/*
 * 
 * Oliver Brandmueller <ob@sysadm.in> 2017/2018
 * Klaus Wilting <verkehrsrot@arcor.de> 2018
 *
 * some lines of code taken from:
 * 
 * Copyright (c) 2017, Łukasz Marcin Podkalicki <lpodkalicki@gmail.com>
 * ESP32/016 WiFi Sniffer.
 * https://github.com/lpodkalicki/blog/tree/master/esp32/016_wifi_sniffer
 * 
 * Arduino-LMIC Library
 * TTN OTAA Example
 * https://github.com/matthijskooijman/arduino-lmic/blob/master/examples/ttn-otaa/
 * 
 * nkolban esp32 snippets
 * BLE Scan
 * https://github.com/nkolban/esp32-snippets/tree/master/cpp_utils/tests/BLETests/Arduino/BLE_scan
 * 
 * parts of code in lorawan.cpp has been grabbed from RadioHead Library
 */

// First things first
#include "main.h"

// std::set for unified array functions
#include <set>

// OLED driver
#include <U8x8lib.h>

#ifdef HAS_DISPLAY
    U8X8_SSD1306_128X64_NONAME_HW_I2C u8x8(OLED_RST, OLED_SCL, OLED_SDA);
#else
    U8X8_NULL u8x8;
#endif

// LMIC-Arduino LoRaWAN Stack
#include <lmic.h>
#include <hal/hal.h>

// Basic Config
#include "loraconf.h"
#include "configmanager.h"

// WiFi Functions
#include <esp_wifi.h>
#include <esp_wifi_types.h>
#include <esp_system.h>
#include <esp_event.h>
#include <esp_event_loop.h>
#include <esp_spi_flash.h>

configData_t cfg; // struct holds current device configuration
osjob_t sendjob, initjob; // LMIC

// Initialize global variables
int macnum = 0, blenum = 0;
uint32_t uptimecounter = 0;
bool joinstate = false;
extern uint8_t mydata[];

std::set<uint64_t, std::greater <uint64_t> > macs; // storage holds MAC frames

// this variable will be changed in the ISR, and read in main loop
static volatile bool ButtonTriggered = false;

// local Tag for logging
static const char *TAG = "paxcnt";
// Note: Log level control seems working during runtime, so we need to switch loglevel
// by compiler build option in platformio.ini
#ifndef VERBOSE
int redirect_log(const char * fmt, va_list args) {
   //do nothing
   return 0;
}
#endif

// defined in configmanager.cpp
void eraseConfig(void);
void saveConfig(void);
void loadConfig(void);


/* begin LMIC specific parts ------------------------------------------------------------ */

// defined in lorawan.cpp
void gen_lora_deveui(uint8_t * pdeveui);
#ifdef VERBOSE
    void printKeys(void);
#endif // VERBOSE

// LMIC callback functions
void os_getArtEui (u1_t *buf) { memcpy(buf, APPEUI, 8);}
void os_getDevKey (u1_t *buf) { memcpy(buf, APPKEY, 16);}
#ifdef DEVEUI // if DEVEUI defined in loraconf.h use that and hardwire it in code ...
    void os_getDevEui (u1_t *buf) { memcpy(buf, DEVEUI, 8);}
#else // ... otherwise generate DEVEUI at runtime from devices's MAC
    void os_getDevEui (u1_t *buf) { gen_lora_deveui(buf);} 
#endif

// LMIC enhanced Pin mapping 
const lmic_pinmap lmic_pins = {
    .mosi = PIN_SPI_MOSI,
    .miso = PIN_SPI_MISO,
    .sck = PIN_SPI_SCK,
    .nss = PIN_SPI_SS,
    .rxtx = LMIC_UNUSED_PIN,
    .rst = RST,
    .dio = {DIO0, DIO1, DIO2}
};

// LMIC functions
void onEvent(ev_t ev);
void do_send(osjob_t* j);

