// editor_session.cpp — the ReaSamplerEditor's SESSION/BRIDGE state (Q-W2v split of
// reasampler_editor.cpp, T4-11): construction, the live-bank snapshot (refreshFromBank /
// rebuildVisible), the S9/S8 sync tick, the commit-and-reload seam, selection loading,
// the picked-capture marker resolution/upsert helpers, and the decoded-PCM + peak
// thumbnail caches (the mirror of bank_panel's, keyed through the pure ThumbnailKey —
// T2-10 rider). UI thread only; every edit commits OFF the audio thread via the
// processor's reloadInstrument.

#include "shell/instrument/reasampler_editor.h"

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

#include "core/audio/peaks.h"            // computeEnvelope (the cached peak thumbnail)
#include "core/capture/capture_paths.h"  // resolveBankFile (shared M4 path resolution)
#include "core/capture/wav_trim.h"       // parseWavLayout, extractFloatFrames
#include "core/ui/bank_grid.h"           // ThumbnailKey / thumbnailKeyString (T2-10: the pure key)
#include "core/util/file_bytes.h"        // shared whole-file loader (Q-W1, T2-03)
#include "ext_keys.h"
#include "core/instrument/ui/browser_scroll.h"  // nameMatchesQuery (S12 type-to-filter)
#include "shell/instrument/reaper_bridge.h"
#include "shell/instrument/reasampler_processor.h"

using namespace Steinberg;

namespace reasampler::vst {

using namespace reasampler::instrument::map;  // sample_map vocabulary (selectSample / listSamples / …)
using audio::computeEnvelope;
using capture::WavLayout;
using capture::extractFloatFrames;
using capture::parseWavLayout;
using capture::resolveBankFile;
using instrument::ui::nameMatchesQuery;
using ui::ThumbnailKey;
using ui::thumbnailKeyString;
using util::readFileBytes;

ReaSamplerEditor::ReaSamplerEditor(ReaSamplerProcessor* processor)
    : CPluginView(nullptr), processor_(processor) {
    // Default view size (S-VIEW-SIZE-1 tuned to the concrete Sample-face band heights). The Sample
    // home stacks: title (26) + hero waveform (150) + cluster (52) + the control strip, whose Gate
    // mode shows 12 rows at ~26px ≈ 312px. 840×620 clears the full three-band face without scroll
    // on a 1080p screen with headroom. Wide enough that the control strip's label + value columns
    // read comfortably.
    ViewRect r(0, 0, 840, 620);
    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();
    const auto prevZoneCount = static_cast<int>(map_.zones.size());
    map_ = processor_->performanceMap();
    channelMode_ = processor_->channelMode();
    voiceCount_ = processor_->voiceCount();      // Phase S voice-deck snapshot
    voiceMode_ = processor_->voiceMode();
    monoTrigger_ = processor_->monoTrigger();
    if (selectedZone_ >= static_cast<int>(map_.zones.size())) selectedZone_ = -1;
    // r11: a refresh that emptied the selection (a bank change on the sync tick) closes the
    // curve popup — the empty-state Sample face no longer draws it, and an open-but-invisible
    // modal would swallow clicks.
    if (selectedId_.empty() && map_.zones.empty()) curvePopupOpen_ = false;
    // FB2: on the Zone surface the popup edits the SELECTED zone; close it if the zones list
    // shrank (selectedZone_ past-end), OR if the zone count changed at all — a mid-list
    // deletion leaves selectedZone_ in range but now naming a DIFFERENT zone (silent retarget).
    if (view_ == View::kZone && curvePopupOpen_) {
        const auto newZoneCount = static_cast<int>(map_.zones.size());
        if (selectedZone_ < 0 || newZoneCount != prevZoneCount) curvePopupOpen_ = false;
    }
    // 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() {
    // S12 composition: the bank filter picks the bank FIRST, then the type-to-filter search
    // narrows the survivors by name substring (nameMatchesQuery — empty query is the identity).
    visible_.clear();
    for (const SampleChoice& s : samples_) {
        const bool inBank = activeFilterBankId_.empty() || s.bankId == activeFilterBankId_;
        if (!inBank) continue;
        const std::string& name = s.displayName.empty() ? s.id : s.displayName;
        if (nameMatchesQuery(name, searchQuery_)) visible_.push_back(s);
    }
    // NOTE: scrollOffset_ is clamped at paint + wheel time (where the browser layout / panel
    // height is known); rebuildVisible runs cross-platform + on the sync-timer refresh, so it
    // must not reset the user's scroll here.
}

#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();
    }

    // S13: decay the drop-affordance banner so it auto-dismisses a few ticks after a drop.
    if (dropHintTicks_ > 0) {
        --dropHintTicks_;
        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 (reloadInstrument bakes them into the live Keymap).
    // pS: the reload also COPIES the picked capture's file ref + intrinsics from the bank
    // blob into the instance-owned refs table (refreshRefsFromBank) — a browser load is the
    // moment the instance becomes self-contained for that sample.
    if (!processor_) return;
    processor_->setSelectedSampleId(selectedId_);
    processor_->setPerformanceMap(map_);
    processor_->reloadInstrument();
    // GA: the reload may have AUTO-DEFAULTED the channel mode from the loaded capture's
    // channel count (implicit mode only) — re-read so the Mono/Stereo toggle draws the mode
    // the engine actually decoded with.
    channelMode_ = processor_->channelMode();
#ifdef _WIN32
    invalidate();
#endif
}

void ReaSamplerEditor::loadSelection(const std::string& id) {
    // Zone-bleed fix (3a): a Sample-face load REPLACES the loaded sound. The previous
    // sample's materialized full-range zone must not linger — first-match resolve would
    // keep playing it while the editor draws the new pick's zone (matched by sampleId,
    // order-blind). Authored Zone-view maps (any narrow key range) are left untouched.
    selectedId_ = id;
    if (reconcileSingleCaptureZones(map_, selectedId_)) {
        selectedZone_ = map_.zones.empty() ? -1 : 0;
    }
    commitAndReload();
}

