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 çš„å¯†ç  */
        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 : "";
        }
        /**
         * æ·»åŠ ä¸€æ¡éœ€è¦sudo执行的命令
         * @param cmd 要执行的命令(字符串中不需要有sudo)
         * @return
         */
        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;
        }
        /**
         * æ·»åŠ ä¸€æ¡æ™®é€šå‘½ä»¤
         * @param cmd
         * @return
         */
        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 æ ‡å‡†è¾“å‡º
         * @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);
                }
        }
}