// 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 fs = require("node:fs");
const crypto = require("node:crypto");
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),
            // "Back to sidebar" from the full-tab view.
            showPanel: () => api.revealSidebar("main"),
            // "On Silent Mode": sign-in identity and file encryption keys come
            // from the vault, so another computer with the same vault reaches
            // and reads the same drives. NEVER CHANGE THESE PATHS: encrypted
            // files would become unreadable.
            secrets: {
              kind: "vault",
              identitySeed: () => vaultKey("pithos/hosted-identity/v1", "Sign in to your drives on Silent Mode."),
              encryptionKey: () => vaultKey("pithos/hosted-encryption/v1", "Open your encrypted files on Silent Mode."),
            },
          });
          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 };
    });
    // Viewer: a 10-minute inline link for one object (images, audio, video).
    api.onMessage("view-url", async ({ path: apiPath } = {}) => {
      const p = await ensureServer();
      return { url: p.viewUrl(apiPath) };
    });

    // Footer updater: stage the newest signed Pithos from the extension
    // channel, then (second click) ask Theseus to restart and apply it.
    // Theseus asks the user before restarting. Older Theseus builds lack
    // these hooks; the panel then points to Settings > Extensions.
    api.onMessage("update", async ({ step = "stage" } = {}) => {
      if (step === "apply") {
        if (typeof api.restartApp !== "function") return { fallback: "settings" };
        return await api.restartApp();
      }
      if (typeof api.checkAndStageSelfUpdate !== "function") return { fallback: "settings" };
      const r = await api.checkAndStageSelfUpdate();
      const staged = r?.status === "staged" || r?.status === "already-staged";
      return { staged, status: r?.status || "unknown", detail: r?.detail || null, current: r?.current || null, next: r?.next || null };
    });
    api.onMessage("open-settings", ({ section = "" } = {}) => { api.openSettings?.(String(section)); return { ok: true }; });

    // ---- pithos.sia/<user>/<drive>/<folder>: the app at its own address ----
    // Theseus hands this add-on the requests for paths under pithos.sia (the
    // root page stays the website). They go to the control server with the
    // internal session, but only for pithos.sia's own requests and the
    // address bar, never another site's fetch or form, and only while the
    // vault is unlocked, the same as the sidebar panel.
    const siteRoutes = typeof api.registerSiteRoute === "function";
    if (siteRoutes) {
      const json = (status, body) => new Response(JSON.stringify(body), { status, headers: { "content-type": "application/json; charset=utf-8", "cache-control": "no-store" } });
      const FORWARD = ["content-type", "x-pithos", "range", "accept", "if-range"];
      const DROP = new Set(["set-cookie", "connection", "keep-alive", "transfer-encoding"]);
      api.registerSiteRoute({ host: "pithos.sia", handle: async (request) => {
        const u = new URL(request.url);
        const fetchSite = request.headers.get("sec-fetch-site");
        const origin = request.headers.get("origin");
        const own = fetchSite ? fetchSite === "same-origin" || fetchSite === "none"
          : !origin || /^(bns|https):\/\/pithos\.sia$/i.test(origin);
        const st = await vaultStatus();
        const locked = st.setup && st.prompt && !st.unlocked;
        if (u.pathname === "/api/host/unlock") {
          if (request.method !== "POST" || request.headers.get("x-pithos") !== "1" || !own) return json(403, { error: "forbidden" });
          if (!locked) return json(200, { ok: true });
          const r = await vault.requestUnlock({ reason: "Open Pithos, your S3 storage on Sia." });
          return json(200, { ok: !!r.ok });
        }
        if (locked && u.pathname === "/api/session") return json(200, { authenticated: false, locked: true, passwordLogin: false, host: "theseus" });
        const p = await ensureServer();
        const headers = { "x-pithos-site": "1" };
        for (const k of FORWARD) { const v = request.headers.get(k); if (v) headers[k] = v; }
        if (own && !locked) headers.cookie = cookie;
        const init = { method: request.method, headers, redirect: "manual" };
        if (request.method !== "GET" && request.method !== "HEAD") init.body = Buffer.from(await request.arrayBuffer());
        const res = await fetch(new URL(u.pathname + u.search, p.url), init);
        if (res.status === 404 && res.headers.get("x-pithos-not-mine")) return null;
        const out = new Headers();
        for (const [k, v] of res.headers) if (!DROP.has(k.toLowerCase())) out.set(k, v);
        return new Response(request.method === "HEAD" ? null : res.body, { status: res.status, headers: out });
      } });
    }

    // Full page: Pithos at pithos.sia/<user>/<drive>/… in an ordinary tab.
    // An older Theseus without site routes gets the loopback address.
    api.onMessage("open-in-tab", async ({ path: appPath } = {}) => {
      const p = await ensureServer();
      const clean = /^\/[^\s]*$/.test(String(appPath || "")) && appPath !== "/" ? appPath : "/drives";
      api.openTab(siteRoutes ? `https://pithos.sia${clean}` : p.authUrl);
      return { ok: true };
    });

    // ---- Theseus vault: PIN gate and the vault-derived recovery phrase ------
    // Older Theseus builds have the vault but no requestUnlock (no PIN prompt);
    // Pithos then runs ungated, as before.
    const vault = api.vault || null;
    const canPrompt = !!(vault && typeof vault.requestUnlock === "function");

    async function vaultStatus() {
      if (!vault || !vault.lifecycle) return { setup: false, unlocked: false, prompt: false };
      const st = await vault.lifecycle.status();
      return { setup: !!st.setup, unlocked: !!st.unlocked, prompt: canPrompt };
    }

    api.onMessage("vault-status", () => vaultStatus());

    async function vaultKey(purpose, reason) {
      const st = await vaultStatus();
      if (!st.setup) throw new Error("Set up the password vault in Settings › Passwords first.");
      if (!st.unlocked) {
        if (!canPrompt) throw new Error("Unlock the password vault in Settings › Passwords first.");
        const r = await vault.requestUnlock({ reason });
        if (!r.ok) throw new Error("The vault stayed locked.");
      }
      const bytes = await vault.derive(purpose);
      const key = Buffer.from(bytes.subarray(0, 32));
      bytes.fill(0);
      return key;
    }

