diff --git a/app/static/js/app.jsx b/app/static/js/app.jsx
index 407ec32..677ea6d 100644
--- a/app/static/js/app.jsx
+++ b/app/static/js/app.jsx
@@ -13941,7 +13941,7 @@ const App = () => {
             apiKey,
             baseUrl: baseUrl.replace(/\/chat\/completions$/, '').replace(/\/$/, ''),
             messages,
-            tools: [window.AIGateway.REARRANGE_TOOL_SPEC],
+            tools: [window.AIGateway.REARRANGE_TOOL_SPEC.function],
             toolChoice: 'auto'
           });
 
diff --git a/app/static/js/app.precompiled.js b/app/static/js/app.precompiled.js
index e8777b6..099adb4 100644
--- a/app/static/js/app.precompiled.js
+++ b/app/static/js/app.precompiled.js
@@ -425,7 +425,7 @@ const snapLoopStart=findZeroCrossing(buffer,loopStart);const snapLoopEnd=findZer
 setTracks(prev=>prev.map(t=>{if(t.id!==activeTrack.id)return t;const existingMarkers=t.markers||[];const filtered=existingMarkers.filter(m=>!m.id.startsWith('ai_loop_'));return{...t,markers:[...filtered,{id:'ai_loop_start_'+Date.now(),time:snapLoopStart,label:'Loop Start (Bar '+(Math.floor(snapLoopStart/barDuration)+1)+')',color:'#06b6d4'},{id:'ai_loop_end_'+Date.now(),time:snapLoopEnd,label:'Loop End (Beat 4)',color:'#a855f7'}]};}));setSelectionStart(snapLoopStart);setSelectionEnd(snapLoopEnd);const startSample=Math.max(0,Math.min(dataLen-1,Math.floor(snapLoopStart*sampleRate)));const endSample=Math.max(0,Math.min(dataLen,Math.floor(snapLoopEnd*sampleRate)));const sliceLength=endSample-startSample;if(sliceLength<=0){showToast("Dải cắt không hợp lệ hoặc khoảng thời gian quá ngắn.","error");setAnalysisState({status:'Thất bại',data:null,isRunning:false});return;}const context=getAudioContext();const numChannels=buffer.numberOfChannels||1;const slicedBuffer=context.createBuffer(numChannels,sliceLength,sampleRate);for(let c=0;c<numChannels;c++){const srcData=buffer.getChannelData(c);const dstData=slicedBuffer.getChannelData(c);dstData.set(srcData.subarray(startSample,endSample));}const newId='track_ai_cut_'+Date.now();const colors=['#0f766e','#1d4ed8','#701a75','#a21caf','#b45309'];const selectColor=colors[tracks.length%colors.length];const barNum=Math.floor(snapLoopStart/barDuration)+1;const barsCount=Math.max(1,Math.round((snapLoopEnd-snapLoopStart)/barDuration));const newTrack={id:newId,name:`Loop_${barNum}bar_${activeTrack.name.replace('.wav','').slice(0,10)}_${snapLoopStart.toFixed(1)}s.wav`,buffer:slicedBuffer,channelInfo:activeTrack.channelInfo?{...activeTrack.channelInfo}:null,startTime:snapLoopStart,clips:[{id:'clip_'+newId,buffer:slicedBuffer,startTime:snapLoopStart,name:`Loop_${barNum}bar_${snapLoopStart.toFixed(1)}s`}],volumeDb:0,pan:0,muted:false,solo:false,color:selectColor,markers:[{id:Date.now()+'_s',time:0},{id:Date.now()+'_e',time:snapLoopEnd-snapLoopStart}],serverFileId:null};setTracks(prev=>{const idx=prev.findIndex(t=>t.id===selectedTrackId);const updated=[...prev];if(idx!==-1){updated.splice(idx+1,0,newTrack);}else{updated.push(newTrack);}return updated;});setSelectedTrackId(newId);setAnalysisState({status:`AI Cut: ${detectedBPM} BPM, ${barsCount} bars loop (Zero-Crossing aligned)`,data:{bpm:detectedBPM,bars:barsCount,timeSig:'4/4'},isRunning:false});showToast(`AI Cut: ${barsCount} bars loop at ${snapLoopStart.toFixed(3)}s - ${snapLoopEnd.toFixed(3)}s [${detectedBPM} BPM]`,"success");setTimeout(()=>lucide.createIcons(),200);}catch(err){showToast("Lỗi khi AI Cut: "+err.message,"error");setAnalysisState({status:'Lỗi AI Cut',data:null,isRunning:false});}},800);};// ── AI Prompt Send to Active Provider ──
 const handleAISend=async()=>{const prompt=aiPrompt.trim();if(!prompt){showToast('Vui lòng nhập nội dung prompt.','warning');return;}// Check if piano roll tab is active → route prompt to MIDI generation
 const activePianoRoll=subTabs.find(s=>s.id===activeTab&&s.type==='PIANO_ROLL');if(activePianoRoll){setAiProcessing(true);setAiActionLog(prev=>[...prev,{type:'status',text:` ⏳ Đang gửi prompt đến AI cho Piano Roll...`,time:Date.now()}]);try{if(aiProviders.length===0||!selectedProviderId){try{const data=await window.SonicAPI.getAIConfigs();if(data&&data.providers&&data.providers.length>0){setAiProviders(data.providers);const active=data.providers.find(p=>p.is_active)||data.providers[0];if(active)setSelectedProviderId(active.id);}}catch(e){}}const prv=aiProviders.find(p=>p.id===selectedProviderId)||(aiProviders.length>0?aiProviders[0]:null);const provider=prv||aiConfig;const baseUrl=provider.api_base_url||provider.baseUrl||`${API_BASE_URL}`;const apiKey=provider.api_key||provider.apiKey||'';const model=provider.model_name||provider.model||'deepseek-chat';setAiActionLog(prev=>[...prev,{type:'info',text:` Provider: ${provider.name||'default'} | Model: ${model}`,time:Date.now()}]);let pianoSystemInstruction='You are a MIDI composer. Output ONLY valid JSON array of notes. No markdown, no explanation. Use 4/4 time. pitch=C4=60, D4=62, E4=64, F4=65, G4=67, A4=69, B4=71, C5=72.';const result=await window.AIGateway.executeAIPrompt({prompt:'Generate MIDI notes for a piano roll. Return ONLY a JSON array: [{pitch(0-127), start_beat, duration_beats, velocity(0.0-1.0)}]. '+prompt,provider:provider.name||'default',model:model,apiKey:apiKey,baseUrl:baseUrl.replace(/\/chat\/completions$/,'').replace(/\/$/,''),systemInstruction:pianoSystemInstruction});if(!result)throw new Error('AI không phản hồi');let notesData=null;const textResp=result.textResponse||result.text||'';if(textResp&&typeof textResp==='string'){try{const cleaned=textResp.replace(/```json?\s*/g,'').replace(/```/g,'').trim();notesData=JSON.parse(cleaned);}catch(e1){console.error('Parse notes error:',e1);}}if(!notesData&&result.functionCalls){for(const fc of result.functionCalls){if(fc.arguments&&fc.arguments.notes){notesData=fc.arguments.notes;break;}}}if(Array.isArray(notesData)&&notesData.length>0){const newNotes=notesData.map((n,i)=>({id:'note_ai_'+Date.now()+'_'+i,pitch:Math.max(0,Math.min(127,n.pitch||60)),start_beat:Math.max(0,parseFloat(n.start_beat)||0),duration_beats:Math.max(0.125,parseFloat(n.duration_beats)||0.25),velocity:Math.max(0.1,Math.min(1.0,n.velocity??0.8)),pan:0.0}));setSubTabs(prev=>prev.map(s=>s.id===activePianoRoll.id?{...s,notes:[...(s.notes||[]),...newNotes],isDirty:true}:s));setAiActionLog(prev=>[...prev,{type:'status',text:` ✅ Đã thêm ${newNotes.length} notes vào Piano Roll`,time:Date.now()}]);setCanvasRedrawCount(n=>n+1);}else{setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ AI không trả về notes hợp lệ.`,time:Date.now()}]);}}catch(err){setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ Lỗi: ${err.message}`,time:Date.now()}]);}setAiProcessing(false);return;}// ── MIDI Rearrange Flow: selected MIDI item → use rearrange tool ──
