#include "Network.h"

#include <WiFi.h>
#include <WiFiClientSecure.h>
#include <HTTPClient.h>

#define ARDUINOJSON_DECODE_UNICODE 1
#include <ArduinoJson.h>

// Static Json from ArduinoJson library
StaticJsonDocument<6000> doc;

void Network::begin()
{
    byte TryCounter = 0;
    
    // Initiating wifi, like in BasicHttpClient example
    WiFi.mode(WIFI_STA);
    WiFi.begin(ssid, pass);

    while ((WiFi.status() != WL_CONNECTED) && (TryCounter < 10))
    {
        delay(1000);
        TryCounter++;
    }

    // Find internet time
    setTime();

    // Update calendar
    setCalendar();
}

// Gets time from ntp server
void Network::getTime(int *timeDigits)
{
    struct tm timeinfo;
    time_t nowSecs = time(nullptr);

    setenv("TZ", timeZone, 1);
    tzset();
    localtime_r(&nowSecs, &timeinfo);

    // fill in the digits
    timeDigits[0] = timeinfo.tm_min % 10;    //minutes (units)
    timeDigits[1] = timeinfo.tm_min / 10;    //minutes (tens)
    timeDigits[2] = timeinfo.tm_hour % 10;   //hours (units)
    timeDigits[3] = timeinfo.tm_hour / 10;   //hours (tens)
}

// Function to get calendar from web
void Network::setCalendar()
{
    // Http object used to make get request
    HTTPClient http;

    http.getStream().setNoDelay(true);
    http.getStream().setTimeout(10);

    // Initiate http
    http.begin(calendarURL);

    // Actually do request
    int httpCode = http.GET();
    if (httpCode == 200)
    {
        int32_t len = http.getSize();

        if (len > 0)
        {
            // Try parsing JSON object
            DeserializationError error = deserializeJson(doc, http.getStream());
            JsonArray arr = doc.as<JsonArray>();

            if (!error)
            {
                // delete array in RTC because a possible smaller new array
                for (int i = 0; i < 5; ++i)
                {
                    calName[i][0] = '\0';
                    calStart[i][0] = '\0';
                    calTitle[i][0] = '\0';
                }

                int i = 0;
                for (JsonArray::iterator it=arr.begin(); it!=arr.end(); ++it)
                {
                    JsonObject row = *it;
                    
                    strncpy(calName[i], row["calendar"].as<char *>(), 30);
                    utf8_to_latin9(calName[i], calName[i], 30);
                    strncpy(calStart[i], row["start"].as<char *>(), 25);
                    strncpy(calTitle[i], row["title"].as<char *>(), 80);
                    utf8_to_latin9(calTitle[i], calTitle[i], 80);
                    if (++i >= 5) break;
                }
            }
        }
    }

    // Clear document and end http
    doc.clear();
    http.end();
}

void Network::off()
{
    WiFi.disconnect(true);
    WiFi.mode(WIFI_OFF);
}

void Network::setTime()
{
    byte TryCounter = 0;

    // Used for setting correct time
    configTime(0, 0, "de.pool.ntp.org", "time.nist.gov");

    delay(2000);  // wait 2s to (re)sync time
                  // if time is already set in RTC,
                  // the loop below doesn't wait for sync
                  // because the time value is valid

    time_t nowSecs = time(nullptr);
    while ((nowSecs < 8 * 3600 * 2)&& (TryCounter < 120))
    {
        delay(500);
//        yield();
        nowSecs = time(nullptr);
        TryCounter++;
    }
}


/* UTF-8 to ISO-8859-1/ISO-8859-15 mapper.
 * Return 0..255 for valid ISO-8859-15 code points, 256 otherwise.
*/
static inline unsigned int to_latin9(const unsigned int code)
{
    /* Code points 0 to U+00FF are the same in both. */
    if (code < 256U)
        return code;
    switch (code) {
    case 0x0152U: return 188U; /* U+0152 = 0xBC: OE ligature */
    case 0x0153U: return 189U; /* U+0153 = 0xBD: oe ligature */
    case 0x0160U: return 166U; /* U+0160 = 0xA6: S with caron */
    case 0x0161U: return 168U; /* U+0161 = 0xA8: s with caron */
    case 0x0178U: return 190U; /* U+0178 = 0xBE: Y with diaresis */
    case 0x017DU: return 180U; /* U+017D = 0xB4: Z with caron */
    case 0x017EU: return 184U; /* U+017E = 0xB8: z with caron */
    case 0x20ACU: return 164U; /* U+20AC = 0xA4: Euro */
    default:      return 256U;
    }
}

