/*
  ESP8266WebServer.cpp - Dead simple web-server.
  Supports only one simultaneous client, knows how to handle GET and POST.

  Copyright (c) 2014 Ivan Grokhotkov. All rights reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  Modified 8 May 2015 by Hristo Gochkov (proper post and file upload handling)
*/


#include <Arduino.h>
#include <libb64/cencode.h>
#include "WiFiServer.h"
#include "WiFiClient.h"
#include "ESP8266WebServer.h"
#include "FS.h"
#include "detail/RequestHandlersImpl.h"

//#define DEBUG_ESP_HTTP_SERVER
#ifdef DEBUG_ESP_PORT
#define DEBUG_OUTPUT DEBUG_ESP_PORT
#else
#define DEBUG_OUTPUT Serial
#endif

const char * AUTHORIZATION_HEADER = "Authorization";

ESP8266WebServer::ESP8266WebServer(IPAddress addr, int port)
: _server(addr, port)
, _currentMethod(HTTP_ANY)
, _currentHandler(0)
, _firstHandler(0)
, _lastHandler(0)
, _currentArgCount(0)
, _currentArgs(0)
, _headerKeysCount(0)
, _currentHeaders(0)
, _contentLength(0)
{
}

ESP8266WebServer::ESP8266WebServer(int port)
: _server(port)
, _currentMethod(HTTP_ANY)
, _currentHandler(0)
, _firstHandler(0)
, _lastHandler(0)
, _currentArgCount(0)
, _currentArgs(0)
, _headerKeysCount(0)
, _currentHeaders(0)
, _contentLength(0)
{
}

ESP8266WebServer::~ESP8266WebServer() {
  if (_currentHeaders)
    delete[]_currentHeaders;
  _headerKeysCount = 0;
  RequestHandler* handler = _firstHandler;
  while (handler) {
    RequestHandler* next = handler->next();
    delete handler;
    handler = next;
  }
  close();
}

void ESP8266WebServer::begin() {
  _currentStatus = HC_NONE;
  _server.begin();
  if(!_headerKeysCount)
    collectHeaders(0, 0);
}

bool ESP8266WebServer::authenticate(const char * username, const char * password){
  if(hasHeader(AUTHORIZATION_HEADER)){
    String authReq = header(AUTHORIZATION_HEADER);
    if(authReq.startsWith("Basic")){
      authReq = authReq.substring(6);
      authReq.trim();
      char toencodeLen = strlen(username)+strlen(password)+1;
      char *toencode = new char[toencodeLen];
      if(toencode == NULL){
        authReq = String();
        return false;
      }
      char *encoded = new char[base64_encode_expected_len(toencodeLen)+1];
      if(encoded == NULL){
        authReq = String();
        delete[] toencode;
        return false;
      }
      sprintf(toencode, "%s:%s", username, password);
      if(base64_encode_chars(toencode, toencodeLen, encoded) > 0 && authReq.equals(encoded)){
        authReq = String();
        delete[] toencode;
        delete[] encoded;
        return true;
      }
      delete[] toencode;
      delete[] encoded;
    }
    authReq = String();
  }
  return false;
}

void ESP8266WebServer::requestAuthentication(){
  sendHeader("WWW-Authenticate", "Basic realm=\"Login Required\"");
  send(401);
}

void ESP8266WebServer::on(const char* uri, ESP8266WebServer::THandlerFunction handler) {
  on(uri, HTTP_ANY, handler);
}

void ESP8266WebServer::on(const char* uri, HTTPMethod method, ESP8266WebServer::THandlerFunction fn) {
  on(uri, method, fn, _fileUploadHandler);
}

void ESP8266WebServer::on(const char* uri, HTTPMethod method, ESP8266WebServer::THandlerFunction fn, ESP8266WebServer::THandlerFunction ufn) {
  _addRequestHandler(new FunctionRequestHandler(fn, ufn, uri, method));
}

void ESP8266WebServer::addHandler(RequestHandler* handler) {
    _addRequestHandler(handler);
}

