/* MQTT Mutual Authentication Example

   This example code is in the Public Domain (or CC0 licensed, at your option.)

   Unless required by applicable law or agreed to in writing, this
   software is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
   CONDITIONS OF ANY KIND, either express or implied.
*/
#include <stdio.h>
#include <stdint.h>
#include <stddef.h>
#include <string.h>
#include "esp_system.h"
#include "nvs_flash.h"
#include "esp_event.h"
#include "esp_netif.h"
#include "protocol_examples_common.h"

#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "freertos/semphr.h"
#include "freertos/queue.h"

#include "lwip/sockets.h"
#include "lwip/dns.h"
#include "lwip/netdb.h"

#include "esp_log.h"
#include "mqtt_client.h"
#include "rsa_sign_alt.h"
#include "esp_secure_cert_read.h"

static const char *TAG = "mqtts_example";

extern const uint8_t server_cert_pem_start[] asm("_binary_mosquitto_org_crt_start");
extern const uint8_t server_cert_pem_end[] asm("_binary_mosquitto_org_crt_end");

/*
 * @brief Event handler registered to receive MQTT events
 *
 *  This function is called by the MQTT client event loop.
 *
 * @param handler_args user data registered to the event.
 * @param base Event base for the handler(always MQTT Base in this example).
 * @param event_id The id for the received event.
 * @param event_data The data for the event, esp_mqtt_event_handle_t.
 */
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=%" PRIi32, base, event_id);
    esp_mqtt_event_handle_t event = event_data;
    esp_mqtt_client_handle_t client = event->client;
    int msg_id;
    // your_context_t *context = event->context;
    switch ((esp_mqtt_event_id_t)event_id) {
    case MQTT_EVENT_CONNECTED:
        ESP_LOGI(TAG, "MQTT_EVENT_CONNECTED");
        msg_id = esp_mqtt_client_subscribe(client, "/topic/qos0", 0);
        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);

        msg_id = esp_mqtt_client_subscribe(client, "/topic/qos1", 1);
        ESP_LOGI(TAG, "sent subscribe successful, msg_id=%d", msg_id);

        msg_id = esp_mqtt_client_unsubscribe(client, "/topic/qos1");
        ESP_LOGI(TAG, "sent unsubscribe successful, msg_id=%d", msg_id);
        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);
        msg_id = esp_mqtt_client_publish(client, "/topic/qos0", "data", 0, 0, 0);
        ESP_LOGI(TAG, "sent publish successful, msg_id=%d", 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");
        printf("TOPIC=%.*s\r\n", event->topic_len, event->topic);
        printf("DATA=%.*s\r\n", event->data_len, event->data);
        break;
    case MQTT_EVENT_ERROR:
        ESP_LOGI(TAG, "MQTT_EVENT_ERROR");
        break;
    default:
        ESP_LOGI(TAG, "Other event id:%d", event->event_id);
        break;
    }
}

static void mqtt_app_start(void)
{
    /* The context is used by the DS peripheral, should not be freed */
    esp_ds_data_ctx_t *ds_data = esp_secure_cert_get_ds_ctx();
    if (ds_data == NULL) {
        ESP_LOGE(TAG, "Error in reading DS data from NVS");
        vTaskDelete(NULL);
    }
    char *device_cert = NULL;
    esp_err_t ret;
    uint32_t len;
    ret = esp_secure_cert_get_device_cert(&device_cert, &len);
    if (ret != ESP_OK) {
        ESP_LOGE(TAG, "Failed to obtain the device certificate");
        vTaskDelete(NULL);
    }

    const esp_mqtt_client_config_t mqtt_cfg = {
        .broker = {
            .address.uri = "mqtts://test.mosquitto.org:8884",
            .verification.certificate =  (const char *)server_cert_pem_start,
        },
        .credentials = {
            .authentication = {
                .certificate = (const char *)device_cert,
                .key = NULL,
                .ds_data = (void *)ds_data
            },
        },
    };

    ESP_LOGI(TAG, "[APP] Free memory: %" PRIu32 " bytes", esp_get_free_heap_size());
    esp_mqtt_client_handle_t client = esp_mqtt_client_init(&mqtt_cfg);
    esp_mqtt_client_register_event(client, ESP_EVENT_ANY_ID, mqtt_event_handler, NULL);
    esp_mqtt_client_start(client);
}

void app_main(void)
{
    ESP_LOGI(TAG, "[APP] Startup..");
    ESP_LOGI(TAG, "[APP] Free memory: %" PRIu32 " bytes", esp_get_free_heap_size());
    ESP_LOGI(TAG, "[APP] IDF version: %s", esp_get_idf_version());

    esp_log_level_set("*", ESP_LOG_INFO);
    esp_log_level_set("mqtt_client", ESP_LOG_VERBOSE);
    esp_log_level_set("transport_base", ESP_LOG_VERBOSE);
    esp_log_level_set("transport", ESP_LOG_VERBOSE);
    esp_log_level_set("outbox", ESP_LOG_VERBOSE);

    ESP_ERROR_CHECK(nvs_flash_init());
    ESP_ERROR_CHECK(esp_netif_init());
    ESP_ERROR_CHECK(esp_event_loop_create_default());

    /* This helper function configures Wi-Fi or Ethernet, as selected in menuconfig.
     * Read "Establishing Wi-Fi or Ethernet Connection" section in
     * examples/protocols/README.md for more information about this function.
     */
    ESP_ERROR_CHECK(example_connect());

    mqtt_app_start();
}