#include <cpu.h>

#include <iostream>
#include <sstream>
#include <stdlib.h>
#include <unistd.h>
#include <math.h> 

CPU::CPU() {
    this->UPDATE_INTERVAL = 1000;
    this->m_isPolling = false;
    std::cout << "Number of hardware threads supported: " << CPU_HARDWARE_THREADS << std::endl;
    for (unsigned int thread; thread < CPU_HARDWARE_THREADS; thread++) {
        std::vector<int> temp1, temp2;
        
        for (int i = 0; i <= 2; i++) {
            temp1.push_back(0);
            temp2.push_back(0);
        }

        CPU_PREVIOUS_CORES_WORK_AND_TOTAL.push_back(temp1);
        CPU_CORES_WORK_AND_TOTAL.push_back(temp2);
    }
}

void CPU::START_CPU_POLLING() {
    if (this->m_isPolling) {
        return;
    }
    this->m_isPolling = true;
    std::cout << "Starting CPU worker thread" << std::endl;
    std::thread* t = new std::thread(&CPU::CPU_POLL, this);
    this->m_pollThread = t; 
}

void CPU::CPU_POLL(CPU* cpu) {
    std::cout << "New CPU worker thread" << std::endl;

    while (true) {
        cpu->CPU_Mutex.lock();
        if (!cpu->m_isPolling) {
            cpu->CPU_Mutex.unlock();
            return;
        }
        cpu->CPU_Mutex.unlock();

        // READ TOTAL CPU
        unsigned long long luser, nice, system, idle, iowait,
            irq, softirq;
        FILE* ProcStat = fopen("/proc/stat", "r");
        fscanf(ProcStat, "cpu %llu %llu %llu %llu %llu %llu %llu", &luser, 
            &nice, &system, &idle, &iowait, &irq, &softirq);

        cpu->CPU_Mutex.lock();

        // CALCULATE TOTAL CPU
        cpu->CPU_PREVIOUS_TOTAL = cpu->CPU_TOTAL;
        cpu->CPU_PREVIOUS_WORK = cpu->CPU_WORK;
        cpu->CPU_TOTAL = luser + nice + system + idle + iowait + irq + softirq;
        cpu->CPU_WORK = luser + nice + system;

        cpu->CPU_Mutex.unlock();
        
        for (unsigned int thread = 0; thread < cpu->CPU_HARDWARE_THREADS; thread++) {
            unsigned long long tluser, tnice, tsystem, tidle, tiowait,
                tirq, tsoftirq;
            
            std::stringstream pattern;
            pattern << "cpu" << thread << " %llu %llu %llu %llu %llu %llu %llu";

            fscanf(ProcStat, pattern.str().c_str(), &tluser, &tnice, &tsystem, 
                &tidle, &tiowait, &tirq, &tsoftirq);

            cpu->CPU_Mutex.lock();

            cpu->CPU_PREVIOUS_CORES_WORK_AND_TOTAL[thread][0] = cpu->CPU_CORES_WORK_AND_TOTAL[thread][0];
            cpu->CPU_PREVIOUS_CORES_WORK_AND_TOTAL[thread][1] = cpu->CPU_CORES_WORK_AND_TOTAL[thread][1];
            cpu->CPU_CORES_WORK_AND_TOTAL[thread][0] = tluser + tnice + tsystem + tidle + tiowait + tirq + tsoftirq;
            cpu->CPU_CORES_WORK_AND_TOTAL[thread][1] = tluser + tnice + tsystem;

            cpu->CPU_Mutex.unlock();
        }

        fclose(ProcStat);
        sleep(1);
    }
}

void CPU::END_CPU_POLLING() {
    if (!this->m_isPolling) {
        return;
    }
    this->m_isPolling = false;
    m_pollThread->join();
    delete m_pollThread;
}

double CPU::CPU_PERCENT(int core) {
    core--;

    this->CPU_Mutex.lock();

    long double totalOverTime = 0.0;
    long double workOverTime = 0.0;
    if (core == -1) {
        totalOverTime = this->CPU_PREVIOUS_TOTAL - this->CPU_TOTAL;
        workOverTime = this->CPU_PREVIOUS_WORK - this->CPU_WORK;
    } else {
        totalOverTime = this->CPU_PREVIOUS_CORES_WORK_AND_TOTAL[core][0] - this->CPU_CORES_WORK_AND_TOTAL[core][0];
        workOverTime = this->CPU_PREVIOUS_CORES_WORK_AND_TOTAL[core][1] - this->CPU_CORES_WORK_AND_TOTAL[core][1];
    }

    this->CPU_Mutex.unlock();

    double percent = (workOverTime / totalOverTime) * 100;
    if (isnan(percent)) percent = -1;
    return (double)percent;
}

std::vector<double> CPU::CPU_CORE_PERCENT() {
    std::vector<double> output;
    return output;    
}

CPU::~CPU() {
    this->m_isPolling = false;
    m_pollThread->join();
    delete m_pollThread;
}