/**
 * @file scope.js
 * @description Server mode's row ownership (phase S2, docs/SERVER-MODE.md) —
 * the ONE place that decides which rows a request may see.
 *
 * A workspace (`lanes.owner_id`) belongs to the user who created it. A session
 * belongs to its workspace: `sessions.lane_id`, or a `dashboard_runs` row of
 * that workspace holding it (a session not stamped yet). Agents, events and
 * token rows belong to their session. A developer sees and changes only what
 * their own workspaces own; an analyst SEES everything but changes only their
 * own (every non-GET request is scoped like a developer's); an admin sees and
 * changes everything, and so does every request in local mode (`req.user` is
 * never set there).
 *
 * Every helper takes `req`, so no caller can pick whose rows it reads.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const sql = (q) => require("../db").db.prepare(q);

/** The user whose rows this request is limited to, or null for "all". */
function memberId(req) {
  const u = req?.user;
  if (!u) return null;
  if (u.role === "developer") return u.id;
  // An analyst reads every user's rows but writes only their own.
  if (u.role === "analyst" && req.method !== "GET" && req.method !== "HEAD") return u.id;
  return null;
}

/** The owner a workspace created by this request gets (null outside server mode). */
const ownerFor = (req) => (req?.user ? req.user.id : null);

/**
 * SQL predicate over a sessions alias: `{where, params}`, `where` = "1" when
 * unrestricted. `col` is the session id expression, `laneCol` its lane id.
 */
function sessionWhere(req, col = "id", laneCol = "lane_id") {
  const uid = memberId(req);
  if (uid == null) return { where: "1", params: [] };
  return {
    where: `(${laneCol} IN (SELECT id FROM lanes WHERE owner_id = ?)
      OR ${col} IN (SELECT r.session_id FROM dashboard_runs r JOIN lanes l ON l.id = r.lane_id
                     WHERE l.owner_id = ? AND r.session_id IS NOT NULL))`,
    params: [uid, uid],
  };
}

/** SQL predicate for any table carrying a session id column (events, agents, tokens). */
function bySessionWhere(req, col = "session_id") {
  const uid = memberId(req);
  if (uid == null) return { where: "1", params: [] };
  const s = sessionWhere(req, "s.id", "s.lane_id");
  return { where: `${col} IN (SELECT s.id FROM sessions s WHERE ${s.where})`, params: s.params };
}

/** SQL predicate over a lanes id column. */
function laneWhere(req, col = "id") {
  const uid = memberId(req);
  if (uid == null) return { where: "1", params: [] };
  return { where: `${col} IN (SELECT id FROM lanes WHERE owner_id = ?)`, params: [uid] };
}

function canSeeLane(req, laneId) {
  const uid = memberId(req);
  if (uid == null) return true;
  // Bound as given, like getLane binds a route param: SQLite's integer
  // affinity reads '9002.0' or ' 9002' as 9002 for both, so the row checked
  // here is the row the route would load.
  const v = typeof laneId === "number" ? laneId : String(laneId);
  const row = sql("SELECT owner_id FROM lanes WHERE id = ?").get(v);
  return Boolean(row) && row.owner_id === uid;
}

function canSeeSession(req, sessionId) {
  if (memberId(req) == null) return true;
  const s = sessionWhere(req);
  return Boolean(
    sql(`SELECT 1 FROM sessions WHERE id = ? AND ${s.where}`).get(String(sessionId), ...s.params)
  );
}

function canSeeAgent(req, agentId) {
  if (memberId(req) == null) return true;
  const row = sql("SELECT session_id FROM agents WHERE id = ?").get(String(agentId));
  return Boolean(row) && canSeeSession(req, row.session_id);
}

/** A run id `agenthub-lane-<n>[-<slot>]` (or an archived `…@<time>`) → its lane. */
function canSeeRun(req, runId) {
  if (memberId(req) == null) return true;
  const m = /^agenthub-lane-(\d+)(?:-\d+)?(?:@.*)?$/.exec(String(runId || ""));
  if (m) return canSeeLane(req, m[1]);
  const row = sql("SELECT lane_id FROM dashboard_runs WHERE id = ?").get(String(runId));
  return Boolean(row && row.lane_id != null) && canSeeLane(req, row.lane_id);
}

/** The ids of every workspace this request may see, or null for "all". */
function visibleLaneIds(req) {
  const uid = memberId(req);
  if (uid == null) return null;
  return sql("SELECT id FROM lanes WHERE owner_id = ?")
    .all(uid)
    .map((r) => r.id);
}

