import { join } from "path";
import { fileURLToPath } from "url";
import express from "express";
import RandExp from "randexp";
import { HTTPError } from "./HTTPError.js";

const { randexp } = RandExp;

const dirname = fileURLToPath(new URL(".", import.meta.url));
const app = express();

const apiKeys = [
    "c4game"
];

const dataPath = "/api/data";
const parametrizedDataPath = "/api/data/:id";

/**
 * The data provided by the api.
 *
 * @type {Record<string, unknown>}
 */
let data = {};

/**
 * Creates a new guid.
 *
 * @returns {string}
 * The newly created guid.
 */
function createGuid()
{
    return randexp(/[0-9a-f]{8}(-[0-9a-f]{4}){4}[0-9a-f]{8}/);
}

app.use(express.static(join(dirname, "..", "..", "game", "lib", "static")));
app.use("/api", express.json());

app.use(
    "/api",
    (request, response, next) =>
    {
        const keyParam = "token";

        if (keyParam in request.query)
        {
            let key = request.query[keyParam];

            if (typeof key === "string" && apiKeys.includes(key))
            {
                next();
            }
            else
            {
                next(new HTTPError(401, "The specified API token is invalid"));
            }
        }
        else
        {
            next(new HTTPError(401, "An API token is required"));
        }
    });

app.get(
    parametrizedDataPath,
    (request, response, next) =>
    {
        let id = request.params.id;
        console.log(`Data ID \`${id}\` requested`);

        if (id in data)
        {
            response.send(data[id]);
        }
        else
        {
            next();
        }
    });

app.post(
    dataPath,
    (request, response, next) =>
    {
        let id = createGuid();
        data[id] = request.body;
        response.send({ id });
    });

app.put(
    parametrizedDataPath,
    (request, response, next) =>
    {
        let id = request.params.id;

        if (id in data)
        {
            data[id] = request.body;
            response.send(data[id]);
        }
        else
        {
            next();
        }
    });

app.delete(
    parametrizedDataPath,
    (request, response, next) =>
    {
        let id = request.params.id;

        if (id in data)
        {
            delete data[id];
            response.send();
            response.status(204);
        }
        else
        {
            next();
        }
    });

app.use(
    [
        (error, request, response, next) =>
        {
            response.send(`${error}`);
            response.status(error instanceof HTTPError ? error.status : 500);
        }
    ]);

app.use(
    "/api",
    (request, response) =>
    {
        response.send({ error: "Not Found" });
        response.status(404);
    });

app.use(
    (request, response) =>
    {
        response.send("Not Found");
        response.status(404);
    });

app.listen(1337);