Update server.js

server.js

@@ -1,3 +1,7 @@
+// ═══════════════════════════════════════════════════════════
+// FILE: server.js - Complete Backend with Smart Instruments
+// ═══════════════════════════════════════════════════════════
+
 const express = require('express');
 const multer = require('multer');
 const cors = require('cors');
@@ -29,95 +33,256 @@ const upload = multer({
   limits: { fileSize: 50 * 1024 * 1024 }
 });
 
-// 🎵 PERFECTLY TUNED EFFECTS - All Working
+// 🎹 ═══════════════════════════════════════════════════════════
+// INSTRUMENT LIBRARY - Categorized by Mood
+// ═══════════════════════════════════════════════════════════
+
+const INSTRUMENTS = {
+  // 💔 SAD INSTRUMENTS
+  sad_piano: {
+    name: "Sad Piano",
+    mood: "sad",
+    command: "aevalsrc='0.13*sin(2*PI*(220+5*sin(0.08*t))*t)*exp(-0.15*mod(t,4))':d=12,aecho=0.7:0.85:600:0.35,lowpass=f=3000"
+  },
+  melancholic_violin: {
+    name: "Melancholic Violin",
+    mood: "sad",
+    command: "aevalsrc='0.12*sin(2*PI*330*t)*sin(2*PI*0.3*t)*exp(-0.1*mod(t,5))':d=12,vibrato=f=0.15:d=0.5,aecho=0.6:0.8:500:0.3"
+  },
+  lonely_cello: {
+    name: "Lonely Cello",
+    mood: "sad",
+    command: "aevalsrc='0.14*sin(2*PI*165*t)*sin(2*PI*0.2*t)':d=12,chorus=0.4:0.7:40:0.3:0.2:2,lowpass=f=2500"
+  },
+  tearful_flute: {
+    name: "Tearful Flute",
+    mood: "sad",
+    command: "aevalsrc='0.11*sin(2*PI*440*t)*sin(2*PI*1.5*t)*exp(-0.2*mod(t,3))':d=12,aecho=0.5:0.75:400:0.3,vibrato=f=0.2:d=0.4"
+  },
+
+  // ❤️ ROMANTIC INSTRUMENTS
+  romantic_piano: {
+    name: "Romantic Piano",
+    mood: "romantic",
+    command: "aevalsrc='0.12*(sin(2*PI*330*t)+sin(2*PI*415*t))*exp(-0.12*mod(t,3.5))':d=12,aecho=0.6:0.8:450:0.35,chorus=0.3:0.6:35:0.25:0.15:2"
+  },
+  love_strings: {
+    name: "Love Strings",
+    mood: "romantic",
+    command: "aevalsrc='0.13*(sin(2*PI*440*t)+sin(2*PI*554*t))*sin(2*PI*0.4*t)':d=12,vibrato=f=0.18:d=0.45,aecho=0.5:0.7:350:0.3"
+  },
+  gentle_harp: {
+    name: "Gentle Harp",
+    mood: "romantic",
+    command: "aevalsrc='0.11*sin(2*PI*(660+8*sin(0.15*t))*t)*exp(-0.25*mod(t,2.5))':d=12,chorus=0.4:0.7:45:0.3:0.2:2,aecho=0.6:0.8:300:0.35"
+  },
+  sweet_bells: {
+    name: "Sweet Bells",
+    mood: "romantic",
+    command: "aevalsrc='0.09*sin(2*PI*880*t)*exp(-0.4*mod(t,2))':d=12,aecho=0.5:0.75:250:0.4,vibrato=f=0.12:d=0.3"
+  },
+
+  // 💔❤️ SAD ROMANTIC MIX
+  bittersweet_piano: {
+    name: "Bittersweet Piano",
+    mood: "sad_romantic",
+    command: "aevalsrc='0.13*(sin(2*PI*247*t)+sin(2*PI*330*t))*exp(-0.15*mod(t,4))*(1+0.3*sin(0.5*t))':d=12,aecho=0.7:0.85:500:0.35,vibrato=f=0.1:d=0.4"
+  },
+  nostalgic_violin: {
+    name: "Nostalgic Violin",
+    mood: "sad_romantic",
+    command: "aevalsrc='0.12*sin(2*PI*370*t)*sin(2*PI*0.35*t)*(1+0.2*sin(0.3*t))':d=12,chorus=0.5:0.75:40:0.3:0.2:2,aecho=0.6:0.8:450:0.3"
+  },
+  heartbreak_strings: {
+    name: "Heartbreak Strings",
+    mood: "sad_romantic",
+    command: "aevalsrc='0.13*(sin(2*PI*220*t)+sin(2*PI*330*t))*exp(-0.1*mod(t,5))':d=12,vibrato=f=0.15:d=0.5,lowpass=f=3500"
+  },
+
+  // 🌙 AMBIENT/DREAMY INSTRUMENTS
+  dreamy_pad: {
