/**
 * AutoConnectUpdate class implementation.
 * @file   AutoConnectUpdate.cpp
 * @author hieromon@gmail.com
 * @version    0.9.9
 * @date   2019-05-03
 * @copyright  MIT license.
 */

#include <functional>
#include "AutoConnectUpdate.h"
#include "AutoConnectUpdatePage.h"
#include "AutoConnectJsonDefs.h"

/**
 * The AutoConnectUpdate class inherits from the HTTPupdate class. The
 * update server corresponding to this class needs a simple script
 * based on an HTTP server. It is somewhat different from the advanced
 * updater script offered by Arduino core of ESP8266.
 * The equipment required for the update server for the
 * AutoConnectUpdate class is as follows:
 *
 * The catalog script:
 *   The update server URI /catalog is a script process that responds to
 *   queries from the AutoConnectUpdate class. The catalog script accepts
 *   the queries such as '/catalog?op=list&path='.
 *   - op:
 *     An op parameter speicies the query operation. In the current
 *     version, available query operation is a list only.
 *   - list:
 *     The query operation list responds with a list of available sketch
 *     binaries. The response of list is a directory list of file paths
 *     on the server specified by the path parameter and describes as a
 *     JSON document. Its JSON document is an array of JSON objects with
 *     the name and the type keys. For example, it is the following
 *     description:
 *     [
 *       {
 *         "name": "somefoler",
 *         "type": "directory"
 *       },
 *       {
 *         "name": "update.ino",
 *         "type": "file"
 *       },
 *       {
 *         "name": "update.bin",
 *         "type": "bin"
 *       }
 *     ]
 *     - name:
 *       Name of file entry on the path.
 *     - type:
 *       The type of the file. It defines either directory, file or bin.
 *       The bin means that the file is a sketch binary, and the
 *       AutoConnectUpdate class recognizes only files type bin as
 *       available update files.
 *   - path:
 *     A path parameter specifies the path on the server storing
 *     available sketch binaries.
 *
 * Access to the path on the server:
 *   It should have access to the bin file. The update server needs to
 *   send a bin file with a content type of application/octet-stream via
 *   HTTP and also needs to attach an MD5 hash value to the x-MD5 header.
 */

/**
 * A destructor. Release the update processing dialogue page generated
 * as AutoConnectAux.
 */
AutoConnectUpdate::~AutoConnectUpdate() {
  _catalog.reset(nullptr);
  _progress.reset(nullptr);
  _result.reset(nullptr);
  _WiFiClient.reset(nullptr);
}

/**
 * Attach the AutoConnectUpdate to the AutoConnect which constitutes
 * the bedrock of the update process. This function creates dialog pages
 * for update operation as an instance of AutoConnectAux and joins to
 * the AutoConnect which is the bedrock of the process.
 * @param  portal   A reference of AutoConnect
 */
void AutoConnectUpdate::attach(AutoConnect& portal) {
  AutoConnectAux* updatePage;

  updatePage = new AutoConnectAux(String(FPSTR(_auxCatalog.uri)), String(FPSTR(_auxCatalog.title)), _auxCatalog.menu);
  _buildAux(updatePage, &_auxCatalog, lengthOf(_elmCatalog));
  _catalog.reset(updatePage);

  updatePage = new AutoConnectAux(String(FPSTR(_auxProgress.uri)), String(FPSTR(_auxProgress.title)), _auxProgress.menu);
  _buildAux(updatePage, &_auxProgress, lengthOf(_elmProgress));
  _progress.reset(updatePage);

  updatePage = new AutoConnectAux(String(FPSTR(_auxResult.uri)), String(FPSTR(_auxResult.title)), _auxResult.menu);
  _buildAux(updatePage, &_auxResult, lengthOf(_elmResult));
  _result.reset(updatePage);
  _catalog->on(std::bind(&AutoConnectUpdate::_onCatalog, this, std::placeholders::_1, std::placeholders::_2), AC_EXIT_AHEAD);
  _result->on(std::bind(&AutoConnectUpdate::_onResult, this, std::placeholders::_1, std::placeholders::_2), AC_EXIT_AHEAD);
  _progress->on(std::bind(&AutoConnectUpdate::_onUpdate, this, std::placeholders::_1, std::placeholders::_2), AC_EXIT_AHEAD);

  portal.join(*_catalog.get());
  portal.join(*_progress.get());
  portal.join(*_result.get());

