/*

UTILS MODULE

Copyright (C) 2017-2018 by Xose Pérez <xose dot perez at gmail dot com>

*/

#include <Ticker.h>
Ticker _defer_reset;

String getIdentifier() {
    char buffer[20];
    snprintf_P(buffer, sizeof(buffer), PSTR("ESPURNA_%06X"), ESP.getChipId());
    return String(buffer);
}

String getCoreVersion() {
    String version = ESP.getCoreVersion();
    #ifdef ARDUINO_ESP8266_RELEASE
        if (version.equals("00000000")) {
            version = String(ARDUINO_ESP8266_RELEASE);
        }
    #endif
    return version;
}

String getCoreRevision() {
    #ifdef ARDUINO_ESP8266_GIT_VER
        return String(ARDUINO_ESP8266_GIT_VER);
    #else
        return String("");
    #endif
}

// WTF
// Calling ESP.getFreeHeap() is making the system crash on a specific
// AiLight bulb, but anywhere else...
unsigned int getFreeHeap() {
    if (getSetting("wtfHeap", 0).toInt() == 1) return 9999;
    return ESP.getFreeHeap();
}

String buildTime() {

    const char time_now[] = __TIME__;   // hh:mm:ss
    unsigned int hour = atoi(&time_now[0]);
    unsigned int minute = atoi(&time_now[3]);
    unsigned int second = atoi(&time_now[6]);

    const char date_now[] = __DATE__;   // Mmm dd yyyy
    const char *months[] = {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };
    unsigned int month = 0;
    for ( int i = 0; i < 12; i++ ) {
        if (strncmp(date_now, months[i], 3) == 0 ) {
            month = i + 1;
            break;
        }
    }
    unsigned int day = atoi(&date_now[3]);
    unsigned int year = atoi(&date_now[7]);

    char buffer[20];
    snprintf_P(
        buffer, sizeof(buffer), PSTR("%04d-%02d-%02d %02d:%02d:%02d"),
        year, month, day, hour, minute, second
    );

    return String(buffer);

}


unsigned long getUptime() {

    static unsigned long last_uptime = 0;
    static unsigned char uptime_overflows = 0;

    if (millis() < last_uptime) ++uptime_overflows;
    last_uptime = millis();
    unsigned long uptime_seconds = uptime_overflows * (UPTIME_OVERFLOW / 1000) + (last_uptime / 1000);

    return uptime_seconds;

}

void heartbeat() {

    unsigned long uptime_seconds = getUptime();
    unsigned int free_heap = getFreeHeap();

    // -------------------------------------------------------------------------
    // MQTT
    // -------------------------------------------------------------------------

    #if MQTT_SUPPORT
        #if (HEARTBEAT_REPORT_INTERVAL)
            mqttSend(MQTT_TOPIC_INTERVAL, HEARTBEAT_INTERVAL / 1000);
        #endif
        #if (HEARTBEAT_REPORT_APP)
            mqttSend(MQTT_TOPIC_APP, APP_NAME);
        #endif
        #if (HEARTBEAT_REPORT_VERSION)
            mqttSend(MQTT_TOPIC_VERSION, APP_VERSION);
        #endif
        #if (HEARTBEAT_REPORT_HOSTNAME)
            mqttSend(MQTT_TOPIC_HOSTNAME, getSetting("hostname").c_str());
        #endif
        #if (HEARTBEAT_REPORT_IP)
            mqttSend(MQTT_TOPIC_IP, getIP().c_str());
        #endif
        #if (HEARTBEAT_REPORT_MAC)
            mqttSend(MQTT_TOPIC_MAC, WiFi.macAddress().c_str());
        #endif
        #if (HEARTBEAT_REPORT_RSSI)
            mqttSend(MQTT_TOPIC_RSSI, String(WiFi.RSSI()).c_str());
        #endif
        #if (HEARTBEAT_REPORT_UPTIME)
            mqttSend(MQTT_TOPIC_UPTIME, String(uptime_seconds).c_str());
        #endif
        #if (HEARTBEAT_REPORT_DATETIME) & (NTP_SUPPORT)
            mqttSend(MQTT_TOPIC_DATETIME, String(ntpDateTime()).c_str());
        #endif
        #if (HEARTBEAT_REPORT_FREEHEAP)
            mqttSend(MQTT_TOPIC_FREEHEAP, String(free_heap).c_str());
        #endif
        #if (HEARTBEAT_REPORT_RELAY)
            relayMQTT();
        #endif
        #if (LIGHT_PROVIDER != LIGHT_PROVIDER_NONE) & (HEARTBEAT_REPORT_LIGHT)
            lightMQTT();
        #endif
        #if (HEARTBEAT_REPORT_VCC)
        #if ADC_VCC_ENABLED
            mqttSend(MQTT_TOPIC_VCC, String(ESP.getVcc()).c_str());
        #endif
        #endif
        #if (HEARTBEAT_REPORT_STATUS)
            mqttSend(MQTT_TOPIC_STATUS, MQTT_STATUS_ONLINE, true);
        #endif
        bool serial = !mqttConnected();
    #else
        bool serial = true;
    #endif