// LoRaWAN Initjob
static void lora_init (osjob_t* j) {
    // reset MAC state
    LMIC_reset();
    // This tells LMIC to make the receive windows bigger, in case your clock is 1% faster or slower.
    LMIC_setClockError(MAX_CLOCK_ERROR * 1 / 100); 
    // start joining
    LMIC_startJoining();
}

// LMIC Task
void lorawan_loop(void * pvParameters) {
    configASSERT( ( ( uint32_t ) pvParameters ) == 1 ); // FreeRTOS check
    while(1) {
        os_runloop_once();
        vTaskDelay(10/portTICK_PERIOD_MS);
        yield();
    }    
}

/* end LMIC specific parts --------------------------------------------------------------- */



/* beginn hardware specific parts -------------------------------------------------------- */

#ifdef LOPY
    // defined in antenna.cpp
    void antenna_init (void);
    void antenna_select (antenna_type_t antenna_type);
#endif

#if defined BLECOUNTER
    void BLECount(void);
#else
    btStop();
#endif

void set_onboard_led(int st){
#ifdef HAS_LED
    switch (st) {
        case 1: digitalWrite(LED_BUILTIN, HIGH); break;
        case 0: digitalWrite(LED_BUILTIN, LOW); break;
    }
#endif
};

#ifdef HAS_BUTTON
    // Button Handling, board dependent -> perhaps to be moved to new hal.cpp
    // IRAM_ATTR necessary here, see https://github.com/espressif/arduino-esp32/issues/855
    void IRAM_ATTR isr_button_pressed(void) {
        ButtonTriggered++; }
#endif

/* end hardware specific parts -------------------------------------------------------- */


/* begin wifi specific parts ---------------------------------------------------------- */

// defined in wifisniffer.cpp
void wifi_sniffer_init(void);
void wifi_sniffer_set_channel(uint8_t channel);
void wifi_sniffer_packet_handler(void *buff, wifi_promiscuous_pkt_type_t type);

//WiFi Sniffer Task
void wifi_sniffer_loop(void * pvParameters) {

    configASSERT( ( ( uint32_t ) pvParameters ) == 1 ); // FreeRTOS check
    uint8_t channel = 1;
    int nloop=0, lorawait=0;

  	while (true) {
        nloop++;
		vTaskDelay(cfg.wifichancycle*10 / portTICK_PERIOD_MS);
        yield();
		wifi_sniffer_set_channel(channel);
		channel = (channel % WIFI_CHANNEL_MAX) + 1;
        
        // duration of one wifi scan loop reached? then send data and begin new scan cycle
        if( nloop >= ((100 / cfg.wifichancycle) * (cfg.wifiscancycle * 2)) ) {
            u8x8.setPowerSave(!cfg.screenon); // set display on if enabled
            nloop = 0; // reset wlan sniffing loop counter
            
            // execute BLE count if BLE function is enabled
            #ifdef BLECOUNTER
                if ( cfg.blescan )
                    BLECount();
            #endif
            
            // Prepare and execute LoRaWAN data upload
            u8x8.setCursor(0,4);
            u8x8.printf("MAC#: %4i", macnum);
            do_send(&sendjob); // send payload
            vTaskDelay(500/portTICK_PERIOD_MS);
            yield();

            // clear counter if not in cumulative counter mode
            if ( cfg.countermode != 1 ) {
                macs.erase(macs.begin(), macs.end()); // clear RAM
                macnum = 0;
                u8x8.clearLine(0); u8x8.clearLine(1); // clear Display counter
            }      

            // wait until payload is sent, while wifi scanning and mac counting task continues
            lorawait = 0;
            while(LMIC.opmode & OP_TXRXPEND) {
                if(!lorawait) u8x8.drawString(0,6,"LoRa wait       ");
                lorawait++;
                // in case sending really fails: reset and rejoin network
                if( (lorawait % MAXLORARETRY ) == 0) {
                    ESP_LOGI(TAG, "Payload not sent, trying reset and rejoin");
                    esp_restart();
                };
                vTaskDelay(1000/portTICK_PERIOD_MS);
                yield();
            }

            u8x8.clearLine(6);
	                    
            if (cfg.screenon && cfg.screensaver) vTaskDelay(2000/portTICK_PERIOD_MS); // pause for displaying results
            yield();
            u8x8.setPowerSave(1 && cfg.screensaver); // set display off if screensaver is enabled
        }
    }
}

