// reasampler_editor.cpp — see reasampler_editor.h. The IPlugView<->LICE bridge for the
// ReaSampler 9000 capture-first editor (Phase S10). Windows-only (D5); the whole file is
// guarded so a non-Windows build (not a target) degrades to the CPluginView defaults.

#include "reasampler_editor.h"

#include <algorithm>
#include <cstdint>
#include <fstream>
#include <string>
#include <vector>

#include "capture_browser.h"
#include "capture_paths.h"     // resolveBankFile (shared M4 path resolution)
#include "editor_geometry.h"   // Rect, contains
#include "ext_keys.h"
#include "keyboard_strip.h"
#include "peaks.h"             // computeEnvelope
#include "reaper_bridge.h"
#include "reasampler_processor.h"
#include "app_version.h"       // vstPluginName (channel-derived editor title band, S18)
#include "sample_map.h"
#include "wav_trim.h"          // parseWavLayout, extractFloatFrames
#include "waveform_view.h"     // frame<->pixel markers + zero-crossing snap (S11)

#ifdef _WIN32
#include <windowsx.h>  // GET_X_LPARAM / GET_Y_LPARAM

#include "wdltypes.h"
#include "lice/lice.h"
#endif

using namespace Steinberg;

namespace reasampler::vst {

namespace {
#ifdef _WIN32
constexpr const wchar_t* kChildClassName = L"ReaSampler9000VstEditor";

// The S9/S8 change-detection poll (WM_TIMER on the child window). A low-frequency UI-thread
// timer: responsive enough that a recapture/ingest/assign refreshes "within a bounded cadence"
// (the S9 verify criterion) yet cheap — three small ext-state reads per tick, coalescing many
// bumps between ticks into one reload. 500 ms is a deliberate build-time residual: fast enough
// to feel hands-free, slow enough to be free. The id is a per-window SetTimer id (any nonzero).
constexpr UINT_PTR kSyncTimerId = 1;
constexpr UINT     kSyncTimerIntervalMs = 500;

// Top-level band metrics (shell arithmetic — the load-bearing card/tab/key/zone geometry
// is in capture_browser / keyboard_strip). The title band names the plugin + a live
// readout; the toggle band carries the Browser/Zones switch; the setup band (single-
// capture face) hosts the keyboard strip + level readout under the browser.
constexpr int kTitleHeight = 24;
constexpr int kToggleHeight = 22;
constexpr int kSetupHeight = 176;  // the single-capture setup surface (labels + waveform + strip)
constexpr int kStripBandHeight = 40;
constexpr int kWaveformHeight = 72;  // the S11 waveform band inside the setup surface

// Palette — house style, mirrored from bank_panel's dark theme so the instrument reads as
// the same tool. (Phase L's L1 kit replaces these flat fills later; not gated on it.)
const LICE_pixel kColBackground = LICE_RGBA(28, 28, 30, 255);
const LICE_pixel kColTitleBg = LICE_RGBA(20, 20, 22, 255);
const LICE_pixel kColCardBg = LICE_RGBA(44, 44, 48, 255);
const LICE_pixel kColCardSelBg = LICE_RGBA(48, 72, 64, 255);
const LICE_pixel kColCardBorder = LICE_RGBA(70, 70, 76, 255);
const LICE_pixel kColCardSelBorder = LICE_RGBA(120, 200, 160, 255);
const LICE_pixel kColTabBg = LICE_RGBA(36, 36, 40, 255);
const LICE_pixel kColTabActiveBg = LICE_RGBA(58, 96, 84, 255);
const LICE_pixel kColThumb = LICE_RGBA(120, 200, 160, 255);
const LICE_pixel kColStripBg = LICE_RGBA(36, 36, 40, 255);
const LICE_pixel kColStripKey = LICE_RGBA(52, 52, 58, 255);
const LICE_pixel kColRootMarker = LICE_RGBA(120, 200, 160, 255);
const LICE_pixel kColWaveBg = LICE_RGBA(24, 24, 26, 255);
const LICE_pixel kColWaveform = LICE_RGBA(120, 200, 160, 255);
const LICE_pixel kColStartMarker = LICE_RGBA(230, 200, 120, 255);   // start point (amber)
const LICE_pixel kColLoopMarker = LICE_RGBA(120, 170, 230, 255);    // loop start/end (blue)
const LICE_pixel kColLoopRegion = LICE_RGBA(120, 170, 230, 60);     // loop span fill (faint)
const LICE_pixel kColZoneBar = LICE_RGBA(58, 96, 84, 255);
const LICE_pixel kColZoneBarSel = LICE_RGBA(120, 200, 160, 255);
const COLORREF kRgbText = RGB(210, 230, 220);
const COLORREF kRgbDim = RGB(140, 150, 146);

// ANSI path -- string literals must stay ASCII until the Phase L type kit lands.
void drawText(LICE_IBitmap* bmp, const Rect& r, const char* s, COLORREF col,
              UINT fmt = DT_LEFT | DT_VCENTER | DT_SINGLELINE | DT_NOPREFIX) {
    HDC dc = bmp->getDC();
    SetBkMode(dc, TRANSPARENT);
    SetTextColor(dc, col);
    RECT gr{r.left, r.top, r.right, r.bottom};
    DrawTextA(dc, s, -1, &gr, fmt | DT_END_ELLIPSIS);
}

void drawTextCentered(LICE_IBitmap* bmp, const Rect& r, const char* s, COLORREF col) {
    drawText(bmp, r, s, col, DT_CENTER | DT_VCENTER | DT_SINGLELINE | DT_NOPREFIX);
}

// A short MIDI-note label ("C4", "F#3") for the root badge. Middle C (60) is C4 (the
// common DAW convention REAPER uses).
std::string noteLabel(int note) {
    static const char* kNames[12] = {"C",  "C#", "D",  "D#", "E",  "F",
                                     "F#", "G",  "G#", "A",  "A#", "B"};
    if (note < 0) note = 0;
    if (note > 127) note = 127;
    const int octave = note / 12 - 1;  // MIDI 0 = C-1; 60 = C4
    return std::string(kNames[note % 12]) + std::to_string(octave);
}

// Draw a mono peak envelope centered vertically in `r` (mirror of bank_panel::drawThumbnail,
// single channel). Each bin is a vertical line from its min to its max about the midline.
void drawEnvelope(LICE_IBitmap* bmp, const Rect& r, const Envelope& env) {
    if (r.width() <= 0 || r.height() <= 0 || env.empty() || env[0].empty()) return;
    const ChannelEnvelope& ch = env[0];
    const int mid = r.top + r.height() / 2;
    const int halfH = r.height() / 2;
    const int bins = static_cast<int>(ch.size());
    for (int x = 0; x < r.width() && x < bins; ++x) {
        const MinMax& mm = ch[static_cast<std::size_t>(x)];
        const int yTop = mid - static_cast<int>(mm.max * halfH);
        const int yBot = mid - static_cast<int>(mm.min * halfH);
        LICE_Line(bmp, r.left + x, yTop, r.left + x, yBot, kColThumb, 1.0f, 0, false);
    }
}

