#include <weave/packet.h>

WEAVE_PACKET_POOL_DEFINE(pool, 16, 128, NULL);
WEAVE_PACKET_SOURCE_DEFINE(sensor_source);

void handler(struct net_buf *buf, void *user_data) {
    LOG_INF("Received %d bytes", buf->len);
}

WEAVE_PACKET_SINK_DEFINE(log_sink, handler, WV_IMMEDIATE, WV_NO_FILTER, NULL);
WEAVE_CONNECT(&sensor_source, &log_sink);

void send_data(void) {
    struct net_buf *buf = weave_packet_alloc(&pool, K_NO_WAIT);
    net_buf_add_mem(buf, data, len);
    weave_packet_send(&sensor_source, buf, K_NO_WAIT);
}

#include <weave/method.h>

WEAVE_MSGQ_DEFINE(service_queue, 8);

int read_handler(const struct read_req *req, struct read_res *res, void *user_data) {
    res->value = get_sensor_value(req->channel);
    return 0;
}

WEAVE_METHOD_DEFINE(read_sensor, read_handler, &service_queue, NULL,
                    struct read_req, struct read_res);

/* Caller side - blocks until handler completes */
struct read_req req = {.channel = 0};
struct read_res res;
int ret = WEAVE_METHOD_CALL(read_sensor, &req, &res);

#include <weave/observable.h>

struct config { uint32_t sample_rate; bool enabled; };

/* Owner handler called on every change */
void on_change(struct weave_observable *obs, void *user_data) {
    struct config cfg;
    WEAVE_OBSERVABLE_GET(settings, &cfg);
    apply_config(&cfg);
}

/* Optional validator can reject invalid values */
int validate(struct weave_observable *obs, const void *new_value, void *user_data) {
    const struct config *cfg = new_value;
    return (cfg->sample_rate <= 10000) ? 0 : -EINVAL;
}

WEAVE_OBSERVABLE_DEFINE(settings, struct config,
                        on_change, WV_IMMEDIATE, NULL,  /* owner handler */
                        validate);                       /* validator */

/* External observers can also subscribe */
WEAVE_OBSERVER_DEFINE(logger, log_change, &log_queue, NULL);
WEAVE_OBSERVER_CONNECT(settings, logger);

/* Update triggers validation, then owner handler, then observers */
struct config new_cfg = {.sample_rate = 100, .enabled = true};
int ret = WEAVE_OBSERVABLE_SET(settings, &new_cfg);
if (ret < 0) { /* Validation failed */ }