#include "osc_server.h"
#include "param_map.h"
#include "daemon_log.h"

#include <oscpp/server.hpp>

#include <cstring>
#include <exception>

// Decode inbound OSC packets and dispatch the whitelisted subset
// (/avatar/parameters/Backglow{R|G|B}{0-9} and /avatar/parameters/BackglowBri)
// into the shared ParamMap. Anything outside the whitelist is dropped silently
// per D-21; malformed OSC throws from oscpp and is caught here to match D-21.

namespace {

// WR-01 (iter-3) fix: returns true iff this message hit a whitelisted Backglow
// address AND actually dispatched into ParamMap. Non-whitelisted traffic must
// NOT mark OSC-arrived — otherwise VRChat's non-backglow avatar param firehose
// pins NsSinceLastOsc at 0 and D-15 silence-fade never triggers.
bool HandleOscMessage(const OSCPP::Server::Message& msg, ParamMap& map) {
    const char* addr = msg.address();
    static constexpr const char* kPrefix = "/avatar/parameters/Backglow";
    static constexpr size_t kPrefixLen = 27;
    if (std::strncmp(addr, kPrefix, kPrefixLen) != 0) return false;  // D-21 silent drop

    const char* suffix = addr + kPrefixLen;  // "R3", "G9", "Bri"
    OSCPP::Server::ArgStream args = msg.args();
    if (args.atEnd() || args.tag() != 'f') return false;  // D-21 malformed -> drop
    const float v = args.float32();

    if (std::strcmp(suffix, "Bri") == 0) {
        map.SetBrightness(v);
        return true;
    }

    if (suffix[0] != 'R' && suffix[0] != 'G' && suffix[0] != 'B') return false;
    if (suffix[1] < '0' || suffix[1] > '9') return false;
    if (suffix[2] != '\0') return false;

    const int channel = (suffix[0] == 'R') ? 0 : (suffix[0] == 'G') ? 1 : 2;
    const int ledIdx  = suffix[1] - '0';
    map.SetChannel(ledIdx, channel, v);
    return true;
}

bool HandleOscPacketImpl(const uint8_t* buf, std::size_t size, ParamMap& map) {
    OSCPP::Server::Packet pkt(buf, size);
    bool anyDispatched = false;
    if (pkt.isBundle()) {
        OSCPP::Server::Bundle b(pkt);
        OSCPP::Server::PacketStream elems = b.packets();
        while (!elems.atEnd()) {
            OSCPP::Server::Packet sub = elems.next();
            if (HandleOscPacketImpl(static_cast<const uint8_t*>(sub.data()),
                                    sub.size(), map)) {
                anyDispatched = true;
            }
        }
    } else {
        if (HandleOscMessage(OSCPP::Server::Message(pkt), map)) {
            anyDispatched = true;
        }
    }
    return anyDispatched;
}

}  // namespace

bool HandleOscPacket(const uint8_t* buf, std::size_t size, ParamMap& map) {
    // D-21: wrap oscpp in try/catch — malformed packet is DROPPED silently.
    try {
        const bool dispatched = HandleOscPacketImpl(buf, size, map);
        // WR-01 (iter-3) fix: only reset silence-fade timer when the packet
        // actually contained at least one whitelisted Backglow address. VRChat
        // streams dozens of non-backglow avatar params per second; marking any
        // valid packet as "OSC arrived" defeats the D-15 silence-fade entirely.
        if (dispatched) map.MarkOscArrived();
        return dispatched;
    } catch (const std::exception& e) {
        DaemonLog("malformed OSC dropped: %s", e.what());
    } catch (...) {
        DaemonLog("malformed OSC dropped (unknown exception)");
    }
    return false;
}