// Pithos for Theseus. The add-on runs the same control server as the web
// console and desktop app, in Theseus's main process, and shows the same UI
// as a left-sidebar panel. The panel is the add-on's own ui/index.html, so
// no loopback address ever appears in the address bar: the UI's API calls,
// uploads and live events travel over the add-on IPC bridge (invoke / emit),
// and this file forwards them to the server with an internal session.
//
// Loaded with require() by the add-on host; core/ is ESM, hence import().

const path = require("node:path");
const { pathToFileURL } = require("node:url");

let pithos = null;
let starting = null;
let cookie = null;
let events = null; // AbortController for the /api/events relay

module.exports = {
  activate(api) {
    // The pinned s3d release lands in the per-add-on data folder, never in the
    // add-on folder itself (that one is replaced on update).
    const dataDir = path.join(api.dataDir || path.join(api.folder, "..", "..", "extensions-data"), "pithos");

    async function ensureServer() {
      if (pithos) return pithos;
      if (!starting) {
        starting = (async () => {
          const { createPithos } = await import(pathToFileURL(path.join(__dirname, "core", "server.js")).href);
          const p = await createPithos({
            host: "127.0.0.1",
            port: 0,
            hostName: "theseus",
            binDir: path.join(dataDir, "bin"),
            openExternal: (url) => api.openTab(url),
          });
          cookie = p.internalSession();
          pithos = p;
          api.log(`control server on ${p.url}`);
          return p;
        })().finally(() => { starting = null; });
      }
      return starting;
    }

    async function call(method, apiPath, { body, headers = {} } = {}) {
      const p = await ensureServer();
      const res = await fetch(new URL(apiPath, p.url), {
        method,
        headers: { cookie, "x-pithos": "1", ...headers },
        body,
      });
      const text = await res.text();
      let data = null;
      try { data = text ? JSON.parse(text) : null; } catch { data = { error: text }; }
      return { status: res.status, data };
    }

    // Relay the server's event stream to the panel as api.emit events.
    async function startEvents() {
      if (events) return;
      const p = await ensureServer();
      const ctl = new AbortController();
      events = ctl;
      try {
        const res = await fetch(new URL("/api/events", p.url), { headers: { cookie }, signal: ctl.signal });
        const reader = res.body.getReader();
        const dec = new TextDecoder();
        let buf = "";
        for (;;) {
          const { value, done } = await reader.read();
          if (done) break;
          buf += dec.decode(value, { stream: true });
          let i;
          while ((i = buf.indexOf("\n\n")) >= 0) {
            const block = buf.slice(0, i);
            buf = buf.slice(i + 2);
            const ev = /^event: (.+)$/m.exec(block);
            const data = /^data: (.+)$/m.exec(block);
            if (ev && data) api.emit("pithos-event", { event: ev[1], data: JSON.parse(data[1]) });
          }
        }
      } catch (e) {
        if (!ctl.signal.aborted) api.log("event relay stopped:", e.message);
      } finally {
        if (events === ctl) events = null;
      }
    }

    api.onMessage("api", ({ method, path: apiPath, body }) =>
      call(method || "GET", apiPath, body === undefined ? {} : { body: JSON.stringify(body), headers: { "content-type": "application/json" } }));

    // Uploads arrive as one ArrayBuffer over IPC; forward it as the PUT body.
    api.onMessage("upload", ({ path: apiPath, bytes, type }) =>
      call("PUT", apiPath, { body: Buffer.from(bytes), headers: { "content-type": type || "application/octet-stream" } }));

    // Hand the file to Theseus's own download manager through a one-time link.
    api.onMessage("download", async ({ path: apiPath }) => {
      const p = await ensureServer();
      const { session } = require("electron");
      session.defaultSession.downloadURL(p.downloadUrl(apiPath));
      return { ok: true };
    });

    api.onMessage("events-start", () => { startEvents(); return { ok: true }; });
    api.onMessage("open-external", ({ url }) => {
      if (!/^https:\/\//.test(url)) throw new Error("only https links");
      api.openTab(url);
      return { ok: true };
    });
    // A full browser-tab view, for anyone who prefers it to the sidebar.
    api.onMessage("open-in-tab", async () => {
      const p = await ensureServer();
      api.openTab(p.authUrl);
      return { ok: true };
    });

    api.registerSidebarPanel({ id: "main", title: "Pithos", page: "ui/index.html" });

    // The host has no quit hook for add-ons; without this an s3d we started
    // would outlive Theseus.
    process.on("exit", () => { try { pithos && pithos.daemon.child && pithos.daemon.child.kill(); } catch {} });
  },

  async deactivate() {
    if (events) { events.abort(); events = null; }
    if (pithos) { const p = pithos; pithos = null; cookie = null; await p.close(); }
  },
};