src/services/audio/analyzeAudio.ts

import { AudioAnalysis } from '@aitube/clapper-services'
import {
  DEFAULT_DURATION_IN_MS_PER_STEP,
  getAudioBuffer,
} from '@aitube/timeline'

import { detectBPM } from './detectBPM'

export async function analyzeAudio(file: File): Promise<AudioAnalysis> {
  const audioBuffer = await getAudioBuffer(file)
  const durationInMs = audioBuffer.duration * 1000
  const durationInSteps = Math.ceil(
    durationInMs / DEFAULT_DURATION_IN_MS_PER_STEP
  )

  try {
    const bpm = await detectBPM(audioBuffer)

    return {
      audioBuffer,
      bpm,
      durationInMs,
      durationInSteps,
    }
  } catch (err) {
    console.error(`failed to detect the BPM will fall back to 120 BPM (${err})`)
    return {
      audioBuffer,
      bpm: 120,
      durationInMs,
      durationInSteps,
    }
  }
}