/******************************************************************************
 * 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 "interface/wifi_interface.h"
#include "log/esp_log.h"
#include "esp_common.h"

static const char* TAG =  "WiFi Interface";
static wifi_config_t wifi_config;
static struct bss_info *bss_link, *head_bss_link;

/******************************************************************************
 * 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)
		{
			ESP_LOGE(TAG, "no RAM!");
			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)
		{
			ESP_LOGE(TAG, "No RAM!");
			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);
			}
			ESP_LOGE(TAG, "deleted linked list");
			return NULL;
		}
		ptr_original_node = ptr_original_node->next.stqe_next;

	}
	return ptr_new_head;
}
/******************************************************************************
 * FunctionName : wifi_timeout_cb
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_timeout_cb(void)
{
	ESP_LOGI(TAG, "wifi connection timed out");
	wifi_config.wifi_process = false;
	if (wifi_config.fail_cb != NULL)
		wifi_config.fail_cb(WIFI_TIMEOUT_FAILURE);
}
/******************************************************************************
 * FunctionName : wifi_event_handler_cb
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_event_handler_cb(System_Event_t *evt)
{
	switch (evt->event)
 	{
		case EVENT_STAMODE_CONNECTED:
		{
			wifi_config.ap_flag = true;

			ESP_LOGD(TAG, "connected to ssid %s, channel %d",
			evt->event_info.connected.ssid,
			evt->event_info.connected.channel);

			break;
		}
		case EVENT_STAMODE_DISCONNECTED:
		{
			wifi_config.ap_flag = false;
			wifi_config.ip_flag = false;

			ESP_LOGD(TAG, "disconnected from ssid %s, reason %d",
			evt->event_info.disconnected.ssid,
			evt->event_info.disconnected.reason);

			if (wifi_config.wifi_process == false)
			{
				wifi_station_disconnect();
				if (wifi_config.fail_cb != NULL)
					wifi_config.fail_cb(WIFI_AP_DISCONNECTED);
			}

			break;
		}
		case EVENT_STAMODE_AUTHMODE_CHANGE:
		{
			wifi_config.ap_flag = false;
			wifi_config.ip_flag = false;

			ESP_LOGD(TAG, "mode: %d -> %d",
			evt->event_info.auth_change.old_mode,
			evt->event_info.auth_change.new_mode);

			if (wifi_config.wifi_process == false)
			{
				if (wifi_config.fail_cb != NULL)
					wifi_config.fail_cb(WIFI_AP_AUTHMODE_CHANGE);
			}

			break;
		}
		case EVENT_STAMODE_GOT_IP:
		{
			wifi_config.ip_flag = true;
			os_timer_disarm(&wifi_config.timeout_timer);

			ESP_LOGD(TAG, "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));

			wifi_config.wifi_process = false;
			if (wifi_config.success_cb != NULL)
				wifi_config.success_cb();
			break;
		}
		default:
		{
			ESP_LOGD(TAG, "unknown Wi-Fi failure code");
			break;
		}
	}
}
/******************************************************************************
 * FunctionName : wifi_process
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static ICACHE_FLASH_ATTR wifi_process(void)
{
	uint8_t ssid[33];
	uint8_t ap_index;
	struct station_config stationConfig[5];

	// retrive stations stored in flash
	uint8_t num = wifi_station_get_ap_info(stationConfig);
	if (num == 0)
	{
		if (wifi_config.fail_cb != NULL)
			wifi_config.fail_cb(WIFI_NO_STORED_APS_FAILURE);
		return;
	}

	// loop through every value in the RSSI sorted linked list
	ESP_LOGD(TAG, "searching stored access points")
	while(bss_link != NULL)
	{
		// feed SW watch dog timer to prevent rest
		system_soft_wdt_feed();

		// retrive SSID from RSSI sorted linked  list
		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);
		}

