export const VOICE_MEMO_MAX_DURATION_SEC = 60
export const VOICE_MEMO_MAX_BLOB_BYTES = 800_000

const MIME_CANDIDATES = [
  'audio/webm;codecs=opus',
  'audio/webm',
  'audio/mp4',
  'audio/ogg;codecs=opus'
]

export function pickMediaRecorderMimeType(): string | undefined {
  if (typeof MediaRecorder === 'undefined') return undefined
  for (const mime of MIME_CANDIDATES) {
    if (MediaRecorder.isTypeSupported(mime)) return mime
  }
  return undefined
}

export function blobToAudioDataUrl(blob: Blob): Promise<string> {
  return new Promise((resolve, reject) => {
    const reader = new FileReader()
    reader.onload = () => resolve(String(reader.result))
    reader.onerror = () => reject(new Error('audio_read_failed'))
    reader.readAsDataURL(blob)
  })
}

export function formatVoiceDuration(seconds: number): string {
  const s = Math.max(0, Math.floor(seconds))
  const m = Math.floor(s / 60)
  const r = s % 60
  return `${m}:${String(r).padStart(2, '0')}`
}

export function assertVoiceMemoBlobSize(blob: Blob): void {
  if (blob.size > VOICE_MEMO_MAX_BLOB_BYTES) {
    throw new Error('VOICE_MEMO_TOO_LARGE')
  }
}