/*
 * URL Helper
 *
 * Copyright (C) 2001 Bertrand Baudet <bertrand_baudet@yahoo.com>
 *
 * This file is part of MPlayer.
 *
 * MPlayer is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * MPlayer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <ctype.h>
#include <inttypes.h>

#include "url.h"
#include "mp_msg.h"

#ifndef SIZE_MAX
#define SIZE_MAX ((size_t)-1)
#endif

URL_t *url_redirect(URL_t **url, const char *redir) {
  URL_t *u = *url;
  URL_t *res;
  if (!strchr(redir, '/') || *redir == '/') {
    char *tmp;
    char *newurl = malloc(strlen(u->url) + strlen(redir) + 1);
    strcpy(newurl, u->url);
    if (*redir == '/') {
      redir++;
      tmp = strstr(newurl, "://");
      if (tmp) tmp = strchr(tmp + 3, '/');
    } else
      tmp = strrchr(newurl, '/');
    if (tmp) tmp[1] = 0;
    strcat(newurl, redir);
    res = url_new(newurl);
    free(newurl);
  } else
    res = url_new(redir);
  url_free(u);
  *url = res;
  return res;
}

static int make_noauth_url(URL_t *url, char *dst, int dst_size)
{
    if (url->port)
        return snprintf(dst, dst_size, "%s://%s:%d%s", url->protocol,
                        url->hostname, url->port, url->file);
    else
        return snprintf(dst, dst_size, "%s://%s%s", url->protocol,
                        url->hostname, url->file);
}

int make_http_proxy_url(URL_t *proxy, const char *host_url, char *dst,
                        int dst_size)
{
    if (proxy->username)
        return snprintf(dst, dst_size, "http_proxy://%s:%s@%s:%d/%s",
                        proxy->username,
                        proxy->password ? proxy->password : "",
                        proxy->hostname, proxy->port, host_url);
    else
        return snprintf(dst, dst_size, "http_proxy://%s:%d/%s",
                        proxy->hostname, proxy->port, host_url);
}

URL_t*
url_new(const char* url) {
	int pos1, pos2,v6addr = 0, noauth_len;
	URL_t* Curl = NULL;
        char *escfilename=NULL;
	char *ptr1=NULL, *ptr2=NULL, *ptr3=NULL, *ptr4=NULL;
	int jumpSize = 3;

	if( url==NULL ) return NULL;

        if (strlen(url) > (SIZE_MAX / 3 - 1)) {
                mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
                goto err_out;
        }
        escfilename=malloc(strlen(url)*3+1);
        if (!escfilename ) {
                mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
                goto err_out;
        }

	// Create the URL container
	Curl = calloc(1, sizeof(*Curl));
	if( Curl==NULL ) {
		mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
		goto err_out;
	}

	url_escape_string(escfilename,url);

	// Copy the url in the URL container
	Curl->url = strdup(escfilename);
	if( Curl->url==NULL ) {
		mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
		goto err_out;
	}
        mp_msg(MSGT_OPEN,MSGL_V,"Filename for url is now %s\n",escfilename);

	// extract the protocol
	ptr1 = strstr(escfilename, "://");
	if( ptr1==NULL ) {
	        // Check for a special case: "sip:" (without "//"):
	        if (strstr(escfilename, "sip:") == escfilename) {
		        ptr1 = (char *)&url[3]; // points to ':'
			jumpSize = 1;
		} else {
		        mp_msg(MSGT_NETWORK,MSGL_V,"Not an URL!\n");
			goto err_out;
		}
	}
	pos1 = ptr1-escfilename;
	Curl->protocol = malloc(pos1+1);
	if( Curl->protocol==NULL ) {
		mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
		goto err_out;
	}
	strncpy(Curl->protocol, escfilename, pos1);
	Curl->protocol[pos1] = '\0';

	// jump the "://"
	ptr1 += jumpSize;
	pos1 += jumpSize;

	// check if a username:password is given
	ptr2 = strstr(ptr1, "@");
	ptr3 = strstr(ptr1, "/");
	if( ptr3!=NULL && ptr3<ptr2 ) {
		// it isn't really a username but rather a part of the path
		ptr2 = NULL;
	}
	if( ptr2!=NULL ) {
		// We got something, at least a username...
		int len = ptr2-ptr1;
		Curl->username = malloc(len+1);
		if( Curl->username==NULL ) {
			mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
			goto err_out;
		}
		strncpy(Curl->username, ptr1, len);
		Curl->username[len] = '\0';

		ptr3 = strstr(ptr1, ":");
		if( ptr3!=NULL && ptr3<ptr2 ) {
			// We also have a password
			int len2 = ptr2-ptr3-1;
			Curl->username[ptr3-ptr1]='\0';
			Curl->password = malloc(len2+1);
			if( Curl->password==NULL ) {
				mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
				goto err_out;
			}
			strncpy( Curl->password, ptr3+1, len2);
			Curl->password[len2]='\0';
			url_unescape_string(Curl->password, Curl->password);
		}
		url_unescape_string(Curl->username, Curl->username);
		ptr1 = ptr2+1;
		pos1 = ptr1-escfilename;
	}

