/*
 * Copyright (C) 2016 AriaLyy(https://github.com/AriaLyy/Aria)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.arialyy.aria.m3u8;

import com.arialyy.aria.core.common.RequestEnum;
import com.arialyy.aria.core.common.SubThreadConfig;
import com.arialyy.aria.core.download.DownloadEntity;
import com.arialyy.aria.core.task.AbsThreadTaskAdapter;
import com.arialyy.aria.exception.AriaIOException;
import com.arialyy.aria.exception.TaskException;
import com.arialyy.aria.http.ConnectionHelp;
import com.arialyy.aria.http.HttpTaskOption;
import com.arialyy.aria.util.ALog;
import java.io.BufferedInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStreamWriter;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import java.net.URLEncoder;
import java.nio.ByteBuffer;
import java.nio.channels.Channels;
import java.nio.channels.FileChannel;
import java.nio.channels.ReadableByteChannel;
import java.util.Map;
import java.util.Set;

/**
 * Created by lyy on 2017/1/18. 下载线程
 */
public class M3U8ThreadTaskAdapter extends AbsThreadTaskAdapter {
  private final String TAG = "M3U8ThreadTask";
  private HttpTaskOption mHttpTaskOption;

  public M3U8ThreadTaskAdapter(SubThreadConfig config) {
    super(config);
    mHttpTaskOption = (HttpTaskOption) getTaskWrapper().getTaskOption();
  }

  @Override protected void handlerThreadTask() {
    if (getThreadRecord().isComplete) {
      handleComplete();
      return;
    }
    HttpURLConnection conn = null;
    BufferedInputStream is = null;
    try {
      URL url = ConnectionHelp.handleUrl(getThreadConfig().url, mHttpTaskOption);
      conn = ConnectionHelp.handleConnection(url, mHttpTaskOption);
      ALog.d(TAG, String.format("分片【%s】开始下载", getThreadRecord().threadId));
      ConnectionHelp.setConnectParam(mHttpTaskOption, conn);
      conn.setConnectTimeout(getTaskConfig().getConnectTimeOut());
      conn.setReadTimeout(getTaskConfig().getIOTimeOut());  //设置读取流的等待时间,必须设置该参数
      if (mHttpTaskOption.isChunked()) {
        conn.setDoInput(true);
        conn.setChunkedStreamingMode(0);
      }
      conn.connect();
      // 传递参数
      if (mHttpTaskOption.getRequestEnum() == RequestEnum.POST) {
        Map<String, String> params = mHttpTaskOption.getParams();
        if (params != null) {
          OutputStreamWriter dos = new OutputStreamWriter(conn.getOutputStream());
          Set<String> keys = params.keySet();
          StringBuilder sb = new StringBuilder();
          for (String key : keys) {
            sb.append(key).append("=").append(URLEncoder.encode(params.get(key))).append("&");
          }
          String paramStr = sb.toString();
          paramStr = paramStr.substring(0, paramStr.length() - 1);
          dos.write(paramStr);
          dos.flush();
          dos.close();
        }
      }

      int code = conn.getResponseCode();
      if (code != HttpURLConnection.HTTP_OK) {
        fail(new TaskException(TAG,
                String.format("连接错误，http错误码：%s，url：%s", code, getThreadConfig().url)),
            false);
        return;
      }

      is = new BufferedInputStream(ConnectionHelp.convertInputStream(conn));
      if (mHttpTaskOption.isChunked()) {
        readChunked(is);
      } else if (getThreadConfig().isBlock) {
        readDynamicFile(is);
      }
    } catch (MalformedURLException e) {
      fail(new TaskException(TAG,
          String.format("分片【%s】下载失败，filePath: %s, url: %s", getThreadRecord().threadId,
              getThreadConfig().tempFile.getPath(), getEntity().getUrl()), e), false);
    } catch (IOException e) {
      fail(new TaskException(TAG,
          String.format("分片【%s】下载失败，filePath: %s, url: %s", getThreadRecord().threadId,
              getThreadConfig().tempFile.getPath(), getEntity().getUrl()), e), true);
    } catch (Exception e) {
      fail(new TaskException(TAG,
          String.format("分片【%s】下载失败，filePath: %s, url: %s", getThreadRecord().threadId,
              getThreadConfig().tempFile.getPath(), getEntity().getUrl()), e), false);
    } finally {
      try {
        if (is != null) {
          is.close();
        }
        if (conn != null) {
          conn.disconnect();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  /**
   * 读取chunked数据
   */
  private void readChunked(InputStream is) {
    FileOutputStream fos = null;
    try {
      fos = new FileOutputStream(getThreadConfig().tempFile, true);
      byte[] buffer = new byte[getTaskConfig().getBuffSize()];
      int len;
      while (getThreadTask().isLive() && (len = is.read(buffer)) != -1) {
        if (getThreadTask().isBreak()) {
          break;
        }
        if (mSpeedBandUtil != null) {
          mSpeedBandUtil.limitNextBytes(len);
        }
        fos.write(buffer, 0, len);
        progress(len);
      }
      handleComplete();
    } catch (IOException e) {
      fail(new AriaIOException(TAG,
          String.format("文件下载失败，savePath: %s, url: %s", getThreadConfig().tempFile.getPath(),
              getThreadConfig().url), e), true);
    } finally {
      if (fos != null) {
        try {
          fos.close();
        } catch (IOException e) {
          e.printStackTrace();
        }
      }
    }
  }

  /**
   * 动态长度文件读取方式
   */
  private void readDynamicFile(InputStream is) {
    FileOutputStream fos = null;
    FileChannel foc = null;
    ReadableByteChannel fic = null;
    try {
      int len;
      fos = new FileOutputStream(getThreadConfig().tempFile, true);
      foc = fos.getChannel();
      fic = Channels.newChannel(is);
      ByteBuffer bf = ByteBuffer.allocate(getTaskConfig().getBuffSize());
      //如果要通过 Future 的 cancel 方法取消正在运行的任务，那么该任务必定是可以 对线程中断做出响应 的任务。

      while (getThreadTask().isLive() && (len = fic.read(bf)) != -1) {
        if (getThreadTask().isBreak()) {
          break;
        }
        if (mSpeedBandUtil != null) {
          mSpeedBandUtil.limitNextBytes(len);
        }
        bf.flip();
        foc.write(bf);
        bf.compact();
        progress(len);
      }
      handleComplete();
    } catch (IOException e) {
      fail(new AriaIOException(TAG,
          String.format("文件下载失败，savePath: %s, url: %s", getThreadConfig().tempFile.getPath(),
              getThreadConfig().url), e), true);
    } finally {
      try {
        if (fos != null) {
          fos.flush();
          fos.close();
        }
        if (foc != null) {
          foc.close();
        }
        if (fic != null) {
          fic.close();
        }
      } catch (IOException e) {
        e.printStackTrace();
      }
    }
  }

  private DownloadEntity getEntity() {
    return (DownloadEntity) getTaskWrapper().getEntity();
  }

  /**
   * 处理完成配置文件的更新或事件回调
   */
  private void handleComplete() {
    if (getThreadTask().isBreak()) {
      return;
    }
    complete();
  }
}