-if(selectedItemIds&&selectedItemIds.size===1){const selId=selectedItemIds.values().next().value;let isMidiItem=false;let sourceTrackId=null;let sourceItemName=null;for(const t of activeTracks||[]){const found=(t.midiItems||[]).find(m=>m.id===selId);if(found){isMidiItem=true;sourceTrackId=t.id;sourceItemName=found.name;break;}}if(isMidiItem&&window.SonicMidiExtractor){try{setAiProcessing(true);setAiActionLog(prev=>[...prev,{type:'status',text:` 🎯 Phát hiện MIDI item được chọn — chuyển sang chế độ Rearrange...`,time:Date.now()}]);if(aiProviders.length===0||!selectedProviderId){try{const d=await window.SonicAPI.getAIConfigs();if(d&&d.providers&&d.providers.length>0){setAiProviders(d.providers);const a=d.providers.find(p=>p.is_active)||d.providers[0];if(a)setSelectedProviderId(a.id);}}catch(e){}}const prv=aiProviders.find(p=>p.id===selectedProviderId)||(aiProviders.length>0?aiProviders[0]:null);const provider=prv||aiConfig;const baseUrl=provider.api_base_url||provider.baseUrl||`${API_BASE_URL}`;const apiKey=provider.api_key||provider.apiKey||'';const model=provider.model_name||provider.model||'deepseek-chat';setAiActionLog(prev=>[...prev,{type:'info',text:` Rearrange Provider: ${provider.name||'default'} | Model: ${model}`,time:Date.now()}]);const srcContext=window.SonicMidiExtractor.extractSelectedMIDIContext(activeTracks||tracks,selId,bpm);setAiActionLog(prev=>[...prev,{type:'info',text:` 📋 Trích xuất ${srcContext.total_notes} notes từ "${srcContext.item_name}" (${srcContext.track_name})`,time:Date.now()}]);if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.rearrangeSourceTrackId=sourceTrackId;window.DAWCommandDispatcher.rearrangeSourceItemName=sourceItemName;}const messages=window.AIGateway.buildRearrangeMessage(prompt,srcContext);const completion=await window.AIGateway.callLLM({provider:provider.name||'default',model,apiKey,baseUrl:baseUrl.replace(/\/chat\/completions$/,'').replace(/\/$/,''),messages,tools:[window.AIGateway.REARRANGE_TOOL_SPEC],toolChoice:'auto'});const functionCalls=window.AIGateway.extractFunctionCalls(completion);if(functionCalls&&functionCalls.length>0){for(const fc of functionCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi lệnh: ${fc.name}(${JSON.stringify(fc.arguments)})`,time:Date.now()}]);const cmdName=fc.name.toUpperCase();if(window.DAWCommandDispatcher){try{let cmdResult=window.DAWCommandDispatcher.execute(cmdName,fc.arguments);if(cmdResult&&typeof cmdResult.then==='function')cmdResult=await cmdResult;setAiActionLog(prev=>[...prev,{type:'status',text:` ✅ ${fc.name}: thành công — ${fc.arguments.rearrange_title||''}`,time:Date.now()}]);}catch(cmdErr){setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: ${cmdErr.message}`,time:Date.now()}]);}}}}else{setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ AI không trả về lệnh rearrange hợp lệ.`,time:Date.now()}]);}const textResp=functionCalls.length===0&&completion.choices&&completion.choices[0]&&completion.choices[0].message&&completion.choices[0].message.content;if(textResp){setAiActionLog(prev=>[...prev,{type:'status',text:` AI: ${textResp.slice(0,500)}`,time:Date.now()}]);}if(prompt){promptHistRef.current=[...promptHistRef.current.slice(-49),prompt];setPromptHistory(promptHistRef.current);}setPromptHistIdx(-1);setAiActionLog(prev=>[...prev,{type:'status',text:` Hoàn tất Rearrange.`,time:Date.now()}]);setAiPrompt('');setTimeout(()=>lucide.createIcons(),200);setAiProcessing(false);return;}catch(err){setAiActionLog(prev=>[...prev,{type:'error',text:` Lỗi Rearrange: ${err.message}`,time:Date.now()}]);showToast(`AI Rearrange Error: ${err.message}`,'error');setAiProcessing(false);return;}}}if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.currentSelectedTrackId=selectedTrackId;window.DAWCommandDispatcher.currentTracks=activeTracks;window.DAWCommandDispatcher.lastCutSourceTrackId=null;window.DAWCommandDispatcher.lastCutNewTrackId=null;}setAiProcessing(true);setAiActionLog(prev=>[...prev,{type:'status',text:` ⏳ Đang gửi prompt đến AI...`,time:Date.now()}]);try{if(aiProviders.length===0||!selectedProviderId){try{const data=await window.SonicAPI.getAIConfigs();if(data&&data.providers&&data.providers.length>0){setAiProviders(data.providers);const active=data.providers.find(p=>p.is_active)||data.providers[0];if(active)setSelectedProviderId(active.id);}}catch(e){}}const prv=aiProviders.find(p=>p.id===selectedProviderId)||(aiProviders.length>0?aiProviders[0]:null);const provider=prv||aiConfig;const baseUrl=provider.api_base_url||provider.baseUrl||`${API_BASE_URL}`;const apiKey=provider.api_key||provider.apiKey||'';const model=provider.model_name||provider.model||'deepseek-chat';setAiActionLog(prev=>[...prev,{type:'info',text:` Provider: ${provider.name||'default'} | Model: ${model} | URL: ${baseUrl.slice(0,40)}`,time:Date.now()}]);const dawContext=window.AIGateway.buildAIPromptContext({tracks:activeTracks,bpm,selectedTrackId,currentTime,selLeft,selRight});let matchedInstruction='';const result=await window.AIGateway.executeAIPrompt({prompt:prompt,provider:provider.name||'default',model:model,apiKey:apiKey,baseUrl:baseUrl.replace(/\/chat\/completions$/,'').replace(/\/$/,''),dawContext,tools:window.AIGateway.DEFAULT_TOOLS,systemInstruction:matchedInstruction});const hasText=!!result.textResponse;const hasCalls=result.functionCalls&&result.functionCalls.length>0;if(hasText){setAiActionLog(prev=>[...prev,{type:'status',text:` AI: ${result.textResponse.slice(0,500)}`,time:Date.now()}]);}if(hasCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi ${result.functionCalls.length} lệnh...