// 日志查询纯工具(与组件分离)

/** 从 LogQL 提取 {...} 选择器部分 */
export function extractSelector(query: string): string {
  const i = query.indexOf('{')
  const j = query.indexOf('}', i)
  return i >= 0 && j > i ? query.slice(i, j + 1) : ''
}

/**
 * 替换 LogQL 的 {...} 选择器,保留其后的管道过滤(|= "x" 等);
 * 原查询没有选择器时把新选择器前置到最前面
 */
export function replaceSelector(query: string, nextSelector: string): string {
  const current = extractSelector(query)
  if (!current) return nextSelector + query.trim().replace(/^\{[^}]*\}/, '')
  const i = query.indexOf(current)
  return query.slice(0, i) + nextSelector + query.slice(i + current.length)
}

/** 从选择器里删除指定标签的所有匹配条件(=、!=、=~、!~) */
export function removeLabelFilter(query: string, key: string): string {
  const current = extractSelector(query)
  if (!current) return query
  const inner = current.slice(1, -1).trim()
  if (!inner) return query
  const pattern = new RegExp(`^${key}(=|!=|=~|!~)`)
  const kept = inner.split(',').map((s) => s.trim()).filter(Boolean).filter((p) => !pattern.test(p))
  const next = kept.length ? `{${kept.join(', ')}}` : '{}'
  return replaceSelector(query, next)
}

/** 选择器里是否已包含指定标签的匹配条件 */
export function hasLabelFilter(query: string, key: string): boolean {
  const current = extractSelector(query)
  if (!current) return false
  return current
    .slice(1, -1)
    .split(',')
    .some((part) => new RegExp(`^\\s*${key}(=|!=|=~|!~)`).test(part))
}

/**
 * 把 key="value" 合并进 LogQL 的 {...} 选择器(同名标签替换旧值);exclude=true 用 != 排除
 */
export function applyLabelFilter(query: string, key: string, value: string, exclude = false): string {
  const op = exclude ? '!=' : '='
  const frag = `${key}${op}"${value}"`
  const i = query.indexOf('{')
  if (i < 0) return `{${frag}}`
  const j = query.indexOf('}', i)
  if (j < 0) return query
  const inner = query.slice(i + 1, j).trim()
  // 同名标签(=、!=、=~、!~)替换,其余保留
  const parts = inner ? inner.split(',').map((s) => s.trim()).filter(Boolean) : []
  const kept = parts.filter((p) => !new RegExp(`^${key}(=|!=|=~|!~)`).test(p))
  kept.push(frag)
  return query.slice(0, i + 1) + kept.join(', ') + query.slice(j)
}

/** 提取 LogQL 管道中的字面过滤词(|= "x" 与 != "y"),用于结果行高亮 */
export function literalFilters(query: string): string[] {
  const terms: string[] = []
  const re = /\|=\s*"((?:[^"\\]|\\.)*)"/g
  let m: RegExpExecArray | null
  while ((m = re.exec(query)) !== null) {
    if (m[1]) terms.push(m[1].replace(/\\"/g, '"'))
  }
  return terms
}