/*
 * MIT License
 *
 * Copyright (c) 2016-2019 xiongziliang <771730766@qq.com>
 *
 * This file is part of ZLMediaKit(https://github.com/xiongziliang/ZLMediaKit).
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <limits.h>
#include <sys/stat.h>

#ifndef _WIN32
#include <sys/resource.h>
#include <unistd.h>
#else
//#include <TlHelp32.h>
#include <windows.h>
#endif

#include <stdexcept>
#include <signal.h>
#include "Util/util.h"
#include "Util/File.h"
#include "Util/logger.h"
#include "Util/uv_errno.h"
#include "Thread/WorkThreadPool.h"
#include "Process.h"
using namespace toolkit;

void Process::run(const string &cmd, const string &log_file_tmp) {
	kill(2000);
#ifdef _WIN32
	STARTUPINFO si;
	PROCESS_INFORMATION pi;
	ZeroMemory(&si, sizeof(si));			//结构体初始化；
	ZeroMemory(&pi, sizeof(pi));

	LPTSTR lpDir = const_cast<char*>(cmd .data());

	if (CreateProcess(NULL, lpDir, NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)){
		//下面两行关闭句柄，解除本进程和新进程的关系，不然有可能 不小心调用TerminateProcess函数关掉子进程 
		CloseHandle(pi.hProcess);
		CloseHandle(pi.hThread);

		_pid = pi.dwProcessId;
		InfoL << "start child proces " << _pid;
	} else {
		WarnL << "start child proces fail: " << GetLastError();
	}
#else	
	_pid = fork();
	if (_pid < 0) {
		throw std::runtime_error(StrPrinter << "fork child process falied,err:" << get_uv_errmsg());
	}
	if (_pid == 0) {
		//子进程关闭core文件生成
		struct rlimit rlim = { 0,0 };
		setrlimit(RLIMIT_CORE, &rlim);

		//在启动子进程时，暂时禁用SIGINT、SIGTERM信号
		// ignore the SIGINT and SIGTERM
		signal(SIGINT, SIG_IGN);
		signal(SIGTERM, SIG_IGN);

		string log_file;
		if (log_file_tmp.empty()) {
			log_file = "/dev/null";
		}
		else {
			log_file = StrPrinter << log_file_tmp << "." << getpid();
		}

		int log_fd = -1;
		int flags = O_CREAT | O_WRONLY | O_APPEND;
		mode_t mode = S_IRWXO | S_IRWXG | S_IRWXU;// S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH;
		File::createfile_path(log_file.data(), mode);
		if ((log_fd = ::open(log_file.c_str(), flags, mode)) < 0) {
			fprintf(stderr, "open log file %s failed:%d(%s)\r\n", log_file.data(), errno, strerror(errno));
		}
		else {
			// dup to stdout and stderr.
			if (dup2(log_fd, STDOUT_FILENO) < 0) {
				fprintf(stderr, "dup2 stdout file %s failed:%d(%s)\r\n", log_file.data(), errno, strerror(errno));
			}
			if (dup2(log_fd, STDERR_FILENO) < 0) {
				fprintf(stderr, "dup2 stderr file  %s failed:%d(%s)\r\n", log_file.data(), errno, strerror(errno));
			}
			// close log fd
			::close(log_fd);
		}
		fprintf(stderr, "\r\n\r\n#### pid=%d,cmd=%s #####\r\n\r\n", getpid(), cmd.data());

		// close other fds
		// TODO: do in right way.
		for (int i = 3; i < 1024; i++) {
			::close(i);
		}

		auto params = split(cmd, " ");
		// memory leak in child process, it's ok.
		char **charpv_params = new char *[params.size() + 1];
		for (int i = 0; i < (int)params.size(); i++) {
			std::string &p = params[i];
			charpv_params[i] = (char *)p.data();
		}
		// EOF: NULL
		charpv_params[params.size()] = NULL;

		// TODO: execv or execvp
		auto ret = execv(params[0].c_str(), charpv_params);
		if (ret < 0) {
			fprintf(stderr, "fork process failed, errno=%d(%s)\r\n", errno, strerror(errno));
		}
		exit(ret);
	}
	InfoL << "start child proces " << _pid;
#endif // _WIN32
}

/**
 * 获取进程是否存活状态
 * @param pid 进程号
 * @param exit_code_ptr 进程返回代码
 * @param block 是否阻塞等待
 * @return 进程是否还在运行
 */
static bool s_wait(pid_t pid,int *exit_code_ptr,bool block) {
    if (pid <= 0) {
        return false;
    }
    int status = 0;
#ifdef _WIN32
	HANDLE hProcess = NULL;
	hProcess = OpenProcess(PROCESS_TERMINATE, FALSE, pid);	//打开目标进程
	if (hProcess == NULL) {
		return false;
	}

	CloseHandle(hProcess);
#else
	pid_t p = waitpid(pid, &status, block ? 0 : WNOHANG);
	int exit_code = (status & 0xFF00) >> 8;
	if (exit_code_ptr) {
		*exit_code_ptr = (status & 0xFF00) >> 8;
	}
	if (p < 0) {
		WarnL << "waitpid failed, pid=" << pid << ", err=" << get_uv_errmsg();
		return false;
	}
	if (p > 0) {
		InfoL << "process terminated, pid=" << pid << ", exit code=" << exit_code;
		return false;
	}
#endif // _WIN32

    return true;
}

static void s_kill(pid_t pid,int max_delay,bool force){
    if (pid <= 0) {
        //pid无效
        return;
    }
#ifdef _WIN32
	HANDLE hProcess = NULL;
	hProcess = OpenProcess(PROCESS_TERMINATE, FALSE, pid);	//打开目标进程
	if (hProcess == NULL) {
		WarnL << "\nOpen Process fAiled: " << GetLastError();
		return;
	}
	DWORD ret = TerminateProcess(hProcess, 0);	//结束目标进程
	if (ret == 0) {
		WarnL << GetLastError;
	}
#else
	if (::kill(pid, force ? SIGKILL : SIGTERM) == -1) {
		//进程可能已经退出了
		WarnL << "kill process " << pid << " failed:" << get_uv_errmsg();
		return;
	}
#endif // _WIN32


    if(force){
        //发送SIGKILL信号后，阻塞等待退出
        s_wait(pid, NULL, true);
        DebugL << "force kill " << pid << " success!";
        return;
    }

    //发送SIGTERM信号后，2秒后检查子进程是否已经退出
    WorkThreadPool::Instance().getPoller()->doDelayTask(max_delay,[pid](){
        if (!s_wait(pid, nullptr, false)) {
            //进程已经退出了
            return 0;
        }
        //进程还在运行
        WarnL << "process still working,force kill it:" << pid;
        s_kill(pid,0, true);
        return 0;
    });
}

void Process::kill(int max_delay,bool force) {
    if (_pid <= 0) {
        return;
    }
    s_kill(_pid,max_delay,force);
    _pid = -1;
}

Process::~Process() {
    kill(2000);
}

Process::Process() {}

bool Process::wait(bool block) {
    return s_wait(_pid,&_exit_code,block);
}

int Process::exit_code() {
    return _exit_code;
}