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

/*
 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
*/

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

#define F_SCHEME 1<<0
#define F_USERNAME 1<<1
#define F_PASSWORD 1<<2
#define F_DOMAIN 1<<3
#define F_PORT 1<<4
#define F_PATH 1<<5
#define F_QUERY_STRING 1<<6
#define F_FRAGMENT_ID 1<<7

char *long_opts[]={"scheme","username","password","domain","port","path","query_string","fragment_id",0};
char *short_opts[]={"s","u","k","d","P","p","q","f"};

int main(int argc,char *argv[]) {
 char *line=0;
 char *scheme=0;
 char *username=0;
 char *password=0;
 char *domain=0;
 char *port=0;
 char *path=0;
 char *query_string=0;
 char *fragment_id=0;
 char sport[10];
 char args[256];
 struct servent *serv;
 int i,j,c=0;
 int size=1024;
 char fixme=0;
 char using_stdin=1;
 char malloced=0;
 if(argc > 1) {
  if(!strcmp(argv[1],"--help") || !strcmp(argv[1],"-h")) {
   printf("usage: echo urls | cuturl [options]\n");
   printf("usage: cuturl [options] url [options] [url]\n\n");
   printf("options: \n");
   for(i=0;long_opts[i];i++) {
    printf("        -%s|--%s\n",short_opts[i],long_opts[i]);
   }
   printf("To set default values use environment variables like: CUTURL_[OPTION]\n");
   return 2;
  }
  argc--;
  argv++;
 }
 while(1) {
  scheme=0;
  username=0;
  password=0;
  domain=0;
  port=0;
  path=0;
  query_string=0;
  fragment_id=0;
  if(!using_stdin) c=0;
  if(argc >= 1) {
   for(;argc>0;argc--,argv++) {
    for(i=0;long_opts[i];i++) {
     if(!strncmp(*argv,"--",2)) {
      if(!strcmp(*argv+2,long_opts[i])) {
       args[c]=1<<i;
       c++;
       break;
      }
     }
    }
    fixme=0;
    if(**argv=='-' && argv[0][1] != '-') {
     for(j=1;argv[0][j];j++) {
      for(i=0;short_opts[i];i++) {
       if(argv[0][j]==*short_opts[i]) {
        args[c]=1<<i;
        c++;
        fixme=1;
       }
      }
     }
    }
    if(fixme) continue;
    if(long_opts[i]) continue;
    //if we get here we are at data instead of flags. work on it.
    line=*argv;
    using_stdin=0;
    argc--;
    argv++;
    break;
   }
  }
  if(!argc && !line) {//if we are out of arguments and it didn't include data
   using_stdin=1;
  }
  if(using_stdin) {
   line=malloc(size+1);
   malloced=1;
   if(!fgets(line,size,stdin)) {
    return 0;
   }
  }
  if(!line) return 0;
  for(i=0;line[i] && line[i] != '\n' && line[i] != '\r';i++);
  line[i]=0;

/// end of interface logic
/// beginning of business logic

  //split at first single / into line and path
  for(i=0;line[i];i++) {
   if(line[i] == '/' && line[i+1] == '/') {
    i++;
    continue;
   }
   if(line[i] == '/') {
    line[i]=0;
    path=line+i+1;
    break;
   }
  }
  if(path) {
   if(strchr(path,'?')) {
    query_string=strchr(path,'?');
    *query_string=0;
    query_string++;
   }
  }

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

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

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

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

  if(domain) {
   if(strchr(domain,']')) {//the end of an IPv6 address
    if(strchr(strchr(domain,']'),':')) {
     port=strchr(strchr(domain,']'),':');
     if(port[1] == '?') {//for magnet links
      port=0;
     } else {
      *port=0;
      port++;
     }
    }
   } else {
    if(strchr(domain,':')) {
     port=strchr(domain,':');
     if(port[1] == '?') {//for magnet links
      port=0;
     } else {
      *port=0;
      port++;
     }
    }
   }
  }

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

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

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

/// end of business logic

  // printf("scheme://username:password@domain:port/path?query_string#fragment_id\n\n");
  //let's set them to what'll get printed now...

  scheme=AorB(scheme,AorB(getenv("CUTURL_SCHEME"),"DEFAULT"));
  username=AorB(username,AorB(getenv("CUTURL_USERNAME"),"DEFAULT"));
  password=AorB(password,AorB(getenv("CUTURL_PASSWORD"),"DEFAULT"));
  domain=AorB(domain,AorB(getenv("CURURL_DOMAIN"),"DEFAULT"));
  serv=getservbyname(scheme,strcmp(scheme,"udp")?"tcp":"udp");
  if(serv) snprintf(sport,sizeof(sport)-1,"%d",ntohs(serv->s_port));
  port=AorB(port,AorB(getenv("CUTURL_PORT"),(serv?sport:"DEFAULT")));
  path=AorB(path,AorB(getenv("CUTURL_PATH"),"DEFAULT"));
  query_string=AorB(query_string,AorB(getenv("CUTURL_QUERY_STRING"),"DEFAULT"));
  fragment_id=AorB(fragment_id,AorB(getenv("CUTURL_FRAGMENT_ID"),"DEFAULT"));

  if(c) {
   for(i=0;i<c;i++) {
    if(args[i]&F_SCHEME) printf("%s\n",scheme);
    if(args[i]&F_USERNAME) printf("%s\n",username);
    if(args[i]&F_PASSWORD) printf("%s\n",password);
    if(args[i]&F_DOMAIN) printf("%s\n",domain);
    if(args[i]&F_PORT) printf("%s\n",port);
    if(args[i]&F_PATH) printf("%s\n",path);
    if(args[i]&F_QUERY_STRING) printf("%s\n",query_string);
    if(args[i]&F_FRAGMENT_ID) printf("%s\n",fragment_id);
   }
  } else {
   printf("scheme: %s\n",scheme);
   printf("username: %s\n",username);
   printf("password: %s\n",password);
   printf("domain: %s\n",domain);
   printf("port: %s\n",port);
   printf("path: %s\n",path);
   printf("query_string: %s\n",query_string);
   printf("fragment_id: %s\n",fragment_id);
  }
  if(malloced) {
   free(line);
   malloced=0;
   line=0;
  } else {
   line=0;//???
  }
 }
 return 0;
}