#ifndef URL_H
#define URL_H

#include <netdb.h>
#include <stdio.h>
#include <string.h>
#include <stdlib.h>

//reserved = gen-delims / sub-delims
#define pe_gen_delims ":/?#[]@"
#define pe_sub_delims "!$&'()*+,;="
//char *pe_reserved[]=pe_gen_delims "" pe_sub_delims; 
#define pe_ALPHA "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
#define pe_DIGIT "0123456789"
#define pe_HPUT "-._~"
//char *pe_unreserved[]=pe_ALPHA "" pe_DIGIT "" pe_HPUT;

unsigned char rfc3086_percent_encoding[256];

#define isxdigit(a) ((a >= 'a' && a <= 'f') || (a >= '0' && a <= '9') || (a >= 'A' && a <= 'F'))
#define toupper(a) ((a >= 'a' && a <= 'z')?a-' ':a)

char *reserved={
  pe_gen_delims
  pe_sub_delims
  pe_ALPHA
  pe_DIGIT
  pe_HPUT
};

int urlescapelength(char *in,int len) {
  int rlen=0;//be sure to add one to this return value if you plan on putting a null byte at the end.
  int i;
  for(i=0;i<len;i++) {
    rlen+=strchr(reserved,in[i])?1:3;
  }
  return rlen;
}

// make sure your out char * has enough space! use urlescapelength for it.
void urlescape(char *in,char *out,int len) {
  int i;
  int j;
  for(i=0,j=0;i<len;i++) {
    if(strchr(reserved,in[i])) {
      out[j]=in[i];
      j++;
    } else {
      out[j]='%';
      j++;
      out[j]="0123456789ABCDEF"[(in[i] >> 4 & 0x15)];
      j++;
      out[j]="0123456789ABCDEF"[(in[i] % 16)];
      j++;
    }
  }
}

int urlunescape(char *in,char *out) {
 char *o=out;
 char *t;
 char a,b;
 char *s=in;
 if(!strchr(s,'%')) memmove(out,in,strlen(in));
 while((t=strchr(s,'%'))) {
  if(t-s) {//if there are actually bytes to copy.
   memmove(o,s,t-s);
   o+=(t-s);
   s+=(t-s);
  }
  if(isxdigit(t[1]) && isxdigit(t[2])) {
   s+=3;//skip the %XX
   a=toupper(t[1]);
   b=toupper(t[2]);
   *o=((a-'0'<10 ? a-'0' : a-'A'+10) << 4) + (b-'0'<10 ? b-'0' : b-'A'+10); 
   o++;
  } else {
   s++;//skip just the %. the next character might be a % //TODO: look up what the "right" thing to do here is.
   *o='%';
   o++;
  }
 }
 //copy the last part.
 memmove(o,s,strlen(s));
 o[strlen(s)]=0;
 return o+strlen(s)-out;
}

struct url {
 char *scheme;
 char *username;
 char *password;
 char *domain;
 char *port;
 char *path;
 char *query_string;
 char *fragment_id;
};


/*
 schemes are case sensitive but cononicals are lower case.
 domain is case insensitive. return it lowercased?
 port is optional and in decimal
 path
 scheme://username:password@domain:port/path?query_string#fragment_id
 mailto:username@domain

 optional stuff:
 scheme, username, password, port, path, query_string, fragment_id
*/

void urlfromline(struct url *u,char *line) {
 int i;
 char hack=0;//we need to allow for // as host//path separator
  //split at first single / into line and path
  //this fails to split scheme://host//path into: scheme, host, /path. needs to be first single / or second double-or-more-/
  for(i=0;line[i];i++) {
   if(line[i] == '/' && line[i+1] == '/') {
    if(!hack) {//only skip out on the first // because it is probably used in the scheme.
     hack=1;
     i++;
     continue;
    }
   }
   if(line[i] == '/') {
    line[i]=0;
    u->path=line+i+1;
    break;
   }
  }
  if(u->path) {
   if(strchr(u->path,'?')) {
    u->query_string=strchr(u->path,'?');
    *u->query_string=0;
    u->query_string++;
   }
  }

