#ifndef NTPCLIENTPLUS_H
#define NTPCLIENTPLUS_H

#include <Arduino.h>
#include <WiFiUdp.h>

#define UNIX_TIMESTAMP_1900 2208988800UL // careful: positive value
#define NTP_PACKET_SIZE 48
#define NTP_DEFAULT_LOCAL_PORT 1337
#define MAX_NTP_CONN_TRIES 50       // 50 * NTP_RECEIVE_WAIT_TIME_MS => 500ms
#define NTP_RECEIVE_WAIT_TIME_MS 10 // 10ms

typedef enum
{
    NTP_UPDATE_TIMEOUT = -1,
    NTP_UPDATE_SUCCESS = 0,
    NTP_UPDATE_DIFFTOOHIGH = 1,
    NTP_UPDATE_TIME_INVALID = 2
} NtpReturnValue;

/**
 * @brief Own NTP Client library for Arduino with code from:
 * - https://github.com/arduino-libraries/NTPClient
 * - SPS&Technik - Projekt WordClock v1.02
 *
 */
class NTPClientPlus
{
public:
    NTPClientPlus(UDP &udp, const char *pool_server_name, int utcx, bool sw_change);
    bool is_leap_year(unsigned int year);
    bool check_daylight_saving_time();
    int get_hours_12() const;
    int get_hours_24() const;
    int get_minutes() const;
    int get_month(int dayOfYear);
    int get_seconds() const;
    int update_ntp();
    long get_time_offset();
    String get_formatted_date();
    String get_formatted_time() const;
    unsigned int get_day_of_week();
    unsigned int get_year();
    unsigned long get_epoch_time() const;
    unsigned long get_secs_since_1900() const;
    void calc_date();
    void end();
    void set_pool_server_name(const char *pool_server_name);
    void set_time_offset(int time_offset);
    void setup_ntp_client();

private:
    UDP *_udp;
    bool _udp_setup = false;

    bool _sw_change = 1;
    const char *_pool_server_name = "pool.ntp.org"; // Default time server
    int _utcx = 0;
    IPAddress _pool_server_ip;
    long _time_offset = 0;
    unsigned int _port = NTP_DEFAULT_LOCAL_PORT;

    unsigned long _update_interval = 60000; // In ms

    unsigned int _date_day = 0;
    unsigned int _date_month = 0;
    unsigned int _date_year = 0;
    unsigned int _day_of_week = 0;
    unsigned long _current_epoc = 0; // In s
    unsigned long _last_secs_since_1900 = 0;
    unsigned long _last_update = 0;     // In ms
    unsigned long _secs_since_1900 = 0; // seconds since 1. Januar 1900, 00:00:00

    unsigned char _packet_buffer[NTP_PACKET_SIZE] = {0};
    void send_ntp_packet();
    void set_summertime(bool summertime);

    static const unsigned long milliseconds_per_second = 1000;
    static const unsigned long minutes_per_hour = 60;
    static const unsigned long seconds_per_day = 86400;
    static const unsigned long seconds_per_hour = 3600;
    static const unsigned long seconds_per_minute = 60;

    // number of days in months
    unsigned int _days_per_month[13] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
};

void wait(unsigned long time_ms);

#endif /* NTPCLIENTPLUS_H */