/*
 * Copyright 2019 by Morgan Allen
 * 
 * This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International
 * https://creativecommons.org/licenses/by-nc/4.0/
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/timers.h"
#include "freertos/event_groups.h"
#include "esp_system.h"
#include "esp_log.h"
#include "esp_console.h"
#include "esp_sleep.h"
#include "esp_vfs_dev.h"
#include "nvs_flash.h"
#include "esp_http_client.h"
#include "driver/uart.h"
#include "driver/mcpwm.h"
#include "soc/mcpwm_reg.h"
#include "soc/mcpwm_struct.h"
#include "linenoise/linenoise.h"
#include "argtable3/argtable3.h"
#include "driver/gpio.h"
#include "driver/spi_master.h"
#include "lwip/sockets.h"
#include "lwip/dns.h"
#include "lwip/netdb.h"

#include "mqtt_client.h"

#include "esp32-wifi-manager.h"

#define TAG "BTN"

#define GPIO_INPUT_IO_0    33
#define GPIO_INPUT_PIN_SEL  ((1ULL<<GPIO_INPUT_IO_0))
#define ESP_INTR_FLAG_DEFAULT 0

#define CONFIG_SLEEP_TIMEOUT (60000 / portTICK_PERIOD_MS)

#define RTC_WAKE_IO RTC_GPIO8
#define RTC_WAKE_PIN GPIO_INPUT_IO_0

#define PIN_NUM_MOSI 22
#define PIN_NUM_CLK  23

#define LED_COUNT (1)
#define SPI_BUF   (LED_COUNT + 2)

#define TOPIC_POWER_STATUS "stat/tasmota_E74A79/POWER"

static uint8_t id;

static EventGroupHandle_t wm_event_group;
static xTimerHandle button_timer;
static xTimerHandle sleep_timer;
static spi_device_handle_t spi;
xQueueHandle gpio_evt_queue = NULL;

enum led_states {
  POR,
  CONNECTING,
  CONNECTED,
  SHOOTING
};

enum led_states led_state;

esp_mqtt_client_handle_t client;

void enter_sleep() {
  ESP_LOGI(TAG, "Enter sleep");

  static spi_transaction_t trans[SPI_BUF];

  int i;
  for (i = 0; i < SPI_BUF; i++) {
    memset(&trans[i], 0, sizeof(spi_transaction_t));

    trans[i].length=8*4;
    trans[i].flags = SPI_TRANS_USE_TXDATA;
  }

  trans[1].tx_data[0] = (0b11100000 | 0);
  trans[1].tx_data[1] = 0;
  trans[1].tx_data[2] = 0;
  trans[1].tx_data[3] = 0;

  memset(&trans[SPI_BUF - 1].tx_data, 0xFF, 4);

  for(i = 0; i < SPI_BUF; i++) {
    spi_device_queue_trans(spi, &trans[i], portMAX_DELAY);
  }

  esp_sleep_enable_ext0_wakeup(RTC_WAKE_PIN, 0);
  esp_sleep_pd_config(ESP_PD_DOMAIN_RTC_PERIPH, ESP_PD_OPTION_ON);

  //rtc_gpio_isolate(GPIO_INPUT_IO_0);
  esp_deep_sleep_start();
}

void reset_sleep_timer() {
  xTimerReset(sleep_timer, portMAX_DELAY);
  xTimerStart(sleep_timer, portMAX_DELAY);
}

uint8_t led_state_new[4];
uint8_t led_state_cur[4];

void led_display_loop() {
  static spi_transaction_t trans[SPI_BUF];

  int i;
  for (i = 0; i < SPI_BUF; i++) {
    memset(&trans[i], 0, sizeof(spi_transaction_t));

    trans[i].length=8*4;
    trans[i].flags = SPI_TRANS_USE_TXDATA;
  }

  trans[1].tx_data[0] = (0b11100000 | 1);
  memset(&trans[SPI_BUF - 1].tx_data, 0xFF, 4);

  bool update = false;

  while(true) {
    /// TODO check _new vs _cur, ramping the channel value per step until they match
    /// only transmit spi data if a change was made
    if(led_state_new[1] != led_state_cur[1]) {
      trans[1].tx_data[1] = 0;
    }
    trans[1].tx_data[2] = 127;
    trans[1].tx_data[3] = 0;

    for(i = 0; i < SPI_BUF; i++) {
      spi_device_queue_trans(spi, &trans[i], portMAX_DELAY);
    }

    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
}

void led_control_loop() {
  uint8_t v = 0;

  while(true) {
    if(xQueueReceive(wm_event_queue, &v, portMAX_DELAY)) {
      EventBits_t ev_bits = xEventGroupGetBits(wm_event_group);
      ESP_LOGI(TAG, "got event: %d", ev_bits);

