reasampler/src/shell/view/view_park.cpp

// See view_park.h. Compiled into the reaper_reasampler module; includes
// reaper_plugin_functions.h without REAPERAPI_IMPLEMENT (main.cpp owns that).

#include "shell/view/view_park.h"

#include <cstring>  // strnlen — bounded read of GetTrackName's buffer
#include <string>
#include <vector>

#define REAPERAPI_MINIMAL
#define REAPERAPI_WANT_GetMediaTrackInfo_Value
#define REAPERAPI_WANT_GetTrackName
#define REAPERAPI_WANT_SetMediaTrackInfo_Value
#define REAPERAPI_WANT_ShowConsoleMsg
#define REAPERAPI_WANT_TrackFX_GetCount
#define REAPERAPI_WANT_TrackFX_GetFXGUID
#define REAPERAPI_WANT_TrackFX_GetOffline
#define REAPERAPI_WANT_guidToString
#include "reaper_plugin_functions.h"

namespace reasampler {

namespace {

// Captures prior driven-flag state, and the chain's per-FX offline state, before
// parking. Never reads B_MUTE/I_SOLO; ints preserve whatever REAPER reported
// (TrackSnapshot's defensive contract). The plain 0..TrackFX_GetCount-1 enumeration
// — never the 0x1000000/0x2000000 input-FX or container forms — is the same one the
// reclaimer resolves against. `fxKeying` stays Identity: a live read always knows
// the chain.
TrackSnapshot snapshotTrack(MediaTrack* tr) {
    TrackSnapshot snap;
    auto read = [tr](Flag f) {
        return static_cast<int>(GetMediaTrackInfo_Value(tr, trackFlagParm(f)));
    };
    snap.showInTcp   = read(Flag::ShowInTcp);
    snap.showInMixer = read(Flag::ShowInMixer);
    snap.mainSend    = read(Flag::MainSend);
    snap.fxEnable    = read(Flag::FxEnable);

    const int fxCount = TrackFX_GetCount(tr);
    snap.fxOffline.reserve(static_cast<std::size_t>(fxCount));
    for (int fx = 0; fx < fxCount; ++fx)
        snap.fxOffline.push_back(
            FxOfflineState{fxGuidString(tr, fx), TrackFX_GetOffline(tr, fx) ? 1 : 0});
    return snap;
}

bool applyFlags(MediaTrack* tr, const std::vector<TrackFlagOp>& flags) {
    bool wrote = false;
    for (const TrackFlagOp& op : flags)
        if (writeIfChanged(tr, trackFlagParm(op.flag), static_cast<double>(op.value)))
            wrote = true;
    return wrote;
}

// The visible/active mirror of a park write: same four ops, value 1 instead of
// whatever the plan says (always 0 for a park plan — see makeParkPlan). Reusing
// the incoming park ops rather than minting a separate "expose plan" keeps the
// two writes provably addressing the same four parameters.
bool exposeFlags(MediaTrack* tr, const std::vector<TrackFlagOp>& parkFlags) {
    bool wrote = false;
    for (const TrackFlagOp& op : parkFlags)
        if (writeIfChanged(tr, trackFlagParm(op.flag), 1.0)) wrote = true;
    return wrote;
}

// The last EXPOSE report, so an unchanged set is not reprinted on every reapply
// the track hasn't yet self-healed from.
ReaProject*              g_reportedOwner = nullptr;
std::vector<std::string> g_reportedExposed;

}  // namespace

const int kViewUndoMask = UNDO_STATE_TRACKCFG | UNDO_STATE_ITEMS | UNDO_STATE_MISCCFG;

