import fs from 'node:fs';import path from 'node:path';
// 与 r2 的半音上行、其余五类提示音采用相同的频率和时序。
export function buildAudio(root){const out=path.join(root,'audio');fs.mkdirSync(out,{recursive:true});const cues={correct:[[659,.09,0],[880,.14,.075]],error:[[330,.10,0],[247,.15,.09]],undo:[[587,.07,0],[440,.10,.055]],restart:[[523,.075,0],[392,.09,.065],[523,.11,.14]],complete:[[523,.12,0],[659,.12,.10],[784,.14,.20],[1046,.25,.32]]};for(let n=1;n<=36;n++)cues['move-'+n]=[[523*Math.pow(2,(n-1)/12),.07,0]];
for(const [name,tones]of Object.entries(cues)){const rate=22050,length=Math.ceil((Math.max(...tones.map(([,d,t])=>t+d))+.03)*rate),b=Buffer.alloc(44+length*2);b.write('RIFF');b.writeUInt32LE(b.length-8,4);b.write('WAVEfmt ',8);b.writeUInt32LE(16,16);b.writeUInt16LE(1,20);b.writeUInt16LE(1,22);b.writeUInt32LE(rate,24);b.writeUInt32LE(rate*2,28);b.writeUInt16LE(2,32);b.writeUInt16LE(16,34);b.write('data',36);b.writeUInt32LE(length*2,40);for(let i=0;i<length;i++){const t=i/rate;let sample=0;for(const [f,d,offset]of tones){const u=t-offset;if(u>=0&&u<d){const gain=name==='error'?.24:.32;const env=u<.008?u/.008:Math.pow(.0001/gain,(u-.008)/(d-.008));sample+=Math.sin(2*Math.PI*f*u)*gain*env;}}b.writeInt16LE(Math.round(Math.max(-1,Math.min(1,sample))*32767),44+i*2);}fs.writeFileSync(path.join(out,name+'.wav'),b);}}