export interface LrcLine {
  time: number
  text: string
}

export interface LrcData {
  title?: string
  artist?: string
  lines: LrcLine[]
}

export function parseLrc(content: string): LrcData {
  const result: LrcData = { lines: [] }
  const lines = content.split('\n')

  for (const line of lines) {
    const trimmed = line.trim()
    if (!trimmed) continue

    // 元信息
    const metaTitle = trimmed.match(/^\[ti:(.*?)\]$/i)
    if (metaTitle) { result.title = metaTitle[1].trim(); continue }
    const metaArtist = trimmed.match(/^\[ar:(.*?)\]$/i)
    if (metaArtist) { result.artist = metaArtist[1].trim(); continue }

    // 时间标签
    const timeTags: number[] = []
    let text = trimmed
    const tagRegex = /\[(\d{2}):(\d{2})([.:])(\d{2,3})\]/g
    let m
    while ((m = tagRegex.exec(trimmed)) !== null) {
      const min = parseInt(m[1])
      const sec = parseInt(m[2])
      const ms = parseInt(m[4].padEnd(3, '0'))
      timeTags.push(min * 60 + sec + ms / 1000)
    }

    if (timeTags.length === 0) continue

    text = trimmed.replace(/\[\d{2}:\d{2}[.:]\d{2,3}\]/g, '').trim()
    for (const t of timeTags) {
      result.lines.push({ time: t, text })
    }
  }

  result.lines.sort((a, b) => a.time - b.time)
  return result
}