/******************************************************************************
 * 2016 IdeasX v0.3.1 Module Firmware
 *
 * File Name: wifi.c
 * Author: Tyler Berezowsky
 * Description: This file is going to need alot of help by a C wizard, but it currently works...I think.
 *
 *     2016/8/8, v1.0 created this file
*******************************************************************************/
#include "util/wifi.h"
#include "esp_common.h"

#define WIFI_TIMEOUT 30*1000 		// time waited before swiping left in seconds
#define WIFI_RECONNECT_LIMIT 5		// number of times connection to AP is attempted before moving on

MQTT_Client mqttClient;	//  setup in user_main.c

static struct station_config stationConf;
static WIFI_PROCESS_FLAGS wifi_process_flags;
static ETSTimer wifi_process_timer;
static struct bss_info  *bss_link, *head_bss_link;

static void ICACHE_FLASH_ATTR wifi_process(void);
static void ICACHE_FLASH_ATTR wifi_process_timer_cb(void);


/******************************************************************************
 * FunctionName : destory_linked_list
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static bool ICACHE_FLASH_ATTR destory_linked_list(void)
{
	if(head_bss_link != NULL)
	{
		while(head_bss_link != NULL)
		{
			bss_link = head_bss_link;
			head_bss_link = head_bss_link->next.stqe_next;
			os_free(bss_link);
		}
		return TRUE;
	}
	else
	{
		return FALSE;
	}
}
/******************************************************************************
 * FunctionName : copy_linked_list
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static struct bss_info* ICACHE_FLASH_ATTR copy_linked_list(struct bss_info *ptr_original_node)
{
	struct bss_info *ptr_new_head, *ptr_new_node;

	if(ptr_original_node != NULL)
	{
		ptr_new_head = (struct bss_info *)os_malloc(sizeof(struct bss_info));
		if (ptr_new_head == NULL)
		{
			os_printf("WIFI PROCESS: No RAM!\r\n");
			return NULL;
		}
	}
	else
		return NULL;

	os_memcpy(ptr_new_head, ptr_original_node, sizeof(struct bss_info));
	ptr_original_node = ptr_original_node->next.stqe_next;

	ptr_new_node = ptr_new_head;

	while(ptr_original_node != NULL)
	{
		ptr_new_node->next.stqe_next = (struct bss_info *)os_malloc(sizeof(struct bss_info));
		ptr_new_node = ptr_new_node->next.stqe_next;
		os_memcpy(ptr_new_node, ptr_original_node, sizeof(struct bss_info));
		if (ptr_new_node == NULL)
		{
			os_printf("WIFI PROCESS: No RAM!\r\n");
			while(ptr_new_head != NULL)
			{
				ptr_new_node = ptr_new_head;
				ptr_new_head = ptr_new_head->next.stqe_next;
				os_free(ptr_new_node);
			}
			os_printf("WIFI PROCESS: Cleaned up list\r\n");
			return NULL;
		}
		ptr_original_node = ptr_original_node->next.stqe_next;

	}
	return ptr_new_head;
}
/******************************************************************************
 * FunctionName : wifi_set_station
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR wifi_set_station(uint8_t* ssid, uint8_t* pass)
{
	bss_link = NULL;

	os_sprintf(stationConf.ssid, "%s", ssid);			// load ssid into stationConf.ssid
	os_sprintf(stationConf.password, "%s", pass);		// load pass into stationConf.password

	wifi_station_set_config_current(&stationConf);				// connect to AP specified in stationConf
	wifi_station_set_auto_connect(TRUE);
	wifi_station_connect();
}
/******************************************************************************
 * FunctionName : disable_wifi_reconnect
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR disable_wifi_reconnect(void)
{
	wifi_station_disconnect();
	wifi_station_set_auto_connect(FALSE);
}
/******************************************************************************
 * FunctionName : show_wifi_config
 * Description  : print current wifi configurations
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR show_wifi_config(void)
{
	uint8_t i, j;
	j = sysCfg.registered_stations;

