/**
 * @file me.js
 * @description `/api/me` — the signed-in account's own UI preferences
 * (`user_prefs`) and its first-run setup (docs/plans/onboarding), so they
 * follow it to any browser, differ between the accounts of one dashboard, and
 * the setup wizard shows once per account. Local mode is one account,
 * `local`; server mode keys a row `u<id>` by the login cookie — the request
 * never names an account. Only the keys in `PREF_KEYS` are kept, each a
 * string of at most 8 KB, and a PUT merges into the row (`null` removes a
 * key). Writes are same-origin and touch only the caller's own row.
 * `/instructions` is the account's own agent instructions (issue #67, at most
 * 16 000 characters, blank clears), put before the workspace's in every pane
 * of a workspace the account owns (`launchExtras` in lib/lane-sources.js);
 * `tools` names the AI tools whose panes receive them.
 * `agenthub.chatUi` ("1") opens Claude/Codex sessions as a chat (`PaneChat`);
 * the appearance keys are `useTheme`'s own (`theme`, `agenthub.theme.dark|light`).
 *
 * `/account` (server mode) is the signed-in account itself for Settings →
 * Account: GET its profile, workspace/session counts and logins; PATCH its
 * display name and email; `POST /password` changes its own password (the old
 * one required, throttled like a step-up; every OTHER login ends);
 * `POST /sign-out-others` ends every login but this one. These writes take the
 * account from the login COOKIE only — a pane token (an agent acting as its
 * owner) may not change the owner's login. Each change is audited.
 * `/avatar` (server mode) is the account's own picture (server/lib/avatars.js):
 * GET serves it (`nosniff`, `sandbox` CSP), PUT takes the raw image bytes
 * (PNG/JPEG/GIF/WebP, at most 1 MB) and DELETE removes it — both writes are
 * account writes like the profile's. The sidebar shows it beside the name.
 *
 * S3 (one Linux user per account): an account's dark/light choice also becomes
 * the theme in their own Claude Code settings, written as them.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const express = require("express");
const { Router } = express;
const { db } = require("../db");
const auth = require("../lib/auth");
const { sameOriginGuard } = require("../lib/same-origin");

const router = Router();

/** The localStorage keys an account's preferences are made of. */
const PREF_KEYS = [
  "theme",
  "agenthub.theme.dark",
  "agenthub.theme.light",
  "i18nextLng",
  "agenthub.terminal.font",
  "agenthub.terminal.fontSize",
  "agenthub.ui.fontSize",
  "agenthub.pet",
  "agenthub.pet.size",
  "agenthub.pet.names",
  "agent-dashboard-sagi-enabled",
  "agent-dashboard-sagi-muted",
  "agent-monitor-notifications",
  "agenthub.defaultTool",
  "agenthub.permissionMode",
  "agenthub.tour",
  "agenthub.chatUi",
  "agenthub.workspace.allTabs",
];
const MAX_VALUE = 8 * 1024;

/** `u<id>` for a server-mode account, `local` in local mode, null when nobody is signed in. */
function userKey(req) {
  if (!auth.isServerMode()) return "local";
  const user = req.user || auth.userFromRequest(req);
  return user ? `u${user.id}` : null;
}

const getRow = db.prepare("SELECT prefs, onboarded_at FROM user_prefs WHERE user_key = ?");
const upsert = db.prepare(
  `INSERT INTO user_prefs (user_key, prefs) VALUES (?, ?)
   ON CONFLICT(user_key) DO UPDATE SET prefs = excluded.prefs,
     updated_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now')`
);
const markOnboarded = db.prepare(
  `INSERT INTO user_prefs (user_key, onboarded_at) VALUES (?, strftime('%Y-%m-%dT%H:%M:%fZ', 'now'))
   ON CONFLICT(user_key) DO UPDATE SET onboarded_at = COALESCE(onboarded_at, excluded.onboarded_at)`
);