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); when that is not readable
    // (extension absent / not yet parsed) the instance-OWNED ref carries the same intrinsics
    // (pS fallback). The override lives in map_.
    if (processor_) {
        std::optional<SelectedSample> sel;
        auto banksJson =
            processor_->bridge().readReasamplerExtState(reasampler::kProjExtBanksKey);
        if (banksJson) sel = selectSample(*banksJson, selectedId_);
        if (!sel) {
            const SampleRefs refs = processor_->sampleRefs();
            if (const SelectedSample* r = findRef(refs, selectedId_)) sel = *r;
        }
        if (sel && 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;
}

int 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.
    // Returns the zone index (0-based) so callers can update selectedZone_.
    SampleLoop loop;
    loop.hasLoop = m.hasLoop;
    loop.start = m.loopStart;
    loop.end = m.loopEnd;
    for (int i = 0; i < static_cast<int>(map_.zones.size()); ++i) {
        PerformanceZone& z = map_.zones[static_cast<std::size_t>(i)];
        if (z.sampleId == selectedId_) {
            z.loopOverride = loop;
            z.startPoint = m.start;
            return i;
        }
    }
    PerformanceZone z;
    z.sampleId = selectedId_;
    z.lowNote = 0;
    z.highNote = 127;
    z.loopOverride = loop;
    z.startPoint = m.start;
    map_.zones.push_back(z);
    return static_cast<int>(map_.zones.size()) - 1;
}

PerformanceZone ReaSamplerEditor::effectiveSampleZone() const {
    // The picked id's one-zone override, if the map already carries one; else a product-default
    // zone bound to the picked id (NOT appended — a read-only resolve; a control edit materializes
    // it via ensureSampleZone). Mirrors the S15-F2 single-storage-site lean.
    for (const PerformanceZone& z : map_.zones) {
        if (z.sampleId == selectedId_) return z;
    }
    PerformanceZone z;
    z.sampleId = selectedId_;
    z.lowNote = 0;
    z.highNote = 127;
    return z;
}

int ReaSamplerEditor::effectiveRoot() const {
    int root = 60;
    for (const SampleChoice& s : samples_) {
        if (s.id == selectedId_ && s.rootNote) root = *s.rootNote;
    }
    for (const PerformanceZone& z : map_.zones) {
        if (z.sampleId == selectedId_ && z.rootOverride) root = *z.rootOverride;
    }
    return root;
}

int ReaSamplerEditor::ensureSampleZone() {
    if (selectedId_.empty()) return -1;
    for (int i = 0; i < static_cast<int>(map_.zones.size()); ++i) {
        if (map_.zones[static_cast<std::size_t>(i)].sampleId == selectedId_) return i;
    }
    PerformanceZone z;
    z.sampleId = selectedId_;
    z.lowNote = 0;
    z.highNote = 127;
    map_.zones.push_back(z);
    return static_cast<int>(map_.zones.size()) - 1;
}

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()) {
            // pS fallback: the bank blob is not readable (extension absent / not yet parsed)
            // or the id went stale there — the instance-OWNED ref still carries the path, so
            // a self-contained instance draws its loaded sound's waveform regardless.
            const SampleRefs refs = processor_->sampleRefs();
            if (const SelectedSample* r = findRef(refs, sampleId)) {
                relativePath = r->relativePath;
            }
        }
        if (!relativePath.empty()) {
            const std::string projectDir = processor_->bridge().activeProjectDir();
            const std::string abs = resolveBankFile(projectDir, relativePath);
            // Shared core/util whole-file loader (Q-W1, T2-03): empty on any failure.
            const std::vector<std::uint8_t> bytes = readFileBytes(abs);
            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) {
    // T2-10 rider: key through the PURE ThumbnailKey (bank_grid) instead of the former
    // ad-hoc "id|binCount" concat, so both thumbnail pipelines share one tested key
    // grammar (length-prefixed id — collision-proof). The editor invalidates by wholesale
    // clear() on refresh/resize, so the bank generation carries no information here — 0.
    const std::string key =
        thumbnailKeyString(ThumbnailKey{sampleId, binCount, /*generation=*/0});
    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()) {
        // Clamp bins to the frame count: computeEnvelope pads binCount > frameCount with
        // trailing empty {0,0} bins, which would render a very short sample as a comb of
        // spikes over flat gaps.
        const std::size_t bins =
            (std::min)(static_cast<std::size_t>((std::max)(1, binCount)), mono.size());
        env = computeEnvelope(mono, 1, mono.size(), bins);
    }
    auto ins = thumbCache_.emplace(key, std::move(env));
    return ins.first->second;
}

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

}  // namespace reasampler::vst