`,time:Date.now()}]);if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.isExecutingAI=true;}try{for(const fc of result.functionCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi lệnh: ${fc.name}(${JSON.stringify(fc.arguments)})`,time:Date.now()}]);const cmdName=fc.name.toUpperCase();if(window.DAWCommandDispatcher){try{let cmdResult=window.DAWCommandDispatcher.execute(cmdName,fc.arguments);if(cmdResult&&typeof cmdResult.then==='function')cmdResult=await cmdResult;setAiActionLog(prev=>[...prev,{type:'status',text:` ✅ ${fc.name}: ${cmdResult&&cmdResult.success?'thành công':'thất bại: '+(cmdResult&&cmdResult.error||'unknown')}`,time:Date.now()}]);}catch(cmdErr){setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: ${cmdErr.message}`,time:Date.now()}]);}}else{setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: DAWCommandDispatcher not available`,time:Date.now()}]);}}}finally{if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.isExecutingAI=false;}}}if(!hasText&&!hasCalls){const rawKeys=result.raw?Object.keys(result.raw).join(', '):'null';const errDetail=result.raw&&result.raw.error?` (${result.raw.error.message||result.raw.error})`:'';setAiActionLog(prev=>[...prev,{type:'error',text:` AI không trả về lệnh hoặc text. Keys: [${rawKeys}]${errDetail}`,time:Date.now()}]);}if(prompt){promptHistRef.current=[...promptHistRef.current.slice(-49),prompt];setPromptHistory(promptHistRef.current);}setPromptHistIdx(-1);setAiActionLog(prev=>[...prev,{type:'status',text:` Hoàn tất.`,time:Date.now()}]);setAiPrompt('');setTimeout(()=>lucide.createIcons(),200);}catch(err){setAiActionLog(prev=>[...prev,{type:'error',text:` Lỗi: ${err.message}`,time:Date.now()}]);showToast(`AI Error: ${err.message}`,'error');}finally{setAiProcessing(false);}};// ── Split Track at Playhead ──
+if(selectedItemIds&&selectedItemIds.size===1){const selId=selectedItemIds.values().next().value;let isMidiItem=false;let sourceTrackId=null;let sourceItemName=null;for(const t of activeTracks||[]){const found=(t.midiItems||[]).find(m=>m.id===selId);if(found){isMidiItem=true;sourceTrackId=t.id;sourceItemName=found.name;break;}}if(isMidiItem&&window.SonicMidiExtractor){try{setAiProcessing(true);setAiActionLog(prev=>[...prev,{type:'status',text:` 🎯 Phát hiện MIDI item được chọn — chuyển sang chế độ Rearrange...`,time:Date.now()}]);if(aiProviders.length===0||!selectedProviderId){try{const d=await window.SonicAPI.getAIConfigs();if(d&&d.providers&&d.providers.length>0){setAiProviders(d.providers);const a=d.providers.find(p=>p.is_active)||d.providers[0];if(a)setSelectedProviderId(a.id);}}catch(e){}}const prv=aiProviders.find(p=>p.id===selectedProviderId)||(aiProviders.length>0?aiProviders[0]:null);const provider=prv||aiConfig;const baseUrl=provider.api_base_url||provider.baseUrl||`${API_BASE_URL}`;const apiKey=provider.api_key||provider.apiKey||'';const model=provider.model_name||provider.model||'deepseek-chat';setAiActionLog(prev=>[...prev,{type:'info',text:` Rearrange Provider: ${provider.name||'default'} | Model: ${model}`,time:Date.now()}]);const srcContext=window.SonicMidiExtractor.extractSelectedMIDIContext(activeTracks||tracks,selId,bpm);setAiActionLog(prev=>[...prev,{type:'info',text:` 📋 Trích xuất ${srcContext.total_notes} notes từ "${srcContext.item_name}" (${srcContext.track_name})`,time:Date.now()}]);if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.rearrangeSourceTrackId=sourceTrackId;window.DAWCommandDispatcher.rearrangeSourceItemName=sourceItemName;}const messages=window.AIGateway.buildRearrangeMessage(prompt,srcContext);const completion=await window.AIGateway.callLLM({provider:provider.name||'default',model,apiKey,baseUrl:baseUrl.replace(/\/chat\/completions$/,'').replace(/\/$/,''),messages,tools:[window.AIGateway.REARRANGE_TOOL_SPEC.function],toolChoice:'auto'});const functionCalls=window.AIGateway.extractFunctionCalls(completion);if(functionCalls&&functionCalls.length>0){for(const fc of functionCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi lệnh: ${fc.name}(${JSON.stringify(fc.arguments)})`,time:Date.now()}]);const cmdName=fc.name.toUpperCase();if(window.DAWCommandDispatcher){try{let cmdResult=window.DAWCommandDispatcher.execute(cmdName,fc.arguments);if(cmdResult&&typeof cmdResult.then==='function')cmdResult=await cmdResult;setAiActionLog(prev=>[...prev,{type:'status',text:` ✅ ${fc.name}: thành công — ${fc.arguments.rearrange_title||''}`,time:Date.now()}]);}catch(cmdErr){setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: ${cmdErr.message}`,time:Date.now()}]);}}}}else{setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ AI không trả về lệnh rearrange hợp lệ.`,time:Date.now()}]);}const textResp=functionCalls.length===0&&completion.choices&&completion.choices[0]&&completion.choices[0].message&&completion.choices[0].message.content;if(textResp){setAiActionLog(prev=>[...prev,{type:'status',text:` AI: ${textResp.slice(0,500)}`,time:Date.now()}]);}if(prompt){promptHistRef.current=[...promptHistRef.current.slice(-49),prompt];setPromptHistory(promptHistRef.current);}setPromptHistIdx(-1);setAiActionLog(prev=>[...prev,{type:'status',text:` Hoàn tất Rearrange.`,time:Date.now()}]);setAiPrompt('');setTimeout(()=>lucide.createIcons(),200);setAiProcessing(false);return;}catch(err){setAiActionLog(prev=>[...prev,{type:'error',text:` Lỗi Rearrange: ${err.message}`,time:Date.now()}]);showToast(`AI Rearrange Error: ${err.message}`,'error');setAiProcessing(false);return;}}}if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.currentSelectedTrackId=selectedTrackId;window.DAWCommandDispatcher.currentTracks=activeTracks;window.DAWCommandDispatcher.lastCutSourceTrackId=null;window.DAWCommandDispatcher.lastCutNewTrackId=null;}setAiProcessing(true);setAiActionLog(prev=>[...prev,{type:'status',text:` ⏳ Đang gửi prompt đến AI...`,time:Date.now()}]);try{if(aiProviders.length===0||!selectedProviderId){try{const data=await window.SonicAPI.getAIConfigs();if(data&&data.providers&&data.providers.length>0){setAiProviders(data.providers);const active=data.providers.find(p=>p.is_active)||data.providers[0];if(active)setSelectedProviderId(active.id);}}catch(e){}}const prv=aiProviders.find(p=>p.id===selectedProviderId)||(aiProviders.length>0?aiProviders[0]:null);const provider=prv||aiConfig;const baseUrl=provider.api_base_url||provider.baseUrl||`${API_BASE_URL}`;const apiKey=provider.api_key||provider.apiKey||'';const model=provider.model_name||provider.model||'deepseek-chat';setAiActionLog(prev=>[...prev,{type:'info',text:` Provider: ${provider.name||'default'} | Model: ${model} | URL: ${baseUrl.slice(0,40)}`,time:Date.now()}]);const dawContext=window.AIGateway.buildAIPromptContext({tracks:activeTracks,bpm,selectedTrackId,currentTime,selLeft,selRight});let matchedInstruction='';const result=await window.AIGateway.executeAIPrompt({prompt:prompt,provider:provider.name||'default',model:model,apiKey:apiKey,baseUrl:baseUrl.replace(/\/chat\/completions$/,'').replace(/\/$/,''),dawContext,tools:window.AIGateway.DEFAULT_TOOLS,systemInstruction:matchedInstruction});const hasText=!!result.textResponse;const hasCalls=result.functionCalls&&result.functionCalls.length>0;if(hasText){setAiActionLog(prev=>[...prev,{type:'status',text:` AI: ${result.textResponse.slice(0,500)}`,time:Date.now()}]);}if(hasCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi ${result.functionCalls.length} lệnh...