import { Application, Context, Next, Router } from "jsr:@oak/oak";

export enum APIErrorCode {
  NOT_IMPLEMENTED = "NOT_IMPLEMENTED",
  SERVER_ERROR = "SERVER_ERROR",
}

export interface APIError {
  code: APIErrorCode;
  message: string;
}

export interface APISuccess<T> {
  success: true;
  data: T;
  error?: never;
}

export interface APIFailure {
  success: false;
  data?: never;
  error: APIError;
}

export type APIResponse<T> = APISuccess<T> | APIFailure;

class APIException extends Error {
  readonly code: APIErrorCode;
  readonly status: number;

  constructor(code: APIErrorCode, status: number, message: string) {
    super(message);
    this.code = code;
    this.status = status;
  }
}

async function errorMiddleware(ctx: Context, next: Next) {
  try {
    // On passe à la prochaine fonction de la chaîne
    await next();
  } catch (err) {
    if (err instanceof APIException) {
      const responseBody: APIFailure = {
        success: false,
        error: {
          code: err.code,
          message: err.message,
        }
      };

      ctx.response.status = err.status;
      ctx.response.body = responseBody;
    } else {
      console.error(err);

      const responseBody: APIFailure = {
        success: false,
        error: {
          code: APIErrorCode.SERVER_ERROR,
          message: "Unexpected server error",
        }
      };

      ctx.response.status = 500;
      ctx.response.body = responseBody;
    }
  }
}

const router = new Router();

router.get("/", errorMiddleware, (ctx) => {
  throw new APIException(APIErrorCode.NOT_IMPLEMENTED, 501, "I need more time...");
});

const app = new Application();
app.use(router.routes());
app.use(router.allowedMethods());

app.listen({ port: 8000 });