From d2a8f8d53dd753328c18effbd691b47d0eb3a81e Mon Sep 17 00:00:00 2001
From: Nathan Singer <nathan.r.singer@gmx.com>
Date: Fri, 28 Feb 2025 00:08:33 -0500
Subject: [PATCH] adds some basic json parsing stuff

---
 src/include/json.h | 10 ++++++++++
 src/json.c         | 42 ++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 src/include/json.h
 create mode 100644 src/json.c

diff --git a/src/include/json.h b/src/include/json.h
new file mode 100644
index 0000000..a63d84b
--- /dev/null
+++ b/src/include/json.h
@@ -0,0 +1,10 @@
+#include <cjson/cJSON.h>
+#include "curl.h"
+
+#ifndef JSON_H
+#define JSON_H
+
+void json_out(cJSON** json);
+void get_json_book(get_response* resp, cJSON** query);
+
+#endif
diff --git a/src/json.c b/src/json.c
new file mode 100644
index 0000000..33e941a
--- /dev/null
+++ b/src/json.c
@@ -0,0 +1,42 @@
+#include <cjson/cJSON.h>
+#include <stdlib.h>
+#include <stdbool.h>
+
+#include "include/curl.h"
+#include "include/json.h"
+
+static bool check_valid_query(cJSON* query) {return (query->valueint != 0);}
+
+#define FILE_OUT "book.json"
+void json_out(cJSON** json)
+{
+	FILE* f = fopen(FILE_OUT, "w");
+	fprintf(f, "%s", cJSON_Print(*json));
+	fclose(f);
+}
+#undef FILE_OUT
+
+void get_json_book(get_response* resp, cJSON** query)
+{
+	bool err;
+	cJSON* json;
+	
+	json = cJSON_Parse(resp->buf);
+	if (!json) {
+		const char* err_ptr = cJSON_GetErrorPtr();
+		if (err_ptr)
+			fprintf(stderr, "cJSON_Parse: %s\n", err_ptr);
+		cJSON_Delete(json);
+		exit(EXIT_FAILURE);
+	}
+
+	err = check_valid_query(cJSON_GetObjectItemCaseSensitive(json, "numFound"));
+	if (!err) {
+		fprintf(stderr, "ISBN not found!\n");
+		exit(EXIT_SUCCESS);
+	}
+
+	// first entry of the "docs" json entry, which is the search result	
+	(*query) = cJSON_GetObjectItemCaseSensitive(json, "docs")->child;
+}
+