/* end wifi specific parts ------------------------------------------------------------ */

// uptime counter 64bit to prevent millis() rollover after 49 days
uint64_t uptime() {
    static uint32_t low32, high32;
    uint32_t new_low32 = millis();
    if (new_low32 < low32) high32++;
    low32 = new_low32;
    return (uint64_t) high32 << 32 | low32;
}

// Print a key on display
void DisplayKey(const uint8_t * key, uint8_t len, bool lsb) {
  uint8_t start=lsb?len:0;
  uint8_t end = lsb?0:len;
  const uint8_t * p ;
  for (uint8_t i=0; i<len ; i++) {
    p = lsb ? key+len-i-1 : key+i;
    u8x8.printf("%02X", *p);
  }
  u8x8.printf("\n");
}

void init_display(const char *Productname, const char *Version) {
    u8x8.begin();
    u8x8.setFont(u8x8_font_chroma48medium8_r);
#ifdef HAS_DISPLAY  
    uint8_t buf[32];
    u8x8.clear();
    u8x8.setFlipMode(0);
    u8x8.setInverseFont(1);
    u8x8.draw2x2String(0, 0, Productname);
    u8x8.setInverseFont(0);
    u8x8.draw2x2String(2, 2, Productname);
    delay(1500);
    u8x8.clear();
    u8x8.setFlipMode(1);
    u8x8.setInverseFont(1);
    u8x8.draw2x2String(0, 0, Productname);
    u8x8.setInverseFont(0);
    u8x8.draw2x2String(2, 2, Productname);
    delay(1500);

    u8x8.setFlipMode(0);
    u8x8.clear();

    // Display chip information
    #ifdef VERBOSE
        esp_chip_info_t chip_info;
        esp_chip_info(&chip_info);
        u8x8.printf("ESP32 %d cores\nWiFi%s%s\n",
            chip_info.cores,
            (chip_info.features & CHIP_FEATURE_BT) ? "/BT" : "",
            (chip_info.features & CHIP_FEATURE_BLE) ? "/BLE" : "");
        u8x8.printf("ESP Rev.%d\n", chip_info.revision);
        u8x8.printf("%dMB %s Flash\n", spi_flash_get_chip_size() / (1024 * 1024),
            (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "int." : "ext.");
    #endif // VERBOSE

    u8x8.print(Productname);
    u8x8.print(" v");
    u8x8.println(PROGVERSION);
    u8x8.println("DEVEUI:");
	os_getDevEui((u1_t*) buf);
    DisplayKey(buf, 8, true);
    delay(5000);
    u8x8.clear();
#endif // HAS_DISPLAY
}

/* begin Aruino SETUP ------------------------------------------------------------ */

void setup() {

    // setup debug output or silence device
#ifdef VERBOSE
    Serial.begin(115200);
    esp_log_level_set("*", ESP_LOG_VERBOSE);
#else
    // mute logs completely by redirecting them to silence function
    esp_log_level_set("*", ESP_LOG_NONE);
    esp_log_set_vprintf(redirect_log);
#endif
    
    ESP_LOGI(TAG, "Starting %s %s", PROGNAME, PROGVERSION);

/*
    tcpip_adapter_init(); // not sure if necessary, but seems needed for TTGOv1
    // ESP Event Loop
    esp_event_loop_init(NULL, NULL);  // not sure if necessary -> to be checked
*/