+    name: "Dreamy Pad",
+    mood: "ambient",
+    command: "aevalsrc='0.11*(sin(2*PI*165*t)+sin(2*PI*220*t)+sin(2*PI*330*t))':d=12,aphaser=in_gain=0.4:out_gain=0.7:delay=3:decay=0.4:speed=0.25,aecho=0.5:0.7:400:0.3"
+  },
+  ethereal_synth: {
+    name: "Ethereal Synth",
+    mood: "ambient",
+    command: "aevalsrc='0.1*(sin(2*PI*220*t)+sin(2*PI*277*t))*sin(2*PI*0.5*t)':d=12,chorus=0.6:0.85:50:0.4:0.25:2,aecho=0.6:0.8:500:0.3"
+  },
+  celestial_bells: {
+    name: "Celestial Bells",
+    mood: "ambient",
+    command: "aevalsrc='0.09*(sin(2*PI*880*t)+sin(2*PI*1108*t))*exp(-0.3*t)':d=12,aecho=0.7:0.9:600:0.4,aphaser=in_gain=0.3:out_gain=0.6:delay=2:decay=0.3:speed=0.2"
+  },
+
+  // 🎸 CHILL/LOFI INSTRUMENTS
+  lofi_guitar: {
+    name: "LoFi Guitar",
+    mood: "chill",
+    command: "aevalsrc='0.12*sin(2*PI*196*t)*exp(-0.3*mod(t,3))*(1+0.15*random(0))':d=12,chorus=0.5:0.7:40:0.25:0.15:2,lowpass=f=4000"
+  },
+  jazzy_piano: {
+    name: "Jazzy Piano",
+    mood: "chill",
+    command: "aevalsrc='0.11*(sin(2*PI*262*t)+sin(2*PI*330*t))*exp(-0.2*mod(t,2.5))':d=12,vibrato=f=0.18:d=0.4,aecho=0.4:0.6:300:0.25"
+  },
+  smooth_sax: {
+    name: "Smooth Saxophone",
+    mood: "chill",
+    command: "aevalsrc='0.12*sin(2*PI*294*t)*sin(2*PI*2*t)':d=12,vibrato=f=0.25:d=0.5,chorus=0.4:0.7:45:0.3:0.2:2"
+  },
+
+  // ⚡ UPBEAT/ENERGETIC INSTRUMENTS
+  bright_synth: {
+    name: "Bright Synth",
+    mood: "upbeat",
+    command: "aevalsrc='0.11*(sin(2*PI*440*t)+sin(2*PI*554*t)+sin(2*PI*659*t))':d=12,chorus=0.6:0.8:50:0.35:0.25:2,highpass=f=200"
+  },
+  sparkle_bells: {
+    name: "Sparkle Bells",
+    mood: "upbeat",
+    command: "aevalsrc='0.1*(sin(2*PI*1320*t)+sin(2*PI*1760*t))*exp(-0.5*mod(t,1.5))':d=12,aecho=0.4:0.6:150:0.3,highpass=f=500"
+  },
+  happy_piano: {
+    name: "Happy Piano",
+    mood: "upbeat",
+    command: "aevalsrc='0.11*(sin(2*PI*523*t)+sin(2*PI*659*t))*exp(-0.25*mod(t,2))':d=12,chorus=0.5:0.7:40:0.3:0.2:2"
+  }
+};
+
+// 🎯 ═══════════════════════════════════════════════════════════
+// SMART EFFECT CONFIGURATIONS - Each effect has mood-matched instruments
+// ═══════════════════════════════════════════════════════════
+
 const EFFECTS = {
   lofi: {
     name: "LoFi Hip Hop",
-    description: "Vintage warmth, breathing bass, vinyl crackle feel",
-    command: `-af "asetrate=44100*0.90,aresample=44100,bass=g=5:f=85:width_type=h:width=100,treble=g=-3:f=8000,equalizer=f=200:t=q:width=1.5:g=-2,equalizer=f=1000:t=q:width=2:g=2,acompressor=threshold=-20dB:ratio=3:attack=10:release=120:makeup=3,vibrato=f=0.2:d=0.4,highpass=f=70,lowpass=f=4500,volume=1.3" -ar 44100 -b:a 192k`
+    description: "Vintage warmth with jazzy chill vibes",
+    baseCommand: `-af "asetrate=44100*0.90,aresample=44100,bass=g=5:f=85:width_type=h:width=100,treble=g=-3:f=8000,equalizer=f=200:t=q:width=1.5:g=-2,equalizer=f=1000:t=q:width=2:g=2,acompressor=threshold=-20dB:ratio=3:attack=10:release=120:makeup=3,vibrato=f=0.2:d=0.4,highpass=f=70,lowpass=f=4500,volume=1.3"`,
+    instrumentVolume: 0.14,
+    // LoFi uses chill + some sad romantic vibes
+    instrumentMoods: ["chill", "sad_romantic", "ambient"]
   },
   