`,time:Date.now()}]);if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.isExecutingAI=true;}try{for(const fc of result.functionCalls){setAiActionLog(prev=>[...prev,{type:'info',text:` Gọi lệnh: ${fc.name}(${JSON.stringify(fc.arguments)})`,time:Date.now()}]);const cmdName=fc.name.toUpperCase();if(window.DAWCommandDispatcher){try{let cmdResult=window.DAWCommandDispatcher.execute(cmdName,fc.arguments);if(cmdResult&&typeof cmdResult.then==='function')cmdResult=await cmdResult;setAiActionLog(prev=>[...prev,{type:'status',text:` ✅ ${fc.name}: ${cmdResult&&cmdResult.success?'thành công':'thất bại: '+(cmdResult&&cmdResult.error||'unknown')}`,time:Date.now()}]);}catch(cmdErr){setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: ${cmdErr.message}`,time:Date.now()}]);}}else{setAiActionLog(prev=>[...prev,{type:'error',text:` ❌ ${fc.name}: DAWCommandDispatcher not available`,time:Date.now()}]);}}}finally{if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.isExecutingAI=false;}}}if(!hasText&&!hasCalls){const rawKeys=result.raw?Object.keys(result.raw).join(', '):'null';const errDetail=result.raw&&result.raw.error?` (${result.raw.error.message||result.raw.error})`:'';setAiActionLog(prev=>[...prev,{type:'error',text:` AI không trả về lệnh hoặc text. Keys: [${rawKeys}]${errDetail}`,time:Date.now()}]);}if(prompt){promptHistRef.current=[...promptHistRef.current.slice(-49),prompt];setPromptHistory(promptHistRef.current);}setPromptHistIdx(-1);setAiActionLog(prev=>[...prev,{type:'status',text:` Hoàn tất.`,time:Date.now()}]);setAiPrompt('');setTimeout(()=>lucide.createIcons(),200);}catch(err){setAiActionLog(prev=>[...prev,{type:'error',text:` Lỗi: ${err.message}`,time:Date.now()}]);showToast(`AI Error: ${err.message}`,'error');}finally{setAiProcessing(false);}};// ── Split Track at Playhead ──
 const handleSplitTrackAtTime=(trackId,clipId,time)=>{const track=tracks.find(t=>t.id===trackId);if(!track)return;const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default',buffer:track.buffer,startTime:track.startTime||0,name:track.name}]:[];const targetClipId=clipId||clips.find(c=>time>=c.startTime&&time<c.startTime+c.buffer.duration)?.id;if(!targetClipId)return;const clip=clips.find(c=>c.id===targetClipId);if(!clip||!clip.buffer)return;const relTime=Math.max(0,time-clip.startTime);const sr=clip.buffer.sampleRate;const cutSample=Math.floor(relTime*sr);const originalData=clip.buffer.getChannelData(0);if(cutSample<=0||cutSample>=originalData.length){showToast("Vị trí cắt nằm ngoài dải âm thanh của clip.","warning");return;}const beforeSnap=captureTrackSnapshot(trackId);const ctx=getAudioContext();const b1=ctx.createBuffer(1,cutSample,sr);b1.copyToChannel(originalData.subarray(0,cutSample),0);const b2=ctx.createBuffer(1,originalData.length-cutSample,sr);b2.copyToChannel(originalData.subarray(cutSample),0);const clip1={id:'clip_'+Date.now()+'_p1',name:`${clip.name.replace(' (Part 1)','').replace(' (Part 2)','')} (Part 1)`,buffer:b1,startTime:clip.startTime};const clip2={id:'clip_'+Date.now()+'_p2',name:`${clip.name.replace(' (Part 1)','').replace(' (Part 2)','')} (Part 2)`,buffer:b2,startTime:clip.startTime+cutSample/sr};setTracks(prev=>prev.map(t=>{if(t.id===trackId){const remainingClips=clips.filter(c=>c.id!==targetClipId);const updatedClips=[...remainingClips,clip1,clip2];return{...t,clips:updatedClips,buffer:updatedClips[0]?.buffer||null,startTime:updatedClips[0]?.startTime||0,name:updatedClips[0]?.name||t.name};}return t;}));setTimeout(()=>{const afterSnap=captureTrackSnapshot(trackId);pushAction('SPLIT_CLIP',trackId,beforeSnap,afterSnap);},50);showToast(`Đã chia nhỏ clip tại ${formatTime(time)}.`,"info");};const handleSplitTrack=trackId=>{handleSplitTrackAtTime(trackId,null,currentTime);};handleSplitTrackRef.current=handleSplitTrack;// ── Glue (Merge) Clips on Selected Track ──
 const handleGlueTracks=()=>{const track=tracks.find(t=>t.id===selectedTrackId);if(!track){showToast('Vui lòng chọn một track để thực hiện gộp (glue).','warning');return;}const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default',buffer:track.buffer,startTime:track.startTime||0,name:track.name}]:[];if(clips.length<2){showToast('Cần ít nhất 2 clip trên track này để gộp (glue).','warning');return;}const beforeSnap=captureTrackSnapshot(track.id);const ctx=getAudioContext();const sr=clips[0].buffer.sampleRate;let minStart=Infinity;let maxEnd=-Infinity;clips.forEach(c=>{const start=c.startTime||0;const end=start+c.buffer.duration;minStart=Math.min(minStart,start);maxEnd=Math.max(maxEnd,end);});const newDur=maxEnd-minStart;const newBuffer=ctx.createBuffer(1,Math.ceil(newDur*sr),sr);const newData=newBuffer.getChannelData(0);clips.forEach(c=>{const data=c.buffer.getChannelData(0);const offset=Math.floor(((c.startTime||0)-minStart)*sr);for(let i=0;i<data.length;i++){if(offset+i<newData.length){newData[offset+i]+=data[i];}}});let maxPeak=0;for(let i=0;i<newData.length;i++){const abs=Math.abs(newData[i]);if(abs>maxPeak)maxPeak=abs;}if(maxPeak>1.0){for(let i=0;i<newData.length;i++)newData[i]/=maxPeak;}const mergedClip={id:'clip_merged_'+Date.now(),name:`${track.name.replace(' (Part 1)','').replace(' (Part 2)','')} (Glued)`,buffer:newBuffer,startTime:minStart};setTracks(prev=>prev.map(t=>{if(t.id===track.id){return{...t,clips:[mergedClip],buffer:newBuffer,startTime:minStart,name:mergedClip.name};}return t;}));setTimeout(()=>{const afterSnap=captureTrackSnapshot(track.id);pushAction('GLUE',track.id,beforeSnap,afterSnap);},50);showToast(`Đã gộp ${clips.length} clips thành công.`,'success');};// ── DAW Command Registration for AI (28_AI_PANEL.md §1 & §2) ──