	os_printf("Number of APs stored: %d\r\n", j);
	for (i=0;i<j;i++)
		os_printf("AP: %d\n\tSSID: %s\n\tPASS: %s\n", i, sysCfg.sta_ssid[i], sysCfg.sta_pwd[i]);
	/* This is not accurate. If the module is not connected to an AP it should display unconnected for
		current station
	*/
	i = sysCfg.current_station;
	j = wifi_station_get_connect_status();
	os_printf("Current AP: %d\r\nWiFi Status %d\r\n", i, j);
}
/******************************************************************************
 * FunctionName : wifi_process_timer_cb
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_process_timer_cb()
{
	os_printf("WIFI PROCESS: Wi-Fi connection timed out.\r\n");
	wifi_process_flags.wifi_flag = FALSE;


	wifi_station_set_auto_connect(FALSE);
	wifi_station_disconnect();
	wifi_process();
}
/******************************************************************************
 * FunctionName : wifi_process
 * Description  : Looks for AP stored in bss_link
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_process(void)
{
	uint8_t ssid[33];
	uint8_t i;

	os_timer_disarm(&wifi_process_timer);								// disarm timeout timer

	if ((wifi_process_flags.wifi_flag == FALSE) && (bss_link != NULL)) // if AP connection failed and bss_link is not empty
	{
		while(bss_link != NULL)	// do this until bss_link is empty or break
		{

			// ssid could be missing null character
			os_memset(ssid, 0, 33);
			if (os_strlen(bss_link->ssid) <= 32)
			{
				os_memcpy(ssid, bss_link->ssid, os_strlen(bss_link->ssid));
			}
			else
			{
				os_memcpy(ssid, bss_link->ssid, 32);
			}

			// compare current ssid from bss_link to registered stations
			for(i=0;i<sysCfg.registered_stations;i++)
			{
				//os_printf("Comparing %s and %s\r\n", ssid, sysCfg.sta_ssid[i]);
				if (!strcmp(ssid, sysCfg.sta_ssid[i]))
				{
					wifi_process_flags.wifi_flag = TRUE; 	// set connect attempt flag
					wifi_process_flags.wifi_count = 0; 		// rst connect attempt count

					os_sprintf(stationConf.ssid, "%s", sysCfg.sta_ssid[i]);
					os_sprintf(stationConf.password, "%s", sysCfg.sta_pwd[i]);	// if AUTH_OPEN pwd should be NULL
					sysCfg.current_station = i;									// store current station number for sysCfg save and UART operations
					wifi_station_set_config_current(&stationConf); 				// load stationConf into SDK, but don't save in SDK flash
					wifi_station_set_auto_connect(TRUE);
					wifi_station_connect();

					bss_link = bss_link->next.stqe_next; 						// inc to next station in case process fails

					//set wifi_process_timer for timeout.
					os_timer_setfn(&wifi_process_timer, (os_timer_func_t *)wifi_process_timer_cb, NULL);
					os_timer_arm(&wifi_process_timer, WIFI_TIMEOUT, 0); 		// arm timeout timer
					break; // break for loop
				}

			}

			// break while if station found, otherwise look for another station.
			if (wifi_process_flags.wifi_flag == TRUE)
			{
				break;	// break while loop
			}
			else
			{
				bss_link = bss_link->next.stqe_next;
			}
		}

	}
	if ((wifi_process_flags.wifi_flag == FALSE) && (bss_link == NULL))
	{
		// this is called twice...which could be a problem.
		sysCfg.module_state.searching = FALSE;
		sysCfg.module_state.asleep = FALSE;
		destory_linked_list();
		os_printf("WIFI PROCESS: Station list removed\r\n");
		os_printf("WIFI PROCESS: No Wi-Fi APs available.\r\n");
		// try again in a second....three times...if motion flag is set keep trying otherwise you should goto sleep.

		if (lsm6ds3_read_motion())		// change this to a poll on the LSM6DS3 line.
			start_wifi_process();
		else
		{
			GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 0xFFFFFFFF);	// clear pending interrupts
			sysCfg.module_state.asleep = TRUE;
			ETS_GPIO_INTR_ENABLE(); 								// enable interrupts to permit PB and LSM6DS3 to wake ESP from sleep.
			/*