    // Watch for the vault locking (Settings › Lock now, or a lock from another
    // extension) and tell the panel at once. This runs in the main process:
    // a hidden panel's own timers are throttled to about once a minute.
    if (canPrompt) {
      let lastUnlocked = null;
      setInterval(async () => {
        try {
          const st = await vaultStatus();
          if (st.unlocked !== lastUnlocked) {
            lastUnlocked = st.unlocked;
            api.emit("pithos-vault", st);
          }
        } catch {}
      }, 3000).unref?.();
    }

    // Pithos shows access-key secrets and can delete buckets, so in Theseus it
    // opens only with the vault unlocked: Theseus asks for the PIN (or the
    // master password after three wrong tries) in its own prompt.
    api.onMessage("gate", async () => {
      const st = await vaultStatus();
      if (!st.setup || !st.prompt || st.unlocked) return { ok: true, ...st };
      const r = await vault.requestUnlock({ reason: "Open Pithos, your S3 storage on Sia." });
      return { ...r, ...(await vaultStatus()) };
    });

    // Connect with a recovery phrase derived from the vault: nothing to write
    // down, and restoring the vault restores access. The phrase is built and
    // handed to s3d here; it never reaches the panel page.
    // CHANGING THE PURPOSE PATH OR THE DERIVATION CUTS USERS OFF FROM THEIR DATA.
    api.onMessage("connect-with-vault", async ({ indexerUrl } = {}) => {
      const st = await vaultStatus();
      if (!st.setup) throw new Error("Set up the password vault in Settings › Passwords first.");
      if (!st.unlocked) {
        if (!canPrompt) throw new Error("Unlock the password vault in Settings › Passwords first.");
        const r = await vault.requestUnlock({ reason: "Create the recovery phrase for your Sia storage." });
        if (!r.ok) throw new Error("The vault stayed locked.");
      }
      const bytes = await vault.derive("pithos/sia-recovery/v1");
      const bip39 = api.require("bip39");
      const phrase = bip39.entropyToMnemonic(Buffer.from(bytes.subarray(0, 16)).toString("hex"));
      bytes.fill(0);
      return call("POST", "/api/login", {
        body: JSON.stringify({ indexerUrl, phrase }),
        headers: { "content-type": "application/json" },
      });
    });

    // Left edge, beside the quick links. Theseus builds without left panels
    // ignore `side` and show it in the right sidebar.
    // ---- Saved credentials: vault-sealed files and the save dialog --------
    // A credentials file protected "with my Theseus vault" is AES-256-GCM
    // under a key derived from the vault, so it needs no extra password and
    // opens only where that vault is unlocked. FIXED PATH: changing it makes
    // every saved file unreadable.
    async function credentialsKey() {
      const st = await vaultStatus();
      if (!st.setup) throw new Error("Set up the password vault in Settings › Passwords first.");
      if (!st.unlocked) {
        if (!canPrompt) throw new Error("Unlock the password vault in Settings › Passwords first.");
        const r = await vault.requestUnlock({ reason: "Protect or open a saved Pithos credentials file." });
        if (!r.ok) throw new Error("The vault stayed locked.");
      }
      return Buffer.from(await vault.derive("pithos/credentials/v1"));
    }

    api.onMessage("vault-seal", async ({ plaintext } = {}) => {
      const key = await credentialsKey();
      try {
        const iv = crypto.randomBytes(12);
        const c = crypto.createCipheriv("aes-256-gcm", key, iv);
        const ct = Buffer.concat([c.update(String(plaintext || ""), "utf8"), c.final(), c.getAuthTag()]);
        return { iv: iv.toString("base64"), ct: ct.toString("base64") };
      } finally { key.fill(0); }
    });

    api.onMessage("vault-open", async ({ iv, ct } = {}) => {
      const key = await credentialsKey();
      try {
        const data = Buffer.from(String(ct || ""), "base64");
        const d = crypto.createDecipheriv("aes-256-gcm", key, Buffer.from(String(iv || ""), "base64"));
        d.setAuthTag(data.subarray(data.length - 16));
        return { plaintext: Buffer.concat([d.update(data.subarray(0, data.length - 16)), d.final()]).toString("utf8") };
      } catch {
        throw new Error("This file was saved with a different Theseus vault.");
      } finally { key.fill(0); }
    });

    // The sidebar page has no download path of its own; ask where to save.
    api.onMessage("save-file", async ({ name, text } = {}) => {
      const { dialog, BrowserWindow, app } = require("electron");
      const safe = String(name || "pithos-credentials.pithoskey").replace(/[\\/:*?"<>|]+/g, "_").slice(0, 120);
      const r = await dialog.showSaveDialog(BrowserWindow.getFocusedWindow() || undefined, {
        defaultPath: path.join(app.getPath("downloads"), safe),
        filters: [{ name: "Pithos credentials", extensions: ["pithoskey"] }],
      });
      if (r.canceled || !r.filePath) return { saved: false };
      fs.writeFileSync(r.filePath, String(text || ""), { mode: 0o600 });
      return { saved: true };
    });

    // Start the control server with Theseus, so an s3d the user left running
    // comes back after a restart or an update without opening Pithos first.
    ensureServer().catch((e) => api.log("control server failed to start:", e.message));

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

    // 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(); }
  },
};