 useEffect(()=>{if(typeof window.DAWCommandDispatcher==='undefined')return;const api={createTrack:args=>{const name=args.name||`AI_Track_${Date.now()}`;const type=args.type||'audio';const newId=addNewTrack();if(name&&name!==`AI_Track_${Date.now()}`){updateTrackName(newId,name);}return{success:true,trackId:newId,name};},deleteTrack:args=>{const tid=args.track_id||selectedTrackId;if(!tid)return{success:false,error:'No track_id provided'};deleteTrack(tid);return{success:true,trackId:tid};},addClip:args=>{const trackId=args.track_id||selectedTrackId;const barDur=60/parseInt(bpm||120)*4;let startTime;if(args.start_time!==undefined&&args.start_time!==null)startTime=args.start_time;else if(args.start_bar!==undefined&&args.start_bar!==null)startTime=args.start_bar*barDur;else startTime=currentTime;const track=tracks.find(t=>t.id===trackId);if(!track)return{success:false,error:'Track not found'};const ctx=getAudioContext();const sr=44100;let duration;if(args.duration_seconds!==undefined&&args.duration_seconds!==null)duration=args.duration_seconds;else if(args.length_bars!==undefined&&args.length_bars!==null)duration=args.length_bars*barDur;else duration=2;const buffer=ctx.createBuffer(1,Math.floor(sr*duration),sr);const data=buffer.getChannelData(0);for(let i=0;i<data.length;i++)data[i]=0;const clipId=nextClipId();setTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;const clips=t.clips&&t.clips.length>0?t.clips:t.buffer?[{id:'default_'+t.id,buffer:t.buffer,startTime:t.startTime||0,name:t.name}]:[];return{...t,clips:[...clips,{id:clipId,buffer,startTime,name:args.name||'AI Clip'}],buffer:clips.length>0?clips[0].buffer:buffer,startTime:clips.length>0?clips[0].startTime:startTime,name:clips.length>0?clips[0].name:args.name||t.name};}));return{success:true,clipId,trackId};},removeClip:args=>{const trackId=args.track_id||selectedTrackId;const clipId=args.clip_id;setTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;const updatedClips=(t.clips||[]).filter(c=>c.id!==clipId);return{...t,clips:updatedClips,buffer:updatedClips[0]?.buffer||null,startTime:updatedClips[0]?.startTime||0,name:updatedClips[0]?.name||t.name};}));return{success:true};},setTrackVolume:args=>{const trackId=args.track_id||selectedTrackId;const vol=args.volume_db??args.volume??0;updateTrackVolumeDb(trackId,parseFloat(vol));return{success:true,trackId,volumeDb:vol};},setTrackPan:args=>{const trackId=args.track_id||selectedTrackId;const pan=args.pan??0;updateTrackPan(trackId,parseInt(pan));return{success:true,trackId,pan};},toggleMute:args=>{const trackId=args.track_id||selectedTrackId;toggleTrackMute(trackId);const track=tracks.find(t=>t.id===trackId);return{success:true,trackId,muted:track?track.muted:null};},toggleSolo:args=>{const trackId=args.track_id||selectedTrackId;toggleTrackSoloEvaluate(trackId);const track=tracks.find(t=>t.id===trackId);return{success:true,trackId,solo:track?track.solo:null};},processAudioDsp:args=>{const trackId=args.track_id||selectedTrackId;const action=args.action;const params=args.params||{};const track=tracks.find(t=>t.id===trackId);if(!track||!track.buffer)return{success:false,error:'Track has no audio buffer'};if(action==='normalize'){const channelData=track.buffer.getChannelData(0);let maxVal=0;for(let i=0;i<channelData.length;i++)maxVal=Math.max(maxVal,Math.abs(channelData[i]));if(maxVal>0){const gain=1.0/maxVal;for(let i=0;i<channelData.length;i++)channelData[i]*=gain;}return{success:true,action:'normalize'};}else if(action==='invert_phase'){const channelData=track.buffer.getChannelData(0);for(let i=0;i<channelData.length;i++)channelData[i]*=-1;return{success:true,action:'invert_phase'};}else if(action==='gain'){const gainDb=params.gain_db??0;const scale=Math.pow(10,gainDb/20);const channelData=track.buffer.getChannelData(0);for(let i=0;i<channelData.length;i++)channelData[i]=Math.max(-1,Math.min(1,channelData[i]*scale));return{success:true,action:'gain',gainDb};}else if(action==='pitch_shift'){const semitones=params.semitones??0;const ratio=Math.pow(2,semitones/12);const applyResample=(data,r)=>{const newLen=Math.round(data.length*r);const out=new Float32Array(newLen);for(let i=0;i<newLen;i++){const srcIdx=i/r;const idx0=Math.floor(srcIdx);const idx1=Math.min(idx0+1,data.length-1);const frac=srcIdx-idx0;out[i]=data[idx0]*(1-frac)+data[idx1]*frac;}return out;};const channelData=track.buffer.getChannelData(0);const newData=applyResample(channelData,1/ratio);const ctx=getAudioContext();const newBuffer=ctx.createBuffer(1,newData.length,track.buffer.sampleRate);newBuffer.copyToChannel(newData,0);setTracks(prev=>prev.map(t=>t.id===trackId?{...t,buffer:newBuffer}:t));return{success:true,action:'pitch_shift',semitones};}return{success:false,error:`Unknown action: ${action}`};},renameTrack:args=>{const tid=args.track_id||selectedTrackId;const name=args.name;if(!tid)return{success:false,error:'No track_id provided'};if(!name)return{success:false,error:'No name provided'};updateTrackName(tid,name);return{success:true,trackId:tid,name};},setSelection:args=>{const barDur=60/parseInt(bpm||120)*4;let start,end;if(args.start_time!==undefined&&args.start_time!==null)start=args.start_time;else if(args.start_bar!==undefined&&args.start_bar!==null)start=args.start_bar*barDur;else start=currentTime;if(args.end_time!==undefined&&args.end_time!==null)end=args.end_time;else if(args.length_bars!==undefined&&args.length_bars!==null)end=start+args.length_bars*barDur;else if(args.end_bar!==undefined&&args.end_bar!==null)end=args.end_bar*barDur;else end=start+barDur;clearLocalSelection();setSelectionMode('global');setSelectionStart(start);setSelectionEnd(end);selectionRef.current={start,end};return{success:true,start:parseFloat(start.toFixed(3)),end:parseFloat(end.toFixed(3)),length:parseFloat((end-start).toFixed(3))};},cutAudio:args=>{const currentTracks=window.DAWCommandDispatcher?.currentTracks||tracks;const currentSelTrackId=window.DAWCommandDispatcher?.currentSelectedTrackId||selectedTrackId;const tid=args.track_id||currentSelTrackId;const track=currentTracks.find(t=>t.id===String(tid));if(!track)return{success:false,error:'Track not found'};if(!track.buffer)return{success:false,error:'Track has no audio buffer'};const barDur=60/parseInt(bpm||120)*4;const sel=selectionRef.current;let rawStart,rawEnd;if(args.start_time!