import { HandlerContext, Handlers } from "$fresh/server.ts";
import { serveFile } from "http/file_server.ts";
import { removePrefixFromPathname } from "../../util/util.ts";

export async function GET(
  req: Request,
  ctx: HandlerContext,
): Promise<Response> {
  const url = new URL(req.url);
  const path = removePrefixFromPathname(decodeURI(url.pathname), "/fs");
  // if auth is required, check if the user is logged in.
  // if not, return a 401.
  const authRequired = Deno.env.get("AUTH_REQUIRED") === "true";
  if (authRequired) {
    const login = ctx.state["login"];
    if (!login) {
      return new Response(null, {
        status: 302,
        headers: {
          "Location": "/login",
          "content-type": "text/plain",
          "Access-Control-Allow-Origin": "*",
          "Access-Control-Allow-Methods": "GET,HEAD,PUT,PATCH,POST,DELETE",
          "Access-Control-Allow-Headers":
            "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With",
        },
      });
    }
  }

  try {
    const fileInfo = await Deno.stat(path);
    if (fileInfo.isDirectory) {
      // if index.html exists, serve it.
      // otherwise, serve a directory listing.
      const indexPath = path + "/index.html";
      try {
        await Deno.stat(indexPath);
        const res = await serveFile(req, indexPath);
        return res;
      } catch (e) {
        if (e instanceof Deno.errors.NotFound) {
          const list: Deno.DirEntry[] = [];
          for await (const entry of Deno.readDir(path)) {
            list.push(entry);
          }
          return new Response(
            JSON.stringify(
              list,
            ),
            {
              headers: {
                "content-type": "application/json",
                "Access-Control-Allow-Origin": "*",
                "Access-Control-Allow-Methods":
                  "GET,HEAD,PUT,PATCH,POST,DELETE",
                "Access-Control-Allow-Headers":
                  "Content-Type, Access-Control-Allow-Headers, Authorization, X-Requested-With",
              },
              status: 200,
            },
          );
        }
      }
    }
    const res = await serveFile(req, path, {
      fileInfo,
    });
    return res;
  } catch (e) {
    if (e instanceof Deno.errors.NotFound) {
      return new Response("Not Found", {
        status: 404,
      });
    }
    throw e;
  }
}

export const handler: Handlers = {
  GET,
};