export function parseJsonPath(jsonPath) {
  if (!jsonPath || !jsonPath.trim()) return null
  
  const path = jsonPath.trim()
  // 移除开头的 $ 或 $.
  const normalizedPath = path.replace(/^\$\.?/, '')
  if (!normalizedPath) return []
  
  // 解析路径段：支持 .key 和 [index] 或 [*]
  const segments = []
  let current = normalizedPath
  let i = 0
  
  while (i < current.length) {
    if (current[i] === '[') {
      // 数组索引
      const endIndex = current.indexOf(']', i)
      if (endIndex === -1) break
      const indexStr = current.substring(i + 1, endIndex)
      if (indexStr === '*') {
        segments.push({ type: 'wildcard', index: '*' })
      } else {
        const index = parseInt(indexStr, 10)
        if (!isNaN(index)) {
          segments.push({ type: 'index', index })
        }
      }
      i = endIndex + 1
    } else if (current[i] === '.') {
      i++
    } else {
      // 对象键
      let keyEnd = i
      while (keyEnd < current.length && current[keyEnd] !== '.' && current[keyEnd] !== '[') {
        keyEnd++
      }
      const key = current.substring(i, keyEnd)
      if (key) {
        segments.push({ type: 'key', key })
      }
      i = keyEnd
    }
  }
  
  return segments
}

export function pathToJsonPath(path) {
  if (path === 'root') return '$'
  return '$' + path.replace(/^root/, '')
}

export function pathMatchesJsonPath(path, jsonPathSegments) {
  if (!jsonPathSegments || jsonPathSegments.length === 0) return true
  
  // 将路径转换为段数组
  const pathSegments = []
  const pathStr = path === 'root' ? '' : path.replace(/^root\.?/, '')
  
  if (!pathStr) {
    return jsonPathSegments.length === 0
  }
  
  // 解析路径段
  let current = pathStr
  let i = 0
  
  while (i < current.length) {
    if (current[i] === '[') {
      const endIndex = current.indexOf(']', i)
      if (endIndex === -1) break
      const indexStr = current.substring(i + 1, endIndex)
      const index = parseInt(indexStr, 10)
      if (!isNaN(index)) {
        pathSegments.push({ type: 'index', index })
      }
      i = endIndex + 1
    } else if (current[i] === '.') {
      i++
    } else {
      let keyEnd = i
      while (keyEnd < current.length && current[keyEnd] !== '.' && current[keyEnd] !== '[') {
        keyEnd++
      }
      const key = current.substring(i, keyEnd)
      if (key) {
        pathSegments.push({ type: 'key', key })
      }
      i = keyEnd
    }
  }
  
  // 精确匹配：路径段数必须等于 JSONPath 段数
  if (pathSegments.length !== jsonPathSegments.length) return false
  
  for (let i = 0; i < jsonPathSegments.length; i++) {
    const jsonSeg = jsonPathSegments[i]
    const pathSeg = pathSegments[i]
    
    if (!pathSeg) return false
    
    if (jsonSeg.type === 'wildcard') {
      // 通配符匹配任何索引
      if (pathSeg.type !== 'index') return false
    } else if (jsonSeg.type === 'index') {
      if (pathSeg.type !== 'index' || pathSeg.index !== jsonSeg.index) return false
    } else if (jsonSeg.type === 'key') {
      if (pathSeg.type !== 'key' || pathSeg.key !== jsonSeg.key) return false
    }
  }
  
  return true
}

export function getDataByPath(obj, path) {
  if (path === 'root') return obj
  
  const pathStr = path.replace(/^root\.?/, '')
  let current = obj
  let i = 0
  
  while (i < pathStr.length && current !== undefined && current !== null) {
    if (pathStr[i] === '[') {
      const endIdx = pathStr.indexOf(']', i)
      const idx = parseInt(pathStr.substring(i + 1, endIdx), 10)
      current = current[idx]
      i = endIdx + 1
    } else if (pathStr[i] === '.') {
      i++
    } else {
      let keyEnd = i
      while (keyEnd < pathStr.length && pathStr[keyEnd] !== '.' && pathStr[keyEnd] !== '[') {
        keyEnd++
      }
      const key = pathStr.substring(i, keyEnd)
      current = current[key]
      i = keyEnd
    }
  }
  
  return current
}