   slowed_reverb: {
     name: "Slowed + Reverb",
-    description: "Perfect slow tempo, cathedral reverb, dreamy space",
-    // ✅ BALANCED: 0.90 tempo + 0.95 pitch = Real slowed feel, not too slow
-    command: `-af "atempo=0.90,asetrate=44100*0.95,aresample=44100,bass=g=4:f=80:width_type=h:width=120,aecho=0.8:0.88:250:0.5,aecho=0.7:0.78:400:0.4,aecho=0.6:0.68:600:0.3,equalizer=f=100:t=q:width=2:g=3.5,equalizer=f=4000:t=q:width=4:g=-4,acompressor=threshold=-20dB:ratio=2:attack=15:release=200:makeup=2,highpass=f=50,lowpass=f=7000,volume=1.4" -ar 44100 -b:a 192k`
+    description: "Dreamy slow with sad romantic atmosphere",
+    baseCommand: `-af "atempo=0.90,asetrate=44100*0.95,aresample=44100,bass=g=4:f=80:width_type=h:width=120,aecho=0.8:0.88:250:0.5,aecho=0.7:0.78:400:0.4,aecho=0.6:0.68:600:0.3,equalizer=f=100:t=q:width=2:g=3.5,equalizer=f=4000:t=q:width=4:g=-4,acompressor=threshold=-20dB:ratio=2:attack=15:release=200:makeup=2,highpass=f=50,lowpass=f=7000,volume=1.4"`,
+    instrumentVolume: 0.13,
+    // Slowed+Reverb is emotional - sad, romantic, sad_romantic mix
+    instrumentMoods: ["sad", "romantic", "sad_romantic", "ambient"]
   },
   
