picomap/firmware/include/dispatch.h

#pragma once
#include <cstdint>
#include <functional>
#include <span>
#include "wire.h"

using handler_fn = size_t (*)(uint32_t message_id, std::span<const uint8_t> payload, span_writer &out);

struct handler_entry {
    int8_t type_id;
    handler_fn handle;
};

template <typename Req, auto Fn>
size_t typed_handler(uint32_t message_id, std::span<const uint8_t> payload, span_writer &out) {
    msgpack::parser p(payload.data(), static_cast<int>(payload.size()));
    Req req;
    auto tup = req.as_tuple();
    auto r = msgpack::unpack(p, tup);
    if (!r) {
        return encode_response_into(out, message_id, DeviceError{1, "decode request ext_id=" +
            std::to_string(Req::ext_id) + ": msgpack error " + std::to_string(static_cast<int>(r.error()))});
    }
    return Fn(message_id, req, out);
}

void dispatch_init();
void dispatch_schedule_ms(uint32_t ms, std::function<void()> fn);
[[noreturn]] void dispatch_run(std::span<const handler_entry> handlers);