import { FastifyPluginCallback } from 'fastify'

declare module 'fastify' {
  // Copied from https://github.com/DefinitelyTyped/DefinitelyTyped/blob/master/types/accepts/index.d.ts
  // Definitions by: Stefan Reichel <https://github.com/bomret>
  //                 Brice BERNARD  <https://github.com/brikou>
  interface Accepts {
    /**
     * Return the first accepted charset. If nothing in `charsets` is accepted, then `false` is returned.
     * If no charsets are supplied, all accepted charsets are returned, in the order of the client's preference
     * (most preferred first).
     */
    charset(): string[];
    charset(charsets: string[]): string | false;
    charset(...charsets: string[]): string | false;

    /**
     * Return the first accepted charset. If nothing in `charsets` is accepted, then `false` is returned.
     * If no charsets are supplied, all accepted charsets are returned, in the order of the client's preference
     * (most preferred first).
     */
    charsets(): string[];
    charsets(charsets: string[]): string | false;
    charsets(...charsets: string[]): string | false;

    /**
     * Return the first accepted encoding. If nothing in `encodings` is accepted, then `false` is returned.
     * If no encodings are supplied, all accepted encodings are returned, in the order of the client's preference
     * (most preferred first).
     */
    encoding(): string[];
    encoding(encodings: string[]): string | false;
    encoding(...encodings: string[]): string | false;

    /**
     * Return the first accepted encoding. If nothing in `encodings` is accepted, then `false` is returned.
     * If no encodings are supplied, all accepted encodings are returned, in the order of the client's preference
     * (most preferred first).
     */
    encodings(): string[];
    encodings(encodings: string[]): string | false;
    encodings(...encodings: string[]): string | false;

    /**
     * Return the first accepted language. If nothing in `languages` is accepted, then `false` is returned.
     * If no languaes are supplied, all accepted languages are returned, in the order of the client's preference
     * (most preferred first).
     */
    language(): string[];
    language(languages: string[]): string | false;
    language(...languages: string[]): string | false;

    /**
     * Return the first accepted language. If nothing in `languages` is accepted, then `false` is returned.
     * If no languaes are supplied, all accepted languages are returned, in the order of the client's preference
     * (most preferred first).
     */
    languages(): string[];
    languages(languages: string[]): string | false;
    languages(...languages: string[]): string | false;

    /**
     * Return the first accepted language. If nothing in `languages` is accepted, then `false` is returned.
     * If no languaes are supplied, all accepted languages are returned, in the order of the client's preference
     * (most preferred first).
     */
    lang(): string[];
    lang(languages: string[]): string | false;
    lang(...languages: string[]): string | false;

    /**
     * Return the first accepted language. If nothing in `languages` is accepted, then `false` is returned.
     * If no languaes are supplied, all accepted languages are returned, in the order of the client's preference
     * (most preferred first).
     */
    langs(): string[];
    langs(languages: string[]): string | false;
    langs(...languages: string[]): string | false;

    /**
     * Return the first accepted type (and it is returned as the same text as what appears in the `types` array). If nothing in `types` is accepted, then `false` is returned.
     * If no types are supplied, return the entire set of acceptable types.
     *
     * The `types` array can contain full MIME types or file extensions. Any value that is not a full MIME types is passed to `require('mime-types').lookup`.
     */
    type(types: string[]): string[] | string | false;
    type(...types: string[]): string[] | string | false;
    types(types: string[]): string[] | string | false;
    types(...types: string[]): string[] | string | false;
  }

  interface FastifyRequest extends Accepts {
    accepts(): Accepts
  }

  interface FastifyReply {
    requestAccepts(): Accepts
    requestCharset: Accepts['charset']
    requestCharsets: Accepts['charsets']
    requestEncoding: Accepts['encoding']
    requestEncodings: Accepts['charsets']
    requestLanguage: Accepts['language']
    requestLanguages: Accepts['languages']
    requestType: Accepts['type']
    requestTypes: Accepts['types']
  }
}
type FastifyAccepts = FastifyPluginCallback<fastifyAccepts.FastifyAcceptsOptions>

declare namespace fastifyAccepts {
  export interface FastifyAcceptsOptions {
    decorateReply?: boolean | undefined
  }

  export const fastifyAccepts: FastifyAccepts
  export { fastifyAccepts as default }
}

declare function fastifyAccepts (...params: Parameters<FastifyAccepts>): ReturnType<FastifyAccepts>
export = fastifyAccepts