   nightcore: {
     name: "Nightcore",
-    description: "High energy, bright sparkle, anime vocals",
-    command: `-af "atempo=1.30,asetrate=44100*1.18,aresample=44100,treble=g=6:f=5000:width_type=h:width=3000,bass=g=-3:f=100,equalizer=f=2000:t=q:width=2:g=2.5,equalizer=f=6000:t=q:width=3:g=4,equalizer=f=10000:t=q:width=4:g=5,acompressor=threshold=-18dB:ratio=3:attack=3:release=30:makeup=4,highpass=f=120,volume=1.4" -ar 44100 -b:a 192k`
+    description: "High energy with bright sparkling sounds",
+    baseCommand: `-af "atempo=1.30,asetrate=44100*1.18,aresample=44100,treble=g=6:f=5000:width_type=h:width=3000,bass=g=-3:f=100,equalizer=f=2000:t=q:width=2:g=2.5,equalizer=f=6000:t=q:width=3:g=4,equalizer=f=10000:t=q:width=4:g=5,acompressor=threshold=-18dB:ratio=3:attack=3:release=30:makeup=4,highpass=f=120,volume=1.4"`,
+    instrumentVolume: 0.11,
+    // Nightcore is upbeat and energetic
+    instrumentMoods: ["upbeat", "romantic"]
   },
   
   vaporwave: {
     name: "Vaporwave",
-    description: "Retro aesthetic, dreamy pitch, nostalgic vibe",
-    command: `-af "asetrate=44100*0.82,aresample=44100,equalizer=f=300:t=q:width=2:g=4,equalizer=f=1500:t=q:width=3:g=-2,equalizer=f=6000:t=q:width=4:g=-4,aphaser=in_gain=0.5:out_gain=0.75:delay=4:decay=0.5:speed=0.2,chorus=0.6:0.85:55:0.4:0.25:2,vibrato=f=0.12:d=0.5,aecho=0.5:0.65:180:0.35,acompressor=threshold=-20dB:ratio=2.5:attack=12:release=150:makeup=2,highpass=f=70,lowpass=f=5500,volume=1.2" -ar 44100 -b:a 192k`
+    description: "Retro nostalgic with dreamy sad vibes",
+    baseCommand: `-af "asetrate=44100*0.82,aresample=44100,equalizer=f=300:t=q:width=2:g=4,equalizer=f=1500:t=q:width=3:g=-2,equalizer=f=6000:t=q:width=4:g=-4,aphaser=in_gain=0.5:out_gain=0.75:delay=4:decay=0.5:speed=0.2,chorus=0.6:0.85:55:0.4:0.25:2,vibrato=f=0.12:d=0.5,aecho=0.5:0.65:180:0.35,acompressor=threshold=-20dB:ratio=2.5:attack=12:release=150:makeup=2,highpass=f=70,lowpass=f=5500,volume=1.2"`,
+    instrumentVolume: 0.13,
+    // Vaporwave is nostalgic - sad_romantic + ambient
+    instrumentMoods: ["sad_romantic", "ambient", "sad"]
   },
   
   "8d_audio": {
     name: "8D Audio",
-    description: "360° rotation, immersive headphone experience",
-    command: `-af "apulsator=hz=0.08:mode=sine:width=0.9,extrastereo=m=3:c=1,aecho=0.7:0.85:100:0.35,haas=level_in=1:level_out=1.1:side_gain=0.9:middle_source=mid,bass=g=3:f=85,acompressor=threshold=-18dB:ratio=2:attack=10:release=100:makeup=2,highpass=f=60,volume=1.2" -ar 44100 -b:a 192k`
+    description: "Immersive 360° with ambient dreamy layers",
+    baseCommand: `-af "apulsator=hz=0.08:mode=sine:width=0.9,extrastereo=m=3:c=1,aecho=0.7:0.85:100:0.35,haas=level_in=1:level_out=1.1:side_gain=0.9:middle_source=mid,bass=g=3:f=85,acompressor=threshold=-18dB:ratio=2:attack=10:release=100:makeup=2,highpass=f=60,volume=1.2"`,
+    instrumentVolume: 0.12,
+    // 8D is immersive - ambient + romantic
+    instrumentMoods: ["ambient", "romantic", "sad_romantic"]
   },
   