  if(u->query_string) {
   if(strchr(u->query_string,'#')) {
    u->fragment_id=strchr(u->query_string,'#');
    *u->fragment_id=0;
    u->fragment_id++;
   }
  }

  if(strstr(line,"://")) {
   u->scheme=line;
   u->domain=strstr(line,"://");
   *u->domain=0;
   u->domain+=3;
  } else {
   u->domain=line;
  }

  if(u->domain) {
   if(strchr(u->domain,'@')) {
    u->username=u->domain;
    u->domain=strchr(u->domain,'@');
    *u->domain=0;
    u->domain++;
   }
  }

  if(u->username) {
   if(strchr(u->username,':')) {
    u->password=strchr(u->username,':');
    *u->password=0;
    u->password++;
   }
  }

  if(u->domain) {
   if(strchr(u->domain,']')) {//the end of an IPv6 address
    if(strchr(strchr(u->domain,']'),':')) {
     u->port=strchr(strchr(u->domain,']'),':');
     if(u->port[1] == '?') {//for magnet links
      u->port=0;
     } else {
      *u->port=0;
      u->port++;
     }
    }
   } else {
    if(strchr(u->domain,':')) {
     u->port=strchr(u->domain,':');
     if(u->port[1] == '?') {//for magnet links
      u->port=0;
     } else {
      *u->port=0;
      u->port++;
     }
    }
   }
  }
  if(u->port) {
   for(i=0;u->port[i];i++) {
    if(u->port[i] < '0' || u->port[i] > '9') {
     //this port number isn't a number!
     //it is probably a different portion of the url then... and the domain is probably the scheme.
     if(u->domain && !u->scheme) {
      u->scheme=u->domain;
      u->domain=0;
     }
     if(!u->path) {
      u->path=u->port;
      u->port=0;
     }
     break;
    }
   }
  }

  if(u->domain) {//for magnet links.
   if(strchr(u->domain,'?')) {
    u->query_string=strchr(u->domain,'?');
    *u->query_string=0;
    u->query_string++;
   }
  }

  if(u->domain) {
   if(strchr(u->domain,':') && !strchr(u->domain,']')) {//for scheme:?query_string
    u->scheme=u->domain;
    *strchr(u->scheme,':')=0;
    u->domain=0;
   }
  }

  if(!u->scheme && u->username) {//for mailto:
   u->scheme=u->username;
   u->username=u->password;
   u->password=0;
  }
}

#define AorB(a,b) ((a)?(a):(b))

void magic_and_defaults(struct url *u) {
  struct servent *serv;
  char sport[10];
  u->scheme=AorB(u->scheme,AorB(getenv("URL_SCHEME"),"DEFAULT"));
  u->username=AorB(u->username,AorB(getenv("URL_USERNAME"),"DEFAULT"));
  u->password=AorB(u->password,AorB(getenv("URL_PASSWORD"),"DEFAULT"));
  u->domain=AorB(u->domain,AorB(getenv("URL_DOMAIN"),"DEFAULT"));
  serv=getservbyname(u->scheme,strcmp(u->scheme,"udp")?"tcp":"udp");//gets default port for the scheme. http -> 80
  if(serv) snprintf(sport,sizeof(sport)-1,"%d",ntohs(serv->s_port));
//  else snprintf(sport,sizeof(sport)-1,"%d",serv);
  u->port=AorB(u->port,AorB(getenv("URL_PORT"),(serv?strdup(sport):"DEFAULT")));

//  if(!strcmp(u->port,"DEFAULT")) {
   //this shouldn't happen most of the time. :/
//   printf("serv: %d\nsport: %s\nu->scheme: %s\n",serv,sport,u->scheme);
//  }

  u->path=AorB(u->path,AorB(getenv("URL_PATH"),"DEFAULT"));
  u->query_string=AorB(u->query_string,AorB(getenv("URL_QUERY_STRING"),"DEFAULT"));
  u->fragment_id=AorB(u->fragment_id,AorB(getenv("URL_FRAGMENT_ID"),"DEFAULT"));
}
#endif