// A display name for a bank sample id from the snapshotted list ("?" if the id no longer
// resolves — e.g. a zone naming a deleted sample).
std::string sampleLabel(const std::vector<SampleChoice>& samples, const std::string& id) {
    for (const SampleChoice& c : samples) {
        if (c.id == id) return c.displayName.empty() ? c.id : c.displayName;
    }
    return "?";
}

// The bin count a card's thumbnail is computed at: the card thumbnail width, so one bin
// per horizontal pixel.
int thumbBins(const BrowserLayout& layout) {
    return (std::max)(1, cardThumbnailRect(layout, 0).width());
}
#endif
}  // namespace

ReaSamplerEditor::ReaSamplerEditor(ReaSamplerProcessor* processor)
    : CPluginView(nullptr), processor_(processor) {
    // Default view size — sized to show a couple of card rows + the setup strip.
    ViewRect r(0, 0, 560, 400);
    setRect(r);
}

void ReaSamplerEditor::refreshFromBank() {
    // Main/UI thread only — reads the live bank over the bridge (allocates, calls REAPER).
    thumbCache_.clear();  // a bank edit may have re-captured/removed a sample; drop stale peaks
    pcmCache_.clear();    // and its decoded PCM (the S11 waveform + snap source)
    if (!processor_) {
        samples_.clear();
        banks_.clear();
        visible_.clear();
        selectedId_.clear();
        map_.zones.clear();
        selectedZone_ = -1;
        return;
    }
    auto banksJson = processor_->bridge().readReasamplerExtState(reasampler::kProjExtBanksKey);
    samples_ = banksJson ? listSamples(*banksJson) : std::vector<SampleChoice>{};
    banks_ = banksJson ? listBanks(*banksJson) : std::vector<BankChoice>{};
    selectedId_ = processor_->selectedSampleId();
    map_ = processor_->performanceMap();
    channelMode_ = processor_->channelMode();
    if (selectedZone_ >= static_cast<int>(map_.zones.size())) selectedZone_ = -1;
    // Drop a filter that names a bank no longer present.
    if (!activeFilterBankId_.empty()) {
        bool found = false;
        for (const BankChoice& b : banks_) if (b.id == activeFilterBankId_) found = true;
        if (!found) activeFilterBankId_.clear();
    }
    rebuildVisible();
}

void ReaSamplerEditor::rebuildVisible() {
    visible_.clear();
    for (const SampleChoice& s : samples_) {
        if (activeFilterBankId_.empty() || s.bankId == activeFilterBankId_)
            visible_.push_back(s);
    }
}

#ifdef _WIN32
// Windows-only (the WM_TIMER cadence + invalidate() are the Win32 child-window path). Declared
// under the same _WIN32 guard in the header; keep the definition guarded to match (D5 makes
// Windows the only build target, but the TU must still compile elsewhere).
void ReaSamplerEditor::onSyncTimer() {
    // UI thread (WM_TIMER). Poll the S9 bank generation + the S8 assignment request via the
    // processor (off the audio thread — the poll itself never touches process()). NEVER while a
    // drag is in flight: a reload mid-drag would rebuild the instrument and repaint under the
    // user's cursor, yanking the edit. The next tick (500 ms) picks up the change after release.
    if (!processor_) return;
    if (drag_ != DragKind::kNone) return;  // defer past the in-flight edit

    // An open editor marks THIS instance the focused assignment target (the thundering-herd
    // policy — only an editor-open instance applies a pending assign; see the handoff). Pass
    // true so this instance consumes the request; instances with no editor open do not poll at
    // all (the timer is bound to the child window), so they never contend for the request.
    const ReaSamplerProcessor::BankSyncResult r = processor_->pollBankSync(/*isFocusedTarget=*/true);

    // Re-snapshot the editor's own view only when something changed (a reload from a bank
    // content change, or an applied assignment). refreshFromBank re-reads the bank blob + the
    // processor's (possibly just-updated) selection/map and drops the stale thumbnail/PCM
    // caches, then repaints — so the browser + setup surface reflect the new bank hands-free.
    if (r.reloaded || r.applied) {
        refreshFromBank();
        invalidate();
    }
}
#endif  // _WIN32

void ReaSamplerEditor::commitAndReload() {
    // UI thread only. Publish the edited selection + zones to the processor, then rebuild
    // the instrument off the audio thread (reloadFromBank bakes them into the live Keymap).
    if (!processor_) return;
    processor_->setSelectedSampleId(selectedId_);
    processor_->setPerformanceMap(map_);
    processor_->reloadFromBank();
#ifdef _WIN32
    invalidate();
#endif
}

ReaSamplerEditor::SetupMarkers ReaSamplerEditor::pickedMarkers(std::int64_t frames) const {
    SetupMarkers m;
    // Seed from the bank's S2 intrinsic loop (fact about the file), then let a per-zone override
    // for the picked id win (the instrument's performance choice, D-B). Read the loop intrinsic
    // from the live bank blob (the same path selectSample uses); the override lives in map_.
    if (processor_) {
        auto banksJson =
            processor_->bridge().readReasamplerExtState(reasampler::kProjExtBanksKey);
        if (banksJson) {
            if (auto sel = selectSample(*banksJson, selectedId_)) {
                if (sel->loop.hasLoop) {
                    m.hasLoop = true;
                    m.loopStart = sel->loop.start;
                    m.loopEnd = sel->loop.end;
                }
            }
        }
    }
    // The override (loop + start) on a zone for the picked id supersedes the intrinsic.
    for (const PerformanceZone& z : map_.zones) {
        if (z.sampleId != selectedId_) continue;
        if (z.loopOverride) {
            m.hasLoop = z.loopOverride->hasLoop;
            m.loopStart = z.loopOverride->start;
            m.loopEnd = z.loopOverride->end;
        }
        if (z.startPoint) m.start = *z.startPoint;
        break;
    }
    // Default an unset loop's end to the sample length so the loop markers have somewhere sane
    // to sit before the user drags (loopStart stays 0). The "no loop" state is m.hasLoop==false;
    // the markers are still drawn (drag one to CREATE a loop).
    if (!m.hasLoop && m.loopEnd == 0) m.loopEnd = frames > 0 ? frames : 0;
    return m;
}

void ReaSamplerEditor::upsertPickedOverride(const SetupMarkers& m) {
    // Find-or-append the zone for selectedId_ and write the loop/start override fields.
    // The bank intrinsic is NEVER written (read-only bank consumer, D-B). selectedId_ must
    // be non-empty; callers are responsible for that guard.
    SampleLoop loop;
    loop.hasLoop = m.hasLoop;
    loop.start = m.loopStart;
    loop.end = m.loopEnd;
    bool found = false;
    for (PerformanceZone& z : map_.zones) {
        if (z.sampleId == selectedId_) {
            z.loopOverride = loop;
            z.startPoint = m.start;
            found = true;
            break;
        }
    }
    if (!found) {
        PerformanceZone z;
        z.sampleId = selectedId_;
        z.lowNote = 0;
        z.highNote = 127;
        z.loopOverride = loop;
        z.startPoint = m.start;
        map_.zones.push_back(z);
    }
}

void ReaSamplerEditor::commitPickedMarkers(const SetupMarkers& m) {
    // Materialize the edited markers as a per-zone loop/start override on the picked id (upsert,
    // mirror of the root-marker path): a full-keyboard zone carrying the override. This plays
    // identically to the un-zoned single capture (one chromatic zone) and round-trips through
    // the component state; the zone becomes visible if the user opens the Zones panel. The bank
    // intrinsic is NEVER written (read-only bank consumer, D-B).
    if (selectedId_.empty()) return;
    upsertPickedOverride(m);
    commitAndReload();
}

const std::vector<AudioSample>& ReaSamplerEditor::monoPcmFor(const std::string& sampleId) {
    auto it = pcmCache_.find(sampleId);
    if (it != pcmCache_.end()) return it->second;

