feature: added currency conversion infobox

src/Utility/JsonHelper.c

@@ -0,0 +1,139 @@
+#include "JsonHelper.h"
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+static int is_whitespace_json(char c) {
+  return c == ' ' || c == '\t' || c == '\n' || c == '\r';
+}
+
+int json_parse_float_map(const char *json, const char *target_key,
+                         JsonFloatMap *result) {
+  memset(result, 0, sizeof(JsonFloatMap));
+
+  if (!json || !target_key)
+    return 0;
+
+  const char *obj_start = strchr(json, '{');
+  if (!obj_start)
+    return 0;
+
+  const char *rates_start = strstr(obj_start, target_key);
+  if (!rates_start)
+    return 0;
+
+  rates_start = strchr(rates_start, '{');
+  if (!rates_start)
+    return 0;
+
+  const char *p = rates_start + 1;
+  while (*p && *p != '}') {
+    while (*p && (*p == ' ' || *p == '\n' || *p == '\t' || *p == ','))
+      p++;
+
+    if (*p == '}')
+      break;
+
+    if (*p != '"')
+      break;
+    p++;
+
+    char key[32] = {0};
+    size_t key_len = 0;
+    while (*p && *p != '"' && key_len < 31) {
+      key[key_len++] = *p++;
+    }
+    if (*p != '"')
+      break;
+    p++;
+
+    while (*p && *p != ':')
+      p++;
+    if (*p != ':')
+      break;
+    p++;
+
+    while (*p && is_whitespace_json(*p))
+      p++;
+
+    double value = 0;
+    int has_digit = 0;
+    while (*p >= '0' && *p <= '9') {
+      value = value * 10 + (*p - '0');
+      has_digit = 1;
+      p++;
+    }
+    if (*p == '.') {
+      p++;
+      double frac = 0.1;
+      while (*p >= '0' && *p <= '9') {
+        value += (*p - '0') * frac;
+        frac *= 0.1;
+        has_digit = 1;
+        p++;
+      }
+    }
+
+    if (has_digit && key_len > 0) {
+      memcpy(result->keys[result->count], key, key_len);
+      result->keys[result->count][key_len] = '\0';
+      result->values[result->count] = value;
+      result->count++;
+      if (result->count >= 256)
+        break;
+    }
+  }
+
+  return result->count > 0;
+}
+
+double json_get_float(const char *json, const char *key) {
+  if (!json || !key)
+    return 0;
+
+  const char *key_pos = strstr(json, key);
+  if (!key_pos)
+    return 0;
+
+  const char *colon = strchr(key_pos, ':');
+  if (!colon)
+    return 0;
+
+  colon++;
+  while (*colon && is_whitespace_json(*colon))
+    colon++;
+
+  return strtod(colon, NULL);
+}
+
+char *json_get_string(const char *json, const char *key) {
+  if (!json || !key)
+    return NULL;
+
+  static char buffer[256];
+
+  const char *key_pos = strstr(json, key);
+  if (!key_pos)
+    return NULL;
+
+  const char *colon = strchr(key_pos, ':');
+  if (!colon)
+    return NULL;
+
+  colon++;
+  while (*colon && is_whitespace_json(*colon))
+    colon++;
+
+  if (*colon != '"')
+    return NULL;
+  colon++;
+
+  size_t len = 0;
+  while (*colon && *colon != '"' && len < 255) {
+    buffer[len++] = *colon++;
+  }
+  buffer[len] = '\0';
+
+  return buffer;
+}

src/Utility/JsonHelper.h

@@ -0,0 +1,17 @@
+#ifndef JSONHELPER_H
+#define JSONHELPER_H
+
+#include <stddef.h>
+
+typedef struct {
+  double values[256];
+  char keys[256][32];
+  size_t count;
+} JsonFloatMap;
+
+int json_parse_float_map(const char *json, const char *target_key,
+                         JsonFloatMap *result);
+double json_get_float(const char *json, const char *key);
+char *json_get_string(const char *json, const char *key);
+
+#endif