From aa0346cdb5a12f8d35468459929c912a734edaff Mon Sep 17 00:00:00 2001
From: Steffen Vogel <info@steffenvogel.de>
Date: Wed, 2 Feb 2011 13:41:03 +0100
Subject: [PATCH] added json parsing (fnordlicht output pending...)

---
 src/fnpom.c | 69 ++++++++++++++++++++++++++++++++++-------------------
 1 file changed, 44 insertions(+), 25 deletions(-)

diff --git a/src/fnpom.c b/src/fnpom.c
index 150d206..83dfa36 100644
--- a/src/fnpom.c
+++ b/src/fnpom.c
@@ -9,11 +9,11 @@
 
 #include "../lib/libfn.h"
 
-char * http_get_body(char * buffer) {
+char * http_get_body(char * response) {
 	char * body;
 
-	for (body = buffer; body != '\0'; body++) {
-		if (body - buffer > 4) {
+	for (body = response; body != '\0'; body++) {
+		if (body - response > 4) {
 			if (body[0] == '\r' && body[1] == '\n' && body[2] == '\r' && body[3] == '\n') {
 				return body + 4;
 			}
@@ -24,18 +24,10 @@ char * http_get_body(char * buffer) {
 	return NULL;
 }
 
-int main(int argc, char * argv[]) {
+char * http_get(char * response, size_t bytes, char * host, char * port, char * path) {
 	int sd, count;
-	
-	char host[] = "volkszaehler.org";
-	char port[] = "80";
-	char path[] = "/demo/backend.php/data/";
-	char uuid[] = "12345678-1234-1234-1234-123456789012";
-	char buffer[8192];
-	
+	char request[1024];
 	struct addrinfo hints, *res;
-	struct json_tokener *tok;
-	struct json_object *obj;
 
 	/* set up connection */
 	memset(&hints, 0, sizeof hints);
@@ -52,26 +44,53 @@ int main(int argc, char * argv[]) {
 	}
 	
 	/* send request */
-	sprintf(buffer, "GET %s/%s.json?from=yesterday&tuples=1 HTTP/1.0\r\n\r\n", path, uuid);
-	send(sd, buffer, strlen(buffer), 0);
+	sprintf(request, "GET %s HTTP/1.0\r\n\r\n", path);
+	send(sd, request, strlen(request), 0);
 
 	/* receive data */
-	do { count = recv(sd, buffer, sizeof(buffer), 0); } while (count > 0);
+	do { count = recv(sd, response, bytes, 0); } while (count > 0);
+	/* close socket */
+	close(sd);
+	
+	return response;
+}
 
-	char * json = http_get_body(buffer);
-	printf("%s\n", json);
+int main(int argc, char * argv[]) {
+	char host[] = "volkszaehler.org";
+	char port[] = "80";
+	char path[] = "/demo/backend.php/data/";
+	char uuid[] = "12345678-1234-1234-1234-123456789012";
+	char response[8192], url[1024],  * json;
+
+	struct json_tokener * json_tok;
+	struct json_object * json_obj;
 	
-	tok = json_tokener_new();
-	obj = json_tokener_parse_ex(tok, json, strlen(json));
+	sprintf(url, "%s/%s.txt?from=yesterday&tuples=1", path, uuid); /* store request uri in buffer */
+	http_get(response, sizeof(response), host, port, url); /* fetch json data to buffer */
+	json = http_get_body(response); /* get pointer to http body */
 	
-	if (tok->err != json_tokener_success)
-		obj = error_ptr(-tok->err);
+	json_tok = json_tokener_new();
+	json_obj = json_tokener_parse_ex(json_tok, json, strlen(json));
+	
+	if (json_tok->err != json_tokener_success) {
+		json_obj = error_ptr(-json_tok->err);
+		exit(-1);
+	}
 		
-	printf("\n%s\n", json_object_to_json_string(obj));
+	/* printf("%s\n", json_object_to_json_string(json_obj)); */
+	
+	json_obj = json_object_object_get(json_obj, "data");
+	json_obj = json_object_object_get(json_obj, "last");
+	
+	if (json_object_get_type(json_obj) != json_type_double) {
+		fprintf(stderr, "invalid json!\n");
+		exit(-1);
+	}
+	
+	printf("Last value: %.2f\n", json_object_get_double(json_obj));
 	
 	/* housekeeping */
-	json_tokener_free(tok);
-	close(sd);
+	json_tokener_free(json_tok);
 	
 	return 0;
 }