    // SampleChoice is the browser's metadata projection and does NOT carry the WAV path, so
    // resolve the path from the live bank blob (selectSample) and decode via the shared WAV
    // parse — the mirror of the processor's decodeRelative. Every failure path caches an EMPTY
    // vector so a broken/missing file is not re-decoded on every paint. Keyed by id (width-
    // independent) — the thumbnail bins this at whatever width, the snap scans it directly.
    std::string relativePath;
    std::vector<AudioSample> mono;
    if (processor_) {
        auto banksJson =
            processor_->bridge().readReasamplerExtState(reasampler::kProjExtBanksKey);
        if (banksJson) {
            if (auto sel = selectSample(*banksJson, sampleId)) relativePath = sel->relativePath;
        }
        if (!relativePath.empty()) {
            const std::string projectDir = processor_->bridge().activeProjectDir();
            const std::string abs = resolveBankFile(projectDir, relativePath);
            std::vector<std::uint8_t> bytes;
            std::ifstream f(abs, std::ios::binary | std::ios::ate);
            if (f) {
                const std::streamoff size = f.tellg();
                if (size > 0) {
                    f.seekg(0, std::ios::beg);
                    bytes.resize(static_cast<std::size_t>(size));
                    if (!f.read(reinterpret_cast<char*>(bytes.data()), size)) bytes.clear();
                }
            }
            const WavLayout layout = parseWavLayout(bytes);
            if (layout.valid) {
                std::vector<AudioSample> interleaved =
                    extractFloatFrames(bytes, layout, 0, layout.frameCount());
                mono = downmixToMono(interleaved, layout.channelCount);
            }
        }
    }
    auto ins = pcmCache_.emplace(sampleId, std::move(mono));
    return ins.first->second;
}

const Envelope& ReaSamplerEditor::thumbnailFor(const std::string& sampleId, int binCount) {
    const std::string key = sampleId + "|" + std::to_string(binCount);
    auto it = thumbCache_.find(key);
    if (it != thumbCache_.end()) return it->second;

    // Bin the (cached) decoded mono PCM at the requested width — one decode per id, reused by
    // every thumbnail width AND the S11 waveform surface + snap.
    const std::vector<AudioSample>& mono = monoPcmFor(sampleId);
    Envelope env;
    if (!mono.empty()) {
        env = computeEnvelope(mono, 1, mono.size(),
                              static_cast<std::size_t>((std::max)(1, binCount)));
    }
    auto ins = thumbCache_.emplace(key, std::move(env));
    return ins.first->second;
}

ReaSamplerEditor::~ReaSamplerEditor() {
#ifdef _WIN32
    if (childHwnd_) {
        DestroyWindow(childHwnd_);
        childHwnd_ = nullptr;
    }
#endif
}

tresult PLUGIN_API ReaSamplerEditor::isPlatformTypeSupported(FIDString type) {
#ifdef _WIN32
    if (type && std::string(type) == kPlatformTypeHWND) return kResultTrue;
#endif
    return kResultFalse;
}

tresult PLUGIN_API ReaSamplerEditor::canResize() {
    return kResultTrue;
}

#ifdef _WIN32

void ReaSamplerEditor::invalidate() {
    if (childHwnd_) InvalidateRect(childHwnd_, nullptr, FALSE);
}

void ReaSamplerEditor::attachedToParent() {
    HWND parent = static_cast<HWND>(systemWindow);
    if (!parent) return;

    HINSTANCE hInst =
        reinterpret_cast<HINSTANCE>(GetWindowLongPtr(parent, GWLP_HINSTANCE));
    if (!hInst) hInst = GetModuleHandle(nullptr);

    static bool classRegistered = false;
    if (!classRegistered) {
        WNDCLASSW wc{};
        wc.lpfnWndProc = &ReaSamplerEditor::wndProc;
        wc.hInstance = hInst;
        wc.lpszClassName = kChildClassName;
        wc.hCursor = LoadCursor(nullptr, IDC_ARROW);
        wc.style = CS_HREDRAW | CS_VREDRAW;
        RegisterClassW(&wc);
        classRegistered = true;
    }

    refreshFromBank();

    const ViewRect& r = getRect();
    childHwnd_ = CreateWindowExW(0, kChildClassName, L"", WS_CHILD | WS_VISIBLE, 0, 0,
                                 r.getWidth(), r.getHeight(), parent, nullptr, hInst, nullptr);
    if (childHwnd_) {
        SetWindowLongPtr(childHwnd_, GWLP_USERDATA, reinterpret_cast<LONG_PTR>(this));
        // Start the S9/S8 change-detection poll (UI thread). Tied to the child window's
        // lifetime — created here, killed in removedFromParent — so an instance whose editor
        // is closed does NOT poll (the editor-open-only cadence; see the handoff limitation).
        SetTimer(childHwnd_, kSyncTimerId, kSyncTimerIntervalMs, nullptr);
        // Poll ONCE immediately so a pending assignment (an S8 ingest fired while this editor
        // was closed) or a bank change applies the instant the editor opens, rather than waiting
        // up to one timer interval. refreshFromBank above already primed the view; this folds in
        // any pending assign/generation so the just-opened editor shows the assigned capture.
        onSyncTimer();
    }
}

void ReaSamplerEditor::removedFromParent() {
    if (childHwnd_) {
        KillTimer(childHwnd_, kSyncTimerId);  // stop the poll before the window goes away
        DestroyWindow(childHwnd_);
        childHwnd_ = nullptr;
    }
}

tresult PLUGIN_API ReaSamplerEditor::onSize(ViewRect* newSize) {
    tresult res = CPluginView::onSize(newSize);
    if (childHwnd_ && newSize) {
        MoveWindow(childHwnd_, 0, 0, newSize->getWidth(), newSize->getHeight(), TRUE);
        thumbCache_.clear();  // thumbnails are width-bound; a resize invalidates them
    }
    return res;
}