/** A row of `table` (`id` = `rowId`) whose `session_id` this request may see. */
function canSeeRowSession(req, table, rowId, idCol = "id") {
  if (memberId(req) == null) return true;
  const row = sql(`SELECT session_id FROM ${table} WHERE ${idCol} = ?`).get(String(rowId));
  return Boolean(row && row.session_id) && canSeeSession(req, row.session_id);
}

/** A `dashboard_runs` row (`/api/run/history/:id`) of one of this request's workspaces. */
function canSeeRunRow(req, id) {
  if (memberId(req) == null) return true;
  const row = sql("SELECT lane_id FROM dashboard_runs WHERE id = ?").get(String(id));
  return Boolean(row && row.lane_id != null) && canSeeLane(req, row.lane_id);
}

/**
 * Path rules for routes that name ONE row: `[pattern, check(req, match)]`,
 * matched against the path under `/api`. Keep this in step with the routers —
 * a new route that takes an id under one of these prefixes is covered by its
 * prefix; one under a new prefix needs a rule here.
 */
// First segments under /lanes (and /workspaces) that are routes, not ids.
const LANE_WORDS = new Set([
  "branches",
  "browse",
  "ensure",
  "gc",
  "pick-path",
  "pipelines",
  "pipeline-stats",
  "worktree",
]);

const PATH_RULES = [
  [/^\/sessions\/(?!facets\/?$)([^/]+)/i, (req, m) => canSeeSession(req, m[1])],
  [/^\/agents\/([^/]+)/i, (req, m) => canSeeAgent(req, m[1])],
  // A segment that is not one of the routes' own words is a lane id: it must
  // be plain digits, which every reader (parseInt, Number, SQLite affinity)
  // takes as the same lane — '1e1' is 10 to SQLite and 1 to parseInt.
  [
    /^\/(?:lanes|workspaces)\/([^/]+)/i,
    (req, m) =>
      LANE_WORDS.has(m[1].toLowerCase()) || (/^\d+$/.test(m[1]) && canSeeLane(req, Number(m[1]))),
  ],
  [/^\/run\/history\/([^/]+)/i, (req, m) => canSeeRunRow(req, m[1])],
  [/^\/run\/([^/]+)/i, (req, m) => !/^agenthub-lane-/i.test(m[1]) || canSeeRun(req, m[1])],
  [/^\/pricing\/cost\/([^/]+)/i, (req, m) => canSeeSession(req, m[1])],
  [/^\/workflows\/session\/([^/]+)/i, (req, m) => canSeeSession(req, m[1])],
  [/^\/workflows\/runs\/([^/]+)/i, (req, m) => canSeeRowSession(req, "workflows", m[1], "run_id")],
  [/^\/alerts\/([^/]+)\/ack/i, (req, m) => canSeeRowSession(req, "alert_events", m[1])],
  [
    /^\/snapshots\/([^/]+)$/i,
    (req, m) => req.method !== "DELETE" || canSeeRowSession(req, "session_snapshots", m[1]),
  ],
];

const list = (v) =>
  (Array.isArray(v) ? v : String(v).split(",")).map((x) => String(x).trim()).filter(Boolean);

/**
 * Ids a request names in its query string or JSON body, by kind. A value
 * that is not a plain string or number (an array from `?x[]=`, an object) is
 * returned in `bad`: a member's request carrying one is refused outright.
 */
function namedIds(req) {
  const q = req.query || {};
  const b = req.body && typeof req.body === "object" && !Array.isArray(req.body) ? req.body : {};
  const out = { lanes: [], sessions: [], bad: false };
  const take = (into, v) => {
    if (v === undefined || v === null || v === "") return;
    if (typeof v === "string" || typeof v === "number") into.push(String(v));
    else out.bad = true;
  };
  for (const v of [q.lane, q.laneId, q.lane_id, b.laneId, b.lane_id]) take(out.lanes, v);
  for (const v of [
    q.session_id,
    q.sessionId,
    q.session,
    b.session_id,
    b.sessionId,
    b.resumeSessionId,
  ]) {
    take(out.sessions, v);
  }
  if (q.session_ids !== undefined) {
    if (typeof q.session_ids !== "string") out.bad = true;
    else out.sessions.push(...list(q.session_ids));
  }
  return out;
}

/**
 * Express middleware (on `/api`, after authGuard): a member naming a row that
 * is not theirs — in the path, the query or the body — gets 404, the same
 * answer as a row that does not exist. A no-op for an admin, an analyst's
 * reads, and local mode.
 */
function scopeGuard(req, res, next) {
  if (memberId(req) == null) return next();
  const notFound = () =>
    res.status(404).json({ error: { code: "ENOTFOUND", message: "not found" } });
  const p = require("./auth").apiPath(req);
  for (const [re, check] of PATH_RULES) {
    const m = re.exec(p);
    if (m && !check(req, m)) return notFound();
  }
  const { lanes, sessions, bad } = namedIds(req);
  if (bad) return notFound();
  if (lanes.some((id) => !/^\d+$/.test(id) || !canSeeLane(req, Number(id)))) return notFound();
  if (sessions.some((id) => !canSeeSession(req, id))) return notFound();
  return next();
}