  _status = UPDATE_IDLE;

#ifdef ARDUINO_ARCH_ESP32
  Update.onProgress(std::bind(&AutoConnectUpdate::_inProgress, this, std::placeholders::_1, std::placeholders::_2));
#endif

  // Attach this to the AutoConnectUpdate
  portal._update.reset(this);
  AC_DBG("AutoConnectUpdate attached\n");
  if (WiFi.status() == WL_CONNECTED)
    enable();
}

/**
 * Detach the update item from the current AutoConnect menu.
 * AutoConnectUpdate still active.
 */
void AutoConnectUpdate::disable(void) {
  if (_catalog) {
    _catalog->menu(false);
    if (_WiFiClient)
      _WiFiClient.reset(nullptr);
    AC_DBG("AutoConnectUpdate disabled\n");
  }
}

/**
 * Make AutoConnectUpdate class available by incorporating the update
 * function into the menu.
 */
void AutoConnectUpdate::enable(void) {
  if (_catalog) {
    _catalog->menu(true);
    _status = UPDATE_IDLE;
    _period = 0;
    AC_DBG("AutoConnectUpdate enabled\n");
  }
}

void AutoConnectUpdate::handleUpdate(void) {
  // Purge WiFiClient instances that have exceeded their retention
  // period to avoid running out of memory.
  if (_WiFiClient) {
    if (millis() - _period > AUTOCONNECT_UPDATE_DURATION)
      if (_status != UPDATE_START) {
        _WiFiClient.reset(nullptr);
        AC_DBG("Purged WifiClient due to duration expired.\n");
      }
  }

  if (isEnable()) {
    if (WiFi.status() == WL_CONNECTED) {
      // Evaluate the processing status of AutoConnectUpdate and
      // execute it accordingly. It is only this process point that
      // requests update processing.
      if (_status == UPDATE_START)
        update();
      else if (_status == UPDATE_RESET) {
        AC_DBG("Restart on %s updated...\n", _binName.c_str());
        ESP.restart();
      }
    }
    // If WiFi is not connected, disables the update menu.
    // However, the AutoConnectUpdate class stills active.
    else
      disable();
  }
}

/**
 * Run the update function of HTTPUpdate that is the base class and
 * fetch the result.
 * @return  AC_UPDATESTATUS_t
 */
AC_UPDATESTATUS_t AutoConnectUpdate::update(void) {
  String  uriBin = uri + '/' + _binName;
  if (_binName.length()) {
    AC_DBG("%s:%d/%s update in progress...", host.c_str(), port, uriBin.c_str());
    if (!_WiFiClient) {
      _WiFiClient.reset(new WiFiClient);
      _period = millis();
    }
    t_httpUpdate_return ret = HTTPUpdateClass::update(*_WiFiClient, host, port, uriBin);
    switch (ret) {
    case HTTP_UPDATE_FAILED:
      _status = UPDATE_FAIL;
      AC_DBG_DUMB(" %s\n", getLastErrorString().c_str());
      break;
    case HTTP_UPDATE_NO_UPDATES:
      _status = UPDATE_IDLE;
      AC_DBG_DUMB(" No available update\n");
      break;
    case HTTP_UPDATE_OK:
      _status = UPDATE_SUCCESS;
      AC_DBG_DUMB(" completed\n");
      break;
    }
    _WiFiClient.reset(nullptr);
  }
  else {
    AC_DBG("An update has not specified");
    _status = UPDATE_NOAVAIL;
  }
  return _status;
}