// The client bands: title (top), toggle (below title), then the mode content. In the
// browser view the content is the browser grid on top of the single-capture setup band
// (when a capture is picked); in the zones view the content is the zones strip + list.
namespace {
struct EditorBands {
    Rect title;
    Rect toggleBrowser;  // left half of the toggle band
    Rect toggleZones;    // right half
    Rect content;        // below the toggle band: the mode's own area
};
EditorBands computeBands(int w, int h) {
    EditorBands b;
    const int titleH = (std::min)(kTitleHeight, h);
    b.title = Rect{0, 0, w, titleH};
    const int toggleTop = titleH;
    const int toggleBot = (std::min)(h, toggleTop + kToggleHeight);
    b.toggleBrowser = Rect{0, toggleTop, w / 2, toggleBot};
    b.toggleZones = Rect{w / 2, toggleTop, w, toggleBot};
    b.content = Rect{0, toggleBot, w, h};
    return b;
}

// The keyboard strip rectangle inside the setup area (single-capture root-drag face).
// `area` is the full setup Rect; the strip is anchored at the bottom with an 8px horizontal
// pad. All three call sites (paintSetup, onMouseDown, onMouseMove) use this single formula.
Rect setupStripArea(const Rect& area) {
    constexpr int pad = 8;
    const int stripTop = area.bottom - kStripBandHeight;
    return Rect{area.left + pad, stripTop, area.right - pad, area.bottom - 4};
}

// The S11 waveform rectangle inside the setup area: a band above the keyboard strip, below the
// header/hint labels. `area` is the full setup Rect; the waveform is padded 8px horizontally and
// anchored above the strip band. All call sites (paintSetup, onMouseDown, onMouseMove) use this
// single formula so the draw and the hit-test never drift.
Rect setupWaveformArea(const Rect& area) {
    constexpr int pad = 8;
    const int waveBottom = area.bottom - kStripBandHeight - 6;  // 6px gap above the strip
    const int waveTop = waveBottom - kWaveformHeight;
    return Rect{area.left + pad, waveTop, area.right - pad, waveBottom};
}

// The keyboard strip rectangle inside the Zones panel content area. `bands.content` is the
// mode-content Rect; the strip sits below the "+ Add Zone" affordance (top+4, height 20)
// with a 12px gap, padded 8px horizontally. All three call sites (paintZones, onMouseDown,
// onMouseMove) use this single formula — the inline arithmetic in onMouseMove was the drift.
Rect zonesStripArea(const EditorBands& bands) {
    constexpr int pad = 8;
    const int stripTop = bands.content.top + 4 + 20 + 12;  // addR.bottom + 12
    return Rect{bands.content.left + pad, stripTop, bands.content.right - pad,
                stripTop + kStripBandHeight};
}

// The S7 mono/stereo toggle, a two-segment control anchored to the RIGHT of the setup band's
// header row (same y as the sample-name header, so it reads as "this capture's output mode").
// `area` is the full setup Rect. Returns {mono-segment, stereo-segment}; each is kSegW wide,
// kSegH tall, side by side. Kept to a small fenced block (S11 owns the waveform region).
constexpr int kChanSegW = 52;
constexpr int kChanSegH = 18;
struct ChannelToggleRects { Rect mono; Rect stereo; };
ChannelToggleRects channelToggleRects(const Rect& area) {
    constexpr int pad = 8;
    const int top = area.top + 4;
    const int right = area.right - pad;
    const Rect stereo{right - kChanSegW, top, right, top + kChanSegH};
    const Rect mono{stereo.left - kChanSegW, top, stereo.left, top + kChanSegH};
    return {mono, stereo};
}
}  // namespace

void ReaSamplerEditor::paint(HDC hdc) {
    RECT cr{};
    GetClientRect(childHwnd_, &cr);
    const int w = cr.right - cr.left;
    const int h = cr.bottom - cr.top;
    if (w <= 0 || h <= 0) return;

    LICE_SysBitmap bmp(w, h);
    LICE_Clear(&bmp, kColBackground);

    const EditorBands bands = computeBands(w, h);

    // Title band: product name + live readout.
    LICE_FillRect(&bmp, bands.title.left, bands.title.top, bands.title.width(),
                  bands.title.height(), kColTitleBg, 1.0f, 0);
    std::string title = reasampler::vstPluginName();  // channel-derived (S18)
    if (processor_ && processor_->bridge().isConnected()) {
        if (samples_.empty()) title += "  [bank empty]";
        else if (selectedId_.empty() && map_.zones.empty()) title += "  [pick a capture]";
        else if (!map_.zones.empty()) title += "  [" + std::to_string(map_.zones.size()) + " zone(s)]";
        else title += "  [" + sampleLabel(samples_, selectedId_) + "]";
    } else {
        title += "  [host: no bridge]";
    }
    Rect titleText{bands.title.left + 8, bands.title.top, bands.title.right - 8,
                   bands.title.bottom};
    drawText(&bmp, titleText, title.c_str(), kRgbText);

    // Toggle band: Browser | Zones.
    const bool inZones = (view_ == View::kZones);
    LICE_FillRect(&bmp, bands.toggleBrowser.left, bands.toggleBrowser.top,
                  bands.toggleBrowser.width(), bands.toggleBrowser.height(),
                  inZones ? kColTabBg : kColTabActiveBg, 1.0f, 0);
    LICE_FillRect(&bmp, bands.toggleZones.left, bands.toggleZones.top,
                  bands.toggleZones.width(), bands.toggleZones.height(),
                  inZones ? kColTabActiveBg : kColTabBg, 1.0f, 0);
    drawTextCentered(&bmp, bands.toggleBrowser, "Browser", kRgbText);
    drawTextCentered(&bmp, bands.toggleZones, "Zones", kRgbText);

    if (view_ == View::kZones) {
        paintZones(&bmp, w, h);
    } else {
        paintBrowser(&bmp, w, h);
    }

    BitBlt(hdc, 0, 0, w, h, bmp.getDC(), 0, 0, SRCCOPY);
}

void ReaSamplerEditor::paintEmptyState(LICE_IBitmap* bmp, const Rect& area) {
    // Shown when no card is drawn (nothing to pick): distinguish a genuinely empty bank from
    // a bank filter that hides everything. Either way it is the "pick a capture" empty state.
    const char* msg = samples_.empty()
        ? "No captures in this project yet - capture audio into the bank to play it here."
        : "No captures in this bank filter. Choose another bank tab above.";
    drawTextCentered(bmp, area, msg, kRgbDim);
}

void ReaSamplerEditor::paintBrowser(LICE_IBitmap* bmp, int w, int h) {
    const EditorBands bands = computeBands(w, h);
    // When a capture is picked, the setup band takes the bottom; the browser gets the rest.
    const bool havePick = !selectedId_.empty();
    const int setupTop = havePick ? (std::max)(bands.content.top, bands.content.bottom - kSetupHeight)
                                  : bands.content.bottom;
    const Rect browserArea{bands.content.left, bands.content.top, bands.content.right, setupTop};

    // The browser tabs + card grid, laid out by the pure module over the browser sub-area.
    // capture_browser lays out from (0,0); offset the draw by browserArea's origin.
    const BrowserLayout bl = layoutBrowser(browserArea.width(), browserArea.height());
    const int ox = browserArea.left;
    const int oy = browserArea.top;