      // TODO XXX rewrite to only update led_state_new and let led_display_loop 
      // handle rendering

      static spi_transaction_t trans[SPI_BUF];

      int i;
      for (i = 0; i < SPI_BUF; i++) {
        memset(&trans[i], 0, sizeof(spi_transaction_t));

        trans[i].length=8*4;
        trans[i].flags = SPI_TRANS_USE_TXDATA;
      }

      trans[1].tx_data[0] = (0b11100000 | 1);

      if(ev_bits & WIFI_CONNECTED) {
        esp_mqtt_client_start(client);

        trans[1].tx_data[1] = 0;
        trans[1].tx_data[2] = 127;
        trans[1].tx_data[3] = 0;
      } else if(ev_bits & WIFI_SCANNING) {
        trans[1].tx_data[1] = 0;
        trans[1].tx_data[2] = 55;
        trans[1].tx_data[3] = 127;
      } else if(ev_bits & WIFI_CONNECTING) {
        trans[1].tx_data[1] = 127;
        trans[1].tx_data[2] = 127;
        trans[1].tx_data[3] = 0;
      } else if(ev_bits & WIFI_IDLE) {
        trans[1].tx_data[1] = 0;
        trans[1].tx_data[2] = 0;
        trans[1].tx_data[3] = 127;
      }

      memset(&trans[SPI_BUF - 1].tx_data, 0xFF, 4);

      for(i = 0; i < SPI_BUF; i++) {
        spi_device_queue_trans(spi, &trans[i], portMAX_DELAY);
      }
    }
  }
}

static void IRAM_ATTR gpio_isr_handler(void* arg)
{
    uint32_t gpio_num = (uint32_t) arg;
    xQueueSendFromISR(gpio_evt_queue, &gpio_num, NULL);
}

static void mqtt_event_handler(void *handler_args, esp_event_base_t base, int32_t event_id, void *event_data)
{
    ESP_LOGD(TAG, "Event dispatched from event loop base=%s, event_id=%d", base, event_id);
    esp_mqtt_event_handle_t event = event_data;
    esp_mqtt_client_handle_t client = event->client;
    int msg_id;
    switch ((esp_mqtt_event_id_t)event_id) {
    case MQTT_EVENT_CONNECTED:
        ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
        esp_mqtt_client_subscribe(client, "espbutton/update", 0);
        esp_mqtt_client_subscribe(client, TOPIC_POWER_STATUS, 0);
        break;
    case MQTT_EVENT_DISCONNECTED:
        ESP_LOGI(TAG, "MQTT_EVENT_DISCONNECTED");
        break;

    case MQTT_EVENT_SUBSCRIBED:
        ESP_LOGI(TAG, "MQTT_EVENT_SUBSCRIBED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_UNSUBSCRIBED:
        ESP_LOGI(TAG, "MQTT_EVENT_UNSUBSCRIBED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_PUBLISHED:
        ESP_LOGI(TAG, "MQTT_EVENT_PUBLISHED, msg_id=%d", event->msg_id);
        break;
    case MQTT_EVENT_DATA:
        ESP_LOGI(TAG, "MQTT_EVENT_DATA [topic: %.*s]", event->topic_len, event->topic);

        if(strncmp(event->topic, (const char*)TOPIC_POWER_STATUS, event->data_len) == 0) {
          ESP_LOGI(TAG, "data_len: %d", event->data_len);
          if(strncmp(event->data, "ON", 2) == 0) {
            xTimerStop(sleep_timer, portMAX_DELAY);
          } else if(strncmp(event->data, "OFF", 3) == 0) {
            reset_sleep_timer();
          }
        }
        break;
    case MQTT_EVENT_ERROR:
        ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
        if (event->error_handle->error_type == MQTT_ERROR_TYPE_TCP_TRANSPORT) {
            ESP_LOGI(TAG, "Last errno string (%s)", strerror(event->error_handle->esp_transport_sock_errno));

        }
        break;
    default:
        ESP_LOGI(TAG, "Other event id:%d", event->event_id);
        break;
    }
}

void gpio_loop() {
  int8_t state = -1;
  uint32_t io_num;

  esp_mqtt_client_config_t mqtt_cfg = {
    .uri = "mqtt://192.168.1.1",
  };

  client = esp_mqtt_client_init(&mqtt_cfg);
  /* The last argument may be used to pass data to the event handler, in this example mqtt_event_handler */
  esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);

  for(;;) {
    if(xQueueReceive(gpio_evt_queue, &io_num, portMAX_DELAY)) {
      uint8_t level = gpio_get_level(io_num);

      // don't act on state level twice
      if(level == state) continue;
      // track level for duplicate
      state = level;

