#include "git-compat-util.h"

#include "hex-ll.h"

#include "strbuf.h"

#include "url.h"

int is_rfc3986_unreserved(char ch)

{

  return isalnum(ch) ||

    ch == '-' || ch == '_' || ch == '.' || ch == '~';

}

int is_casefolding_rfc3986_unreserved(char c)

{

  return (c >= 'a' && c <= 'z') ||

         (c >= '0' && c <= '9') ||

         c == '-' || c == '.' || c == '_' || c == '~';

}

int is_urlschemechar(int first_flag, int ch)

{

  /*

   * The set of valid URL schemes, as per STD66 (RFC3986) is

   * '[A-Za-z][A-Za-z0-9+.-]*'. But use slightly looser check

   * of '[A-Za-z0-9][A-Za-z0-9+.-]*' because earlier version

   * of check used '[A-Za-z0-9]+' so not to break any remote

   * helpers.

   */

  int alphanumeric, special;

  alphanumeric = ch > 0 && isalnum(ch);

  special = ch == '+' || ch == '-' || ch == '.';

  return alphanumeric || (!first_flag && special);

}

int is_url(const char *url)

{

  /* Is "scheme" part reasonable? */

  if (!url || !is_urlschemechar(1, *url++))

    return 0;

  while (*url && *url != ':') {

    if (!is_urlschemechar(0, *url++))

      return 0;

  }

  /* We've seen "scheme"; we want colon-slash-slash */

  return (url[0] == ':' && url[1] == '/' && url[2] == '/');

}

static char *url_decode_internal(const char **query, int len,

         const char *stop_at, struct strbuf *out,

         int decode_plus)

{

  const char *q = *query;

  while (len) {

    unsigned char c = *q;

    if (!c)

      break;

    if (stop_at && strchr(stop_at, c)) {

      q++;

      len--;

      break;

    }

    if (c == '%' && (len < 0 || len >= 3)) {

      int val = hex2chr(q + 1);

      if (0 < val) {

        strbuf_addch(out, val);

        q += 3;

        len -= 3;

        continue;

      }

    }

    if (decode_plus && c == '+')

      strbuf_addch(out, ' ');

    else

      strbuf_addch(out, c);

    q++;

    len--;

  }

  *query = q;

  return strbuf_detach(out, NULL);

}

char *url_decode(const char *url)

{

  return url_decode_mem(url, strlen(url));

}

char *url_decode_mem(const char *url, int len)

{

  struct strbuf out = STRBUF_INIT;

  const char *colon = memchr(url, ':', len);

  /* Skip protocol part if present */

  if (colon && url < colon) {

    strbuf_add(&out, url, colon - url);

    len -= colon - url;

    url = colon;

  }

  return url_decode_internal(&url, len, NULL, &out, 0);

}

char *url_percent_decode(const char *encoded)

{

  struct strbuf out = STRBUF_INIT;

  return url_decode_internal(&encoded, strlen(encoded), NULL, &out, 0);

}

char *url_decode_parameter_name(const char **query)

{

  struct strbuf out = STRBUF_INIT;

  return url_decode_internal(query, -1, "&=", &out, 1);

}

char *url_decode_parameter_value(const char **query)

{

  struct strbuf out = STRBUF_INIT;

  return url_decode_internal(query, -1, "&", &out, 1);

}

void end_url_with_slash(struct strbuf *buf, const char *url)

{

  strbuf_addstr(buf, url);

  strbuf_complete(buf, '/');

}

void str_end_url_with_slash(const char *url, char **dest)

{

  struct strbuf buf = STRBUF_INIT;

  end_url_with_slash(&buf, url);

  free(*dest);

  *dest = strbuf_detach(&buf, NULL);

}