// Lifetime is settled: the string copy is taken immediately and the GUID* is never held
// past this call (reaper_plugin_functions.h:7348 documents no null contract for
// TrackFX_GetFXGUID; treating null as "no identity" is the safe read).
//
// [verify — DAW] STABILITY across a chain mutation is not settled the same way: confirm
// the GUID for one FX instance survives a native drag-reorder, an SWS move
// (SNM_MoveOrRemoveTrackFX — SWS issue #802 reports the FXID lines do not follow the
// plugin after that call, i.e. wrong-plugin restores or mass drops through fx_offline on
// that path specifically), a save/reload round trip, and two live instances of one plugin
// type staying distinguishable. See src/shell/view/CLAUDE.md's Gotchas for the SWS-path
// risk this leaves open.
std::string fxGuidString(MediaTrack* tr, int fx) {
    GUID* g = TrackFX_GetFXGUID(tr, fx);
    if (!g) return {};
    char buf[64] = {0};  // guidToString needs a >=64-char destination (SDK contract)
    guidToString(g, buf);
    return std::string(buf);
}

bool writeIfChanged(MediaTrack* tr, const char* parm, double value) {
    if (GetMediaTrackInfo_Value(tr, parm) == value) return false;
    SetMediaTrackInfo_Value(tr, parm, value);
    return true;
}

TrackParkResult parkTrack(ViewModeModel& model, const std::string& guid, MediaTrack* tr,
                          const std::vector<TrackFlagOp>& flags) {
    TrackParkResult result;

    if (!model.holdsSnapshotFlags(guid)) {
        const TrackSnapshot* prior = model.snapshot(guid);

        // No record of ANY kind (see parkTrack's header doc for why prior == nullptr
        // is the right gate): the ambiguous case. A live chain already reading
        // park-shaped is EXPOSEd — handed back visible, no snapshot stored — rather
        // than adopted as the user's intent.
        if (!prior) {
            auto read = [tr](Flag f) {
                return static_cast<int>(GetMediaTrackInfo_Value(tr, trackFlagParm(f)));
            };
            if (chainReadsParked(flags, read)) {
                if (exposeFlags(tr, flags)) result.wrote = true;
                result.exposed = true;
                return result;  // this cycle hands the track back; it does not park it
            }
        }

        TrackSnapshot snap = snapshotTrack(tr);

        // A restore hands the flags back immediately but leaves the chain offline
        // until the reclaimer gets to it, so a re-park lands here with the FX half
        // still held over a still-parked chain. Union the live read against the
        // record rather than overwriting either way — see unionFxOfflineOnRepark.
        //
        // `prior->fxHeld` is provably redundant here today — eraseIfSpent
        // (view_mode_model.cpp) guarantees a surviving record has fxHeld == true
        // — so the false arm is unreached. Kept anyway: it is the direct
        // statement of what this branch actually needs, and cheaper to keep true
        // than to re-derive if that guarantee ever loosens.
        if (prior && prior->fxHeld && prior->fxKeying == FxKeying::Identity) {
            snap.fxOffline = unionFxOfflineOnRepark(prior->fxOffline, snap.fxOffline);
            snap.fxKeying  = FxKeying::Identity;
        } else if (prior && prior->fxHeld) {
            // Slot-keyed legacy record (lifted from a pre-identity view_state): no
            // identities to union against, so fall back to the old behavior and
            // trust the record verbatim over live slots that may have moved since.
            snap.fxOffline = prior->fxOffline;
            snap.fxKeying  = prior->fxKeying;
        }
        model.storeSnapshot(guid, snap);
    }

    if (applyFlags(tr, flags)) result.wrote = true;
    return result;
}

bool restoreTrack(ViewModeModel& model, const std::string& guid, MediaTrack* tr,
                  const std::vector<TrackFlagOp>& flags) {
    const bool wrote = applyFlags(tr, flags);
    model.releaseSnapshotFlags(guid);
    return wrote;
}

std::string trackDisplayName(MediaTrack* tr) {
    std::vector<char> buf(1024, '\0');
    if (!GetTrackName || !GetTrackName(tr, buf.data(), static_cast<int>(buf.size())))
        return "(name unavailable)";
    return std::string(buf.data(), strnlen(buf.data(), buf.size()));
}

void reportExposedTracks(ReaProject* proj, const std::vector<std::string>& trackNames) {
    if (!shouldReport(proj == g_reportedOwner, g_reportedExposed, trackNames)) return;
    g_reportedOwner   = proj;
    g_reportedExposed = trackNames;

    const std::string msg = describeExposedTracks(trackNames);
    // "!SHOW:" so an unattended project-load reapply cannot force the console open
    // (reaper_plugin_functions.h:6536).
    if (!msg.empty()) ShowConsoleMsg(("!SHOW:" + msg).c_str());
}

}  // namespace reasampler