void ESP8266WebServer::_addRequestHandler(RequestHandler* handler) {
    if (!_lastHandler) {
      _firstHandler = handler;
      _lastHandler = handler;
    }
    else {
      _lastHandler->next(handler);
      _lastHandler = handler;
    }
}

void ESP8266WebServer::serveStatic(const char* uri, FS& fs, const char* path, const char* cache_header) {
    _addRequestHandler(new StaticRequestHandler(fs, path, uri, cache_header));
}

void ESP8266WebServer::handleClient() {
  if (_currentStatus == HC_NONE) {
    WiFiClient client = _server.available();
    if (!client) {
      return;
    }

#ifdef DEBUG_ESP_HTTP_SERVER
    DEBUG_OUTPUT.println("New client");
#endif

    _currentClient = client;
    _currentStatus = HC_WAIT_READ;
    _statusChange = millis();
  }

  if (!_currentClient.connected()) {
    _currentClient = WiFiClient();
    _currentStatus = HC_NONE;
    return;
  }

  // Wait for data from client to become available
  if (_currentStatus == HC_WAIT_READ) {
    if (!_currentClient.available()) {
      if (millis() - _statusChange > HTTP_MAX_DATA_WAIT) {
        _currentClient = WiFiClient();
        _currentStatus = HC_NONE;
      }
      yield();
      return;
    }

    if (!_parseRequest(_currentClient)) {
      _currentClient = WiFiClient();
      _currentStatus = HC_NONE;
      return;
    }

    _contentLength = CONTENT_LENGTH_NOT_SET;
    _handleRequest();

    if (!_currentClient.connected()) {
      _currentClient = WiFiClient();
      _currentStatus = HC_NONE;
      return;
    } else {
      _currentStatus = HC_WAIT_CLOSE;
      _statusChange = millis();
      return;
    }
  }

  if (_currentStatus == HC_WAIT_CLOSE) {
    if (millis() - _statusChange > HTTP_MAX_CLOSE_WAIT) {
      _currentClient = WiFiClient();
      _currentStatus = HC_NONE;
    } else {
      yield();
      return;
    }
  }
}

void ESP8266WebServer::close() {
  _server.close();
}

void ESP8266WebServer::stop() {
  close();
}

void ESP8266WebServer::sendHeader(const String& name, const String& value, bool first) {
  String headerLine = name;
  headerLine += ": ";
  headerLine += value;
  headerLine += "\r\n";

  if (first) {
    _responseHeaders = headerLine + _responseHeaders;
  }
  else {
    _responseHeaders += headerLine;
  }
}


void ESP8266WebServer::_prepareHeader(String& response, int code, const char* content_type, size_t contentLength) {
    response = "HTTP/1.1 ";
    response += String(code);
    response += " ";
    response += _responseCodeToString(code);
    response += "\r\n";

    if (!content_type)
        content_type = "text/html";

    sendHeader("Content-Type", content_type, true);
    if (_contentLength == CONTENT_LENGTH_NOT_SET) {
        sendHeader("Content-Length", String(contentLength));
    } else if (_contentLength != CONTENT_LENGTH_UNKNOWN) {
        sendHeader("Content-Length", String(_contentLength));
    }
    sendHeader("Connection", "close");
    sendHeader("Access-Control-Allow-Origin", "*");

    response += _responseHeaders;
    response += "\r\n";
    _responseHeaders = String();
}

void ESP8266WebServer::send(int code, const char* content_type, const String& content) {
    String header;
    _prepareHeader(header, code, content_type, content.length());
    sendContent(header);

    sendContent(content);
}

void ESP8266WebServer::send_P(int code, PGM_P content_type, PGM_P content) {
    size_t contentLength = 0;

    if (content != NULL) {
        contentLength = strlen_P(content);
    }

    String header;
    char type[64];
    memccpy_P((void*)type, (PGM_VOID_P)content_type, 0, sizeof(type));
    _prepareHeader(header, code, (const char* )type, contentLength);
    sendContent(header);
    sendContent_P(content);
}

