#include <sys/statvfs.h>

#include <array>
#include <chrono>
#include <cstdint>
#include <cstdlib>
#include <ctime>
#include <fstream>
#include <iomanip>
#include <iostream>
#include <sstream>
#include <string>
#include <thread>

#include "include/LCDDisplay.hpp"
#include "include/linux-system-usage.hpp"

#define LCD_PORT "/dev/ttyACM0"
#define LCD_INTERVAL_MS 1000
#define LCD_CONTRAST 225

struct gpuHwmon_t {
    std::string fan_speed;
    std::string core_clock;
    std::string mem_clock;
    std::string core_mv;
    std::string power_avg;
    std::string power_cap;
    std::string power_max;
    std::string fan_pwm;
    std::string edge_temp;
    std::string junction_temp;
    std::string mem_temp;
};

struct mem_usage_t {
    std::string free;
    std::string used;
    std::string total;
};

std::string pBytes(double i, bool isKbytes = false) {
    std::stringstream ss;
    std::array suffix = {'K', 'M', 'G', 'T', 'P', 'E', 'Z'};
    for (auto &s : suffix) {
        if (s == 'K' && isKbytes) continue;
        i /= 1024.0;
        if (i < 1024) {
            ss << std::fixed << std::setprecision(i > 100 ? 1 : 2) << i << s;
            return ss.str();
        }
    }
    return "++++";
}

std::string pad(std::string s, uint8_t w, bool ljust = false) {
    if (w > s.size()) s.insert(ljust ? s.end() : s.begin(), w - s.size(), ' ');
    return s;
}

std::string getAvgs() {
    std::stringstream ss;
    double avgs[3];
    getloadavg(avgs, 3);
    ss << std::fixed << std::setprecision(2);
    ss << avgs[0] << " " << avgs[1] << " " << avgs[2];
    return ss.str();
}

std::array<std::string, 2> getTimeDate() {
    std::array months = {"sty", "lut", "mar", "kwi", "maj", "cze", "lip", "sie", "wrz", "paz", "lis", "gru"};
    std::array wdays = {"nie", "pon", "wto", "sro", "czw", "pia", "sob"};
    auto now = std::time(nullptr);
    auto tm = *std::localtime(&now);
    std::stringstream time, date;
    time << std::setfill('0');
    time << std::setw(2) << tm.tm_hour << ":";
    time << std::setw(2) << tm.tm_min << ":";
    time << std::setw(2) << tm.tm_sec;
    date << wdays[tm.tm_wday] << ", " << tm.tm_mday << " " << months[tm.tm_mon];
    return {time.str(), date.str()};
}

mem_usage_t getRam() {
    mem_usage_t mem;
    auto memory_data = get_system_usage_linux::read_memory_data();
    mem.free = pBytes(memory_data.available_memory, true);
    mem.used = pBytes(memory_data.total_memory - memory_data.available_memory, true);
    mem.total = pBytes(memory_data.total_memory, true);
    return mem;
}

mem_usage_t getDisk(std::string mount) {
    mem_usage_t disk;
    struct statvfs diskData;
    statvfs(mount.c_str(), &diskData);
    disk.free = pBytes(diskData.f_bfree * diskData.f_frsize);
    disk.used = pBytes((diskData.f_blocks - diskData.f_bfree) * diskData.f_frsize);
    disk.total = pBytes(diskData.f_blocks * diskData.f_frsize);
    return disk;
}

std::string readFile(std::string path, uint8_t trim = 0) {
    std::string ret;
    std::stringstream ss;
    std::ifstream fs(path);
    if (!fs.good()) {
        std::cerr << "Error reading " << path << std::endl;
        exit(1);
    }
    ss << fs.rdbuf();
    fs.close();
    ret = ss.str();
    return ret.substr(0, ret.size() - trim - 1);
}

gpuHwmon_t getGpu(std::string hw) {
    gpuHwmon_t gpu;

    gpu.fan_speed = readFile(hw + "/fan1_input");
    gpu.core_clock = readFile(hw + "/freq1_input", 6);
    gpu.mem_clock = readFile(hw + "/freq2_input", 6);
    gpu.core_mv = readFile(hw + "/in0_input");
    gpu.power_avg = readFile(hw + "/power1_average", 6);
    gpu.power_cap = readFile(hw + "/power1_cap", 6);
    gpu.power_max = readFile(hw + "/power1_cap_max", 6);
    gpu.fan_pwm = readFile(hw + "/pwm1");
    gpu.edge_temp = readFile(hw + "/temp1_input", 3);
    gpu.junction_temp = readFile(hw + "/temp2_input", 3);
    gpu.mem_temp = readFile(hw + "/temp3_input", 3);

    return gpu;
}

std::string getCpuTemp() {
    return readFile("/sys/devices/pci0000:00/0000:00:18.3/hwmon/hwmon3/temp1_input");
}

void collectAndDraw(LCDDisplay *lcd) {
    auto td = getTimeDate();
    auto ram = getRam();
    auto anime = getDisk("/mnt/anime");
    auto home = getDisk("/var/home/drath");
    auto gpu = getGpu("/sys/devices/pci0000:00/0000:00:03.1/0000:08:00.0/0000:09:00.0/0000:0a:00.0/hwmon/hwmon2");

    std::array<std::string, 4> lines;

    lines[0] = td[1] + " " + td[0] + pad(getAvgs(), 20);

    lines[1] = pad(ram.used + "/" + ram.total, 13, true) + "    ";
    lines[1] += pad(gpu.fan_speed + "R", 5) + " ";
    lines[1] += pad(gpu.power_avg + "/" + gpu.power_cap + "W", 8) + " ";
    lines[1] += pad(gpu.edge_temp + "/" + gpu.junction_temp + "C", 8);

    lines[2] = "/home/drath:" + pad(home.free + " free of " + home.total, 28);

    lines[3] = "/mnt/anime: " + pad(anime.free + " free of " + anime.total, 28);

    lcd->writeLines(lines);
}

int main(int argc, char *argv[]) {
    LCDDisplay lcd(LCD_PORT, 0010002);

    if (argc > 1 && std::string(argv[1]) == "-d") {
        std::cout << "[Chrono] Running in daemon mode, " << LCD_INTERVAL_MS << "ms interval" << std::endl;
        lcd.setContrast(LCD_CONTRAST);
        std::chrono::milliseconds interval(LCD_INTERVAL_MS);
        auto start = std::chrono::steady_clock::now();
        while (true) {
            collectAndDraw(&lcd);
            std::this_thread::sleep_until(start + interval);
            start += interval;
        }
    } else {
        collectAndDraw(&lcd);
    }

    return 0;
}