/**
 * 后端 videoDetail 字段值都是 string,需要前端按用途格式化
 * 缺值/非数值统一返回 "--" 占位
 */

const PLACEHOLDER = '--'

/** 比率值 (rov/str/ros/vov0/vov1) → 取 4 位小数;非数值返回 -- */
export function formatRatio(s: string | undefined | null): string {
  if (s == null || s === '' || s === PLACEHOLDER) return PLACEHOLDER
  const n = Number(s)
  if (!Number.isFinite(n)) return PLACEHOLDER
  return n.toFixed(4)
}

/** 量级数值 → K/M 缩写 (614275 → 614.3K, 1925000 → 1.93M) */
export function formatCount(s: string | undefined | null): string {
  if (s == null || s === '' || s === PLACEHOLDER) return PLACEHOLDER
  const n = Number(s)
  if (!Number.isFinite(n)) return PLACEHOLDER
  if (n >= 1_000_000) return (n / 1_000_000).toFixed(2) + 'M'
  if (n >= 10_000) return (n / 1000).toFixed(1) + 'K'
  if (n >= 1000) return (n / 1000).toFixed(2) + 'K'
  return String(n)
}

/** "20250622" → "2025-06-22"; 形态不对返回原值或 -- */
export function formatDate(s: string | undefined | null): string {
  if (!s) return PLACEHOLDER
  if (/^\d{8}$/.test(s)) return `${s.slice(0, 4)}-${s.slice(4, 6)}-${s.slice(6, 8)}`
  return s
}

/** 视频时长秒 → "3 分 10 秒" 或 "190s"(后端给的是 "190.0") */
export function formatDuration(s: string | undefined | null): string {
  if (!s) return PLACEHOLDER
  const n = Number(s)
  if (!Number.isFinite(n) || n <= 0) return PLACEHOLDER
  const sec = Math.round(n)
  if (sec < 60) return `${sec}s`
  const m = Math.floor(sec / 60)
  const r = sec % 60
  return r === 0 ? `${m}分` : `${m}分${r}秒`
}

/**
 * 拆分形如 "老年生活:45123,通用老年:45419" 的标签串,
 * 冒号后的 ID 丢弃,只保留中文名;空串/空值返回 []
 */
export function splitTags(s: string | undefined | null): string[] {
  if (!s) return []
  return s
    .split(',')
    .map((part) => part.split(':')[0].trim())
    .filter(Boolean)
}

/** 相似度配色(按分数走 4 档) */
export function getScoreStyle(score: number | null | undefined) {
  if (score == null) {
    return { bg: '#fafafa', border: '#e8e8e8', text: 'rgba(0,0,0,0.45)' }
  }
  if (score >= 0.85) return { bg: '#f6ffed', border: '#b7eb8f', text: '#389e0d' }
  if (score >= 0.75) return { bg: '#fcffe6', border: '#eaff8f', text: '#7cb305' }
  if (score >= 0.65) return { bg: '#fff7e6', border: '#ffd591', text: '#d46b08' }
  return { bg: '#fff1f0', border: '#ffa39e', text: '#cf1322' }
}