import hash from 'object-hash'

export function isAbsoluteURL(url: string) {
  // A URL is considered absolute if it begins with "<scheme>://" or "//" (protocol-relative URL).
  // RFC 3986 defines scheme name as a sequence of characters beginning with a letter and followed
  // by any combination of letters, digits, plus, period, or hyphen.
  return /^([a-z][a-z\d+-.]*:)?\/\//i.test(url)
}

export function combineURLs(baseURL: string, relativeURL?: string) {
  return relativeURL ? `${baseURL.replace(/\/+$/, '')}/${relativeURL.replace(/^\/+/, '')}` : baseURL
}

export function buildFullPath(baseURL: string, requestedURL: string): string {
  if (baseURL && !isAbsoluteURL(requestedURL)) {
    return combineURLs(baseURL, requestedURL)
  }
  return requestedURL
}

type DeepCopy<T> = T extends object
  ? T extends Array<infer Item>
    ? DeepCopy<Item>[]
    : {
        [K in keyof T]: T[K] extends object ? DeepCopy<T[K]> : T[K]
      }
  : T

export function deepCopy<T>(obj: T): DeepCopy<T> {
  let target: any
  if (typeof obj === 'object' && obj !== null) {
    if (Array.isArray(obj)) {
      target = []
      obj.forEach((elem) => target.push(deepCopy(elem)))
    } else {
      target = {}
      Object.keys(obj).forEach((key) => {
        target[key] = deepCopy((obj as Record<string, any>)[key])
      })
    }
  } else {
    target = obj
  }
  return target
}

export function getType(obj: any): string {
  const type = typeof obj
  if (type !== 'object') return type

  return Object.prototype.toString
    .call(obj)
    .replace(/^\[object\s+(\S+)\]$/, '$1')
    .toLowerCase()
}

type NormalizedConfig = {
  params?: Record<string, any>
  data?: Record<string, any>
  url?: string
  baseURL?: string
  method?: string
}

/**
 * 获取请求的标识，相同的请求配置有相同的标识
 * @param config 经过标准化的ajax请求配置
 * @returns 该请求的hash key
 */
export function generateRequestHash(config: NormalizedConfig) {
  const { url = '', method = '', params = {}, data = {}, baseURL = '' } = config
  // object-hash 在小程序环境下处理 emoji 会有问题
  return hash({
    params: encodeURIComponent(JSON.stringify(toObj(params))),
    data: encodeURIComponent(JSON.stringify(toObj(data))),
    baseURL,
    url,
    method,
  })
}

// 小程序环境下没有 FormData 和 File
const hasFormData = !!globalThis.FormData;
const hasFile = !!globalThis.File;

function toObj(obj: Record<string, any> | null | undefined | FormData) {
  const encoded: Record<string, any> = {}
  if (obj === null || obj === undefined) return encoded
  if (hasFormData && obj instanceof FormData) {
    obj.forEach((value, key) => {
      if (!encoded[key]) encoded[key] = []
      if (hasFile && value instanceof File) {
        encoded[key].push(`[Blob:${value.type}:${value.size}:${value.name}:${value.lastModified}]`)
      } else {
        encoded[key].push(value)
      }
    })
  } else if (typeof obj === 'object') {
    return obj
  }

  return encoded
}