#coding=utf-8
import os
import sys
import syslog
import subprocess
import time
import re

##define KERN_EMERG    "<0>"  /* system is unusable               */
##define KERN_ALERT    "<1>"  /* action must be taken immediately */
##define KERN_CRIT     "<2>"  /* critical conditions              */
##define KERN_ERR      "<3>"  /* error conditions                 */
##define KERN_WARNING  "<4>"  /* warning conditions               */
##define KERN_NOTICE   "<5>"  /* normal but significant condition */
##define KERN_INFO     "<6>"  /* informational                    */
##define KERN_DEBUG    "<7>"  /* debug-level messages             */

MSG_PREFIX = ['EMERG', 'ALERT', 'CRIT', 'ERR', 'WARNING', 'NOTICE', 'INFO', 'DEBUG']

G_LOCAL_NODE_NAME = "TSG_MXN"

class CommandException(Exception):
    pass
    
def tsg_restart_err_log(error_num, user_msg):
    msg = "[%s] %s" %(MSG_PREFIX[syslog.LOG_ERR], user_msg)
    syslog.syslog(syslog.LOG_ERR, msg) 
    print (msg)
    
    msg = "[%s] %s" %(MSG_PREFIX[syslog.LOG_ERR], "tsg software reboot error")
    syslog.syslog(syslog.LOG_ERR, msg)
    print (msg)
    
    sys.exit(error_num)

def tsg_restart_succ_log():
    msg = "[%s] %s" %(MSG_PREFIX[syslog.LOG_NOTICE], "tsg software reboot success")
    syslog.syslog(syslog.LOG_NOTICE, msg)
    print (msg)
    sys.exit(0)

#return exitcode value + output message:
#    0: succ
#    1: error
def system_cmd_run(cmd_str):
    dangerous_cmd = {"rm", "mv", "poweroff", "shutdown"}
    
    for cmd in dangerous_cmd:
        pattern = "\s*%s" %(cmd)
        match_str = re.match(pattern, cmd_str)
        if not match_str is None:
            print("can't run this cmd:%s" %(cmd_str))
            sys.exit(1)
            
    try:
        exitcode, output = subprocess.getstatusoutput(cmd_str)
    except Exception as e:  
        print(e)    
        print("###### %s" %(e.message))
        #if exitcode != 0:
        #    output = ""
        return 1, e.message

    return exitcode, output
    
#return value:
# 1: progcess of prog_name is exist
# 0: progcess of prog_name is not exist  
def tsg_check_process_health_by_ps(module_name):
    cmd_str = "ps -afx | grep %s | grep -v grep" %(module_name)
    exitcode, output = system_cmd_run(cmd_str)
    if exitcode == 0:
        return 1
    
    return 0

#return value:
# 1: progcess of prog_name is exist
# 0: progcess of prog_name is not exist    
def tsg_check_process_health_by_systemctl_status(module_name):
    print("systemctl_status check method TODO!")
    sys.exit(1)
    return 0

def tsg_kill_app_process_by_killall(module_name, extra_progs):
    #todo , stop sapp, xxx, check process exist or not, maybe zombie, maybe very slow
    command = "killall -9 %s %s" %(module_name, extra_progs)
    try:    
        exitcode, output = subprocess.getstatusoutput(command)
        #print("%d" %(exitcode))
    except Exception as e:
        pass
    
    if exitcode != 0:
        return 1
        
    return 0    

def tsg_kill_app_process_by_systemctl_stop(module_name):
    print("TODO")
    sys.exit(1)
    return 0
    
def tsg_stop_app_process(module_name, extra_progs, stop_method, check_method):
    res_code = 0
    running_flag = 0
    
    if check_method == 'ps':
        check_func = tsg_check_process_health_by_ps
    elif check_method == 'systemctl_status':
        check_func = tsg_check_process_health_by_systemctl_status
    else:
        print("not support check method:%s" %(check_method))
        sys.exit(1)
    
    running_flag = check_func(module_name)    
        
    if running_flag == 0:
        #print("%s is not running, start it..." %(module_name))
        return 0
    #ready to stop progcess,  retry for 3 times

