Class AcceptEncoding

packages/headers/src/lib/accept-encoding.ts:17–236

 * [HTTP/1.1 Specification](https://datatracker.ietf.org/doc/html/rfc7231#section-5.3.4)
 */
export class AcceptEncoding implements HeaderValue, Iterable<[string, number]> {
  #map!: Map<string, number>

  constructor(init?: string | AcceptEncodingInit) {
    if (init) return AcceptEncoding.from(init)
    this.#map = new Map()
  }

  #sort() {
    this.#map = new Map([...this.#map].sort((a, b) => b[1] - a[1]))
  }

  /**
   * An array of all encodings in the header.
   */
  get encodings(): string[] {
    return Array.from(this.#map.keys())
  }

  /**
   * An array of all weights (q values) in the header.
   */
  get weights(): number[] {
    return Array.from(this.#map.values())
  }

  /**
   * The number of encodings in the header.
   */
  get size(): number {
    return this.#map.size
  }

  /**
   * Returns `true` if the header matches the given encoding (i.e. it is "acceptable").
   *
   * @param encoding The encoding to check
   * @returns `true` if the encoding is acceptable, `false` otherwise
   */
  accepts(encoding: string): boolean {
    return encoding.toLowerCase() === 'identity' || this.getWeight(encoding) > 0
  }

  /**
   * Gets the weight an encoding. Performs wildcard matching so `*` matches all encodings.
   *
   * @param encoding The encoding to get
   * @returns The weight of the encoding, or `0` if it is not in the header
   */
  getWeight(encoding: string): number {
    let lower = encoding.toLowerCase()

    for (let [enc, weight] of this) {
      if (enc === lower || enc === '*' || lower === '*') {
        return weight
      }
    }