import { serve } from "https://deno.land/std/http/server.ts";
import "https://deno.land/x/dotenv/load.ts";
const SERVER_PORT = Deno.env.get("SERVER_PORT") ?? "8080";
const SERVER_HOST = Deno.env.get("SERVER_HOST") ?? "localhost";
const API_URL = Deno.env.get("API_URL") ?? "https://git.sr.ht/query";
const API_KEY = Deno.env.get("API_KEY");

interface QueryResponse {
    data: {
        repositories: {
            results: Repository[];
        };
    };
}

interface Repository {
    id: string,
    name: string,
    description: string,
    updated: string,
    visibility: "PUBLIC" | "UNLISTED" | "PRIVATE"
}

window.onload = function() {
    if(!API_KEY) {
        throw new Error("API_KEY is empty");
    }
}

const cache = {
    added: 0,
    value: {} as QueryResponse,
    set(data: QueryResponse) {
        cache.value = data;
        cache.added = +new Date();
    }
}

async function getRepositories(): Promise<Repository[] | undefined> {
    const response = await fetch(API_URL, {
        method: "POST",
        headers: {
            "Authorization": "Bearer " + API_KEY,
            "Content-Type": "application/json"
        },
        body: JSON.stringify({
            query: `
{
    repositories {
        results {
            id,
            name,
            description,
            updated,
            visibility
        }
    }
}
    `
        })
    })

    if (response.ok) {
        let json

        if (cache.added < (+new Date() - 3.6E6)) { // cached for 1 hour
            json = await response.json() as QueryResponse;
            cache.set(json);
            console.log("from api");
        } else {
            json = cache.value;
            console.log("from cache");
        }

        return json?.data.repositories.results?.filter(repo => repo.visibility === "PUBLIC") ?? [];
    } else {
        throw response;
    }
}

console.log("srht-git-feed is running on: http://" + SERVER_HOST + ":" + SERVER_PORT);
for await (const req of serve({ port: parseInt(SERVER_PORT), hostname: SERVER_HOST })) {
    try {
        if (req.url === "/version.txt") {
            req.respond({ body: await Deno.readTextFile("version.txt") });
        } else if (req.url === "/") {
            const headers = new Headers();
            headers.append("Cache-Control", "public,no-transform,max-age=3600");
            headers.append("Content-Type", "application/json");
            headers.append("Expires", new Date(Date.now() + 3600).toUTCString());
            req.respond({ body: JSON.stringify(await getRepositories()), headers: headers });
        } else {
            req.respond({
                status: 404
            });
        }
    } catch(err) {
        req.respond({ body: JSON.stringify(err) });
    }
}