/*******************************************************************************
 * Copyright 上海赜睿信息科技有限公司(Zilliz) - All Rights Reserved
 * Unauthorized copying of this file, via any medium is strictly prohibited.
 * Proprietary and confidential.
 ******************************************************************************/

#include "SystemInfo.h"

#include <sys/types.h>
#include <unistd.h>
#include <iostream>
#include <fstream>
#include "nvml.h"
//#include <mutex>
//
//std::mutex mutex;


namespace zilliz {
namespace vecwise {
namespace server {

void SystemInfo::Init() {
    if(initialized_) return;

    initialized_ = true;

    // initialize CPU information
    FILE* file;
    struct tms time_sample;
    char line[128];
    last_cpu_ = times(&time_sample);
    last_sys_cpu_ = time_sample.tms_stime;
    last_user_cpu_ = time_sample.tms_utime;
    file = fopen("/proc/cpuinfo", "r");
    num_processors_ = 0;
    while(fgets(line, 128, file) != NULL){
        if (strncmp(line, "processor", 9) == 0) num_processors_++;
    }
    total_ram_ = GetPhysicalMemory();
    fclose(file);

    //initialize GPU information
    nvmlReturn_t nvmlresult;
    nvmlresult = nvmlInit();
    if(NVML_SUCCESS != nvmlresult) {
        printf("System information initilization failed");
        return ;
    }
    nvmlresult = nvmlDeviceGetCount(&num_device_);
    if(NVML_SUCCESS != nvmlresult) {
        printf("Unable to get devidce number");
        return ;
    }

}

long long
SystemInfo::ParseLine(char *line) {
    // This assumes that a digit will be found and the line ends in " Kb".
    int i = strlen(line);
    const char *p = line;
    while (*p < '0' || *p > '9') p++;
    line[i - 3] = '\0';
    i = atoi(p);
    return static_cast<long long>(i);
}

unsigned long
SystemInfo::GetPhysicalMemory() {
    struct sysinfo memInfo;
    sysinfo (&memInfo);
    unsigned long totalPhysMem = memInfo.totalram;
    //Multiply in next statement to avoid int overflow on right hand side...
    totalPhysMem *= memInfo.mem_unit;
    return totalPhysMem;
}

unsigned long
SystemInfo::GetProcessUsedMemory() {
    //Note: this value is in KB!
    FILE* file = fopen("/proc/self/status", "r");
    constexpr int64_t line_length = 128;
    long long result = -1;
    constexpr int64_t KB_SIZE = 1024;
    char line[line_length];

    while (fgets(line, line_length, file) != NULL){
        if (strncmp(line, "VmRSS:", 6) == 0){
            result = ParseLine(line);
            break;
        }
    }
    fclose(file);
    // return value in Byte
    return (result*KB_SIZE);

}

double
SystemInfo::MemoryPercent() {
    if (!initialized_) Init();
    return GetProcessUsedMemory()*100/total_ram_;
}

double
SystemInfo::CPUPercent() {
    if (!initialized_) Init();
    struct tms time_sample;
    clock_t now;
    double percent;

    now = times(&time_sample);
    if (now <= last_cpu_ || time_sample.tms_stime < last_sys_cpu_ ||
        time_sample.tms_utime < last_user_cpu_){
        //Overflow detection. Just skip this value.
        percent = -1.0;
    }
    else{
        percent = (time_sample.tms_stime - last_sys_cpu_) +
            (time_sample.tms_utime - last_user_cpu_);
        percent /= (now - last_cpu_);
        percent /= num_processors_;
        percent *= 100;
    }
    last_cpu_ = now;
    last_sys_cpu_ = time_sample.tms_stime;
    last_user_cpu_ = time_sample.tms_utime;

    return percent;
}

//std::unordered_map<int,std::vector<double>>
//SystemInfo::GetGPUMemPercent(){
//    // return GPUID: MEM%
//
//    //write GPU info to a file
//    system("nvidia-smi pmon -c 1 > GPUInfo.txt");
//    int pid = (int)getpid();
//
//    //parse line
//    std::ifstream read_file;
//    read_file.open("GPUInfo.txt");
//    std::string line;
//    while(getline(read_file, line)){
//        std::vector<std::string> words = split(line);
//        //                    0      1     2    3   4    5    6      7
//        //words stand for gpuindex, pid, type, sm, mem, enc, dec, command respectively
//        if(std::stoi(words[1]) != pid) continue;
//        int GPUindex = std::stoi(words[0]);
//        double sm_percent = std::stod(words[3]);
//        double mem_percent = std::stod(words[4]);
//
//    }
//
//}

//std::vector<std::string>
//SystemInfo::split(std::string input) {
//    std::vector<std::string> words;
//    input += " ";
//    int word_start = 0;
//    for (int i = 0; i < input.size(); ++i) {
//        if(input[i] != ' ') continue;
//        if(input[i] == ' ') {
//            word_start = i + 1;
//            continue;
//        }
//        words.push_back(input.substr(word_start,i-word_start));
//    }
//    return words;
//}

std::vector<unsigned int>
SystemInfo::GPUPercent() {
    // get GPU usage percent
    if(!initialized_) Init();
    std::vector<unsigned int> result;
    nvmlUtilization_t utilization;
    for (int i = 0; i < num_device_; ++i) {
        nvmlDevice_t device;
        nvmlDeviceGetHandleByIndex(i, &device);
        nvmlDeviceGetUtilizationRates(device, &utilization);
        result.push_back(utilization.gpu);
    }
    return result;
}

std::vector<unsigned long long>
SystemInfo::GPUMemoryUsed() {
    // get GPU memory used
    if(!initialized_) Init();

    std::vector<unsigned long long int> result;
    nvmlMemory_t nvmlMemory;
    for (int i = 0; i < num_device_; ++i) {
        nvmlDevice_t device;
        nvmlDeviceGetHandleByIndex(i, &device);
        nvmlDeviceGetMemoryInfo(device, &nvmlMemory);
        result.push_back(nvmlMemory.used);
    }
    return result;
}

}
}
}