      EventBits_t ev_bits = xEventGroupGetBits(wm_event_group);
      ESP_LOGI(TAG, "gpio_loop: %d", ev_bits);

      if(level == 0 && (ev_bits & WIFI_CONNECTED) == 0) {
        ESP_LOGI(TAG, "No connectiong, connecting");

        wifi_manager_scan();

        continue;
      }

      printf("GPIO[%d] intr, val: %d\n", io_num, level);

      reset_sleep_timer();

      if(level == 0) {
        xTimerChangePeriod(button_timer, 100 / portTICK_PERIOD_MS, portMAX_DELAY);
        xTimerStart(button_timer, portMAX_DELAY);
      } else {
        xTimerStop(button_timer, portMAX_DELAY);
      }
    }
  }
}

void handle_button_timer() {
  esp_mqtt_client_publish(client, "cmnd/tasmota_E74A79/POWER", "TOGGLE", 0, 1, 0);
}

void gpio_init() {
  gpio_config_t io_conf;

  io_conf.intr_type = GPIO_PIN_INTR_ANYEDGE;
  io_conf.mode = GPIO_MODE_INPUT;
  io_conf.pin_bit_mask = GPIO_INPUT_PIN_SEL;
  io_conf.pull_down_en = 0;
  io_conf.pull_up_en = 1;
  gpio_config(&io_conf);

  gpio_install_isr_service(ESP_INTR_FLAG_DEFAULT);
  gpio_isr_handler_add(GPIO_INPUT_IO_0, gpio_isr_handler, (void*) GPIO_INPUT_IO_0);

  //create a queue to handle gpio event from isr
  gpio_evt_queue = xQueueCreate(10, sizeof(uint32_t));
  //start gpio task

  button_timer = xTimerCreate("gpio_timer", 1000, pdFALSE, (void*)NULL, handle_button_timer);
  sleep_timer = xTimerCreate("sleep_timer", CONFIG_SLEEP_TIMEOUT, pdFALSE, (void*)NULL, enter_sleep);
  reset_sleep_timer();

  xTaskCreate(gpio_loop, "gpio_loop", 2048, NULL, 10, NULL);
}

void spi_init() {
  esp_err_t ret;
  spi_bus_config_t buscfg={
    .mosi_io_num=PIN_NUM_MOSI,
    .sclk_io_num=PIN_NUM_CLK,
    .quadwp_io_num=-1,
    .quadhd_io_num=-1,
    .max_transfer_sz=120*320*2+8
  };
  spi_device_interface_config_t devcfg={
    .clock_speed_hz=10*1000*1000,           //Clock out at 10 MHz
    .mode=0,                                //SPI mode 0
    .queue_size=7,                          //We want to be able to queue 7 transactions at a time
    //.pre_cb=lcd_spi_pre_transfer_callback,  //Specify pre-transfer callback to handle D/C line
  };
  //Initialize the SPI bus
  ret=spi_bus_initialize(HSPI_HOST, &buscfg, 1);
  ESP_ERROR_CHECK(ret);
  //Attach the LCD to the SPI bus
  ret=spi_bus_add_device(HSPI_HOST, &devcfg, &spi);
  ESP_ERROR_CHECK(ret);

  static spi_transaction_t trans[SPI_BUF];

  int i;
  for (i = 0; i < SPI_BUF; i++) {
    memset(&trans[i], 0, sizeof(spi_transaction_t));

    trans[i].length=8*4;
    trans[i].flags = SPI_TRANS_USE_TXDATA;
  }

  trans[1].tx_data[0] = (0b11100000 | 1);
  trans[1].tx_data[1] = 127;
  trans[1].tx_data[2] = 127;
  trans[1].tx_data[3] = 127;

  memset(&trans[SPI_BUF - 1].tx_data, 0xFF, 4);

  for(i = 0; i < SPI_BUF; i++) {
    ret = spi_device_queue_trans(spi, &trans[i], portMAX_DELAY);
    assert(ret==ESP_OK);
  }
}

void app_main() {
  esp_err_t ret;

  // Initialize NVS.
  ret = nvs_flash_init();
  if (ret == ESP_ERR_NVS_NO_FREE_PAGES) {
    ESP_LOGI(TAG, "Erasing flash memory");
    ESP_ERROR_CHECK(nvs_flash_erase());
    ret = nvs_flash_init();
  }
  ESP_ERROR_CHECK( ret );

  uint8_t *mac;
  mac = (uint8_t *)malloc(6);
  esp_efuse_mac_get_default(mac);
  id = mac[5];

  ESP_LOGI(TAG, "MAC: %X:%X:%X:%X:%X:%X\n", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);

  wm_event_group = wifi_manager_start();
  wifi_manager_reset_store();

  if(wifi_manager_ap_count() == 0) {
    ESP_LOGI(TAG, "Adding new AP");

    if(strlen(CONFIG_WIFI_MANAGER_TEST_AP) > 0) {
      wifi_manager_add_ap(CONFIG_WIFI_MANAGER_TEST_AP, CONFIG_WIFI_MANAGER_TEST_PWD);
    }
  }

  gpio_init();
  spi_init();

  xTaskCreate(&led_display_loop, "led_display_loop",  4096, NULL, 6, NULL);
  xTaskCreate(&led_control_loop, "led_control_loop",  4096, NULL, 6, NULL);

  wifi_manager_scan();

  while(true) {
    vTaskDelay(1000 / portTICK_PERIOD_MS);
  }
};