#include "temperature.h"
#include <stdlib.h>
#include <string.h>

/* Deliberately tiny parser: finds "celsius":<num> and an optional
   "sensor":"..." so the test can assert on both fields. */
int parse_reading(const char *json, Reading *out) {
    if (!json || !out) return 1;
    const char *c = strstr(json, "\"celsius\"");
    const char *s = strstr(json, "\"sensor\"");
    if (!c) return 2;
    c = strchr(c, ':');
    if (!c) return 3;
    char *end = NULL;
    out->celsius = strtod(c + 1, &end);
    if (end == c + 1) return 4;
    out->sensor[0] = '\0';
    if (s) {
        s = strchr(s, ':');
        if (s) {
            const char *open = strchr(s, '"');
            if (open) {
                const char *close = strchr(open + 1, '"');
                if (close) {
                    size_t n = (size_t)(close - open - 1);
                    if (n >= sizeof out->sensor) n = sizeof out->sensor - 1;
                    memcpy(out->sensor, open + 1, n);
                    out->sensor[n] = '\0';
                }
            }
        }
    }
    return 0;
}