	// before looking for a port number check if we have an IPv6 type numeric address
	// in IPv6 URL the numeric address should be inside square braces.
	ptr2 = strstr(ptr1, "[");
	ptr3 = strstr(ptr1, "]");
	ptr4 = strstr(ptr1, "/");
	if( ptr2!=NULL && ptr3!=NULL && ptr2 < ptr3 && (!ptr4 || ptr4 > ptr3)) {
		// we have an IPv6 numeric address
		ptr1++;
		pos1++;
		ptr2 = ptr3;
		v6addr = 1;
	} else {
		ptr2 = ptr1;

	}

	// look if the port is given
	ptr2 = strstr(ptr2, ":");
	// If the : is after the first / it isn't the port
	ptr3 = strstr(ptr1, "/");
	if(ptr3 && ptr3 - ptr2 < 0) ptr2 = NULL;
	if( ptr2==NULL ) {
		// No port is given
		// Look if a path is given
		if( ptr3==NULL ) {
			// No path/filename
			// So we have an URL like http://www.hostname.com
			pos2 = strlen(escfilename);
		} else {
			// We have an URL like http://www.hostname.com/file.txt
                        pos2 = ptr3-escfilename;
		}
	} else {
		// We have an URL beginning like http://www.hostname.com:1212
		// Get the port number
		Curl->port = atoi(ptr2+1);
		pos2 = ptr2-escfilename;
	}
	if( v6addr ) pos2--;
	// copy the hostname in the URL container
	Curl->hostname = malloc(pos2-pos1+1);
	if( Curl->hostname==NULL ) {
		mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
		goto err_out;
	}
	strncpy(Curl->hostname, ptr1, pos2-pos1);
	Curl->hostname[pos2-pos1] = '\0';

	// Look if a path is given
	ptr2 = strstr(ptr1, "/");
	if( ptr2!=NULL ) {
		// A path/filename is given
		// check if it's not a trailing '/'
		if( strlen(ptr2)>1 ) {
			// copy the path/filename in the URL container
			Curl->file = strdup(ptr2);
			if( Curl->file==NULL ) {
				mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
				goto err_out;
			}
		}
	}
	// Check if a filename was given or set, else set it with '/'
	if( Curl->file==NULL ) {
		Curl->file = malloc(2);
		if( Curl->file==NULL ) {
			mp_tmsg(MSGT_NETWORK,MSGL_FATAL,"Memory allocation failed.\n");
			goto err_out;
		}
		strcpy(Curl->file, "/");
	}

	noauth_len = make_noauth_url(Curl, NULL, 0);
	if (noauth_len > 0) {
		noauth_len++;
		Curl->noauth_url = malloc(noauth_len);
		if (!Curl->noauth_url) {
			mp_msg(MSGT_NETWORK, MSGL_FATAL, "Memory allocation failed.\n");
			goto err_out;
		}
		make_noauth_url(Curl, Curl->noauth_url, noauth_len);
	}

        free(escfilename);
	return Curl;
err_out:
	free(escfilename);
	if (Curl) url_free(Curl);
	return NULL;
}

void
url_free(URL_t* url) {
	if(!url) return;
	free(url->url);
	free(url->protocol);
	free(url->hostname);
	free(url->file);
	free(url->username);
	free(url->password);
	free(url);
}


/* Replace escape sequences in an URL (or a part of an URL) */
/* works like strcpy(), but without return argument,
   except that outbuf == inbuf is allowed */
void
url_unescape_string(char *outbuf, const char *inbuf)
{
	unsigned char c,c1,c2;
        int i,len=strlen(inbuf);
        for (i=0;i<len;i++){
		c = inbuf[i];
		if (c == '%' && i<len-2) { //must have 2 more chars
			c1 = toupper(inbuf[i+1]); // we need uppercase characters
			c2 = toupper(inbuf[i+2]);
			if (	((c1>='0' && c1<='9') || (c1>='A' && c1<='F')) &&
				((c2>='0' && c2<='9') || (c2>='A' && c2<='F')) ) {
				if (c1>='0' && c1<='9') c1-='0';
				else c1-='A'-10;
				if (c2>='0' && c2<='9') c2-='0';
				else c2-='A'-10;
				c = (c1<<4) + c2;
                                i=i+2; //only skip next 2 chars if valid esc
			}
		}
		*outbuf++ = c;
	}
        *outbuf++='\0'; //add nullterm to string
}