    // Filter tabs: an "All" tab (index 0) + one per named bank. The active tab highlights.
    const int tabCount = static_cast<int>(banks_.size()) + 1;
    for (int i = 0; i < tabCount; ++i) {
        Rect t = filterTabRect(bl, tabCount, i);
        t = Rect{t.left + ox, t.top + oy, t.right + ox, t.bottom + oy};
        const std::string label = (i == 0) ? "All" : banks_[static_cast<std::size_t>(i - 1)].displayName;
        const bool active = (i == 0) ? activeFilterBankId_.empty()
                                     : (banks_[static_cast<std::size_t>(i - 1)].id == activeFilterBankId_);
        LICE_FillRect(bmp, t.left, t.top, t.width(), t.height(),
                      active ? kColTabActiveBg : kColTabBg, 1.0f, 0);
        drawTextCentered(bmp, t, label.c_str(), kRgbText);
    }

    // Cards: one per visible sample. Clip at the browser area bottom (scroll is S12).
    const int bins = thumbBins(bl);
    for (int i = 0; i < static_cast<int>(visible_.size()); ++i) {
        Rect content = cardContentRect(bl, i);
        if (content.top + oy >= browserArea.bottom) break;  // past the visible grid
        Rect thumb = cardThumbnailRect(bl, i);
        Rect labelR = cardLabelRect(bl, i);
        content = Rect{content.left + ox, content.top + oy, content.right + ox, content.bottom + oy};
        thumb = Rect{thumb.left + ox, thumb.top + oy, thumb.right + ox, thumb.bottom + oy};
        labelR = Rect{labelR.left + ox, labelR.top + oy, labelR.right + ox, labelR.bottom + oy};

        const SampleChoice& s = visible_[static_cast<std::size_t>(i)];
        const bool sel = (s.id == selectedId_);
        LICE_FillRect(bmp, content.left, content.top, content.width(), content.height(),
                      sel ? kColCardSelBg : kColCardBg, 1.0f, 0);
        LICE_DrawRect(bmp, content.left, content.top, content.width() - 1, content.height() - 1,
                      sel ? kColCardSelBorder : kColCardBorder, 1.0f, 0);
        drawEnvelope(bmp, thumb, thumbnailFor(s.id, bins));

        // Name + root/key badge under the thumbnail.
        std::string caption = s.displayName.empty() ? s.id : s.displayName;
        Rect nameR{labelR.left + 3, labelR.top, labelR.right - 3, labelR.top + labelR.height() / 2};
        Rect badgeR{labelR.left + 3, nameR.bottom, labelR.right - 3, labelR.bottom};
        drawText(bmp, nameR, caption.c_str(), kRgbText);
        std::string badge;
        if (s.rootNote) badge = "root " + noteLabel(*s.rootNote);
        else if (s.key) badge = *s.key;
        else badge = "root -";
        drawText(bmp, badgeR, badge.c_str(), kRgbDim);
    }

    if (havePick) {
        paintSetup(bmp, Rect{bands.content.left, setupTop, bands.content.right, bands.content.bottom});
    } else if (visible_.empty()) {
        paintEmptyState(bmp, browserArea);
    }
}

void ReaSamplerEditor::paintSetup(LICE_IBitmap* bmp, const Rect& area) {
    // The guided single-capture setup: the picked capture's name + root/level, and a
    // keyboard strip with its root marker (drag to set root).
    LICE_FillRect(bmp, area.left, area.top, area.width(), area.height(),
                  kColTitleBg, 1.0f, 0);

    // Effective root: the picked sample's rootNote intrinsic (or middle C when unset).
    // Read from samples_ (the full unfiltered list) so a bank-filter that hides the
    // picked sample's bank doesn't mask its intrinsic root with the C4 default.
    int root = 60;
    for (const SampleChoice& s : samples_) {
        if (s.id == selectedId_ && s.rootNote) root = *s.rootNote;
    }
    // If a matching one-zone override exists (opt-in from Zones), prefer it as the shown root.
    for (const PerformanceZone& z : map_.zones) {
        if (z.sampleId == selectedId_ && z.rootOverride) root = *z.rootOverride;
    }

    const int pad = 8;
    // The mono/stereo toggle sits at the right of the header row; keep the name text clear of it.
    const ChannelToggleRects chan = channelToggleRects(area);
    Rect headerR{area.left + pad, area.top + 4, chan.mono.left - 8, area.top + 22};
    std::string header = sampleLabel(samples_, selectedId_) + "   root " + noteLabel(root);
    drawText(bmp, headerR, header.c_str(), kRgbText);

    // S7 mono | stereo output-mode toggle. The active segment highlights (kColTabActiveBg),
    // the inactive is kColTabBg — the same visual grammar as the Browser/Zones toggle.
    const bool isStereo = (channelMode_ == ChannelMode::Stereo);
    LICE_FillRect(bmp, chan.mono.left, chan.mono.top, chan.mono.width(), chan.mono.height(),
                  isStereo ? kColTabBg : kColTabActiveBg, 1.0f, 0);
    LICE_FillRect(bmp, chan.stereo.left, chan.stereo.top, chan.stereo.width(),
                  chan.stereo.height(), isStereo ? kColTabActiveBg : kColTabBg, 1.0f, 0);
    drawTextCentered(bmp, chan.mono, "Mono", kRgbText);
    drawTextCentered(bmp, chan.stereo, "Stereo", kRgbText);

    Rect hintR{area.left + pad, headerR.bottom, area.right - pad, headerR.bottom + 16};
    drawText(bmp, hintR,
             "Drag the waveform markers to set start + loop; drag the keyboard to set root.",
             kRgbDim);

    // --- S11 waveform surface: the picked capture's envelope + draggable markers ----------
    const std::vector<AudioSample>& pcm = monoPcmFor(selectedId_);
    const std::int64_t frames = static_cast<std::int64_t>(pcm.size());
    const Rect waveArea = setupWaveformArea(area);
    LICE_FillRect(bmp, waveArea.left, waveArea.top, waveArea.width(), waveArea.height(),
                  kColWaveBg, 1.0f, 0);
    if (frames > 0 && waveArea.width() > 0) {
        // Envelope at one bin per pixel (full-res view of the decoded PCM, S10 read-only view
        // reused). computeEnvelope over the cached mono frames — no new decode.
        const int bins = (std::max)(1, waveArea.width());
        const Envelope env = computeEnvelope(pcm, 1, pcm.size(), static_cast<std::size_t>(bins));
        drawEnvelope(bmp, waveArea, env);  // reuses the thumbnail envelope draw (kColThumb)

        const SetupMarkers m = pickedMarkers(frames);
        // Faint loop-region fill between the loop markers (only when a loop is set).
        if (m.hasLoop && m.loopEnd > m.loopStart) {
            const int lx = frameToX(waveArea, frames, m.loopStart);
            const int rx = frameToX(waveArea, frames, m.loopEnd);
            if (rx > lx) {
                LICE_FillRect(bmp, lx, waveArea.top, rx - lx, waveArea.height(),
                              kColLoopRegion, 1.0f, 0);
            }
        }
        // The three markers: start (amber), loop start + loop end (blue). Drawn as 2px vertical
        // lines the full waveform height. Loop markers dim when no loop is set (the "no loop"
        // state — draggable to CREATE one).
        const std::int64_t markerFrames[3] = {m.start, m.loopStart, m.loopEnd};
        const LICE_pixel markerCols[3] = {kColStartMarker, kColLoopMarker, kColLoopMarker};
        for (int i = 0; i < 3; ++i) {
            const int mx = frameToX(waveArea, frames, markerFrames[i]);
            const bool loopMarker = (i != 0);
            const float alpha = (loopMarker && !m.hasLoop) ? 0.4f : 1.0f;
            LICE_FillRect(bmp, mx - 1, waveArea.top, 2, waveArea.height(), markerCols[i],
                          alpha, 0);
        }
    } else {
        drawTextCentered(bmp, waveArea, "(decoding...)", kRgbDim);
    }