		// search the linked list for an AP stored in the cache which was also
		// found in the access point scan
		for (ap_index=0;ap_index<num;ap_index++)
		{
			ESP_LOGV(TAG, "comparing aps \"%s\" and \"%s\"", ssid, stationConfig[ap_index].ssid);
			if (!strcmp(ssid, stationConfig[ap_index].ssid))
			{
				ESP_LOGD(TAG, "access point located: %s", ssid);
				wifi_config.ap_found = true;
				os_timer_arm(&wifi_config.timeout_timer, wifi_config.timeout_delay, false);
				wifi_station_ap_change(ap_index);
				wifi_station_connect();
				break;
			}
		}

		bss_link = bss_link->next.stqe_next;

		// stop looping through RSSI sorted scan results and start connection
		// timeout timer
		if (wifi_config.ap_found)
		{
			break;
		}
	}

	if (!wifi_config.ap_found)
	{
		if (wifi_config.fail_cb != NULL)
			wifi_config.fail_cb(WIFI_NO_AVAILABLE_APS_FAILURE);
		ESP_LOGD(TAG, "access point not found")

	}
	destory_linked_list();
}
/******************************************************************************
 * FunctionName : wifi_scan_done
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
static void ICACHE_FLASH_ATTR wifi_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;

		if (bss_link == NULL)
		{
			if (wifi_config.fail_cb != NULL)
				wifi_config.fail_cb(WIFI_NO_AVAILABLE_APS_FAILURE);
			return;
		}

		// copy linked list because SDK will end up destorying it
    	bss_link = copy_linked_list(bss_link);
    	bss_link_head = bss_link;

		// get len of linked list
		numAP=0;
		while(bss_link != NULL)
		{
			numAP++;
			bss_link = bss_link->next.stqe_next;
		}

		ESP_LOGD(TAG, "number of APs found: %d", 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();
				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);
      		}

      		ESP_LOGD(TAG, "(%d,\"%s\",%x, %d)", 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.

		wifi_set_event_handler_cb(wifi_event_handler_cb);
  		wifi_process();
  	}
  	else // if scan was unsuccessful
  	{
  		ESP_LOGD(TAG, "scan failed");
		if (wifi_config.fail_cb != NULL)
			wifi_config.fail_cb(WIFI_SCAN_FAILURE);
		wifi_config.wifi_process = false;
  	}
}
/******************************************************************************
 * FunctionName : WiFi_Initialize
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR WiFi_Initialize(void)
{
	wifi_set_opmode(STATION_MODE);
	wifi_station_ap_number_set(5);
	wifi_station_disconnect();
	wifi_station_set_auto_connect(false);

	wifi_config.fail_cb = NULL;
	wifi_config.success_cb = NULL;
}
/******************************************************************************
 * FunctionName : WiFi_Disconnect
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR WiFi_Disconnect(void)
{
	wifi_config.ip_flag = false;
	wifi_config.ap_flag = false;
	wifi_station_disconnect();
}
/******************************************************************************
 * FunctionName : WiFi_SetCallbacks
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR WiFi_SetCallbacks(wifi_success_function_t success_cb, wifi_fail_function_t fail_cb)
{
	wifi_config.success_cb = success_cb;
	wifi_config.fail_cb = fail_cb;
}
/******************************************************************************
 * FunctionName : WiFi_Connect
 * Description  :
 * Parameters   :
 * Returns      :
*******************************************************************************/
void ICACHE_FLASH_ATTR WiFi_Connect(uint32_t timeout_delay)
{
	wifi_config.timeout_delay = timeout_delay;
	wifi_config.ip_flag = false;
	wifi_config.ap_flag = false;
	wifi_config.ap_found = false;
	wifi_config.wifi_process = true;

	wifi_set_event_handler_cb(NULL);

	os_timer_disarm(&wifi_config.timeout_timer);
	os_timer_setfn(&wifi_config.timeout_timer, (os_timer_func_t *)wifi_timeout_cb, NULL);

	// check for stored APs
	// if none call no_credentials_cb(), shutdown WIFI, return
	ESP_LOGI(TAG, "starting Wi-Fi scan");
	wifi_station_scan(NULL, wifi_scan_done);				// start Wi-Fi scan.
}