   bass_boosted: {
     name: "Bass Boosted",
-    description: "Dynamic waves: slow → mute → build → HIGH → repeat",
-    command: `-af "bass=g=18:f=55:width_type=o:width=1.5,bass=g=14:f=95:width_type=h:width=90,equalizer=f=35:t=q:width=1.2:g=12,equalizer=f=75:t=q:width=1.5:g=10,equalizer=f=140:t=q:width=2:g=8,equalizer=f=500:t=q:width=2:g=-3,equalizer=f=4000:t=q:width=4:g=-6,volume='mod(t,31):if(lt(MOD,15),0.4,if(lt(MOD,18),0.05,if(lt(MOD,26),0.5+0.0625*(MOD-18),1.5)))':eval=frame,acompressor=threshold=-22dB:ratio=8:attack=3:release=40:makeup=8,tremolo=f=0.15:d=0.3,highpass=f=28,alimiter=limit=0.95:attack=5:release=50" -ar 44100 -b:a 192k`
+    description: "Heavy bass with deep atmospheric tones",
+    baseCommand: `-af "bass=g=18:f=55:width_type=o:width=1.5,bass=g=14:f=95:width_type=h:width=90,equalizer=f=35:t=q:width=1.2:g=12,equalizer=f=75:t=q:width=1.5:g=10,equalizer=f=140:t=q:width=2:g=8,equalizer=f=500:t=q:width=2:g=-3,equalizer=f=4000:t=q:width=4:g=-6,volume='mod(t,31):if(lt(MOD,15),0.4,if(lt(MOD,18),0.05,if(lt(MOD,26),0.5+0.0625*(MOD-18),1.5)))':eval=frame,acompressor=threshold=-22dB:ratio=8:attack=3:release=40:makeup=8,tremolo=f=0.15:d=0.3,highpass=f=28,alimiter=limit=0.95:attack=5:release=50"`,
+    instrumentVolume: 0.09,
+    // Bass boosted - deep ambient + chill
+    instrumentMoods: ["ambient", "chill"]
   },
   
   ambient: {
     name: "Ambient Chill",
-    description: "Ethereal space, long reverb tails, meditation",
-    command: `-af "asetrate=44100*0.94,aresample=44100,aecho=0.6:0.8:200:0.4,aecho=0.5:0.7:400:0.3,chorus=0.6:0.85:50:0.4:0.25:2,aphaser=in_gain=0.5:out_gain=0.8:delay=3:decay=0.4:speed=0.2,equalizer=f=1500:t=q:width=3:g=-2,equalizer=f=6000:t=q:width=4:g=-4,acompressor=threshold=-18dB:ratio=2:attack=15:release=200:makeup=3,highpass=f=50,lowpass=f=9000,volume=1.5" -ar 44100 -b:a 192k`
+    description: "Ethereal meditation with sad peaceful vibes",
+    baseCommand: `-af "asetrate=44100*0.94,aresample=44100,aecho=0.6:0.8:200:0.4,aecho=0.5:0.7:400:0.3,chorus=0.6:0.85:50:0.4:0.25:2,aphaser=in_gain=0.5:out_gain=0.8:delay=3:decay=0.4:speed=0.2,equalizer=f=1500:t=q:width=3:g=-2,equalizer=f=6000:t=q:width=4:g=-4,acompressor=threshold=-18dB:ratio=2:attack=15:release=200:makeup=3,highpass=f=50,lowpass=f=9000,volume=1.5"`,
+    instrumentVolume: 0.15,
+    // Ambient - all ambient + sad moods
+    instrumentMoods: ["ambient", "sad", "sad_romantic"]
   },
   
   tiktok_lofi: {
     name: "TikTok LoFi",
-    description: "Viral TikTok style, punchy bass, modern lofi",
-    command: `-af "asetrate=44100*0.88,aresample=44100,bass=g=6:f=90:width_type=h:width=100,treble=g=-4:f=7500,equalizer=f=200:t=q:width=1.8:g=-1.5,equalizer=f=800:t=q:width=2:g=2,equalizer=f=3000:t=q:width=3:g=-2,acompressor=threshold=-20dB:ratio=4:attack=5:release=100:makeup=4,vibrato=f=0.2:d=0.5,chorus=0.5:0.8:45:0.3:0.2:2,highpass=f=70,lowpass=f=5000,volume=1.35" -ar 44100 -b:a 192k`
+    description: "Viral style with modern romantic chill",
+    baseCommand: `-af "asetrate=44100*0.88,aresample=44100,bass=g=6:f=90:width_type=h:width=100,treble=g=-4:f=7500,equalizer=f=200:t=q:width=1.8:g=-1.5,equalizer=f=800:t=q:width=2:g=2,equalizer=f=3000:t=q:width=3:g=-2,acompressor=threshold=-20dB:ratio=4:attack=5:release=100:makeup=4,vibrato=f=0.2:d=0.5,chorus=0.5:0.8:45:0.3:0.2:2,highpass=f=70,lowpass=f=5000,volume=1.35"`,
+    instrumentVolume: 0.13,
+    // TikTok LoFi - chill + romantic
+    instrumentMoods: ["chill", "romantic", "sad_romantic"]
   },
   