/**
 * Create the update operation pages using a predefined page structure
 * with two structures as ACPage_t and ACElementProp_t which describe
 * for AutoConnectAux configuration.
 * This function receives instantiated AutoConnectAux, instantiates
 * defined AutoConnectElements by ACPage_t, and configures it into
 * received AutoConnectAux.
 * @param  aux        An instantiated AutoConnectAux that will configure according to ACPage_t.
 * @param  page       Pre-defined ACPage_t
 * @param  elementNum Number of AutoConnectElements to configure.  
 */
void AutoConnectUpdate::_buildAux(AutoConnectAux* aux, const AutoConnectUpdate::ACPage_t* page, const size_t elementNum) {
  for (size_t n = 0; n < elementNum; n++) {
    if (page->element[n].type == AC_Element) {
      AutoConnectElement* element = new AutoConnectElement;
      element->name = String(FPSTR(page->element[n].name));
      if (page->element[n].value)
        element->value = String(FPSTR(page->element[n].value));
      aux->add(reinterpret_cast<AutoConnectElement&>(*element));
    }
    else if (page->element[n].type == AC_Radio) {
      AutoConnectRadio* element = new AutoConnectRadio;
      element->name = String(FPSTR(page->element[n].name));
      aux->add(reinterpret_cast<AutoConnectElement&>(*element));
    }
    else if (page->element[n].type == AC_Submit) {
      AutoConnectSubmit* element = new AutoConnectSubmit;
      element->name = String(FPSTR(page->element[n].name));
      if (page->element[n].value)
        element->value = String(FPSTR(page->element[n].value));
      if (page->element[n].peculiar)
        element->uri = String(FPSTR(page->element[n].peculiar));
      aux->add(reinterpret_cast<AutoConnectElement&>(*element));
    }
    else if (page->element[n].type == AC_Text) {
      AutoConnectText* element = new AutoConnectText;
      element->name = String(FPSTR(page->element[n].name));
      if (page->element[n].value)
        element->value = String(FPSTR(page->element[n].value));
      if (page->element[n].peculiar)
        element->format = String(FPSTR(page->element[n].peculiar));
      aux->add(reinterpret_cast<AutoConnectText&>(*element));
    }
  }
}

/**
 * Register only bin type file name as available sketch binary to
 * AutoConnectRadio value based on the response from the update server.
 * @param  radio        A reference to AutoConnectRadio
 * @param  responseBody JSON variant of a JSON document responded from the Update server
 * @return              Number of available sketch binaries
 */
size_t AutoConnectUpdate::_insertCatalog(AutoConnectRadio& radio, JsonVariant& responseBody) {
  ArduinoJsonArray  firmwares = responseBody.as<JsonArray>();
  radio.empty(firmwares.size());
  for (ArduinoJsonObject entry : firmwares)
    if (entry[F("type")] == "bin")
      radio.add(entry[F("name")].as<String>());
  return firmwares.size();
}

/**
 * AUTOCONNECT_URI_UPDATE page handler.
 * It queries the update server for cataloged sketch binary and
 * displays the result on the page as an available updater list.
 * The update execution button held by this page will be enabled only
 * when there are any available updaters.
 * @param  catalog A reference of the AutoConnectAux as AUTOCONNECT_URI_UPDATE
 * @param  args    A reference of the PageArgument of the PageBuilder
 * @return         Additional string to the page but it always null.
 */
String AutoConnectUpdate::_onCatalog(AutoConnectAux& catalog, PageArgument& args) {
  AC_UNUSED(args);
  HTTPClient httpClient;

  // Reallocate WiFiClient if it is not existence.
  if (!_WiFiClient) {
    _WiFiClient.reset(new WiFiClient);
    _period = millis();
  }

  AutoConnectText&  caption = catalog.getElement<AutoConnectText>(String(F("caption")));
  AutoConnectRadio& firmwares = catalog.getElement<AutoConnectRadio>(String(F("firmwares")));
  AutoConnectSubmit&  submit = catalog.getElement<AutoConnectSubmit>(String(F("update")));
  firmwares.empty();
  submit.enable = false;
  _binName = String("");

  String  qs = String(F(AUTOCONNECT_UPDATE_CATALOG)) + '?' + String(F("op=list&path=")) + uri;
  AC_DBG("Update query %s:%d%s\n", host.c_str(), port, qs.c_str());