    // -------------------------------------------------------------------------
    // Serial
    // -------------------------------------------------------------------------

    if (serial) {
        DEBUG_MSG_P(PSTR("[MAIN] Uptime: %ld seconds\n"), uptime_seconds);
        DEBUG_MSG_P(PSTR("[MAIN] Free heap: %d bytes\n"), free_heap);
        #if ADC_VCC_ENABLED
            DEBUG_MSG_P(PSTR("[MAIN] Power: %d mV\n"), ESP.getVcc());
        #endif
    }
    #if NTP_SUPPORT
        DEBUG_MSG_P(PSTR("[MAIN] Time: %s\n"), (char *) ntpDateTime().c_str());
    #endif

    // -------------------------------------------------------------------------
    // InfluxDB
    // -------------------------------------------------------------------------

    #if INFLUXDB_SUPPORT
        #if (HEARTBEAT_REPORT_UPTIME)
            idbSend(MQTT_TOPIC_UPTIME, String(uptime_seconds).c_str());
        #endif
        #if (HEARTBEAT_REPORT_FREEHEAP)
            idbSend(MQTT_TOPIC_FREEHEAP, String(free_heap).c_str());
        #endif
    #endif

    // -------------------------------------------------------------------------
    // WebSockets
    // -------------------------------------------------------------------------
    #if WEB_SUPPORT
    #if NTP_SUPPORT
    {
        char buffer[200];
        snprintf_P(
            buffer,
            sizeof(buffer) - 1,
            PSTR("{\"time\": \"%s\", \"uptime\": %lu, \"heap\": %lu}"),
            ntpDateTime().c_str(), uptime_seconds, free_heap
        );
        wsSend(buffer);
    }
    #endif
    #endif

}

// -----------------------------------------------------------------------------

unsigned char resetReason() {
    static unsigned char status = 255;
    if (status == 255) {
        status = EEPROM.read(EEPROM_CUSTOM_RESET);
        if (status > 0) resetReason(0);
        if (status > CUSTOM_RESET_MAX) status = 0;
    }
    return status;
}

void resetReason(unsigned char reason) {
    EEPROM.write(EEPROM_CUSTOM_RESET, reason);
    EEPROM.commit();
}

void reset(unsigned char reason) {
    resetReason(reason);
    ESP.restart();
}

void deferredReset(unsigned long delay, unsigned char reason) {
    _defer_reset.once_ms(delay, reset, reason);
}

// -----------------------------------------------------------------------------

#if SYSTEM_CHECK_ENABLED

// Call this method on boot with start=true to increase the crash counter
// Call it again once the system is stable to decrease the counter
// If the counter reaches SYSTEM_CHECK_MAX then the system is flagged as unstable
// setting _systemOK = false;
//
// An unstable system will only have serial access, WiFi in AP mode and OTA

bool _systemStable = true;

void systemCheck(bool stable) {
    unsigned char value = EEPROM.read(EEPROM_CRASH_COUNTER);
    if (stable) {
        value = 0;
        DEBUG_MSG_P(PSTR("[MAIN] System OK\n"));
    } else {
        if (++value > SYSTEM_CHECK_MAX) {
            _systemStable = false;
            value = 0;
            DEBUG_MSG_P(PSTR("[MAIN] System UNSTABLE\n"));
        }
    }
    EEPROM.write(EEPROM_CRASH_COUNTER, value);
    EEPROM.commit();
}

bool systemCheck() {
    return _systemStable;
}

void systemCheckLoop() {
    static bool checked = false;
    if (!checked && (millis() > SYSTEM_CHECK_TIME)) {
        // Check system as stable
        systemCheck(true);
        checked = true;
    }
}

#endif

// -----------------------------------------------------------------------------

char * ltrim(char * s) {
    char *p = s;
    while ((unsigned char) *p == ' ') ++p;
    return p;
}

double roundTo(double num, unsigned char positions) {
    double multiplier = 1;
    while (positions-- > 0) multiplier *= 10;
    return round(num * multiplier) / multiplier;
}

void nice_delay(unsigned long ms) {
    unsigned long start = millis();
    while (millis() - start < ms) delay(1);
}