==undefined&&args.start_time!==null)rawStart=args.start_time;else if(args.start_bar!==undefined&&args.start_bar!==null)rawStart=args.start_bar*barDur;else if(sel.start!==null)rawStart=sel.start;else rawStart=currentTime;if(args.end_time!==undefined&&args.end_time!==null)rawEnd=args.end_time;else if(args.end_bar!==undefined&&args.end_bar!==null)rawEnd=args.end_bar*barDur;else if(args.length_bars!==undefined&&args.length_bars!==null)rawEnd=rawStart+args.length_bars*barDur;else if(sel.end!==null&&sel.end>rawStart)rawEnd=sel.end;else return{success:false,error:'No end position provided. Provide end_time, end_bar, or length_bars.'};if(rawEnd<=rawStart)return{success:false,error:'End position must be after start position.'};const buffer=track.buffer;const ctx=getAudioContext();const snap=args.snap_silence!==false;const loopStart=snap?findZeroCrossing(buffer,rawStart):rawStart;const loopEnd=snap?findZeroCrossing(buffer,rawEnd):rawEnd;const sampleRate=buffer.sampleRate;const startSample=Math.max(0,Math.min(buffer.length-1,Math.floor(loopStart*sampleRate)));const endSample=Math.max(0,Math.min(buffer.length,Math.floor(loopEnd*sampleRate)));const sliceLength=endSample-startSample;if(sliceLength<=100)return{success:false,error:'Selection too short or invalid'};const numChannels=buffer.numberOfChannels||1;const slicedBuffer=ctx.createBuffer(numChannels,sliceLength,sampleRate);for(let c=0;c<numChannels;c++){const src=buffer.getChannelData(c);const dst=slicedBuffer.getChannelData(c);dst.set(src.subarray(startSample,endSample));}const newId='track_cut_'+Date.now();const colors=['#0f766e','#1d4ed8','#701a75','#a21caf','#b45309'];const color=colors[currentTracks.length%colors.length];const cutName=args.new_track_name||`Cut_${track.name}`;const newTrack={id:newId,name:cutName,buffer:slicedBuffer,startTime:0,volumeDb:0,pan:0,muted:false,solo:false,color,markers:[],clips:[{id:'clip_'+newId,buffer:slicedBuffer,startTime:0,name:cutName}],serverFileId:null};const idx=currentTracks.findIndex(t=>t.id===tid);const nextTracks=[...currentTracks];if(idx!==-1){nextTracks.splice(idx+1,0,newTrack);}else{nextTracks.push(newTrack);}if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.currentTracks=nextTracks;window.DAWCommandDispatcher.currentSelectedTrackId=newId;window.DAWCommandDispatcher.lastCutSourceTrackId=tid;window.DAWCommandDispatcher.lastCutNewTrackId=newId;}setTracks(nextTracks);setSelectedTrackId(newId);selectionRef.current={start:0,end:slicedBuffer.duration};clearLocalSelection();setSelectionMode('global');setSelectionStart(0);setSelectionEnd(slicedBuffer.duration);setTimeout(()=>lucide.createIcons(),200);return{success:true,trackId:newId,trackName:cutName,cutStart:parseFloat(loopStart.toFixed(3)),cutEnd:parseFloat(loopEnd.toFixed(3)),duration:parseFloat(slicedBuffer.duration.toFixed(3))};},scanTrack:args=>{const tid=args.track_id||selectedTrackId;const track=tracks.find(t=>t.id===tid);if(!track)return{success:false,error:'Track not found'};if(!track.buffer)return{success:false,error:'Track has no audio buffer. Load audio first.'};const buffer=track.buffer;const data=buffer.getChannelData(0);const sr=buffer.sampleRate;const channels=buffer.numberOfChannels;const duration=buffer.duration;const totalSamples=buffer.length;const windowSize=Math.min(sr*3,data.length);let detectedBPM=0;if(windowSize>sr){let maxCorr=0;for(let lag=Math.floor(sr*0.3);lag<=Math.floor(sr*2.0);lag++){let corr=0;const step=4;for(let i=0;i<windowSize&&i+lag<data.length;i+=step)corr+=data[i]*data[i+lag];corr/=windowSize/step;if(corr>maxCorr){maxCorr=corr;detectedBPM=60/(lag/sr);}}}detectedBPM=Math.round(Math.min(300,Math.max(30,detectedBPM)));if(args.set_tempo!==false&&detectedBPM>0){setBpm(String(detectedBPM));}const bitDepth=16;const bitrate=Math.round(sr*channels*bitDepth/1000);return{success:true,trackId:tid,trackName:track.name,bpm:detectedBPM,sampleRate:sr,channels,duration:parseFloat(duration.toFixed(3)),totalSamples,bitDepth,bitrateKbps:bitrate,hasAudio:true};},setBpm:args=>{const bpmVal=args.bpm||args.tempo||120;setBpm(String(bpmVal));return{success:true,bpm:bpmVal};},setPlayhead:args=>{const barDur=60/parseInt(bpm||120)*4;let time;if(args.time!==undefined&&args.time!==null)time=args.time;else if(args.bar!==undefined&&args.bar!==null)time=args.bar*barDur;else time=0;handlePlayheadSet(time);return{success:true,time:parseFloat(time.toFixed(3))};},exportAudio:async args=>{const currentTracks=window.DAWCommandDispatcher?.currentTracks||tracks;const currentSelTrackId=window.DAWCommandDispatcher?.currentSelectedTrackId||selectedTrackId;let tid=args.track_id;if(tid&&window.DAWCommandDispatcher?.lastCutSourceTrackId&&(String(tid)===String(window.DAWCommandDispatcher.lastCutSourceTrackId)||'track_'+tid===String(window.DAWCommandDispatcher.lastCutSourceTrackId))){tid=window.DAWCommandDispatcher.lastCutNewTrackId;}if(!tid)tid=currentSelTrackId;const track=tid&&currentTracks.find(t=>t.id===String(tid)||t.id==='track_'+tid);if(!track)return{success:false,error:'No track found'};const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default_'+track.id,buffer:track.buffer,startTime:track.startTime||0,name:track.name}]:[];if(clips.length===0&&(!track.midiItems||track.midiItems.length===0))return{success:false,error:'Track has no audio clips'};const beatsPerSec=parseFloat(bpm||120)/60;const totalDuration=Math.max(clips.length>0?Math.max(...clips.map(c=>(c.startTime||0)+(c.buffer?c.buffer.duration/(c.speed||1.0):0))):0,...(track.midiItems||[]).map(m=>(m.startTime||0)+(m.duration||4)),...(track.sections||[]).map(s=>(s.start||0)+(s.duration||4)));const barDur=60/parseInt(bpm||120)*4;const sel=selectionRef.current;let rawStart,rawEnd;if(args.start_time!==undefined)rawStart=args.start_time;else if(args.start_bar!==undefined)rawStart=args.start_bar*barDur;else if(sel.start!==null)rawStart=sel.start;else rawStart=0;if(args.end_time!==undefined)rawEnd=args.end_time;else if(args.length_bars!==undefined)rawEnd=(rawStart||0)+args.length_bars*barDur;else if(args.end_bar!==undefined)rawEnd=args.end_bar*barDur;else if(sel.end!==null&&sel.end>rawStart)rawEnd=sel.end;else rawEnd=totalDuration;if(rawEnd<=rawStart)return{success:false,error:'Export range is empty or invalid.'