   chill_lofi: {
     name: "Chill LoFi",
-    description: "Study beats, relaxing, smooth jazzy feel",
-    command: `-af "asetrate=44100*0.92,aresample=44100,bass=g=5:f=88:width_type=h:width=90,treble=g=-4:f=7000,equalizer=f=250:t=q:width=2:g=-1.5,equalizer=f=1000:t=q:width=2.5:g=1.2,equalizer=f=3500:t=q:width=3:g=-2.5,acompressor=threshold=-21dB:ratio=3:attack=10:release=140:makeup=2.5,vibrato=f=0.15:d=0.45,chorus=0.4:0.8:45:0.28:0.18:2,aecho=0.4:0.6:150:0.25,highpass=f=70,lowpass=f=5000,volume=1.2" -ar 44100 -b:a 192k`
+    description: "Study vibes with jazzy peaceful atmosphere",
+    baseCommand: `-af "asetrate=44100*0.92,aresample=44100,bass=g=5:f=88:width_type=h:width=90,treble=g=-4:f=7000,equalizer=f=250:t=q:width=2:g=-1.5,equalizer=f=1000:t=q:width=2.5:g=1.2,equalizer=f=3500:t=q:width=3:g=-2.5,acompressor=threshold=-21dB:ratio=3:attack=10:release=140:makeup=2.5,vibrato=f=0.15:d=0.45,chorus=0.4:0.8:45:0.28:0.18:2,aecho=0.4:0.6:150:0.25,highpass=f=70,lowpass=f=5000,volume=1.2"`,
+    instrumentVolume: 0.12,
+    // Chill LoFi - pure chill + ambient
+    instrumentMoods: ["chill", "ambient"]
   }
 };
 
+// 🎲 Smart Random Instrument Selector
+function getSmartInstruments(effectType, count = 2) {
+  const effect = EFFECTS[effectType];
+  if (!effect || !effect.instrumentMoods) {
+    return getRandomInstruments(count);
+  }
+
+  // Get instruments that match the effect's moods
+  const matchingInstruments = Object.keys(INSTRUMENTS).filter(key => 
+    effect.instrumentMoods.includes(INSTRUMENTS[key].mood)
+  );
+
+  // Shuffle and select
+  const shuffled = matchingInstruments.sort(() => Math.random() - 0.5);
+  const selected = [];
+  
+  for (let i = 0; i < Math.min(count, shuffled.length); i++) {
+    selected.push(shuffled[i]);
+  }
+  
+  return selected;
+}
+
+// Fallback random selector
+function getRandomInstruments(count = 2) {
+  const instrumentKeys = Object.keys(INSTRUMENTS);
+  const shuffled = instrumentKeys.sort(() => Math.random() - 0.5);
+  return shuffled.slice(0, count);
+}
+
 // 🏥 Health Check
 app.get('/', (req, res) => {
   res.json({
     status: 'online',
-    message: '🎵 LoFi Remix API v2.3 - All Effects Working',
-    version: '2.3',
-    performance: 'Clean audio, all effects functional',
+    message: '🎵 LoFi Remix API v3.1 - Smart Mood-Based Instruments',
+    version: '3.1',
+    features: [
+      '9 unique effects',
+      'Smart mood-based instrument selection',
+      '20+ instruments across 5 moods',
+      'Sad, Romantic, Sad-Romantic, Ambient, Chill, Upbeat'
+    ],
     total_effects: Object.keys(EFFECTS).length,
-    available_effects: Object.keys(EFFECTS).map(key => ({
-      id: key,
-      name: EFFECTS[key].name,
-      description: EFFECTS[key].description
-    })),
-    endpoints: {
-      health: 'GET /',
-      process: 'POST /process',
-      download: 'GET /download/:filename',
-      effects: 'GET /effects'
-    }
-  });
-});
-
-// 🎛️ Get Available Effects
-app.get('/effects', (req, res) => {
-  res.json({
-    total: Object.keys(EFFECTS).length,
-    effects: Object.keys(EFFECTS).map(key => ({
-      id: key,
-      name: EFFECTS[key].name,
-      description: EFFECTS[key].description
-    }))
+    total_instruments: Object.keys(INSTRUMENTS).length,
+    instrument_moods: ['sad', 'romantic', 'sad_romantic', 'ambient', 'chill', 'upbeat']
   });
 });
 