function read(key) {
  const row = getRow.get(key);
  let prefs = {};
  try {
    prefs = row ? JSON.parse(row.prefs) : {};
  } catch {
    /* a damaged row reads as empty */
  }
  return { prefs, onboardedAt: row?.onboarded_at || null };
}

const unauth = (res) =>
  res.status(401).json({ error: { code: "EAUTH", message: "sign in first" } });

router.get("/prefs", (req, res) => {
  const key = userKey(req);
  if (!key) return unauth(res);
  res.json(read(key));
});

router.put("/prefs", sameOriginGuard, (req, res) => {
  const key = userKey(req);
  if (!key) return unauth(res);
  const patch = req.body?.prefs;
  if (!patch || typeof patch !== "object" || Array.isArray(patch)) {
    return res.status(400).json({ error: { code: "EBADPREFS", message: "prefs: an object" } });
  }
  const { prefs } = read(key);
  for (const [k, v] of Object.entries(patch)) {
    if (!PREF_KEYS.includes(k)) {
      return res.status(400).json({ error: { code: "EBADPREFS", message: `unknown key ${k}` } });
    }
    if (v === null) delete prefs[k];
    else if (typeof v === "string" && v.length <= MAX_VALUE) prefs[k] = v;
    else
      return res
        .status(400)
        .json({ error: { code: "EBADPREFS", message: `${k}: a short string` } });
  }
  upsert.run(key, JSON.stringify(prefs));
  if ("theme" in patch) followClaudeTheme(req, patch.theme);
  res.json(read(key));
});

const sources = require("../lib/lane-sources");
const instructionsView = (key) => ({
  instructions: sources.getUserInstructions(key) || "",
  max: sources.MAX_INSTRUCTIONS,
  // The tools a pane of which actually receives them (see launchExtras).
  tools: [...sources.SUPPORTED_TOOLS],
});

router.get("/instructions", (req, res) => {
  const key = userKey(req);
  if (!key) return unauth(res);
  res.json(instructionsView(key));
});

router.put("/instructions", sameOriginGuard, (req, res) => {
  const key = userKey(req);
  if (!key) return unauth(res);
  try {
    sources.setUserInstructions(key, req.body?.instructions ?? null);
  } catch (err) {
    const status = err.code === "ETOOBIG" ? 413 : 400; // as PUT /api/lanes/:id/instructions
    return res.status(status).json({ error: { code: err.code, message: err.message } });
  }
  res.json(instructionsView(key));
});

router.post("/onboarded", sameOriginGuard, (req, res) => {
  const key = userKey(req);
  if (!key) return unauth(res);
  markOnboarded.run(key);
  res.json(read(key));
});

// ── The account itself (server mode) ─────────────────────────────────────────

const { sessionWhere } = require("../lib/scope");
const { recordAccountChange } = require("../lib/audit");

const ACCOUNT_STATUS = {
  EBADFIELD: 400,
  EBADEMAIL: 400,
  EBADPASSWORD: 400,
  EBADIMAGE: 400,
  ETOOBIG: 413,
  EREAUTH: 403,
  ETOOMANY: 429,
};

function accountView(userId) {
  const row = db.prepare("SELECT * FROM users WHERE id = ?").get(userId);
  const w = sessionWhere({ user: { id: userId, role: "developer" } });
  return {
    mode: "server",
    user: auth.publicUser(row),
    workspaces: db.prepare("SELECT COUNT(*) AS n FROM lanes WHERE owner_id = ?").get(userId).n,
    sessions: db.prepare(`SELECT COUNT(*) AS n FROM sessions WHERE ${w.where}`).get(...w.params).n,
    ...auth.loginStats(userId),
  };
}

