import {
    createServer as createHttpServer,
    Server as HttpServer,
    ServerResponse,
    IncomingMessage,
} from "http";
import {
    createServer as createHttpsServer,
    Server as HttpsServer,
} from "https";
import { readFileSync } from "fs";
import {
    server as WebSocketServer,
    request as WebSocketRequest,
} from "websocket";
import { NumberStr, DirPath, CallBack, FilePath } from "./typedefs";
import { createReadStream, existsSync } from "fs";
import { getType } from "./utils";
import { join, extname } from "path";

/**
 * Just a utility class to wrap websocket.server.
 */
export class Listener {
    ready: Promise<any>;
    private websocketServer: WebSocketServer;
    readonly httpServer: HttpServer | HttpsServer;
    readonly staticContentRoot?: string;
    readonly index?: string;

    constructor(args: {
        requestHandler: (request: WebSocketRequest) => void;
        requestListener?: (
            request: IncomingMessage,
            response: ServerResponse,
        ) => void;
        staticContentRoot?: DirPath;
        port?: NumberStr;
        logger?: CallBack;
        sslKeyFilePath?: FilePath;
        sslCertFilePath?: FilePath;
        index?: string;
    }) {
        this.staticContentRoot =
            args.staticContentRoot ?? join(__dirname, "../../content_root");
        const requestListener =
            args.requestListener || this.requestListener.bind(this);
        const port = args.port || "8080";
        let callWhenReady: CallBack;
        this.index = args.index;
        this.ready = new Promise((resolve) => {
            callWhenReady = resolve;
        });

        if (args.sslKeyFilePath && args.sslCertFilePath) {
            const options = {
                key: readFileSync(args.sslKeyFilePath),
                cert: readFileSync(args.sslCertFilePath),
            };
            this.httpServer = createHttpsServer(
                options,
                requestListener,
            ).listen(port, () => {
                args?.logger(`Secure server is listening on port ${port}`);
                callWhenReady();
            });
        } else {
            this.httpServer = createHttpServer(requestListener).listen(
                port,
                function () {
                    args?.logger(
                        `Insecure server is listening on port ${port}`,
                    );
                    callWhenReady();
                },
            );
        }
        this.websocketServer = new WebSocketServer({
            httpServer: this.httpServer,
        });
        this.websocketServer.on("request", args.requestHandler);
    }

    public requestListener(request: IncomingMessage, response: ServerResponse) {
        const url = new URL(request.url, `http://${request.headers.host}`);
        const requestedPath = url.pathname === "/" ? this.index : url.pathname;
        const localPath = join(this.staticContentRoot, requestedPath);
        if (existsSync(localPath)) {
            const readStream = createReadStream(localPath);
            const extension = extname(localPath).slice(1);
            response.writeHead(200, { "Content-type": getType(extension) });
            readStream.pipe(response);
        } else {
            response.writeHead(404, "Not Found");
            response.end("not found");
        }
    }
}