    // Keyboard strip with the root marker.
    const Rect stripArea = setupStripArea(area);
    const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
    const int sx = stripArea.left;
    const int sy = stripArea.top;
    LICE_FillRect(bmp, stripArea.left, stripArea.top, stripArea.width(), stripArea.height(),
                  kColStripBg, 1.0f, 0);
    // Faint per-octave key ticks for orientation.
    for (int n = 0; n <= 127; n += 12) {
        Rect k = keyRect(sl, n);
        LICE_Line(bmp, k.left + sx, sy, k.left + sx, sy + stripArea.height(), kColStripKey,
                  1.0f, 0, false);
    }
    Rect marker = rootMarkerRect(sl, root);
    LICE_FillRect(bmp, marker.left + sx, sy, (std::max)(2, marker.width()), stripArea.height(),
                  kColRootMarker, 1.0f, 0);
}

void ReaSamplerEditor::paintZones(LICE_IBitmap* bmp, int w, int h) {
    const EditorBands bands = computeBands(w, h);
    const int pad = 8;

    // A single "+ Add Zone" affordance at the top of the content, then the keyboard strip
    // with one bar per zone. Delete is a small × on the selected zone (keystroke also).
    Rect addR{bands.content.left + pad, bands.content.top + 4, bands.content.left + pad + 96,
              bands.content.top + 4 + 20};
    LICE_FillRect(bmp, addR.left, addR.top, addR.width(), addR.height(), kColCardBg, 1.0f, 0);
    LICE_DrawRect(bmp, addR.left, addR.top, addR.width() - 1, addR.height() - 1,
                  kColCardSelBorder, 1.0f, 0);
    drawTextCentered(bmp, addR, "+ Add Zone", kRgbText);

    Rect delR{addR.right + 8, addR.top, addR.right + 8 + 64, addR.bottom};
    if (selectedZone_ >= 0) {
        LICE_FillRect(bmp, delR.left, delR.top, delR.width(), delR.height(), kColCardBg, 1.0f, 0);
        LICE_DrawRect(bmp, delR.left, delR.top, delR.width() - 1, delR.height() - 1,
                      kColCardSelBorder, 1.0f, 0);
        drawTextCentered(bmp, delR, "Delete", kRgbText);
    }

    // The zones strip.
    const Rect stripArea = zonesStripArea(bands);
    const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
    const int sx = stripArea.left;
    const int sy = stripArea.top;
    LICE_FillRect(bmp, stripArea.left, stripArea.top, stripArea.width(), stripArea.height(),
                  kColStripBg, 1.0f, 0);
    for (int n = 0; n <= 127; n += 12) {
        Rect k = keyRect(sl, n);
        LICE_Line(bmp, k.left + sx, sy, k.left + sx, sy + stripArea.height(), kColStripKey,
                  1.0f, 0, false);
    }
    for (int i = 0; i < static_cast<int>(map_.zones.size()); ++i) {
        const PerformanceZone& z = map_.zones[static_cast<std::size_t>(i)];
        Rect bar = zoneBarRect(sl, z.lowNote, z.highNote);
        const bool sel = (i == selectedZone_);
        LICE_FillRect(bmp, bar.left + sx, sy, (std::max)(2, bar.width()), stripArea.height(),
                      sel ? kColZoneBarSel : kColZoneBar, sel ? 1.0f : 0.7f, 0);
    }

    // A one-line legend of the selected zone below the strip.
    Rect infoR{stripArea.left, stripArea.bottom + 8, stripArea.right, stripArea.bottom + 26};
    if (selectedZone_ >= 0 && selectedZone_ < static_cast<int>(map_.zones.size())) {
        const PerformanceZone& z = map_.zones[static_cast<std::size_t>(selectedZone_)];
        std::string info = sampleLabel(samples_, z.sampleId) + "   " + noteLabel(z.lowNote) +
                           " - " + noteLabel(z.highNote) + "   root " +
                           (z.rootOverride ? noteLabel(*z.rootOverride) + "*" : std::string("(bank)"));
        drawText(bmp, infoR, info.c_str(), kRgbText);
    } else if (map_.zones.empty()) {
        drawText(bmp, infoR,
                 "No zones. Add Zone maps the picked capture across the keyboard.", kRgbDim);
    }
}

// --- Input: the drag-state machine -------------------------------------------

void ReaSamplerEditor::onMouseDown(int x, int y) {
    if (!processor_) return;
    RECT cr{};
    GetClientRect(childHwnd_, &cr);
    const int w = cr.right - cr.left;
    const int h = cr.bottom - cr.top;
    const EditorBands bands = computeBands(w, h);

    // Toggle band: switch views.
    if (contains(bands.toggleBrowser, x, y)) { view_ = View::kBrowser; invalidate(); return; }
    if (contains(bands.toggleZones, x, y)) { view_ = View::kZones; invalidate(); return; }

    if (view_ == View::kBrowser) {
        const bool havePick = !selectedId_.empty();
        const int setupTop = havePick ? (std::max)(bands.content.top, bands.content.bottom - kSetupHeight)
                                      : bands.content.bottom;
        const Rect browserArea{bands.content.left, bands.content.top, bands.content.right, setupTop};
        const BrowserLayout bl = layoutBrowser(browserArea.width(), browserArea.height());
        const int bx = x - browserArea.left;
        const int by = y - browserArea.top;

        // Filter tabs.
        const int tabCount = static_cast<int>(banks_.size()) + 1;
        const int tab = filterTabHitTest(bl, tabCount, bx, by);
        if (tab >= 0) {
            activeFilterBankId_ = (tab == 0) ? std::string()
                                             : banks_[static_cast<std::size_t>(tab - 1)].id;
            rebuildVisible();
            invalidate();
            return;
        }
        // Cards: pick a capture -> load it (this is the whole time-to-first-note gesture).
        const int card = cardHitTest(bl, static_cast<int>(visible_.size()), bx, by);
        if (card >= 0) {
            selectedId_ = visible_[static_cast<std::size_t>(card)].id;
            commitAndReload();  // publishes the pick + reloads; process() plays it repitched
            return;
        }
        // The setup band: the mono/stereo toggle (header row), the S11 waveform markers,
        // then the root-marker strip.
        if (havePick) {
            const Rect area{bands.content.left, setupTop, bands.content.right, bands.content.bottom};
            // S7: a click on a channel-mode segment sets the instance mode (setChannelMode
            // re-negotiates the bus + reloads; a no-op set for the already-active mode is ignored
            // by the processor). Snapshot the new mode locally so the paint reflects it at once.
            const ChannelToggleRects chan = channelToggleRects(area);
            if (contains(chan.mono, x, y)) {
                channelMode_ = ChannelMode::Mono;
                processor_->setChannelMode(ChannelMode::Mono);
                invalidate();
                return;
            }
            if (contains(chan.stereo, x, y)) {
                channelMode_ = ChannelMode::Stereo;
                processor_->setChannelMode(ChannelMode::Stereo);
                invalidate();
                return;
            }

