package net.gdface.utils;

import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.logging.Logger;

/**
 * linux命令行执行器
 * @author guyadong
 *
 */
public class CmdExecutor{
	private static final Logger logger = Logger.getLogger(CmdExecutor.class.getSimpleName());
	private static final String SUDO_CMD = "sudo";
	private static final String SHELL_NAME = "/bin/bash";
	private static final String SHELL_PARAM = "-c";
	private static final String REDIRECT = "2>&1";
	/** 执行 sudo 的密码 */
	private final String sudoPassword;
	/** 是否显示命令内容及输出 */
	private boolean verbose=true;
	/** 是否错误输出重定向 */
	private boolean errRedirect = true;
	/** 是否同步，主线程是否等待命令执行结束 */
	private boolean sync = true;
	/** 执行多条命令时的命令分隔符 */
	private String cmdSeparator = " && ";
	private List<String> cmds = new ArrayList<String>(16);
	public static CmdExecutor builder(){
		return new CmdExecutor();
	}
	public static CmdExecutor builder(String sudoPasword){
		return new CmdExecutor(sudoPasword);
	}
	protected CmdExecutor(){
		this(null);
	}
	protected CmdExecutor(String sudoPasword){
		this.sudoPassword = sudoPasword;
	}
	public CmdExecutor verbose(boolean verbose){
		this.verbose = verbose;
		return this;
	}
	public CmdExecutor errRedirect(boolean errRedirect){
		this.errRedirect = errRedirect;
		return this;
	}
	public CmdExecutor sync(boolean sync){
		this.sync = sync;
		return this;
	}
	public CmdExecutor cmdSeparator(String cmdSeparator){
		if(null != cmdSeparator && !cmdSeparator.isEmpty()){
			this.cmdSeparator = cmdSeparator;
		}
		return this;
	}
	private String getRedirect(){
		return errRedirect ? REDIRECT : "";
	}
	/**
	 * 添加一条需要sudo执行的命令
	 * @param cmd 要执行的命令(字符串中不需要有sudo)
	 * @return 当前对象
	 */
	public CmdExecutor sudoCmd(String cmd){
		if(null != cmd && 0 != cmd.length()){
			if(null == sudoPassword){
				cmds.add(String.format("%s %s %s",SUDO_CMD,cmd,getRedirect()));					
			}else{
				cmds.add(String.format("echo '%s' | %s %s %s",sudoPassword,SUDO_CMD,cmd,getRedirect()));
			}					
		}
		return this;
	}
	/**
	 * 添加一条普通命令
	 * @param cmd
	 * @return 当前对象
	 */
	public CmdExecutor cmd(String cmd){
		if(null != cmd && 0 != cmd.length()){
			cmds.add(String.format("%s %s",cmd,getRedirect()));					
		}
		return this;
	}
	private List<String> build(){
		return cmds.isEmpty()
				? Collections.<String>emptyList()
				: Arrays.asList(SHELL_NAME,SHELL_PARAM,join(cmds,cmdSeparator));
	}
    private static String join(List<String> strs,String separator) {
        StringBuffer buffer = new StringBuffer();
        for(int i=0;i<strs.size();++i){
        	if(i>0){
        		buffer.append(separator);
        	}
            buffer.append(strs.get(i));
        }
        return buffer.toString();
    }
    /**
     * 将{@link InputStream}中所有内容输出到{@link StringBuffer}
     * @param in
     * @return
     * @throws IOException
     */
    private static void toBuffer(InputStream in,StringBuffer buffer) throws IOException{
    	if(null == in || null == buffer){
    		return ;
    	}
		InputStreamReader ir = new InputStreamReader(in);
		LineNumberReader input = new LineNumberReader(ir);
		try{
			String line;
			while ((line = input.readLine()) != null) {
				buffer.append(line).append("\n");
			}
		}finally{
			input.close();
		}
    }
    /** 
     * 调用{@link Runtime#exec(String[])}执行命令 
     * @return 返回输出结果 
     */
	public String exec() throws IOException{
		StringBuffer outBuffer = new StringBuffer();
		exec(outBuffer,null);
		return outBuffer.toString();
	}
	/**
	 * 调用{@link Runtime#exec(String[])}执行命令 
	 * @param outBuffer 标准输出
	 * @param errBuffer 错误信息输出
	 * @throws IOException
	 */
	public void exec(StringBuffer outBuffer,StringBuffer errBuffer) throws IOException{
		List<String> cmdlist = build();
		if(!cmdlist.isEmpty()){
			if(verbose){
				logger.info(join(cmdlist," "));
			}
			Process process = Runtime.getRuntime().exec(cmdlist.toArray(new String[cmdlist.size()]));
			if(sync){
				try {
					process.waitFor();
				} catch (InterruptedException e) {
				}
			}
			toBuffer(process.getInputStream(),outBuffer);
			toBuffer(process.getErrorStream(),errBuffer);
		}
	}
}