputLine);
        }
        in.close();
        conn.disconnect();
        
        return response.toString();
    }
    
    private List<Job> extractJobsFromHtml(String html) {
        List<Job> jobs = new ArrayList<>();
        
        // 简化的正则表达式，实际项目中可能需要更复杂的解析
        // 这里使用模拟数据，因为实际解析HTML需要更复杂的逻辑
        // 在真实环境中，建议使用Jsoup等库进行HTML解析
        
        // 模拟数据
        for (int i = 1; i <= 10; i++) {
            Job job = new Job(
                    "Java开发工程师" + i,
                    "科技公司" + i,
                    (10 + i) + "K-" + (20 + i) + "K",
                    "北京",
                    "3-5年",
                    "本科",
                    "Java Spring Boot MySQL Redis"
            );
            jobs.add(job);
        }
        
        return jobs;
    }
}