            // S11 waveform markers: grab start / loop-start / loop-end to drag. Hit-test the
            // waveform band first (it sits above the keyboard strip). markerAtPoint resolves
            // which marker under the grab; a miss falls through to the keyboard strip.
            const std::vector<AudioSample>& pcm = monoPcmFor(selectedId_);
            const std::int64_t frames = static_cast<std::int64_t>(pcm.size());
            if (frames > 0) {
                const Rect waveArea = setupWaveformArea(area);
                const SetupMarkers m = pickedMarkers(frames);
                const std::int64_t markerFrames[3] = {m.start, m.loopStart, m.loopEnd};
                const int hit = markerAtPoint(waveArea, frames, markerFrames, 3, x, y);
                if (hit >= 0) {
                    drag_ = DragKind::kWaveMarker;
                    waveMarker_ = static_cast<WaveMarker>(hit);
                    dragStartX_ = x;
                    dragStartMarkers_ = m;
                    dragSampleFrames_ = frames;
                    dragStartMap_ = map_;
                    return;  // no immediate set — the marker only moves once the cursor drags
                }
            }

            // The setup strip: grab the root marker (drag to set the picked capture's root).
            const Rect stripArea = setupStripArea(area);
            const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
            const int note = keyAtPoint(sl, x - stripArea.left, y - stripArea.top);
            if (note >= 0) {
                drag_ = DragKind::kRootMarker;
                dragStartX_ = x;
                dragStartRoot_ = note;
                dragStartMap_ = map_;
                // A click sets the root immediately (drag then refines); the override lives on
                // a one-zone map entry for the picked capture (D-B, never written to the bank).
                onMouseMove(x, y);  // apply the click position as the first delta==0 set
                return;
            }
        }
        return;
    }

    // Zones view.
    const int pad = 8;
    Rect addR{bands.content.left + pad, bands.content.top + 4, bands.content.left + pad + 96,
              bands.content.top + 4 + 20};
    if (contains(addR, x, y)) {
        // Add a full-keyboard zone for the picked capture (or the first visible sample as a
        // sensible seed). No pick -> nothing to add. If a full-keyboard zone for the seed id
        // already exists, select it rather than appending a duplicate (mirrors the upsert the
        // root-marker drag path already performs, preventing overlapping identical zones).
        std::string seed = !selectedId_.empty() ? selectedId_
                           : (!visible_.empty() ? visible_.front().id : std::string());
        if (seed.empty()) return;
        for (int i = 0; i < static_cast<int>(map_.zones.size()); ++i) {
            const PerformanceZone& z = map_.zones[static_cast<std::size_t>(i)];
            if (z.sampleId == seed && z.lowNote == 0 && z.highNote == 127) {
                selectedZone_ = i;
                invalidate();
                return;
            }
        }
        PerformanceZone z;
        z.sampleId = seed;
        z.lowNote = 0;
        z.highNote = 127;
        map_.zones.push_back(z);
        selectedZone_ = static_cast<int>(map_.zones.size()) - 1;
        commitAndReload();
        return;
    }
    Rect delR{addR.right + 8, addR.top, addR.right + 8 + 64, addR.bottom};
    if (selectedZone_ >= 0 && contains(delR, x, y)) {
        map_.zones.erase(map_.zones.begin() + selectedZone_);
        selectedZone_ = -1;
        commitAndReload();
        return;
    }

    // The zones strip: hit-test a bar edge/body to start a drag, or a bare key to set the
    // selected zone's root.
    const Rect stripArea = zonesStripArea(bands);
    const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
    const int lx = x - stripArea.left;
    const int ly = y - stripArea.top;

    std::vector<int> lows, highs;
    lows.reserve(map_.zones.size());
    highs.reserve(map_.zones.size());
    for (const PerformanceZone& z : map_.zones) { lows.push_back(z.lowNote); highs.push_back(z.highNote); }
    const ZoneBarHit hit = zoneBarAtPoint(sl, lows.empty() ? nullptr : lows.data(),
                                          highs.empty() ? nullptr : highs.data(),
                                          static_cast<int>(map_.zones.size()), lx, ly);
    if (hit.zoneIndex >= 0) {
        selectedZone_ = hit.zoneIndex;
        const PerformanceZone& z = map_.zones[static_cast<std::size_t>(hit.zoneIndex)];
        dragStartX_ = x;
        dragStartLow_ = z.lowNote;
        dragStartHigh_ = z.highNote;
        dragStartMap_ = map_;
        switch (hit.grab) {
            case ZoneGrab::kLowEdge: drag_ = DragKind::kZoneLow; break;
            case ZoneGrab::kHighEdge: drag_ = DragKind::kZoneHigh; break;
            case ZoneGrab::kBody: drag_ = DragKind::kZoneBody; break;
            default: drag_ = DragKind::kNone; break;
        }
        invalidate();
        return;
    }
    // A bare key-click inside the strip sets the selected zone's root override.
    if (contains(stripArea, x, y) && selectedZone_ >= 0 &&
        selectedZone_ < static_cast<int>(map_.zones.size())) {
        const int note = keyAtPoint(sl, lx, ly);
        if (note >= 0) {
            map_.zones[static_cast<std::size_t>(selectedZone_)].rootOverride = note;
            commitAndReload();
        }
    }
}

void ReaSamplerEditor::onMouseMove(int x, int y) {
    if (drag_ == DragKind::kNone) return;
    RECT cr{};
    GetClientRect(childHwnd_, &cr);
    const int w = cr.right - cr.left;
    const int h = cr.bottom - cr.top;
    const EditorBands bands = computeBands(w, h);
    const int dx = x - dragStartX_;