/* Convert an UTF-8 string to ISO-8859-15.
 * All invalid sequences are ignored.
 * Note: output == input is allowed,
 * but   input < output < input + length
 * is not.
 * Output has to have room for (length+1) chars, including the trailing NUL byte.
*/
size_t Network::utf8_to_latin9(char *const output, const char *const input, const size_t length)
{
    unsigned char             *out = (unsigned char *)output;
    const unsigned char       *in  = (const unsigned char *)input;
    const unsigned char *const end = (const unsigned char *)input + length;
    unsigned int               c;

    while (in < end)
        if (*in < 128)
            *(out++) = *(in++); /* Valid codepoint */
        else
        if (*in < 192)
            in++;               /* 10000000 .. 10111111 are invalid */
        else
        if (*in < 224) {        /* 110xxxxx 10xxxxxx */
            if (in + 1 >= end)
                break;
            if ((in[1] & 192U) == 128U) {
                c = to_latin9( (((unsigned int)(in[0] & 0x1FU)) << 6U)
                             |  ((unsigned int)(in[1] & 0x3FU)) );
                if (c < 256)
                    *(out++) = c;
            }
            in += 2;

        } else
        if (*in < 240) {        /* 1110xxxx 10xxxxxx 10xxxxxx */
            if (in + 2 >= end)
                break;
            if ((in[1] & 192U) == 128U &&
                (in[2] & 192U) == 128U) {
                c = to_latin9( (((unsigned int)(in[0] & 0x0FU)) << 12U)
                             | (((unsigned int)(in[1] & 0x3FU)) << 6U)
                             |  ((unsigned int)(in[2] & 0x3FU)) );
                if (c < 256)
                    *(out++) = c;
            }
            in += 3;

        } else
        if (*in < 248) {        /* 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx */
            if (in + 3 >= end)
                break;
            if ((in[1] & 192U) == 128U &&
                (in[2] & 192U) == 128U &&
                (in[3] & 192U) == 128U) {
                c = to_latin9( (((unsigned int)(in[0] & 0x07U)) << 18U)
                             | (((unsigned int)(in[1] & 0x3FU)) << 12U)
                             | (((unsigned int)(in[2] & 0x3FU)) << 6U)
                             |  ((unsigned int)(in[3] & 0x3FU)) );
                if (c < 256)
                    *(out++) = c;
            }
            in += 4;

        } else
        if (*in < 252) {        /* 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
            if (in + 4 >= end)
                break;
            if ((in[1] & 192U) == 128U &&
                (in[2] & 192U) == 128U &&
                (in[3] & 192U) == 128U &&
                (in[4] & 192U) == 128U) {
                c = to_latin9( (((unsigned int)(in[0] & 0x03U)) << 24U)
                             | (((unsigned int)(in[1] & 0x3FU)) << 18U)
                             | (((unsigned int)(in[2] & 0x3FU)) << 12U)
                             | (((unsigned int)(in[3] & 0x3FU)) << 6U)
                             |  ((unsigned int)(in[4] & 0x3FU)) );
                if (c < 256)
                    *(out++) = c;
            }
            in += 5;

        } else
        if (*in < 254) {        /* 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx */
            if (in + 5 >= end)
                break;
            if ((in[1] & 192U) == 128U &&
                (in[2] & 192U) == 128U &&
                (in[3] & 192U) == 128U &&
                (in[4] & 192U) == 128U &&
                (in[5] & 192U) == 128U) {
                c = to_latin9( (((unsigned int)(in[0] & 0x01U)) << 30U)
                             | (((unsigned int)(in[1] & 0x3FU)) << 24U)
                             | (((unsigned int)(in[2] & 0x3FU)) << 18U)
                             | (((unsigned int)(in[3] & 0x3FU)) << 12U)
                             | (((unsigned int)(in[4] & 0x3FU)) << 6U)
                             |  ((unsigned int)(in[5] & 0x3FU)) );
                if (c < 256)
                    *(out++) = c;
            }
            in += 6;

        } else
            in++;               /* 11111110 and 11111111 are invalid */

    /* Terminate the output string. */
    *out = '\0';

    return (size_t)(out - (unsigned char *)output);
}