#include <stdio.h>
#include <unistd.h>
#include <sys/socket.h>
#include <netdb.h>
#include <netinet/in.h>
#include <string.h>
#include <errno.h>
#include <signal.h>

#define MAX_RECURS	5

#include "web.h"

char lastcontenttype[256];

/* init_sockaddr : some stuff....!
 */
int init_sockaddr (struct sockaddr_in * name, const char * hostname,
		   unsigned short int port)
{
    struct hostent * hostinfo;
    name -> sin_family = AF_INET;
    name -> sin_port = htons (port);
    hostinfo = gethostbyname (hostname);
    if (hostinfo == NULL)
    {
	fprintf (stderr, "Unknown host (%s)\n", hostname);
	return 1;
    }
    name -> sin_addr = * (struct in_addr *)hostinfo -> h_addr;
    return 0;
}

void remove_end_crap(char * s)
{
    char * p = s;
    while (*p) p++;
    while (--p >= s)
    {
        if (*p == '\n' || *p == '\r') 
            *p = 0;
        else
            return;
    }
}

sig_atomic_t alarmoccured = 0;

void alarmhandler(int sig)
{
    alarmoccured = 1;
}

FILE * Download (char * pszHost, int nPort, char * pszFile, char * pszDest,
	      int level, int bOverwrite)
{
    struct sockaddr_in socketaddr;
    int		hSocket, bInHeader;
    char	szRequest [512];
    char	szLine[256];
    int		i, l;
    int		eof = 0;
    FILE	* fp = NULL;
    int		bGotContenttype = 0;

    alarmoccured = 0;

    if (level == 0)
    {
	if (options.bVerbose) printf("%s:%d/%s ", pszHost, nPort, pszFile);
	fflush(stdout);
    }
    else if (level > MAX_RECURS)
    {
	printf("Too many redirects\n");
	return NULL;
    }

    if (!bOverwrite && file_exists(pszDest, pszHost, nPort, pszFile))
    {
	if (options.bVerbose) printf("exists\n");
	return NULL;
    }

    hSocket = socket (PF_INET, SOCK_STREAM, 0);
    if (hSocket < 0) 
    {
	printf("SOCKET FAILED\n");
	return NULL;
    }
    if (init_sockaddr (&socketaddr, pszHost, nPort))
	return NULL;

    if (options.timeout != 0)
    {
	signal(SIGALRM, alarmhandler);
	alarm(options.timeout);
    }
    if (connect (hSocket, (struct sockaddr *)&socketaddr, sizeof (socketaddr)))
    {
	printf("CONNECT FAILED\n");
	return NULL;
    }
    if (options.timeout && options.bNoDataTO)
    {
	alarm(options.timeout);
    }

    snprintf (szRequest, 512, "GET http://%s/%s HTTP/1.0\n", pszHost, pszFile);
    strcat (szRequest, "User-Agent: "); 
    strcat (szRequest, options.userAgent);
    strcat (szRequest, "\n\n");

    write (hSocket, szRequest, strlen (szRequest) );
    if (options.timeout && options.bNoDataTO)
    {
	alarm(options.timeout);
    }

    bInHeader = 1;

    strcpy(lastcontenttype, "text/plain"); /* default content type */
    while (! eof)
    {
	l = 0;
	while (l < 255 && ! eof)
	{
	    if (! read(hSocket, & (szLine[l]), 1))
		eof = 1;
	    else 
		if (szLine[l++] == '\n') break;
	    if (alarmoccured) {
		if (options.bVerbose) printf ("TIMEOUT\n");
		close(hSocket);
		if (bInHeader) /* no data */
		{
		    fclose(fp);
		    return NULL;
		}
		return fp;
	    }
	    if (options.timeout && options.bNoDataTO)
	    {
		alarm(options.timeout);
	    }
	}
	szLine[l] = '\0';

	/* Need to recognised 'HTTP/xxx nnn status' line at start of header */

	if (bInHeader)			/* in the header */
	{
	    if (! strcmp (szLine,"\r\n"))     /* line empty => end of header */
	    {
		/* needs modification to support If-Modified-Since? */
		bInHeader = 0;

		pszFile = rename_object(pszHost, nPort, pszFile,
					bGotContenttype ? lastcontenttype 
					    : "application/x-unknown");

		fp = CreateFile(pszDest, pszHost, nPort, pszFile, bOverwrite);
		if (! fp)
		{
		    alarm(0);
		    printf("COULDN'T CREATE\n");
		    close(hSocket);
		    return NULL;
		}
	    }
	    else if (! strncmp(szLine, "Location: ", 10))
	    {
		SplitURL (& (szLine[17]), pszHost, pszFile, &nPort);
		close(hSocket);
		if (options.bVerbose)
		    printf("-> %s:%d/%s ", pszHost, nPort, pszFile);
		fflush(stdout);
		/* need to consider creating a symlink to new location */
		alarm(0);
		return Download(pszHost, nPort, pszFile, pszDest, 
			     level + 1, bOverwrite);

	    }
	    else if (! strncmp(szLine, "Content-Type: ", 14)
		   || ! strncmp(szLine, "Content-type: ", 14))
	    {
		strcpy(lastcontenttype, & (szLine[14]));
		remove_end_crap(lastcontenttype);
		bGotContenttype = 1;
	    }
	    /* ignore any other header lines... */

	    continue;
	}
	else				/* in body of file */
	{
	    for (i = 0; i < l; i++)
		fputc(szLine[i], fp);
	}

    }
    close(hSocket);
    alarm(0);

    if (bInHeader)
    {
	printf("NO DATA\n");
	fclose(fp);
	return NULL;
    }
    if (options.bVerbose) printf("OK\n");
    return fp;
}