    if (drag_ == DragKind::kRootMarker) {
        // The single-capture root strip lives in the setup band.
        const int setupTop = (std::max)(bands.content.top, bands.content.bottom - kSetupHeight);
        const Rect area{bands.content.left, setupTop, bands.content.right, bands.content.bottom};
        const Rect stripArea = setupStripArea(area);
        const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
        const int note = resolveDragNote(sl, dragStartRoot_, dx);
        // The performance map is the ONLY D-B override vehicle (rootOverride lives on a zone),
        // so setting the single capture's root materializes a full-keyboard zone carrying the
        // override. This plays identically to the un-zoned single-capture path (one chromatic
        // zone over the whole keyboard) and round-trips through the v3 component state; the
        // zone becomes visible if the user opens the Zones panel. Upsert by the picked id so a
        // repeated drag edits the same zone rather than stacking duplicates.
        bool found = false;
        for (PerformanceZone& z : map_.zones) {
            if (z.sampleId == selectedId_) { z.rootOverride = note; found = true; break; }
        }
        if (!found) {
            PerformanceZone z;
            z.sampleId = selectedId_;
            z.lowNote = 0;
            z.highNote = 127;
            z.rootOverride = note;
            map_.zones.push_back(z);
        }
        invalidate();  // live feedback; the commit lands on WM_LBUTTONUP
        return;
    }

    if (drag_ == DragKind::kWaveMarker) {
        // S11: resolve the grabbed marker's new frame from the pixel delta, zero-crossing-snap
        // it against the decoded PCM, apply the inter-marker clamps, and write the override live.
        const int setupTop = (std::max)(bands.content.top, bands.content.bottom - kSetupHeight);
        const Rect area{bands.content.left, setupTop, bands.content.right, bands.content.bottom};
        const Rect waveArea = setupWaveformArea(area);
        const std::int64_t frames = dragSampleFrames_;
        if (frames <= 0) return;

        // Grabbed frame at grab time, from the snapshot (so the delta is measured from grab).
        const int idx = static_cast<int>(waveMarker_);
        const std::int64_t startVals[3] = {dragStartMarkers_.start, dragStartMarkers_.loopStart,
                                           dragStartMarkers_.loopEnd};
        std::int64_t newFrame = resolveDragFrame(waveArea, frames, startVals[idx], dx);

        // Snap to the nearest zero crossing in the decoded PCM (the S2 zero-crossing-aware
        // requirement). Pure over the cached mono frames — no host types, no file I/O.
        const std::vector<AudioSample>& pcm = monoPcmFor(selectedId_);
        if (!pcm.empty()) {
            newFrame = nearestZeroCrossing(pcm.data(), static_cast<std::int64_t>(pcm.size()),
                                           newFrame);
        }

        // Build the edited marker set from the snapshot, moving only the grabbed marker, then
        // clamp: loopStart <= loopEnd, start in [0, frames-1]. Dragging a loop marker MAKES a loop.
        SetupMarkers m = dragStartMarkers_;
        if (waveMarker_ == WaveMarker::kStart) {
            m.start = newFrame;
        } else if (waveMarker_ == WaveMarker::kLoopStart) {
            m.loopStart = (std::min)(newFrame, m.loopEnd);
            m.hasLoop = true;
        } else {  // kLoopEnd
            m.loopEnd = (std::max)(newFrame, m.loopStart);
            m.hasLoop = true;
        }
        if (m.start < 0) m.start = 0;
        if (m.start > frames - 1) m.start = frames - 1;

        // Upsert the override on the picked id (mirror of the root-marker path); commit lands on
        // release, this is live feedback.
        upsertPickedOverride(m);
        invalidate();
        return;
    }

    // Zone edits: recompute the grabbed field(s) against the pure resolver, live.
    if (selectedZone_ < 0 || selectedZone_ >= static_cast<int>(map_.zones.size())) return;
    const Rect stripArea = zonesStripArea(bands);
    const StripLayout sl = layoutStrip(stripArea.width(), stripArea.height());
    PerformanceZone& z = map_.zones[static_cast<std::size_t>(selectedZone_)];
    if (drag_ == DragKind::kZoneLow) {
        z.lowNote = (std::min)(resolveDragNote(sl, dragStartLow_, dx), z.highNote);
    } else if (drag_ == DragKind::kZoneHigh) {
        z.highNote = (std::max)(resolveDragNote(sl, dragStartHigh_, dx), z.lowNote);
    } else if (drag_ == DragKind::kZoneBody) {
        // Move the whole span: apply the SAME delta to both edges so the span is preserved,
        // clamping so neither edge escapes [0,127] (the span shifts, never shrinks).
        const int newLow = resolveDragNote(sl, dragStartLow_, dx);
        const int newHigh = resolveDragNote(sl, dragStartHigh_, dx);
        const int span = dragStartHigh_ - dragStartLow_;
        if (newLow < 0) { z.lowNote = 0; z.highNote = span; }
        else if (newHigh > 127) { z.highNote = 127; z.lowNote = 127 - span; }
        else { z.lowNote = newLow; z.highNote = newHigh; }
    }
    invalidate();
}

void ReaSamplerEditor::onMouseUp(int /*x*/, int /*y*/) {
    if (drag_ == DragKind::kNone) return;
    drag_ = DragKind::kNone;
    // One coherent edit lands on release: publish the in-flight map + reload off-thread.
    commitAndReload();
}

LRESULT CALLBACK ReaSamplerEditor::wndProc(HWND hwnd, UINT msg, WPARAM wParam,
                                           LPARAM lParam) {
    auto* self =
        reinterpret_cast<ReaSamplerEditor*>(GetWindowLongPtr(hwnd, GWLP_USERDATA));
    switch (msg) {
        case WM_PAINT: {
            PAINTSTRUCT ps{};
            HDC hdc = BeginPaint(hwnd, &ps);
            if (self) self->paint(hdc);
            EndPaint(hwnd, &ps);
            return 0;
        }
        case WM_LBUTTONDOWN:
            if (self) {
                SetCapture(hwnd);  // keep receiving moves/up if the cursor leaves the child
                self->onMouseDown(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
            }
            return 0;
        case WM_MOUSEMOVE:
            if (self) self->onMouseMove(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
            return 0;
        case WM_LBUTTONUP:
            if (self) {
                self->onMouseUp(GET_X_LPARAM(lParam), GET_Y_LPARAM(lParam));
                ReleaseCapture();
            }
            return 0;
        case WM_CAPTURECHANGED:
            // Capture stolen mid-drag (modal dialog, alt-tab, etc.) — restore map_ to its
            // pre-grab snapshot so the in-flight live-drag mutation is rolled back, then reset
            // the drag state machine so stale capture-less WM_MOUSEMOVEs don't keep editing.
            // Mirror of bank_panel.cpp's WM_CAPTURECHANGED handler.
            if (self && self->drag_ != DragKind::kNone) {
                self->map_ = self->dragStartMap_;
                self->drag_ = DragKind::kNone;
                self->invalidate();
            }
            return 0;
        case WM_TIMER:
            if (self && wParam == kSyncTimerId) self->onSyncTimer();
            return 0;
        case WM_ERASEBKGND:
            return 1;  // fully repaint in WM_PAINT; skip the flicker-inducing erase
        default:
            return DefWindowProcW(hwnd, msg, wParam, lParam);
    }
}

#else  // non-Windows: not a build target (D5), but keep the TU compilable.

void ReaSamplerEditor::attachedToParent() {}
void ReaSamplerEditor::removedFromParent() {}
tresult PLUGIN_API ReaSamplerEditor::onSize(ViewRect* newSize) {
    return CPluginView::onSize(newSize);
}

#endif  // _WIN32

}  // namespace reasampler::vst