#include <sys/statvfs.h>

#include <array>
#include <chrono>
#include <csignal>
#include <cstdint>
#include <cstdlib>
#include <iostream>
#include <print>
#include <sstream>
#include <stop_token>
#include <string>
#include <thread>
//
#include <LCDDisplay.hpp>
#include <cpu.hpp>
#include <gpu.hpp>
#include <hass.hpp>
#include <sys.hpp>
#include <utils.hpp>

#define LCD_PORT "/dev/serial/by-id/usb-Raspberry_Pi_Pico_E6616407E37AA12F-if00"  // tis a symlink, can also be just /dev/ttyACM0
#define LCD_INTERVAL_MS 1000
#define LCD_CONTRAST 215
#define FILL_CHAR ' '

std::chrono::milliseconds interval(LCD_INTERVAL_MS);
std::stop_source sigint;

struct mem_usage_t {
    uint64_t free = 0;
    uint64_t used = 0;
    uint64_t total = 0;
};

struct sensors_t {
    std::array<std::string, 2> td;
    std::string loadavg;
    mem_usage_t ram;
    mem_usage_t home;
    gpu_t gpu;
    cpu_t cpu;
    float hass_state = 0;
};

/* DISPLAY FUNCS */

// pads given string to length
std::string pad(std::string s, uint8_t len, bool ljust = false) {
    if (len > s.size())
        s.insert(ljust ? s.end() : s.begin(), len - s.size(), FILL_CHAR);
    return s;
}

// fills n spaces
std::string fill(uint8_t n) {
    return std::string(n, FILL_CHAR);
}

/* GETTERS */

mem_usage_t getRam() {
    mem_usage_t mem;
    std::ifstream proc_meminfo("/proc/meminfo");

    if (proc_meminfo.good()) {
        std::string content((std::istreambuf_iterator<char>(proc_meminfo)), std::istreambuf_iterator<char>());
        mem.free = get_val("MemAvailable:", content);
        mem.total = get_val("MemTotal:", content);
        mem.used = mem.total - mem.free;
    }
    proc_meminfo.close();
    return mem;
}

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

void sighandler(int s) {
    std::println("[Signal] got SIGINT, exiting...");
    sigint.request_stop();
}

void hass_thread(sensors_t *s, std::stop_token st) {
    std::println("[Thread] Starting hass_thread, pid {}", gettid());
    hass_connect();
    while (!st.stop_requested()) {
        hass_poll();
        s->hass_state = hass_get();
        std::this_thread::sleep_for(std::chrono::milliseconds(100));
    }
    hass_disconnect();
}

void sensors_thread(sensors_t *s, std::stop_token st) {
    std::println("[Thread] Starting sensors_thread, pid {}", gettid());
    /* find hwmon paths from pci addresses */
    cpu_hwmon_t cpu_hwmon = detectCpuHwmon("0000:00:18.3");
    std::string gpu_hwmon = detectGpuHwmon("0000:08:00.0");

    while (!st.stop_requested()) {
        auto start = std::chrono::steady_clock::now();
        s->td = getTimeDate();
        s->loadavg = getAvgs();
        s->ram = getRam();
        s->home = getDisk("/home/drath");
        s->cpu = getCpu(cpu_hwmon);
        s->gpu = getGpu(gpu_hwmon);

        // std::print("[Sensors] took {} microseconds   \r", std::chrono::duration_cast<std::chrono::microseconds>(std::chrono::steady_clock::now() - start).count());
        // std::cout << std::flush;
        std::this_thread::sleep_until(start + interval);
    }
}

void display_thread(sensors_t *s, std::stop_token st) {
    std::println("[Thread] Starting display_thread, pid {}", gettid());
    LCDDisplay lcd(LCD_PORT);
    lcd.setCustomChar(0, {16, 6, 9, 8, 8, 9, 6, 0});  // celcius

    std::println("[Chrono] Running in daemon mode, {} ms interval", LCD_INTERVAL_MS);
    lcd.setContrast(LCD_CONTRAST);
    lcd.setBacklight(true);
    lcd.clear();

    while (!st.stop_requested()) {
        auto start = std::chrono::steady_clock::now();
        std::array<std::string, 4> lines;

        auto gpu_temps = (s->gpu.hotspot_temp) ? "/" + std::to_string(s->gpu.hotspot_temp) : "";
        gpu_temps += (s->gpu.mem_temp) ? "/" + std::to_string(s->gpu.mem_temp) : "";

        lcd.writeBuf(0, 0, pad(s->td[1], 11, true) + "   " + s->td[0] + lcd.bar(1, s->gpu.core_usage / 100.0) + pad(s->loadavg, 17));

        lcd.writeBuf(1, 0, pad(std::to_string(s->cpu.tctl) + "/" + std::to_string(s->cpu.tccd1) + lcd.cc[0], 8, true));
        lcd.writeBuf(1, 11, pad(pBytes(s->ram.used, true) + "B", 7, true));
        lcd.writeBuf(1, 22, pad(pBytes(s->gpu.vram_used) + "B", 7));
        lcd.writeBuf(1, 29, pad(std::to_string(s->gpu.edge_temp) + gpu_temps + lcd.cc[0], 11));

        lcd.writeBuf(2, 0, pad(pNum(s->cpu.ptotal, 1) + "W", 8, true));
        lcd.writeBuf(2, 10, pad(pNum(s->hass_state) + "W", 4));
        lcd.writeBuf(2, 15, pad("h:" + pBytes(s->home.free), 8));

        lcd.writeBuf(2, 25, pad(s->gpu.fan_speed + "R", 5));
        std::println("{}", s->gpu.fan_speed);
        lcd.writeBuf(2, 31, pad(std::to_string(s->gpu.power_avg) + "/" + std::to_string(s->gpu.power_cap) + "W", 9));

        lcd.writeBuf(3, 0, pad(pNum(s->cpu.vcore, 3) + "V", 7, true));
        lcd.writeBuf(3, 7, std::to_string(s->cpu.avg_freq) + "MHz");
        lcd.writeBuf(3, 21, pad(std::to_string(s->gpu.core_clock) + "/" + std::to_string(s->gpu.mem_clock) + "MHz ", 13));
        lcd.writeBuf(3, 34, pad(pNum(s->gpu.vcore, 3) + "V", 5));

        lcd.flushBuffer();

        std::this_thread::sleep_until(start + interval);
    }
}

int main(int argc, char *argv[]) {
    signal(SIGINT, sighandler);

    sensors_t sensors;

    std::jthread producer(sensors_thread, &sensors, sigint.get_token());
    std::jthread hass(hass_thread, &sensors, sigint.get_token());

    display_thread(&sensors, sigint.get_token());
    return 0;
}