#include "XD0OTA.h"

#include <WiFi.h>
#include <WiFiClient.h>

#include <HTTPClient.h>
#include <HTTPUpdate.h>

#include <time.h>

static const char* TAG = "OTA";

XD0OTA::XD0OTA(String deviceName) : deviceName{deviceName} {}

// Set time via NTP, as required for x.509 validation
void XD0OTA::setClock() {
  configTime(0, 0, "pool.ntp.org", "time.nist.gov");  // UTC

  Serial.print(F("Waiting for NTP time sync: "));
  time_t now = time(nullptr);
  int tries = 0;
  while (now < 8 * 3600 * 2) {
    yield();
    delay(500);
    Serial.print(F("."));
    now = time(nullptr);
    tries++;
    if (tries>15) return;
  }

  Serial.println(F(""));
  struct tm timeinfo;
  gmtime_r(&now, &timeinfo);
  Serial.print(F("Current time: "));
  Serial.print(asctime(&timeinfo));
}

String XD0OTA::getMAC() {
  uint8_t mac[6];
  char result[14];

  WiFi.macAddress( mac );
  snprintf( result, sizeof( result ), "%02x%02x%02x%02x%02x%02x", mac[ 0 ], mac[ 1 ], mac[ 2 ], mac[ 3 ], mac[ 4 ], mac[ 5 ] );

  return String( result );
}

String XD0OTA::getUpdateURL(String file, String extension) {
  String updateURL = String(fwUrlBase);
  updateURL.concat(file);
  updateURL.concat(extension);
  return updateURL;
}

void XD0OTA::update(void) {
  setClock();

  // try device specific image first
  String fwURL = getUpdateURL(getMAC(), ".bin");
  int newVersion = checkForUpdates(fwURL + ".version");

  if (newVersion < 1) {
    ESP_LOGW(TAG, "[update] no device specific update found..\n");
    fwURL = getUpdateURL(deviceName, ".bin");
    newVersion = checkForUpdates(fwURL + ".version");
    // try project specific image
    if (newVersion < 1) {
      ESP_LOGW(TAG, "[update] Error while looking for updates..\n");
      return;
    }
  }

  if( newVersion > FW_VERSION ) {
    ESP_LOGW(TAG,  "Preparing to update.\n" );

    ESP_LOGW(TAG,  "Firmware image URL: " );
    ESP_LOGW(TAG,  "%s\n", fwURL.c_str() );

    WiFiClientSecure client;
    client.setCACert(rootCACertificate);

    client.setTimeout(12); // seconds

    httpUpdate.setLedPin(LED_BUILTIN, HIGH);

    t_httpUpdate_return ret = httpUpdate.update( client, fwURL );

    switch(ret) {
        case HTTP_UPDATE_FAILED:
            ESP_LOGW(TAG, "HTTP_UPDATE_FAILED Error (%d): %s\n",  httpUpdate.getLastError(), httpUpdate.getLastErrorString().c_str());
            break;
        case HTTP_UPDATE_NO_UPDATES:
            ESP_LOGW(TAG, "HTTP_UPDATE_NO_UPDATES\n");
            break;
        case HTTP_UPDATE_OK:
            ESP_LOGW(TAG, "[update] Update ok.\n"); // may not called we reboot the ESP
            break;
    }
  } else {
    ESP_LOGW(TAG,  "[update] Already on latest version\n" );
  }
}

int XD0OTA::checkForUpdates(String url) {
  int newVersion = -1;

  ESP_LOGW(TAG,  "Checking for firmware updates.\n" );
  ESP_LOGW(TAG,  "Firmware version URL: " );
  ESP_LOGW(TAG,  "%s\n", url.c_str() );

  WiFiClientSecure client;
  client.setCACert(rootCACertificate);
  client.setTimeout(5); // seconds

  HTTPClient httpClient;

  httpClient.begin( client, url );
  int httpCode = httpClient.GET();
  if( httpCode == HTTP_CODE_OK || httpCode == HTTP_CODE_MOVED_PERMANENTLY ) {
    String newFWVersion = httpClient.getString();

    ESP_LOGW(TAG,  "Current firmware version: " );
    ESP_LOGW(TAG,  "%s\n", String(FW_VERSION).c_str() );
    ESP_LOGW(TAG,  "Available firmware version: " );
    ESP_LOGW(TAG,  "%s\n", newFWVersion.c_str() );

    newVersion = newFWVersion.toInt();
  } else {
    ESP_LOGW(TAG,  "Firmware version check failed, got HTTP response code " );
    ESP_LOGW(TAG,  "%d\n", httpCode );
    newVersion = -1;
  }
  httpClient.end();
  client.stop();
  return newVersion;
}