};const ctx=getAudioContext();const sr=parseInt(args.sample_rate||'44100');const firstBuffer=clips.find(c=>c.buffer)?.buffer;const numCh=args.channels==='mono'?1:firstBuffer?firstBuffer.numberOfChannels:2;const bd=parseInt(args.bit_depth||'16');const fmt=args.format||'wav';const renderLength=rawEnd-rawStart;const offlineCtx=new OfflineAudioContext(numCh,Math.ceil(sr*renderLength),sr);clips.forEach(clip=>{if(!clip.buffer)return;const clipStart=clip.startTime||0;const clipDuration=clip.buffer.duration/(clip.speed||1.0);const clipEnd=clipStart+clipDuration;if(clipEnd<=rawStart||clipStart>=rawEnd)return;const source=offlineCtx.createBufferSource();source.buffer=clip.buffer;source.playbackRate.value=clip.speed||1.0;source.connect(offlineCtx.destination);if(rawStart<clipStart){const delay=clipStart-rawStart;const playDur=Math.min(clipDuration,rawEnd-clipStart);source.start(delay,0,playDur*(clip.speed||1.0));}else{const offsetInClip=rawStart-clipStart;const playDur=Math.min(clipEnd-rawStart,renderLength);source.start(0,offsetInClip*(clip.speed||1.0),playDur*(clip.speed||1.0));}});const renderedBuffer=await offlineCtx.startRendering();const len=renderedBuffer.length;const bps=bd/8;const hdrSz=44;const fileBuf=new ArrayBuffer(hdrSz+len*bps*numCh);const vw=new DataView(fileBuf);const ws=(off,s)=>{for(let i=0;i<s.length;i++)vw.setUint8(off+i,s.charCodeAt(i));};ws(0,'RIFF');vw.setUint32(4,fileBuf.byteLength-8,true);ws(8,'WAVE');ws(12,'fmt ');vw.setUint32(16,16,true);vw.setUint16(20,1,true);vw.setUint16(22,numCh,true);vw.setUint32(24,sr,true);vw.setUint32(28,sr*bps*numCh,true);vw.setUint16(32,bps*numCh,true);vw.setUint16(34,bd,true);ws(36,'data');vw.setUint32(40,len*bps*numCh,true);let ofs=44;for(let i=0;i<len;i++){for(let ch=0;ch<numCh;ch++){const smp=Math.max(-1,Math.min(1,renderedBuffer.getChannelData(ch)[i]));if(bd===8)vw.setUint8(ofs,Math.floor((smp+1)*127.5));else if(bd===16)vw.setInt16(ofs,Math.floor(smp<0?smp*0x8000:smp*0x7FFF),true);else{const v24=Math.floor(smp<0?smp*0x800000:smp*0x7FFFFF);vw.setUint8(ofs,v24&0xFF);vw.setUint8(ofs+1,v24>>8&0xFF);vw.setUint8(ofs+2,v24>>16&0xFF);}ofs+=bps;}}const blob=new Blob([fileBuf],{type:'audio/wav'});const localUrl=URL.createObjectURL(blob);const targetFilename=`export_${Date.now()}.${fmt}`;const triggerDownload=(downloadUrl,finalFilename)=>{if(window.DAWCommandDispatcher?.isExecutingAI){showToast(`Xuất nhạc thành công (${fmt.toUpperCase()})!`,"success","Tải về",()=>{const a=document.createElement('a');a.href=downloadUrl;a.download=finalFilename;a.click();if(downloadUrl.startsWith('blob:')){URL.revokeObjectURL(downloadUrl);}});}else{const a=document.createElement('a');a.href=downloadUrl;a.download=finalFilename;a.click();showToast("Xuất bản âm thanh hoàn tất!","success");if(downloadUrl.startsWith('blob:')){URL.revokeObjectURL(downloadUrl);}}};if((fmt==='mp3'||fmt==='ogg')&&serverStatus==='connected'){try{const file=new File([blob],`export_ai.wav`,{type:'audio/wav'});const formData=new FormData();formData.append('file',file);const uploadResp=await fetch(`${API_AUDIO}/upload`,{method:'POST',body:formData});if(!uploadResp.ok)throw new Error("Upload failed");const uploadData=await uploadResp.json();const uploadId=uploadData.file_id;const exportResp=await fetch(`${API_AUDIO}/export`,{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify({file_id:uploadId,format:fmt,sample_rate:sr,bit_depth:bd})});if(!exportResp.ok)throw new Error("Export failed");const exportData=await exportResp.json();const result=await pollTaskResult(exportData.task_id,20);if(result.success){const downloadUrl=`${API_AUDIO}/download/${result.output_file_id}`;triggerDownload(downloadUrl,targetFilename);}else{throw new Error(result.error||'Server encoding failed');}}catch(transcodeErr){showToast(`Lỗi chuyển đổi: ${transcodeErr.message}. Tải về dạng WAV thay thế.`,"warning");triggerDownload(localUrl,`export_${Date.now()}.wav`);}}else{const finalFilename=fmt==='wav'?`export_${Date.now()}.wav`:`export_${Date.now()}.wav`;if(fmt!=='wav'){showToast("Đang ngoại tuyến. Tải về định dạng WAV thay thế.","warning");}triggerDownload(localUrl,finalFilename);}return{success:true,trackId:tid,range:parseFloat((rawEnd-rawStart).toFixed(3))+'s',format:fmt,channels:numCh===1?'mono':'stereo'};},selectItem:args=>{if(args.select_all){setSelectedTrackId(null);clearLocalSelection();setSelectionMode('global');setSelectionStart(0);const maxDur=tracks.reduce((max,t)=>{const dur=t.buffer?t.buffer.duration:0;const clips=t.clips||[];const clipMax=clips.reduce((m,c)=>Math.max(m,(c.startTime||0)+(c.buffer?c.buffer.duration:0)),0);return Math.max(max,dur,clipMax);},0);setSelectionEnd(Math.max(maxDur,currentTime+10));return{success:true,selection:'all',duration:parseFloat(Math.max(maxDur,currentTime+10).toFixed(3))};}const tid=args.track_id||selectedTrackId;const track=tracks.find(t=>t.id===tid);if(!track)return{success:false,error:`Track ${tid} not found`};const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default_'+track.id,name:track.name,buffer:track.buffer,startTime:track.startTime||0}]:[];if(args.item_name){const match=clips.find(c=>c.name&&c.name.toLowerCase().includes(args.item_name.toLowerCase()));if(!match)return{success:false,error:`No clip matching "${args.item_name}" on track ${track.name}`};setSelectedTrackId(tid);clearLocalSelection();setSelectionMode('global');const start=match.startTime||0;const end=start+(match.buffer?match.buffer.duration:2);setSelectionStart(start);setSelectionEnd(end);return{success:true,trackId:tid,trackName:track.name,clipId:match.id,clipName:match.name,start:parseFloat(start.toFixed(3)),end:parseFloat(end.toFixed(3))};}setSelectedTrackId(tid);clearLocalSelection();setSelectionMode('global');const trackEnd=track.buffer?track.buffer.duration:clips.length>0?Math.max(...clips.map(c=>(c.startTime||0)+(c.buffer?c.buffer.duration:0))):4;setSelectionStart(0);setSelectionEnd(trackEnd);return{success:true,trackId:tid,trackName:track.name,duration:parseFloat(trackEnd.toFixed(3))};},addMarker:args=>{const trackId=args.track_id||selectedTrackId;const time=args.time??currentTime;const track=tracks.find(t=>t.id===trackId);if(!track)return{success:false,error:'Track not found'};setTracks(prev=>prev.map(t=>{if(t.id!==trackId)return t;return{...t,markers:[...