			 *	The ESP8266 should be placed into light sleep or modem sleep here

			 */
		}
	}

}
/******************************************************************************
 * FunctionName : wifi_handle_event_cb
 * Description  : callback function for wifi events.
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_handle_event_cb(System_Event_t *evt)
{
	switch (evt->event)
 	{
		case EVENT_STAMODE_CONNECTED:
		{
			wifi_process_flags.wifi_count = 0;	// rst wifi connection cnt

			os_printf("WIFI PROCESS: connect to ssid %s, channel %d\n",
			evt->event_info.connected.ssid,
			evt->event_info.connected.channel);
			break;
		}
		case EVENT_STAMODE_DISCONNECTED:
		{
			/*
				There is an issue where if the module is connected to an AP and then loses it, it continously scans for the
				last access point it attempted to connect to.
			*/
			sysCfg.module_state.connected = FALSE;	// set global connected flag false
			sysCfg.module_state.searching = TRUE;
			/*
				The only way to cancel the auto-connect functionaity of the SDK's OS is to
				send the command wifi_station_disconnect(), this ALWAYS calles the wifi event
				handler. Checking for this flag lets us ignore it.
			*/
			if (wifi_process_flags.wifi_flag == TRUE)
			{
				MQTT_Disconnect(&mqttClient);
				wifi_process_flags.wifi_count++;

				os_printf("WIFI PROCESS: disconnect from ssid %s, reason %d, attempt %d/%d\r\n",
				evt->event_info.disconnected.ssid,
				evt->event_info.disconnected.reason,
				wifi_process_flags.wifi_count,
				WIFI_RECONNECT_LIMIT);

				if (wifi_process_flags.wifi_count >= WIFI_RECONNECT_LIMIT)	// allow WIFI_RECONNECT_LIMIT for reconnect and 1st attempts
				{
					if (wifi_process_flags.ip_flag == TRUE)	// if was connected, but then lost connection
					{
						start_wifi_process();				// rst apd mode process, flags will automatically be reset
					}
					else									// if never got a connection finish looking at all the available stations.
					{
						wifi_process_flags.wifi_flag = FALSE;
						wifi_station_set_auto_connect(FALSE);
						wifi_station_disconnect();
						wifi_process();
					}
				}
			}
			break;
		}
		case EVENT_STAMODE_AUTHMODE_CHANGE:
		{
			os_printf("WIFI PROCESS: mode: %d -> %d\n",
			evt->event_info.auth_change.old_mode,
			evt->event_info.auth_change.new_mode);
			break;
		}
		case EVENT_STAMODE_GOT_IP:
		{
			os_timer_disarm(&wifi_process_timer);								// disarm timeout timer
			wifi_process_flags.ip_flag = TRUE;

			sysCfg.module_state.connected = TRUE;								// set global connected flag
			sysCfg.module_state.searching = FALSE;								// set global searching flag false

			os_printf("WIFI PROCESS: ip:" IPSTR ",mask:" IPSTR ",gw:" IPSTR,
			IP2STR(&evt->event_info.got_ip.ip),
			IP2STR(&evt->event_info.got_ip.mask),
			IP2STR(&evt->event_info.got_ip.gw));

			destory_linked_list();
			os_printf("\r\nWIFI PROCESS: Station list removed\r\n");

			lsm6ds3_motion_disable(); 											// disable LSM6DS3 significant motion functionality
			MQTT_Connect(&mqttClient); 											// start MQTT client

			break;
		}
		default:
		{
			os_printf("WIFI PROCESS: Oh, crap. I have no idea what is going on,\r\n");
			break;
		}
	}
}
/******************************************************************************
 * FunctionName : wifi_station_scan_done
 * Description  : Cb function of scan, organizes a linked list of stations
 	from scan function. Make sure to free linked list when done.
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_station_scan_done(void *arg, STATUS status)
{

 	uint8_t ssid[33];
 	uint8_t bssid[6];

 	if (status == OK)	// if the scan was sucessful
 	{
    	bss_link = (struct bss_info *)arg;
    	struct bss_info *bss_link_next, *bss_link_curr, *bss_link_prev, *bss_link_head;
    	uint32_t i,numAP,j;

    	bss_link = copy_linked_list(bss_link);	// SDK provived linked list will be destroyed automatically

    	bss_link_head = bss_link;				// store head for traversing list

		// get len of linked list
		numAP=0;
		while(bss_link != NULL) {
			numAP++;
			bss_link = bss_link->next.stqe_next;
		}
		os_printf("Number of APs found: %d\r\n", numAP);