void ESP8266WebServer::send_P(int code, PGM_P content_type, PGM_P content, size_t contentLength) {
    String header;
    char type[64];
    memccpy_P((void*)type, (PGM_VOID_P)content_type, 0, sizeof(type));
    _prepareHeader(header, code, (const char* )type, contentLength);
    sendContent(header);
    sendContent_P(content, contentLength);
}

void ESP8266WebServer::send(int code, char* content_type, const String& content) {
  send(code, (const char*)content_type, content);
}

void ESP8266WebServer::send(int code, const String& content_type, const String& content) {
  send(code, (const char*)content_type.c_str(), content);
}

void ESP8266WebServer::sendContent(const String& content) {
  const size_t unit_size = HTTP_DOWNLOAD_UNIT_SIZE;
  size_t size_to_send = content.length();
  const char* send_start = content.c_str();

  while (size_to_send) {
    size_t will_send = (size_to_send < unit_size) ? size_to_send : unit_size;
    size_t sent = _currentClient.write(send_start, will_send);
    if (sent == 0) {
      break;
    }
    size_to_send -= sent;
    send_start += sent;
  }
}

void ESP8266WebServer::sendContent_P(PGM_P content) {
    char contentUnit[HTTP_DOWNLOAD_UNIT_SIZE + 1];

    contentUnit[HTTP_DOWNLOAD_UNIT_SIZE] = '\0';

    while (content != NULL) {
        size_t contentUnitLen;
        PGM_P contentNext;

        // due to the memccpy signature, lots of casts are needed
        contentNext = (PGM_P)memccpy_P((void*)contentUnit, (PGM_VOID_P)content, 0, HTTP_DOWNLOAD_UNIT_SIZE);

        if (contentNext == NULL) {
            // no terminator, more data available
            content += HTTP_DOWNLOAD_UNIT_SIZE;
            contentUnitLen = HTTP_DOWNLOAD_UNIT_SIZE;
        }
        else {
            // reached terminator. Do not send the terminator
            contentUnitLen = contentNext - contentUnit - 1;
            content = NULL;
        }

        // write is so overloaded, had to use the cast to get it pick the right one
        _currentClient.write((const char*)contentUnit, contentUnitLen);
    }
}

void ESP8266WebServer::sendContent_P(PGM_P content, size_t size) {
    char contentUnit[HTTP_DOWNLOAD_UNIT_SIZE + 1];
    contentUnit[HTTP_DOWNLOAD_UNIT_SIZE] = '\0';
    size_t remaining_size = size;

    while (content != NULL && remaining_size > 0) {
        size_t contentUnitLen = HTTP_DOWNLOAD_UNIT_SIZE;

        if (remaining_size < HTTP_DOWNLOAD_UNIT_SIZE) contentUnitLen = remaining_size;
        // due to the memcpy signature, lots of casts are needed
        memcpy_P((void*)contentUnit, (PGM_VOID_P)content, contentUnitLen);

        content += contentUnitLen;
        remaining_size -= contentUnitLen;

        // write is so overloaded, had to use the cast to get it pick the right one
        _currentClient.write((const char*)contentUnit, contentUnitLen);
    }
}


String ESP8266WebServer::arg(String name) {
  for (int i = 0; i < _currentArgCount; ++i) {
    if ( _currentArgs[i].key == name ) 
      return _currentArgs[i].value;
  }
  return String();
}

String ESP8266WebServer::arg(int i) {
  if (i < _currentArgCount)
    return _currentArgs[i].value;
  return String();
}

String ESP8266WebServer::argName(int i) {
  if (i < _currentArgCount)
    return _currentArgs[i].key;
  return String();
}

int ESP8266WebServer::args() {
  return _currentArgCount;
}

bool ESP8266WebServer::hasArg(String  name) {
  for (int i = 0; i < _currentArgCount; ++i) {
    if (_currentArgs[i].key == name)
      return true;
  }
  return false;
}