    if stop_method == 'killall':
        stop_func = tsg_kill_app_process_by_killall
    elif stop_method == 'systemctl_stop':
        stop_func = tsg_kill_app_process_by_systemctl_stop
    else:
        print("not support stop method:%s" %(check_method))
        sys.exit(1)
    
    for times in range(3):
        stop_func(module_name, extra_progs)
        #此处不判断stop_func的返回值, 可能程序不存在, 可能守护不存在,等原因
        #直接用check()方法检测stop()的成功
        res_code = tsg_check_process_health_by_ps(module_name)
        if res_code != 0:
            continue
        else:
            break    
            
    if res_code != 0: 
        errmsg = "can't stop process %s" %(module_name)
        tsg_restart_err_log(res_code, errmsg)
    
    return res_code

def tsg_start_app_process_by_exec_call(module_name, module_cwd, module_exe, check_method):
    try:
        os.chdir(module_cwd)
    except Exception as e: 
        print("%s" %(e))
        return 1
    
    cmd_str = "./%s" %(module_exe)
    ret_code, output = system_cmd_run(cmd_str)
    if ret_code != 0:
        errmsg = "start program %s error, call %s/%s failed" %(module_name, module_cwd, module_exe)
        tsg_restart_err_log(ret_code, errmsg)
    
    if check_method == 'ps':
        check_func = tsg_check_process_health_by_ps
    elif check_method == 'systemctl_status':
        check_func = tsg_check_process_health_by_systemctl_status
    else:
        print("not support check method:%s" %(check_method))
        return 1
    
    running_flag = check_func(module_name)    
    if running_flag == 0:
        errmsg = "start process %s error" %(module_name)
        tsg_restart_err_log(ret_code, errmsg)
 
    return 0
    
def tsg_start_app_process_by_systemctl_start(module_name, module_cwd, module_exe, check_method):
    print("TODO")
    sys.exit(1)

def tsg_start_app_process(module_name, module_cwd, module_exe, start_method, check_method):
    if start_method == 'exec_call':
        start_func = tsg_start_app_process_by_exec_call
    elif start_method == 'systemctl_start':
        start_func = tsg_start_app_process_by_systemctl_start
    else:
        print("not support start method:%s" %(start_method))
        sys.exit(1)

    ret = start_func(module_name, module_cwd, module_exe, check_method)        
    if ret != 0:
        sys.exit(1) 

    return 0
    
#参数说明:
#
# module_name: 模块名称
# extra_progs: 其他需要kill的附加程序, 如sapp的r3守护, 需要杀掉, 否则后台可能会重复启动sapp
# module_cwd:  应用的绝对路径
# module_exe: 启动应用的名称, 可能跟module_name不一样, 比如用r2启动sapp
# stop_method: 停止应用方法  
# start_method: 启动应用方法  
# check_method: 检测应用是否运行方法  
#  
def tsg_restart_app_process(module_name, extra_progs, module_cwd, module_exe, stop_method, start_method, check_method):
    res_code = 0
    
    res_code = tsg_stop_app_process(module_name, extra_progs, stop_method, check_method)
    if res_code != 0:
        return res_code
        
    res_code = tsg_start_app_process(module_name, module_cwd, module_exe, start_method, check_method)
    if res_code != 0:
        return res_code
    
    return 0
    
def tsg_software_reboot():
    #G_LOCAL_NODE_NAME = get_local_node_name()
    
    log_handle = syslog.openlog(G_LOCAL_NODE_NAME)

    tsg_restart_app_process("sapp", "r3", "/home/tsg/kni", "r2", "killall", "exec_call", "ps")
    #tsg_restart_app_process("telegraf", "systemctl_stop", "systemctl_start", "systemctl_status")
    #tsg_restart_app_process("marsio", "systemctl_stop", "systemctl_start", "systemctl_status")
    #tsg_restart_app_process("influxd", "systemctl_stop", "systemctl_start", "systemctl_status")
    
    tsg_restart_succ_log()

if __name__ == '__main__':
    tsg_software_reboot()