#include <curl/curl.h>
#include <curl/easy.h>

#include <unistd.h>
#include <stdio.h>
#include <stdlib.h>

#include "hscurl.h"

static CURL *c = NULL;
static int curl_init_done = 0;
const size_t UASZ = 60;

// get_curl returns an error code
// cache_time is -1 for default cachability
int get_curl(const char *darcs_version, const char *proxypass, const char *filename, const char *url, int cache_time) {
  char user_agent[UASZ];
  CURLcode err;
  FILE *f;
  struct curl_slist *headers = NULL;

  if(!curl_init_done) {
      curl_global_init(CURL_GLOBAL_ALL);
      curl_init_done=1;
  }
  if (c == NULL) c = curl_easy_init();
  if (c == NULL) return -2;

  f = fopen(filename,"wb");
  if (f == NULL) return -1;

  err = curl_easy_setopt(c, CURLOPT_URL, url);
  /*curl_easy_setopt(c, CURLOPT_NOSIGNAL, NULL);*/
  snprintf(user_agent,UASZ,"darcs/%s (libcurl/%s)",
           darcs_version, curl_version());

  err += curl_easy_setopt(c, CURLOPT_USERAGENT, user_agent);
#ifdef CURLOPT_WRITEDATA
  err += curl_easy_setopt(c, CURLOPT_WRITEDATA, f);
#else
  err += curl_easy_setopt(c, CURLOPT_FILE, f);
#endif
  err += curl_easy_setopt(c, CURLOPT_FOLLOWLOCATION, 1);
  err += curl_easy_setopt(c, CURLOPT_FAILONERROR, 1);
  err += curl_easy_setopt(c, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
  /* libcurl currently always sends Pragma: no-cache, but never
     Cache-Control, which is contradictory.  We override both, just to
     be sure. */
  headers = curl_slist_append(headers, "Accept: */*");
  if(cache_time == 0) {
      headers = curl_slist_append(headers, "Pragma: no-cache");
      headers = curl_slist_append(headers, "Cache-Control: no-cache");
  } else if(cache_time > 0) {
      /* This won't work well with HTTP/1.0 proxies. */
      char buf[40];
      snprintf(buf, 40, "Cache-Control: max-age=%d", cache_time);
      headers = curl_slist_append(headers, "Pragma:");
      headers = curl_slist_append(headers, buf);
  } else {
      headers = curl_slist_append(headers, "Pragma:");
      headers = curl_slist_append(headers, "Cache-Control:");
  }
  err += curl_easy_setopt(c, CURLOPT_HTTPHEADER, headers);

  /* don't set the proxy user and password to an empty string */
  if (proxypass && *proxypass)
    err += curl_easy_setopt(c, CURLOPT_PROXYUSERPWD, proxypass );

  if(!err)
      err += curl_easy_perform(c);
  curl_slist_free_all(headers);
  fclose(f);
  return (int)err;
}