String ESP8266WebServer::header(String name) {
  for (int i = 0; i < _headerKeysCount; ++i) {
    if (_currentHeaders[i].key == name)
      return _currentHeaders[i].value;
  }
  return String();
}

void ESP8266WebServer::collectHeaders(const char* headerKeys[], const size_t headerKeysCount) {
  _headerKeysCount = headerKeysCount + 1;
  if (_currentHeaders)
     delete[]_currentHeaders;
  _currentHeaders = new RequestArgument[_headerKeysCount];
  _currentHeaders[0].key = AUTHORIZATION_HEADER;
  for (int i = 1; i < _headerKeysCount; i++){
    _currentHeaders[i].key = headerKeys[i-1];
  }
}

String ESP8266WebServer::header(int i) {
  if (i < _headerKeysCount)
    return _currentHeaders[i].value;
  return String();
}

String ESP8266WebServer::headerName(int i) {
  if (i < _headerKeysCount)
    return _currentHeaders[i].key;
  return String();
}

int ESP8266WebServer::headers() {
  return _headerKeysCount;
}

bool ESP8266WebServer::hasHeader(String name) {
  for (int i = 0; i < _headerKeysCount; ++i) {
    if ((_currentHeaders[i].key == name) &&  (_currentHeaders[i].value.length() > 0))
      return true;
  }
  return false;
}

String ESP8266WebServer::hostHeader() {
  return _hostHeader;
}

void ESP8266WebServer::onFileUpload(THandlerFunction fn) {
  _fileUploadHandler = fn;
}

void ESP8266WebServer::onNotFound(THandlerFunction fn) {
  _notFoundHandler = fn;
}

void ESP8266WebServer::_handleRequest() {
  bool handled = false;
  if (!_currentHandler){
#ifdef DEBUG_ESP_HTTP_SERVER
    DEBUG_OUTPUT.println("request handler not found");
#endif
  }
  else {
    handled = _currentHandler->handle(*this, _currentMethod, _currentUri);
#ifdef DEBUG_ESP_HTTP_SERVER
    if (!handled) {
      DEBUG_OUTPUT.println("request handler failed to handle request");
    }
#endif
  }

  if (!handled) {
    if(_notFoundHandler) {
      _notFoundHandler();
    }
    else {
      send(404, "text/plain", String("Not found: ") + _currentUri);
    }
  }

  _currentUri = String();
}

const char* ESP8266WebServer::_responseCodeToString(int code) {
  switch (code) {
    case 100: return "Continue";
    case 101: return "Switching Protocols";
    case 200: return "OK";
    case 201: return "Created";
    case 202: return "Accepted";
    case 203: return "Non-Authoritative Information";
    case 204: return "No Content";
    case 205: return "Reset Content";
    case 206: return "Partial Content";
    case 300: return "Multiple Choices";
    case 301: return "Moved Permanently";
    case 302: return "Found";
    case 303: return "See Other";
    case 304: return "Not Modified";
    case 305: return "Use Proxy";
    case 307: return "Temporary Redirect";
    case 400: return "Bad Request";
    case 401: return "Unauthorized";
    case 402: return "Payment Required";
    case 403: return "Forbidden";
    case 404: return "Not Found";
    case 405: return "Method Not Allowed";
    case 406: return "Not Acceptable";
    case 407: return "Proxy Authentication Required";
    case 408: return "Request Time-out";
    case 409: return "Conflict";
    case 410: return "Gone";
    case 411: return "Length Required";
    case 412: return "Precondition Failed";
    case 413: return "Request Entity Too Large";
    case 414: return "Request-URI Too Large";
    case 415: return "Unsupported Media Type";
    case 416: return "Requested range not satisfiable";
    case 417: return "Expectation Failed";
    case 500: return "Internal Server Error";
    case 501: return "Not Implemented";
    case 502: return "Bad Gateway";
    case 503: return "Service Unavailable";
    case 504: return "Gateway Time-out";
    case 505: return "HTTP Version not supported";
    default:  return "";
  }
}