static void
url_escape_string_part(char *outbuf, const char *inbuf) {
	unsigned char c,c1,c2;
        int i,len=strlen(inbuf);

	for  (i=0;i<len;i++) {
		c = inbuf[i];
                if ((c=='%') && i<len-2 ) { //need 2 more characters
                    c1=toupper(inbuf[i+1]); c2=toupper(inbuf[i+2]); // need uppercase chars
                   } else {
                    c1=129; c2=129; //not escape chars
                   }

		if(	(c >= 'A' && c <= 'Z') ||
			(c >= 'a' && c <= 'z') ||
			(c >= '0' && c <= '9')) {
			*outbuf++ = c;
                } else if ( c=='%' && ((c1 >= '0' && c1 <= '9') || (c1 >= 'A' && c1 <= 'F')) &&
                           ((c2 >= '0' && c2 <= '9') || (c2 >= 'A' && c2 <= 'F'))) {
                                                              // check if part of an escape sequence
                            *outbuf++=c;                      // already

                                                              // dont escape again
                            mp_tmsg(MSGT_NETWORK,MSGL_ERR,"String appears to be already escaped in url_escape %c%c1%c2\n",c,c1,c2);
                                                              // error as this should not happen against RFC 2396
                                                              // to escape a string twice
		} else {
			/* all others will be escaped */
			c1 = ((c & 0xf0) >> 4);
			c2 = (c & 0x0f);
			if (c1 < 10) c1+='0';
			else c1+='A'-10;
			if (c2 < 10) c2+='0';
			else c2+='A'-10;
			*outbuf++ = '%';
			*outbuf++ = c1;
			*outbuf++ = c2;
		}
	}
        *outbuf++='\0';
}

/* Replace specific characters in the URL string by an escape sequence */
/* works like strcpy(), but without return argument */
void
url_escape_string(char *outbuf, const char *inbuf) {
	unsigned char c;
        int i = 0,j,len = strlen(inbuf);
	char* tmp,*unesc = NULL, *in;

	// Look if we have an ip6 address, if so skip it there is
	// no need to escape anything in there.
	tmp = strstr(inbuf,"://[");
	if(tmp) {
		tmp = strchr(tmp+4,']');
		if(tmp && (tmp[1] == '/' || tmp[1] == ':' ||
			   tmp[1] == '\0')) {
			i = tmp+1-inbuf;
			strncpy(outbuf,inbuf,i);
			outbuf += i;
			tmp = NULL;
		}
	}

	tmp = NULL;
	while(i < len) {
		// look for the next char that must be kept
		for  (j=i;j<len;j++) {
			c = inbuf[j];
			if(c=='-' || c=='_' || c=='.' || c=='!' || c=='~' ||	/* mark characters */
			   c=='*' || c=='\'' || c=='(' || c==')' || 	 	/* do not touch escape character */
			   c==';' || c=='/' || c=='?' || c==':' || c=='@' || 	/* reserved characters */
			   c=='&' || c=='=' || c=='+' || c=='$' || c==',') 	/* see RFC 2396 */
				break;
		}
		// we are on a reserved char, write it out
		if(j == i) {
			*outbuf++ = c;
			i++;
			continue;
		}
		// we found one, take that part of the string
		if(j < len) {
			if(!tmp) tmp = malloc(len+1);
			strncpy(tmp,inbuf+i,j-i);
			tmp[j-i] = '\0';
			in = tmp;
		} else // take the rest of the string
			in = (char*)inbuf+i;

		if(!unesc) unesc = malloc(len+1);
		// unescape first to avoid escaping escape
		url_unescape_string(unesc,in);
		// then escape, including mark and other reserved chars
		// that can come from escape sequences
		url_escape_string_part(outbuf,unesc);
		outbuf += strlen(outbuf);
		i += strlen(in);
	}
	*outbuf = '\0';
	free(tmp);
	free(unesc);
}

#ifdef URL_DEBUG
void
url_debug(const URL_t *url) {
	if( url==NULL ) {
		printf("URL pointer NULL\n");
		return;
	}
	if( url->url!=NULL ) {
		printf("url=%s\n", url->url );
	}
	if( url->protocol!=NULL ) {
		printf("protocol=%s\n", url->protocol );
	}
	if( url->hostname!=NULL ) {
		printf("hostname=%s\n", url->hostname );
	}
	printf("port=%d\n", url->port );
	if( url->file!=NULL ) {
		printf("file=%s\n", url->file );
	}
	if( url->username!=NULL ) {
		printf("username=%s\n", url->username );
	}
	if( url->password!=NULL ) {
		printf("password=%s\n", url->password );
	}
}
#endif /* URL_DEBUG */