import { Config } from "./config.ts";

const ws = new WebSocket(Deno.args[0])
// deno-lint-ignore no-unused-vars
let config: Config = {} as unknown as Config

const supported = [
    "youtube-channel-info"
]
function key_to_url(key: string): string {
    const [kind, id] = key.split(":", 2)
    if (kind == "youtube-channel-info") return `https://youtube.com/channel/${id}`
    throw new Error(`unknown kind ${kind}`);
}

async function dfile(path: string, url: string) {
    console.log(`thumbnail download ${path} from ${url}`);
    const r = await fetch(url)
    if (!r.body) return console.error("thumbnail download failed");
    await Deno.writeFile(path, new Uint8Array(await r.arrayBuffer()))
}

async function save_infojson(url: string, key: string, data: { [key: string]: unknown }) {
    if (!data.output) throw new Error("output dir missing");
    const output = data.output
    const infojson = `${output}/channel.info.json`;
    const o = await new Deno.Command("yt-dlp", {
        args: [
            "--skip-download",
            "--write-info-json",
            "-o", `${output}/channel`,
            "--playlist-items", "0",
            url
        ],
        stdout: "piped",
        stderr: "inherit",
    }).output()
    if (!o.success) throw new Error("info json download failed");

    ws.send(JSON.stringify({ t: "metadata", key, data: { progress: 0.5 } }))

    const oj = JSON.parse(await Deno.readTextFile(infojson))
    const avatar = oj.thumbnails?.find((t: { id: string }) => t.id == "avatar_uncropped") ?? oj?.thumbnails?.[oj.thumbnails?.length - 1]
    const banner = oj.thumbnails?.find((t: { id: string }) => t.id == "banner_uncropped")
    if (avatar) await dfile(`${output}/poster.jpeg`, avatar.url)
    ws.send(JSON.stringify({ t: "metadata", key, data: { progress: 0.75 } }))
    if (banner) await dfile(`${output}/backdrop.jpeg`, banner.url)
    ws.send(JSON.stringify({ t: "metadata", key, data: { progress: 1 } }))
}

ws.onerror = () => console.error("ws error")
ws.onclose = () => {
    console.error("ws closed")
    Deno.exit(1)
}
ws.onopen = () => {
    console.log("ws open");
    ws.send(JSON.stringify({ t: "register", name: "yt-dlp channel info generator", task_kinds: supported }))
    ws.send(JSON.stringify({ t: "accept" }))
}
ws.onmessage = async ev => {
    if (typeof ev.data != "string") return
    const p = JSON.parse(ev.data)
    if (p.t == "config") config = p.config
    if (p.t == "error") console.error(`error: ${p.message}`);
    if (p.t == "work") {
        const url = key_to_url(p.key)
        if (!p.data.output) throw new Error("no output");
        console.log(`got work ${p.key}`);
        await save_infojson(url, p.key, p.data)
        ws.send(JSON.stringify({ t: "complete", key: p.key }))
        ws.send(JSON.stringify({ t: "save" }))
        ws.send(JSON.stringify({ t: "accept" }))
    }
}