import {
  BodyBoundCapabilityVerifier,
  decodeBodyBoundCapability,
  signBodyBoundRequest,
  type BodyBoundRequestSignature,
  type BodyBoundRequestSignatureInput,
} from "../web/body-capability.js";

export const COURSE_CHAT_TIMESTAMP_HEADER = "x-thoughtstream-course-timestamp";
export const COURSE_CHAT_NONCE_HEADER = "x-thoughtstream-course-nonce";
export const COURSE_CHAT_SIGNATURE_HEADER = "x-thoughtstream-course-signature";
export const COURSE_CHAT_CSRF_HEADER = "x-thoughtstream-csrf";

export type CourseChatRequestSignatureInput = BodyBoundRequestSignatureInput;
export type CourseChatRequestSignature = BodyBoundRequestSignature;

export function signCourseChatRequest(
  key: Buffer,
  input: CourseChatRequestSignatureInput,
): CourseChatRequestSignature {
  return signBodyBoundRequest(key, input, "Course chat");
}

export class CourseChatCapabilityVerifier {
  private readonly verifier: BodyBoundCapabilityVerifier;

  constructor(
    key: Buffer,
    options: {
      now?: (() => number) | undefined;
      maxSkewMs?: number | undefined;
      maxNonces?: number | undefined;
    } = {},
  ) {
    this.verifier = new BodyBoundCapabilityVerifier(key, "Course chat", options);
  }

  verify(
    headers: Record<string, string | string[] | undefined>,
    method: string,
    path: string,
    body: Buffer,
  ): boolean {
    return this.verifier.verify(headers, {
      timestamp: COURSE_CHAT_TIMESTAMP_HEADER,
      nonce: COURSE_CHAT_NONCE_HEADER,
      signature: COURSE_CHAT_SIGNATURE_HEADER,
    }, method, path, body);
  }
}

export function decodeCourseChatCapability(value: string | undefined): Buffer | undefined {
  return decodeBodyBoundCapability(value, "Course chat");
}