    // Print chip information on startup
#ifdef VERBOSE
    esp_chip_info_t chip_info;
    esp_chip_info(&chip_info);
    ESP_LOGI(TAG, "This is ESP32 chip with %d CPU cores, WiFi%s%s, silicon revision %d, %dMB %s Flash",
            chip_info.cores,
            (chip_info.features & CHIP_FEATURE_BT) ? "/BT" : "",
            (chip_info.features & CHIP_FEATURE_BLE) ? "/BLE" : "", 
            chip_info.revision, spi_flash_get_chip_size() / (1024 * 1024),
            (chip_info.features & CHIP_FEATURE_EMB_FLASH) ? "embedded" : "external");
    ESP_LOGI(TAG, "ESP32 SDK: %s", ESP.getSdkVersion());
#endif // VERBOSE

    // Read settings from NVRAM
    loadConfig(); // includes initialize if necessary
      
    // initialize hardware -> perhaps to be moved to new hal.cpp
#ifdef HAS_LED
    // initialize LED
    pinMode(LED_BUILTIN, OUTPUT); // white LED on Heltec board
    digitalWrite(LED_BUILTIN, LOW);
#endif

#ifdef HAS_BUTTON
    // install button interrupt
    pinMode(GPIO_NUM_0, INPUT_PULLDOWN); // button "PROG" on Heltec board
    attachInterrupt(digitalPinToInterrupt(GPIO_NUM_0), isr_button_pressed, FALLING); 
#endif

    // initialize wifi antenna
#ifdef LOPY
    antenna_init();
    antenna_select(WIFI_LOPY_ANTENNA);
#endif

    // initialize display
    init_display(PROGNAME, PROGVERSION);     
    u8x8.setPowerSave(!cfg.screenon); // set display off if disabled
    u8x8.setCursor(0,5);
    u8x8.printf(!cfg.rssilimit ? "RLIM:  off" : "RLIM: %4i", cfg.rssilimit);
    u8x8.drawString(0,6,"Join Wait       ");
    
    // output LoRaWAN keys to console
#ifdef VERBOSE
    printKeys();
#endif // VERBOSE

    os_init(); // setup LMIC
    os_setCallback(&initjob, lora_init); // setup initial job & join network 
    wifi_sniffer_init(); // setup wifi in monitor mode and start MAC counting
 
    // Start FreeRTOS tasks
#if CONFIG_FREERTOS_UNICORE // run all tasks on core 0 and switch off core 1
    ESP_LOGI(TAG, "Starting Lora task on core 0");
    xTaskCreatePinnedToCore(lorawan_loop, "loratask", 2048, ( void * ) 1,  ( 5 | portPRIVILEGE_BIT ), NULL, 0);  
    ESP_LOGI(TAG, "Starting Wifi task on core 0");
    xTaskCreatePinnedToCore(wifi_sniffer_loop, "wifisniffer", 4096, ( void * ) 1, 1, NULL, 0);
    // to come here: code for switching off core 1
#else // run wifi task on core 0 and lora task on core 1
    ESP_LOGI(TAG, "Starting Lora task on core 1");
    xTaskCreatePinnedToCore(lorawan_loop, "loratask", 2048, ( void * ) 1,  ( 5 | portPRIVILEGE_BIT ), NULL, 1);  
    ESP_LOGI(TAG, "Starting Wifi task on core 0");
    xTaskCreatePinnedToCore(wifi_sniffer_loop, "wifisniffer", 4096, ( void * ) 1, 1, NULL, 0);
#endif
    
    // Kickoff first sendjob, use payload "0000"
    uint8_t mydata[] = "0000";
    do_send(&sendjob);
}

/* end Aruino SETUP ------------------------------------------------------------ */


/* begin Aruino LOOP ------------------------------------------------------------ */

// Arduino main moop, runs on core 1
// https://techtutorialsx.com/2017/05/09/esp32-get-task-execution-core/
void loop() {
    while(1) {

    if (ButtonTriggered) {
        ButtonTriggered = false;
        ESP_LOGI(TAG, "Button pressed, resetting device to factory defaults");
        eraseConfig();
        esp_restart();
        }
    else {
        vTaskDelay(1000/portTICK_PERIOD_MS);
        uptimecounter = uptime() / 1000; // count uptime seconds
        }
    }
}

/* end Aruino LOOP ------------------------------------------------------------ */