package youdao;

import java.io.BufferedReader;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

public class GithubIssueImageDownloader {

  private static final String PREFIX = "C:\\Users\\i042416\\Pictures\\";
  private static final String ISSUEURL = "C:\\Users\\i042416\\git\\JavaTwoPlusTwoEquals5\\src\\youdao\\privateIssue.txt";
  
  private static void createFolder(String title){
    DownloadTask.FOLDER = PREFIX + title;
    File file = new File( DownloadTask.FOLDER);
    file.mkdir();
  }
  
  private static String getUrl(String line){
    int start = line.indexOf("(");
    int last = line.indexOf(")");
    return line.substring(++start, last);
  }
  private static List<DownloadTask> getPicUrlList(){
    int index = 0;
    List<DownloadTask> resultPic = new ArrayList<DownloadTask>();
    BufferedReader br = null;
    try { 
       br = new BufferedReader(new InputStreamReader(new FileInputStream(ISSUEURL ), "utf-8")); 
       String line = null;
       while ((line = br.readLine()) != null) {
        line = getUrl(line);
        DownloadTask task = new DownloadTask( line, index++);
        resultPic.add(task);
       }
       br.close();
    }
    catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e1) {
        e1.printStackTrace();
    }
    return resultPic;
  }
  
  private static void start(List<DownloadTask> task){
    if( task.isEmpty()){
      System.out.println("No picture to download!");
      return;
    }
    System.out.println("Total pic to be downloaded: " + task.size());
    ExecutorService executor = Executors.newFixedThreadPool(10);
    
    for( int i = 0; i < task.size(); i++){
      PictureDownloader cc = new PictureDownloader(task.get(i));
      executor.execute(cc);     
    }
    
    executor.shutdown();
    while (!executor.isTerminated()) {
        }
    
    System.out.println("download finished");
  }
  
  public static void main(String[] args) {
    createFolder("Test");
    List<DownloadTask> task = getPicUrlList();
    start(task);
  }
}