import path from "node:path";
import { listFiles, downloadFile } from "@huggingface/hub";

import { sha256 } from "../utils/sha256";
import { Mod } from "./mod";
import { Server } from "../server/server";
import { ModMetadata } from "./mod-metadata";

export class ModManager {
    private server: Server;
    private bucketId = "buckets/NSMP/NSMP-Server-Storage";
    private bucketFolder = "mods";

    constructor(server: Server) {
        this.server = server;
    }

    public async createModEndpoints(): Promise<void> {
        const mods: Mod[] = await this.getModList();

        this.server.get("/mods/", (_req, res) => {
            res.send(JSON.stringify(mods));
        });

        this.server.get("/files/mods/:filename", async (req, res) => {
            try {
                const filename = req.params.filename;

                const mod = mods.find(m => m.filename === filename);

                if (!mod) {
                    res.status(404).send("Mod not found in index");
                    return;
                }

                const blob = await downloadFile({
                    repo: this.bucketId,
                    path: mod.path,
                    accessToken: process.env.HF_TOKEN
                });

                if (!blob) {
                    res.status(404).send("Mod not found");
                    return;
                }

                const buffer = Buffer.from(await blob.arrayBuffer());

                res.setHeader(
                    "Content-Disposition",
                    `attachment; filename="${filename}"`
                );
                res.setHeader("Content-Type", "application/java-archive");

                res.send(buffer);
            } catch (err) {
                console.error(err);
                res.status(500).send("Failed to fetch mod from bucket");
            }
        });
    }

    private async getModList(): Promise<Mod[]> {
        const mods: Mod[] = [];

        for await (const item of listFiles({
            repo: this.bucketId,
            path: this.bucketFolder,
            recursive: true,
            accessToken: process.env.HF_TOKEN
        })) {
            if (item.type !== "file" || !item.path.toLowerCase().endsWith(".jar")) {
                continue;
            }

            const jarPath = item.path;
            const jsonPath = `${jarPath}.json`;

            const [jarBlob, metadataBlob] = await Promise.all([
                downloadFile({ repo: this.bucketId, path: jarPath }),
                downloadFile({ repo: this.bucketId, path: jsonPath }),
            ]);

            if (!jarBlob || !metadataBlob) {
                continue;
            }

            const jarBuffer = Buffer.from(await jarBlob.arrayBuffer());
            const metadataContent = Buffer.from(await metadataBlob.arrayBuffer()).toString("utf-8");

            const metadata = JSON.parse(metadataContent) as ModMetadata;
            const hash = sha256(jarBuffer);

            const filename = path.basename(jarPath);

            mods.push({
                name: metadata.name,
                filename,
                path: jarPath,
                sha256: hash,
                url: `https://NSMP-NSMP-Server.hf.space/files/mods/${encodeURIComponent(filename)}`,
            });
        }

        return mods;
    }
}