/** A write to the account: the cookie's own user, never a pane token's. */
function accountWrite(handler) {
  return async (req, res) => {
    if (!auth.isServerMode()) {
      return res
        .status(403)
        .json({ error: { code: "ELOCALMODE", message: "no account in local mode" } });
    }
    const user = auth.userFromRequest(req);
    if (!user) return unauth(res);
    try {
      const body = req.body && typeof req.body === "object" ? req.body : {};
      const { out, action } = await handler(req, user, body);
      recordAccountChange(user.id, user.id, req.method, `${user.username}: ${action}`);
      res.json(out);
    } catch (err) {
      const status = ACCOUNT_STATUS[err.code];
      if (!status) return res.status(500).json({ error: { message: err.message } });
      res.status(status).json({ error: { code: err.code, message: err.message } });
    }
  };
}

router.get("/account", (req, res) => {
  if (!auth.isServerMode()) return res.json({ mode: "local" });
  const user = req.user || auth.userFromRequest(req);
  if (!user) return unauth(res);
  res.json(accountView(user.id));
});

router.patch(
  "/account",
  sameOriginGuard,
  accountWrite(async (_req, user, body) => {
    const fields = auth.validateProfile({ displayName: body.displayName, email: body.email });
    auth.setProfile(user.id, fields);
    return { out: accountView(user.id), action: "own profile" };
  })
);

router.post(
  "/password",
  sameOriginGuard,
  accountWrite(async (req, user, body) => {
    await auth.confirmPassword(user, body.currentPassword);
    await auth.setPassword(user.username, body.newPassword, { keepToken: auth.cookieToken(req) });
    return { out: { ok: true }, action: "own password changed" };
  })
);

router.post(
  "/sign-out-others",
  sameOriginGuard,
  accountWrite(async (req, user) => {
    const ended = auth.endSessions(user.id, auth.cookieToken(req));
    return { out: { ended }, action: `signed out ${ended} other login(s)` };
  })
);

const avatars = require("../lib/avatars");

router.get("/avatar", (req, res) => {
  if (!auth.isServerMode()) return res.status(404).json({ error: { code: "ENOAVATAR" } });
  const user = req.user || auth.userFromRequest(req);
  if (!user) return unauth(res);
  const file = avatars.avatarFile(user.id);
  if (!file) return res.status(404).json({ error: { code: "ENOAVATAR", message: "no avatar" } });
  res.set("Content-Type", file.type);
  res.set("X-Content-Type-Options", "nosniff");
  res.set("Content-Security-Policy", "sandbox; default-src 'none'");
  // The client versions the URL with `avatarAt`, so a new picture is a new URL.
  res.set("Cache-Control", "private, max-age=86400");
  res.sendFile(file.path);
});

router.put(
  "/avatar",
  sameOriginGuard,
  express.raw({ type: () => true, limit: avatars.MAX_AVATAR_BYTES }),
  accountWrite(async (req, user) => {
    avatars.setAvatar(user.id, req.body);
    return { out: accountView(user.id), action: "own avatar set" };
  })
);

router.delete(
  "/avatar",
  sameOriginGuard,
  accountWrite(async (_req, user) => {
    avatars.removeAvatar(user.id);
    return { out: accountView(user.id), action: "own avatar removed" };
  })
);

// An avatar past its limit reaches here as express.raw's 413.
router.use((e, _req, res, next) => {
  if (e && e.type === "entity.too.large")
    return res.status(413).json({ error: { code: "ETOOBIG", message: "the image is too large" } });
  return next(e);
});

/** S3: an account's dark/light mode becomes their Claude Code theme (best effort). */
function followClaudeTheme(req, mode) {
  if (mode !== "dark" && mode !== "light") return;
  try {
    const runAs = require("../lib/run-as");
    const acct = runAs.accountForUser(req.user?.username);
    if (acct) require("../lib/member-claude").setTheme(acct, mode);
  } catch (err) {
    console.warn("[me] Claude theme not written:", err.message);
  }
}

module.exports = router;
module.exports.PREF_KEYS = PREF_KEYS;