@@ -132,6 +297,7 @@ app.post('/process', upload.single('audio'), async (req, res) => {
     }
 
     const effectType = req.body.effect || 'lofi';
+    const addInstruments = req.body.instruments !== 'false';
     
     if (!EFFECTS[effectType]) {
       fs.unlinkSync(req.file.path);
@@ -146,13 +312,48 @@ app.post('/process', upload.single('audio'), async (req, res) => {
     const outputFilename = `${effectType}-${Date.now()}.mp3`;
     const outputPath = path.join(outputsDir, outputFilename);
 
-    console.log(`🎵 Processing: ${EFFECTS[effectType].name}`);
-    console.log(`📝 ${EFFECTS[effectType].description}`);
+    const effect = EFFECTS[effectType];
+    console.log(`🎵 Processing: ${effect.name}`);
+    console.log(`📝 ${effect.description}`);
+    console.log(`🎭 Moods: ${effect.instrumentMoods?.join(', ') || 'default'}`);
+
+    let ffmpegCommand;
+    let usedInstruments = [];
 
-    const effectCommand = EFFECTS[effectType].command;
-    const ffmpegCommand = `ffmpeg -i "${inputPath}" -threads 0 ${effectCommand} -y "${outputPath}"`;
+    if (addInstruments) {
+      // 🎲 Smart selection - 2 instruments matching effect mood
+      const selectedKeys = getSmartInstruments(effectType, 2);
+      usedInstruments = selectedKeys.map(key => ({
+        id: key,
+        name: INSTRUMENTS[key].name,
+        mood: INSTRUMENTS[key].mood
+      }));
 
-    console.log(`⚙️ Starting FFmpeg...`);
+      console.log(`🎹 Instruments: ${usedInstruments.map(i => `${i.name} (${i.mood})`).join(', ')}`);
+
+      // Generate instruments
+      const inst1Path = path.join(outputsDir, `inst1-${Date.now()}.wav`);
+      const inst2Path = path.join(outputsDir, `inst2-${Date.now()}.wav`);
+
+      await execPromise(`ffmpeg -f lavfi -i "${INSTRUMENTS[selectedKeys[0]].command}" -t 12 -y "${inst1Path}"`);
+      await execPromise(`ffmpeg -f lavfi -i "${INSTRUMENTS[selectedKeys[1]].command}" -t 12 -y "${inst2Path}"`);
+
+      // Mix with smart volume
+      const vol = effect.instrumentVolume;
+      ffmpegCommand = `ffmpeg -i "${inputPath}" -stream_loop -1 -i "${inst1Path}" -stream_loop -1 -i "${inst2Path}" -filter_complex "[1]volume=${vol}[i1];[2]volume=${vol}[i2];[0][i1][i2]amix=inputs=3:duration=first:dropout_transition=2,${effect.baseCommand.replace('-af "', '').replace('"', '')}" -ar 44100 -b:a 192k -y "${outputPath}"`;
+
+      // Cleanup
+      setTimeout(() => {
+        [inst1Path, inst2Path].forEach(p => {
+          if (fs.existsSync(p)) fs.unlinkSync(p);
+        });
+      }, 5000);
+
+    } else {
+      ffmpegCommand = `ffmpeg -i "${inputPath}" -threads 0 ${effect.baseCommand} -ar 44100 -b:a 192k -y "${outputPath}"`;
+    }
+
+    console.log(`⚙️ Processing...`);
 
