#include "HermitCrab.h"
#include "TimeManager.h"
#include "ConnectWiFi.h"
#include <sys/time.h>
#include "Config.h"
#define TAG_TIME "Time"
TimeManager timeManager;

void TimeManager::begin() {
    setenv("TZ", "UTC", 1); // Set time zone to Asia/Seoul (UTC+9)
    tzset();  // Apply the timezone setting

    // Initialize UDP only if WiFi is connected
    if (isWiFiConnected() && !udpInitialized) {
        udpInitialized =  udp.begin(localPort);
    }
    // Send an initial NTP request on startup
    sendNTPRequest();
    lastNTPRequestMillis = millis();
}

void TimeManager::Stop() {
    if (udpInitialized) {
        udp.stop();
    }
}

bool TimeManager::getTime(unsigned long tickMillis) {
    // Check WiFi Connection
    if (!isWiFiConnected()) {
        //ESP_LOGI(TAG_TIME,"TimeManager - getTime called while not connected");
        if (udpInitialized) udpInitialized = false;
        return false;
    }

    // Check if 30 minutes have passed since last NTP request
    if (udpInitialized && 
        ((tickMillis - lastNTPRequestMillis >= NTP_REQUEST_INTERVAL) ||
        !bHasNTPTime && (tickMillis - lastNTPRequestMillis >= NTP_FAILED_INTERNAL))) {
        sendNTPRequest();
        lastNTPRequestMillis = tickMillis;
    }

    // Check if there is an NTP response, and if so, update the system clock
    return checkNTPResponse();
}

MY_IRAM_ATTR void TimeManager::sendNTPRequest() {
    byte ntpPacket[48] = {0};
    ntpPacket[0] = 0b11100011;  // LI, Version, Mode
    ntpPacket[1] = 0;           // Stratum, or type of clock
    ntpPacket[2] = 6;           // Polling Interval
    ntpPacket[3] = 0xEC;        // Peer Clock Precision

    udp.beginPacket(ntpServer, 123); // NTP requests are sent to port 123
    udp.write(ntpPacket, 48);
    udp.endPacket();
}

MY_IRAM_ATTR bool TimeManager::checkNTPResponse() {
    if (udp.parsePacket() == 0) {
        // No response yet
        return false;
    }

    byte ntpBuffer[48];
    udp.read(ntpBuffer, 48);

    // Extract and set the time if response is valid
    unsigned long epochTime = (unsigned long)ntpBuffer[40] << 24 |
                              (unsigned long)ntpBuffer[41] << 16 |
                              (unsigned long)ntpBuffer[42] << 8 |
                              (unsigned long)ntpBuffer[43];
    epochTime -= 2208988800UL; // Convert from NTP to Unix time
    // epochTime += (9 * 3600); // GMT+9
    if (!bHasNTPTime) {
        bHasNTPTime = true;
        firstNTPTime = epochTime;
        config.m_nEpochTime = epochTime;
    }
    setSystemClock(epochTime);
    // ESP_LOGI(TAG_TIME,printTime());
    return true;
}


void TimeManager::setSystemClock(unsigned long epochTime) {
    struct timeval now;
    now.tv_sec = epochTime;
    now.tv_usec = 0;
    settimeofday(&now, NULL);
}