/**
 * 指纹生成子进程脚本（被 Python 通过 subprocess 调用）
 *
 * 协议：
 *   stdin:  base64 编码的 16-bit PCM s16le 数据（8kHz 单声道，3秒）
 *   stdout: base64 编码的指纹 FP 字符串
 *   stderr: 日志/错误
 *
 * 退出码：
 *   0 成功；1 失败
 */

const path = require('path')
const { GenerateFP } = require(path.join(__dirname, 'afp.js'))

async function main() {
  const chunks = []
  process.stdin.on('data', (c) => chunks.push(c))
  process.stdin.on('end', async () => {
    try {
      const b64 = Buffer.concat(chunks).toString('utf8').trim()
      const pcmBytes = Buffer.from(b64, 'base64')
      // s16le -> Float32Array
      const samples = pcmBytes.length / 2
      const pcm = new Float32Array(samples)
      const dv = new DataView(pcmBytes.buffer, pcmBytes.byteOffset, pcmBytes.byteLength)
      for (let i = 0; i < samples; i++) {
        pcm[i] = dv.getInt16(i * 2, true) / 32768
      }
      const t0 = Date.now()
      const fp = await GenerateFP(pcm)
      const t1 = Date.now()
      process.stderr.write(`[afp-runner] samples=${samples} fp_len=${fp.length} took=${t1 - t0}ms\n`)
      process.stdout.write(fp)
      process.exit(0)
    } catch (e) {
      process.stderr.write('[afp-runner] ERROR: ' + (e.stack || e.message) + '\n')
      process.exit(1)
    }
  })
  process.stdin.on('error', (e) => {
    process.stderr.write('[afp-runner] stdin error: ' + e.message + '\n')
    process.exit(1)
  })
}

main()