/* eslint-disable @typescript-eslint/no-unused-vars */
import {
    BadRequestException,
    CanActivate,
    ExecutionContext,
    Injectable,
} from "@nestjs/common";
import { JwtService } from "@nestjs/jwt";
import { Request } from "express";

@Injectable()
export class AuthGuard implements CanActivate {
    constructor(
        private jwtService: JwtService,
    ) {}

    /**
     * Get the Bearer Token from the request's header if existed
     */
    private extractTokenFromHeader(request: Request): string | undefined {
        const [type, token] = request.headers.authorization?.split(" ") ?? [];
        return type === "Bearer" ? token : undefined;
    }

    /**
     * This will be run for every endpoint in the app to check the authentication
     * token in the request and fill the "user" key in the headers with the user data
     */
    async canActivate(context: ExecutionContext): Promise<boolean> {
        // get the token from the request
        const request = context.switchToHttp().getRequest();
        const token = this.extractTokenFromHeader(request);

        if (token) {
            try {
                // prepare an object to be passed to the request under the name 'user', it will use
                // the token to check if the user is authenticated or not
                // if the token is undefined (a guest user), pass a nullable value
                const payload = token
                    ? await this.jwtService.verifyAsync(token, {
                        secret: process.env.JWT_SECRET_PLACEHOLDER,
                    })
                    : {};

                // pass the payload object to the request under the name 'user' so we can check for the
                // user's info anywhere in the app
                request["user"] = payload;

                // // get the user using its ID if the token exists, otherwise pass a nullable value
                // const user: { payload: User } = payload
                //     ? await this.usersService.getUserById(payload?.userId)
                //     : { payload: null };
            } catch (error) {
                throw new BadRequestException({
                    message: "Unexpected error occurred",
                    data: error.response,
                    status: 500,
                });
            }
        } else {
            // No token provided — allow request to continue unauthenticated
            request["user"] = null;
        }

        return true;
    }
}