#include <stdio.h>
#include <string.h>
#include <curl/curl.h>

#include "getwebfile.h"

static int getwebfile_printprogress(void *clientp, double dltotal, double dlnow, double ultotal,  double ulnow);

/*----------------
/* getwebfile
/*----------------*/
int getwebfile(const char *url)
{
	FILE *f;
	CURL *curl;
	int ungzip = 0;

	/* Check if file is already here */
	const char *fname = url;
	const char *ptr;
	do{
		ptr = strstr(fname, "/");
		if(ptr)fname=&ptr[1];
	}while(ptr!=NULL);
	f = fopen(fname,"r");
	if(f){
		/* File already exists. Do nothing. */
		fclose(f);
		printf("Using local file \"%s\"\n", fname);
	}else{
		/* File does not exist. Try downloading. */
		printf("No local file: \"%s\".\nAttempting download from %s \n", fname, url);
		
		/* This should be done globally when there is only one thread */
		curl_global_init(CURL_GLOBAL_ALL);

		/* File does not exist. Try obtaining from URL */
		curl = curl_easy_init();

		/* Setup the options for the download */
		f = fopen(fname,"w");
		curl_easy_setopt(curl, CURLOPT_VERBOSE, 0);
		curl_easy_setopt(curl, CURLOPT_URL, url);
		curl_easy_setopt(curl, CURLOPT_WRITEDATA, f);
		curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0);
		curl_easy_setopt(curl, CURLOPT_PROGRESSFUNCTION, getwebfile_printprogress);
		
		/* Download the file */
		curl_easy_perform(curl);

		/* Close CURL */
		curl_easy_cleanup(curl);
		
		/* Close the downloaded file */
		printf("\n");
		fclose(f);
		
		/* This should be done at program exit when there is only one thread */
		curl_global_cleanup();
		
		/* Set flag to automatically ungzip if this is a gzipped file */
		ungzip = 1;
	}
	
	/* If the file is gzipped (and has a .gz suffix) then unzip it */
	if(strlen(fname)>3 && !strcmp(&fname[strlen(fname)-3], ".gz")){
		char *uncompressed_fname = strdup(fname);
		char cmd[256];
		
		uncompressed_fname[strlen(uncompressed_fname)-3] = 0; /* cut off ".gz" suffix */
		
		/* Check if the uncompressed file already exists. Only uncompress if either */
		/* it doesn't exist or was just now (re)downloaded. */
		f = fopen(uncompressed_fname,"r");
		if(!f){
			ungzip = 1;
		}else{
			if(ungzip){
				printf("Un-gzipped version (\"%s\") already exists. Overwriting with\n", uncompressed_fname);
				printf("file just downloaded (\"%s\")\n", fname);
			}else{
				printf("Using existing un-gzipped file \"%s\"\n", uncompressed_fname);
			}
			fclose(f);
		}
		
		/* Ungzip the file, explicitly giving it's uncompressed filename */
		if(ungzip){
			sprintf(cmd, "gzip -cd %s > %s", fname, uncompressed_fname);
			printf("The file \"%s\" appears to be gzipped. Attempting to uncompress with:\n", fname);
			printf("    %s\n", cmd);
			system(cmd);
		}
		
		/* free memory allocated for uncompressed filename */
		free(uncompressed_fname);
	}
	
	return 0;
}

/*----------------
/* getwebfile_printprogress
/*----------------*/
int getwebfile_printprogress(void *clientp, double dltotal, double dlnow, double ultotal,  double ulnow)
{
	printf("  %dkB      \r", (unsigned long)(dlnow/1024.0));
	fflush(stdout);
}


#if 0
/* For testing */
int m ain(int narg, char *argv[])
{
	
	const char *url = "http://zeus.phys.uconn.edu/halld/tagger/simulation/taggerBfield-quad-map.gz";
	
	getwebfile(url);

	return 0;
}
#endif