  // Throw a query to the update server and parse the response JSON
  // document. After that, display the bin type file name contained in
  // its JSON document as available updaters to the page.
  if (httpClient.begin(*_WiFiClient.get(), host, port, qs, false)) {
    int responseCode = httpClient.GET();
    if (responseCode == HTTP_CODE_OK) {

      // The size of the JSON buffer is a fixed. It can be a problem
      // when parsing with ArduinoJson V6. If memory insufficient has
      // occurred during the parsing, increase this buffer size.
      ArduinoJsonBuffer json(AUTOCONNECT_UPDATE_CATALOG_JSONBUFFER_SIZE);

      JsonVariant jb;
      bool parse;
      Stream& responseBody = httpClient.getStream();
#if ARDUINOJSON_VERSION_MAJOR<=5
      jb = json.parse(responseBody);
      parse = jb.success();
#else
      DeserializationError err = deserializeJson(json, responseBody);
      parse = !(err == true);
      if (parse)
        jb = json.as<JsonVariant>();
#endif
      if (parse) {
        caption.value = String(F("<h3>Available firmwares</h3>"));
        JsonVariant firmwareList = json.as<JsonVariant>();
        if (_insertCatalog(firmwares, firmwareList) > 0)
          submit.enable = true;
      }
      else
        caption.value = String(F("Invalid catalog list:")) + String(err.c_str());
#if defined(AC_DEBUG)
      AC_DBG("Update server responds catalog list\n");
      ARDUINOJSON_PRINT(jb, AC_DEBUG_PORT);
      AC_DBG_DUMB("\n");
#endif
    }
    else {
      caption.value = String(F("Update server responds (")) + String(responseCode) + String("):");
      caption.value += HTTPClient::errorToString(responseCode);
    }
    httpClient.end();
  }
  else
    caption.value = String(F("http failed connect to ")) + host + String(':') + String(port);

  return String("");
}

/**
 * AUTOCONNECT_URI_UPDATE_ACT page handler
 * Only display a dialog indicating that the update is in progress.
 * @param  progress A reference of the AutoConnectAux as AUTOCONNECT_URI_UPDATE_ACT
 * @param  args     A reference of the PageArgument of the PageBuilder
 * @return          Additional string to the page but it always null.
 */
String AutoConnectUpdate::_onUpdate(AutoConnectAux& progress, PageArgument& args) {
  AC_UNUSED(args);
  AutoConnectText&  flash = progress.getElement<AutoConnectText>(String(F("flash")));
  _binName = _catalog->getElement<AutoConnectRadio>(String(F("firmwares"))).value();
  flash.value = _binName;
  _status = UPDATE_START;
  return String("");
}

/**
 * AUTOCONNECT_URI_UPDATE_RESULT page handler
 * Display the result of the update function of HTTPUpdate class.
 * @param  result A reference of the AutoConnectAux as AUTOCONNECT_URI_UPDATE_RESULT
 * @param  args   A reference of the PageArgument of the PageBuilder
 * @return        Additional string to the page but it always null.
 */
String AutoConnectUpdate::_onResult(AutoConnectAux& result, PageArgument& args) {
  AC_UNUSED(args);
  String  resForm;
  String  resColor;
  bool    restart = false;

  switch (_status) {
  case UPDATE_SUCCESS:
    resForm = String(F(" sucessfully updated. restart..."));
    resColor = String(F("blue"));
    restart = true;
    break;
  case UPDATE_FAIL:
    resForm = String(F(" failed."));
    resForm += String(F("<br>")) + getLastErrorString();
    resColor = String(F("red"));
    break;
  default:
    resForm = String(F("<br>No available update."));
    resColor = String(F("red"));
    break;
  }
  AutoConnectText& resultElm = result.getElement<AutoConnectText>(String(F("status")));
  resultElm.value = _binName + resForm;
  resultElm.style = String(F("font-size:120%;color:")) + resColor;
  result.getElement<AutoConnectElement>(String(F("restart"))).enable = restart;
  if (restart)
    _status = UPDATE_RESET;
  return String("");
}