(t.markers||[]),{id:'ai_marker_'+Date.now(),time,label:args.label||'AI Marker'}]};}));return{success:true,trackId,time};},fadeIn:args=>{const currentTracks=window.DAWCommandDispatcher?.currentTracks||tracks;const currentSelTrackId=window.DAWCommandDispatcher?.currentSelectedTrackId||selectedTrackId;let trackIdRaw=args.track_id;if(trackIdRaw&&window.DAWCommandDispatcher?.lastCutSourceTrackId&&(String(trackIdRaw)===String(window.DAWCommandDispatcher.lastCutSourceTrackId)||'track_'+trackIdRaw===String(window.DAWCommandDispatcher.lastCutSourceTrackId))){trackIdRaw=window.DAWCommandDispatcher.lastCutNewTrackId;}if(!trackIdRaw)trackIdRaw=currentSelTrackId;const track=currentTracks.find(t=>t.id===String(trackIdRaw)||t.id==='track_'+trackIdRaw);if(!track)return{success:false,error:`Track ${trackIdRaw} not found`};const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default_'+track.id,buffer:track.buffer,startTime:track.startTime||0,name:track.name}]:[];if(clips.length===0)return{success:false,error:'No clips on track'};let clip=null;if(args.clip_id){clip=clips.find(c=>c.id===args.clip_id);}else if(args.clip_index!==undefined){const idx=parseInt(args.clip_index);const realIdx=idx>0?idx-1:0;clip=clips[realIdx]||clips[0];}else{clip=clips[0];}if(!clip||!clip.buffer)return{success:false,error:'Clip has no audio buffer'};const duration=parseFloat(args.duration_seconds||3);const buffer=clip.buffer;const sr=buffer.sampleRate;const numChannels=buffer.numberOfChannels;const length=buffer.length;const ctx=getAudioContext();const newBuffer=ctx.createBuffer(numChannels,length,sr);for(let c=0;c<numChannels;c++){newBuffer.getChannelData(c).set(buffer.getChannelData(c));}const fadeSamples=Math.min(length,Math.floor(duration*sr));for(let c=0;c<numChannels;c++){const data=newBuffer.getChannelData(c);for(let i=0;i<fadeSamples;i++){const factor=(1-Math.cos(Math.PI*i/fadeSamples))/2;data[i]*=factor;}}const beforeSnap=captureTrackSnapshot(track.id);const nextTracks=currentTracks.map(t=>{if(t.id!==track.id)return t;const existingClips=t.clips&&t.clips.length>0?t.clips:t.buffer?[{id:'default_'+t.id,buffer:t.buffer,startTime:t.startTime||0,name:t.name}]:[];const updatedClips=existingClips.map(c=>{if(c.id===clip.id||clip.id.startsWith('default_')&&c.id==='default'){return{...c,buffer:newBuffer};}return c;});const mainBuffer=updatedClips[0]?.buffer||t.buffer;return{...t,clips:updatedClips,buffer:mainBuffer};});if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.currentTracks=nextTracks;}setTracks(nextTracks);setTimeout(()=>{const afterSnap=captureTrackSnapshot(track.id);pushAction('AI_FADE_IN',track.id,beforeSnap,afterSnap);},50);return{success:true,trackId:track.id,clipId:clip.id,duration_seconds:duration};},fadeOut:args=>{const currentTracks=window.DAWCommandDispatcher?.currentTracks||tracks;const currentSelTrackId=window.DAWCommandDispatcher?.currentSelectedTrackId||selectedTrackId;let trackIdRaw=args.track_id;if(trackIdRaw&&window.DAWCommandDispatcher?.lastCutSourceTrackId&&(String(trackIdRaw)===String(window.DAWCommandDispatcher.lastCutSourceTrackId)||'track_'+trackIdRaw===String(window.DAWCommandDispatcher.lastCutSourceTrackId))){trackIdRaw=window.DAWCommandDispatcher.lastCutNewTrackId;}if(!trackIdRaw)trackIdRaw=currentSelTrackId;const track=currentTracks.find(t=>t.id===String(trackIdRaw)||t.id==='track_'+trackIdRaw);if(!track)return{success:false,error:`Track ${trackIdRaw} not found`};const clips=track.clips&&track.clips.length>0?track.clips:track.buffer?[{id:'default_'+track.id,buffer:track.buffer,startTime:track.startTime||0,name:track.name}]:[];if(clips.length===0)return{success:false,error:'No clips on track'};let clip=null;if(args.clip_id){clip=clips.find(c=>c.id===args.clip_id);}else if(args.clip_index!==undefined){const idx=parseInt(args.clip_index);const realIdx=idx>0?idx-1:0;clip=clips[realIdx]||clips[0];}else{clip=clips[0];}if(!clip||!clip.buffer)return{success:false,error:'Clip has no audio buffer'};const duration=parseFloat(args.duration_seconds||3);const buffer=clip.buffer;const sr=buffer.sampleRate;const numChannels=buffer.numberOfChannels;const length=buffer.length;const ctx=getAudioContext();const newBuffer=ctx.createBuffer(numChannels,length,sr);for(let c=0;c<numChannels;c++){newBuffer.getChannelData(c).set(buffer.getChannelData(c));}const fadeSamples=Math.min(length,Math.floor(duration*sr));for(let c=0;c<numChannels;c++){const data=newBuffer.getChannelData(c);for(let i=0;i<fadeSamples;i++){const idx=length-fadeSamples+i;const factor=(1+Math.cos(Math.PI*i/fadeSamples))/2;data[idx]*=factor;}}const beforeSnap=captureTrackSnapshot(track.id);const nextTracks=currentTracks.map(t=>{if(t.id!==track.id)return t;const existingClips=t.clips&&t.clips.length>0?t.clips:t.buffer?[{id:'default_'+t.id,buffer:t.buffer,startTime:t.startTime||0,name:t.name}]:[];const updatedClips=existingClips.map(c=>{if(c.id===clip.id||clip.id.startsWith('default_')&&c.id==='default'){return{...c,buffer:newBuffer};}return c;});const mainBuffer=updatedClips[0]?.buffer||t.buffer;return{...t,clips:updatedClips,buffer:mainBuffer};});if(window.DAWCommandDispatcher){window.DAWCommandDispatcher.currentTracks=nextTracks;}setTracks(nextTracks);setTimeout(()=>{const afterSnap=captureTrackSnapshot(track.id);pushAction('AI_FADE_OUT',track.id,beforeSnap,afterSnap);},50);return{success:true,trackId:track.id,clipId:clip.id,duration_seconds:duration};},generateMultitrackMidi:args=>{const{composition_title,bpm:aiBpm,total_bars,tracks:aiTracks}=args;if(aiBpm){setBpm(aiBpm.toString());}const bpmVal=aiBpm||parseInt(bpm)||120;const secondsPerBeat=60.0/bpmVal;const secondsPerBar=secondsPerBeat*4;const durationSec=total_bars*secondsPerBar;updateActiveTracks(prev=>{let updatedTracks=[...prev];aiTracks.forEach(aiTrack=>{let targetTrack=updatedTracks.find(t=>t.name.toLowerCase()===aiTrack.track_name.toLowerCase());if(!targetTrack){const newId=(updatedTracks.length+1).toString();const colors=['#0f766e','#1d4ed8','#701a75','#a21caf','#b45309'];const selectColor=colors[updatedTracks.length%colors.length];targetTrack={id:newId,name:aiTrack.track_name,type:'MIDI',volumeDb:0,pan:0,muted:false,solo:false,color:selectColor,markers:[],serverFileId:null,clips:[],sections:[],midiItems:[],isArmed:false,monitoringEnabled:true,inputSource:{deviceType:'NONE',deviceId:''}};updatedTracks.push(targetTrack);}// Place MIDI item at current playhead position