/*
	Spacebar: A FOSS re-implementation and extension of the Discord.com backend.
	Copyright (C) 2023 Spacebar and Spacebar Contributors
	
	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU Affero General Public License as published
	by the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU Affero General Public License for more details.
	
	You should have received a copy of the GNU Affero General Public License
	along with this program.  If not, see <https://www.gnu.org/licenses/>.
*/

import { Request, Response, Router } from "express";
import fs from "fs/promises";
import { HTTPError } from "lambert-server";
import { join } from "path";
import { fileTypeFromBuffer } from "file-type";

const defaultAvatarHashMap = new Map([
    ["0", "4a8562cf00887030c416d3ec2d46385a"],
    ["1", "9b0bb198936784c45c72833cc426cc55"],
    ["2", "22341bdb500c7b63a93bbce957d1601e"],
    ["3", "d9977836b82058bf2f74eebd50edc095"],
    ["4", "9d6ddb4e4d899a533a8cc617011351c9"],
    ["5", "7213ab6677377974697dfdfbaf5f6a6f"],
]);

const defaultGroupDMAvatarHashMap = new Map([
    ["0", "3b70bb66089c60f8be5e214bf8574c9d"],
    ["1", "9581acd31832465bdeaa5385b0e919a3"],
    ["2", "a8a4727cf2dc2939bd3c657fad4463fa"],
    ["3", "2e46fe14586f8e95471c0917f56726b5"],
    ["4", "fac7e78de9753d4a37083bba74c1d9ef"],
    ["5", "4ab900144b0865430dc9be825c838faa"],
    ["6", "1276374a404452756f3c9cc2601508a5"],
    ["7", "904bf9f1b61f53ef4a3b7a893afeabe3"],
]);

const router = Router({ mergeParams: true });

async function getFile(path: string) {
    try {
        return fs.readFile(path);
    } catch (error) {
        try {
            const files = await fs.readdir(path);
            if (!files.length) return null;
            return fs.readFile(join(path, files[0]));
        } catch (error) {
            return null;
        }
    }
}

router.get("/avatars/:id", async (req: Request, res: Response) => {
    let { id } = req.params;
    id = id.split(".")[0]; // remove .file extension
    const hash = defaultAvatarHashMap.get(id);
    if (!hash) throw new HTTPError("not found", 404);
    const path = join(__dirname, "..", "..", "..", "assets", "public", `${hash}.png`);

    const file = await getFile(path);
    if (!file) throw new HTTPError("not found", 404);
    const type = await fileTypeFromBuffer(file);

    res.set("Content-Type", type?.mime);
    res.set("Cache-Control", "public, max-age=31536000");

    return res.send(file);
});

router.get("/group-avatars/:id", async (req: Request, res: Response) => {
    let { id } = req.params;
    id = id.split(".")[0]; // remove .file extension
    const hash = defaultGroupDMAvatarHashMap.get(id);
    if (!hash) throw new HTTPError("not found", 404);
    const path = join(__dirname, "..", "..", "..", "assets", "public", `${hash}.png`);

    const file = await getFile(path);
    if (!file) throw new HTTPError("not found", 404);
    const type = await fileTypeFromBuffer(file);

    res.set("Content-Type", type?.mime);
    res.set("Cache-Control", "public, max-age=31536000");

    return res.send(file);
});

export default router;