sems/apps/sbc/call_control/rest/RestParams.cpp

#include "RestParams.h"
#include "log.h"
#include <curl/curl.h>
#include <map>
#include "jsonArg.h"

using namespace std;

static void trim_spaces(string &s)
{
  size_t pos = s.find_last_not_of(" \t\r\n");
  if (pos != string::npos) {
    s.erase(pos + 1);
    pos = s.find_first_not_of(' ');
    if (pos != string::npos) s.erase(0, pos);
  }
  else s.erase(s.begin(), s.end());
}

static bool str2bool(const char *s)
{
  if ((!s) || (!*s)) return true; // understand as just bool option which should be true
  if (strcasecmp(s, "yes") == 0) return true;
  if (strcasecmp(s, "true") == 0) return true;
  if (strcmp(s, "1") == 0) return true;
  
  return false;
}

////////////////////////////////////////////////////////////////////////////////

void RestParams::getIfSet(const char *param_name, string &dst)
{
  if (params.hasMember(param_name)) {
    const AmArg &a = params[param_name];
    if (isArgCStr(a)) dst = a.asCStr();
  }
}

void RestParams::getIfSet(const char *param_name, bool &dst)
{
  if (params.hasMember(param_name)) {
    const AmArg &a = params[param_name];
    if (isArgCStr(a)) dst = str2bool(a.asCStr());
    if (isArgBool(a)) dst = a.asBool();
  }
}

void RestParams::handleParamLine(const string &line, size_t begin, size_t end)
{
  size_t pos;

  pos = line.find('=', begin);
  if (pos == string::npos) return; // "=" not found, ignore this param
  if (pos >= end) return; // "=" found on another line, ignore this param

  string name(line.substr(begin, pos - begin));
  string value(line.substr(pos + 1, end - pos));

  trim_spaces(name);
  trim_spaces(value);

  if (name.size() > 0) {
    DBG("REST: param %s='%s'\n", name.c_str(), value.c_str());
    params.push(name, AmArg(value));
  }
}
    
bool RestParams::readFromText(const string &data)
{
  size_t first = 0;
  size_t last;

  params.assertStruct();
  while (true) { 
    last = data.find('\n', first);
    if (last == string::npos) {
      handleParamLine(data, first, data.size());
      break;
    }
    else handleParamLine(data, first, last);
    first = last + 1;
  }

  string dbg = arg2json(params);
  return true;
}

bool RestParams::readFromJson(const string &data)
{
  return json2arg(data, params);
}

bool RestParams::readFromXML(const string &data)
{
  // TODO
  ERROR("REST: trying to decode XML data - not implemented yet!\n");
  return false;
}

bool RestParams::retrieve(const string &url, Format fmt)
{
  string data;
    
  DBG("REST: reading from url %s\n", url.c_str());

  if (!get(url, data)) return false;

  switch (fmt) {
    case TEXT: return readFromText(data);
    case JSON: return readFromJson(data);
    case XML: return readFromXML(data);
  }

  return false;
}

static size_t store_data_cb(void *contents, size_t size, size_t nmemb, void *userp)
{
  size_t realsize = size * nmemb;
  string &mem = *((string *)userp);

  try {
    if (realsize > 0) mem.append((char *)contents, realsize);
  }
  catch (...) {
    ERROR("error while reading data from an URL\n");
    return 0;
  }
  return realsize;
}

bool RestParams::get(const string &url, string &data)
{
  // based on http://curl.haxx.se/libcurl/c/getinmemory.html
  CURL *curl_handle = curl_easy_init();

  data.clear();

  if (!curl_handle) {
    // this can't be ignored
    throw string("curl_easy_init() failed\n");
  }

  curl_easy_setopt(curl_handle, CURLOPT_URL, url.c_str());
  curl_easy_setopt(curl_handle, CURLOPT_WRITEFUNCTION, store_data_cb);
  curl_easy_setopt(curl_handle, CURLOPT_WRITEDATA, (void *)&data);
  curl_easy_setopt(curl_handle, CURLOPT_USERAGENT, "REST-in-peace/0.1");
  CURLcode res = curl_easy_perform(curl_handle);
  
  long code = 0;
  curl_easy_getinfo(curl_handle, CURLINFO_RESPONSE_CODE, &code);

  curl_easy_cleanup(curl_handle);

  if (res != 0) {
    // really ignore these errors?
    DBG("libcurl returned error %d\n", res);
    return false;
  }

  if ((code < 200) || (code > 299)) {
    DBG("non-ok response code when downloading data: %ld\n", code);
    return false;
  }

  return true;
}