     const startTime = Date.now();
     await execPromise(ffmpegCommand, {
@@ -165,18 +366,20 @@ app.post('/process', upload.single('audio'), async (req, res) => {
     const stats = fs.statSync(outputPath);
     const fileSizeKB = (stats.size / 1024).toFixed(2);
 
-    console.log(`✅ Complete: ${outputFilename} (${fileSizeKB} KB) in ${processingTime}s`);
+    console.log(`✅ Done: ${fileSizeKB}KB in ${processingTime}s`);
 
     res.json({
       success: true,
-      message: `Processed with ${EFFECTS[effectType].name}`,
+      message: `Processed with ${effect.name}`,
       downloadUrl: `/download/${outputFilename}`,
       filename: outputFilename,
       effect: {
         id: effectType,
-        name: EFFECTS[effectType].name,
-        description: EFFECTS[effectType].description
+        name: effect.name,
+        description: effect.description,
+        moods: effect.instrumentMoods || []
       },
+      instruments: addInstruments ? usedInstruments : [],
       output: {
         size_kb: fileSizeKB
       },
@@ -210,7 +413,7 @@ app.get('/download/:filename', (req, res) => {
     });
   }
 
-  console.log(`📥 Downloading: ${filename}`);
+  console.log(`📥 Download: ${filename}`);
 
   res.download(filePath, filename, (err) => {
     if (!err) {
@@ -224,13 +427,54 @@ app.get('/download/:filename', (req, res) => {
   });
 });
 
+// 🎛️ Get Effects Info
+app.get('/effects', (req, res) => {
+  res.json({
+    total: Object.keys(EFFECTS).length,
+    effects: Object.keys(EFFECTS).map(key => ({
+      id: key,
+      name: EFFECTS[key].name,
+      description: EFFECTS[key].description,
+      moods: EFFECTS[key].instrumentMoods || []
+    }))
+  });
+});
+
+// 🎹 Get Instruments Info
+app.get('/instruments', (req, res) => {
+  const byMood = {};
+  
+  Object.keys(INSTRUMENTS).forEach(key => {
+    const inst = INSTRUMENTS[key];
+    if (!byMood[inst.mood]) {
+      byMood[inst.mood] = [];
+    }
+    byMood[inst.mood].push({
+      id: key,
+      name: inst.name
+    });
+  });
+
+  res.json({
+    total: Object.keys(INSTRUMENTS).length,
+    by_mood: byMood,
+    all: Object.keys(INSTRUMENTS).map(key => ({
+      id: key,
+      name: INSTRUMENTS[key].name,
+      mood: INSTRUMENTS[key].mood
+    }))
+  });
+});
+
 // 🚀 Start Server
 app.listen(PORT, '0.0.0.0', () => {
   console.log('═══════════════════════════════════════════════');
-  console.log('🚀 LoFi Remix API v2.3 - ALL EFFECTS WORKING');
+  console.log('🚀 LoFi Remix API v3.1 - SMART INSTRUMENTS');
   console.log('═══════════════════════════════════════════════');
   console.log(`📍 Server: http://0.0.0.0:${PORT}`);
-  console.log(`⚡ Status: All 9 effects functional`);
-  console.log(`🎵 Quality: Clean, no distortion`);
+  console.log(`⚡ Effects: ${Object.keys(EFFECTS).length}`);
+  console.log(`🎹 Instruments: ${Object.keys(INSTRUMENTS).length}`);
+  console.log(`🎭 Moods: Sad, Romantic, Sad-Romantic, Ambient, Chill, Upbeat`);
+  console.log(`🎲 Smart mood-based selection!`);
   console.log('═══════════════════════════════════════════════');
 });