    	bss_link = bss_link_head;	// reset to head

    	// sort linked list by rssi
    	for(i=0;i<numAP-1;i++)
    	{

	    	bss_link_prev = NULL;
	    	bss_link_curr = bss_link;
	    	bss_link_next = bss_link->next.stqe_next;

	 		for(j=0; j<numAP-1-i; j++)
	 		{
	 			system_soft_wdt_feed(); 												// reset sw watchdog timer
				if (bss_link_next->rssi > bss_link_curr->rssi) {
					if (bss_link_prev == NULL) {
						// swap node position and head position
						bss_link_curr->next.stqe_next = bss_link_next->next.stqe_next;
						bss_link_next->next.stqe_next = bss_link_curr;
						bss_link = bss_link_next; // store new head

						bss_link_prev = bss_link_next;
						bss_link_next = bss_link_curr->next.stqe_next;
					} else {
						// swap node positions
						bss_link_prev->next.stqe_next = bss_link_next;
						bss_link_curr->next.stqe_next = bss_link_next->next.stqe_next; // could be null
						bss_link_next->next.stqe_next = bss_link_curr;

						bss_link_prev = bss_link_next;
						bss_link_next = bss_link_curr->next.stqe_next;
					}
				} else {
					// move along like nothing happened
					bss_link_prev = bss_link_curr;
					bss_link_curr = bss_link_next;
					bss_link_next = bss_link_next->next.stqe_next;
				}
			}
		}

		bss_link_head = bss_link; // store head

		// print sorted list of stations
    	while (bss_link != NULL) {
      		os_memset(ssid, 0, 33);
      		os_memset(bssid, 0, 6);

      		if (os_strlen(bss_link->ssid) <= 32) {
        		os_memcpy(ssid, bss_link->ssid, os_strlen(bss_link->ssid));
      		} else {
        		os_memcpy(ssid, bss_link->ssid, 32);
      		}

      		os_printf("WiFi Scan: (%d,\"%s\",%x, %d)\n", bss_link->authmode, ssid, bssid, bss_link->rssi);
      		bss_link = bss_link->next.stqe_next;
  		}
  		bss_link = bss_link_head;		// reset to head
  		head_bss_link = bss_link_head;	// ahhh, this is lazy.

  		os_printf("Activating event handler\r\n");
		wifi_set_event_handler_cb(wifi_handle_event_cb);
  		os_printf("Analysis scan results\r\n");
  		wifi_process();
  	}
  	else // if scan was unsuccessful
  	{
  		sysCfg.module_state.searching = FALSE;
  		os_printf("Scan Failed\r\n");
  		GPIO_REG_WRITE(GPIO_STATUS_W1TC_ADDRESS, 0xFFFFFFFF);	// clear pending interrupts
		sysCfg.module_state.asleep = TRUE;
		ETS_GPIO_INTR_ENABLE(); 								// enable interrupts to permit PB and LSM6DS3 to wake ESP from sleep.

  	}
}
/******************************************************************************
 * FunctionName : start_wifi_process
 * Description  : scans for available AP and attempts to connect to the AP with
 	the highest RSSI.
 * Parameters   :  restart - resets wifi_process_count
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR start_wifi_process(void)
{

	ETS_GPIO_INTR_DISABLE(); 					// disable I/O interrupts
	lsm6ds3_motion_enable();					// enable LSM6DS3 Significant Motion Process

	wifi_process_flags.process_count = 0;
	wifi_process_flags.wifi_flag = FALSE; 		// clear wifi_process_flags
	wifi_process_flags.ip_flag = FALSE;
	wifi_process_flags.wifi_count = 0;

	sysCfg.module_state.searching = TRUE;		// setup global flags for searching
	sysCfg.module_state.connected = FALSE;
	sysCfg.module_state.broker = FALSE;

	wifi_station_set_auto_connect(FALSE);	// disable wifi auto connect
	wifi_station_ap_number_set(0);			// don't store Wi-Fi configurations in SDK flash

	os_printf("Start Wi-Fi Scan\r\n");
	wifi_set_opmode(STATION_MODE);
	wifi_station_scan(NULL, wifi_station_scan_done);				// start Wi-Fi scan.
}