// ── WebSocket broadcasts ───────────────────────────────────────────────────

const STAFF = { staffOnly: true };

/** Owner ids of the workspaces that own a session (stamped or held by a run). */
function sessionOwners(sessionId) {
  if (!sessionId) return new Set();
  const rows = sql(
    `SELECT l.owner_id FROM sessions s JOIN lanes l ON l.id = s.lane_id WHERE s.id = ?
     UNION
     SELECT l.owner_id FROM dashboard_runs r JOIN lanes l ON l.id = r.lane_id WHERE r.session_id = ?`
  ).all(String(sessionId), String(sessionId));
  return new Set(rows.map((r) => r.owner_id).filter((x) => x != null));
}

function laneOwners(laneId) {
  const row =
    laneId == null ? null : sql("SELECT owner_id FROM lanes WHERE id = ?").get(Number(laneId));
  return new Set(row && row.owner_id != null ? [row.owner_id] : []);
}

/**
 * Who a broadcast may reach: `null` = every client, `{owners: Set<userId>}` =
 * admin/analyst plus those members, `{staffOnly: true}` = admin/analyst only.
 * A message type not listed here reaches no member — add it when a member's
 * page needs it.
 */
function broadcastAudience(type, data) {
  const d = data && typeof data === "object" ? data : {};
  switch (type) {
    case "session_created":
    case "session_updated":
      return { owners: sessionOwners(d.id) };
    case "agent_created":
    case "agent_updated":
    case "new_event":
    case "workflow_upserted":
      return { owners: sessionOwners(d.session_id) };
    case "alert_triggered":
    case "alert_updated":
      if (d.acked_all) return null;
      return d.session_id ? { owners: sessionOwners(d.session_id) } : STAFF;
    case "lane_update":
      // A removal names an id that no longer resolves; it reveals nothing.
      if (d.removed != null && !d.lane) return null;
      return { owners: laneOwners(d.lane?.id) };
    case "lane_hook_output":
    case "lane_hook_result":
    case "lane_runtime":
      return { owners: laneOwners(d.laneId) };
    case "update_status":
    // No payload: each client refetches its own `GET /api/run/interrupted`.
    case "runs_interrupted":
      return null;
    // A member's prompt box refetches its command list on these, but the
    // payload names the host's profiles and files: members get the type only.
    case "cc_config_changed":
    case "codex_config_changed":
      return { strip: true };
    default:
      return STAFF;
  }
}

/** Whether a client logged in as `user` (undefined in local mode) gets it. */
function audienceIncludes(audience, user) {
  if (!user || user.role !== "developer") return true;
  if (audience === null || audience.strip) return true;
  return Boolean(audience.owners && audience.owners.has(user.id));
}

/**
 * A non-admin's own folder, `<AGENTHUB_USERS_ROOT>/<username>`, or null (no
 * root set, or an admin). Whatever the method: an analyst reads every user's
 * ROWS, but a path named in a request is read with the dashboard's own rights
 * (CAP_DAC_READ_SEARCH under S3), so an analyst's GET is held to it too.
 */
function ownFolder(req) {
  const root = (process.env.AGENTHUB_USERS_ROOT || "").trim();
  if (!req?.user || req.user.role === "admin" || !root) return null;
  const path = require("node:path");
  return path.join(path.resolve(root), req.user.username);
}

/**
 * The folder a member's workspace may use: anywhere outside server mode or for
 * an admin; for a member, only inside `<AGENTHUB_USERS_ROOT>/<username>` when
 * that root is set. `dir` must already be absolute and canonical. Until
 * accounts are Linux users (S3) this keeps workspaces apart, not agents: a
 * terminal can still reach any folder the host account can. Under S3 the
 * home ITSELF is no workspace (its dot folders hold the member's logins and
 * pane tokens, which a workspace's file views would serve) — `allowHome`
 * is for browsing to a folder, not for making one a workspace.
 */
function folderAllowed(req, dir, { allowHome = false } = {}) {
  const home = ownFolder(req);
  if (!home) return true;
  const path = require("node:path");
  const rel = path.relative(home, path.resolve(dir));
  if (rel === "") return allowHome || !require("./linux-accounts").s3Enabled();
  return rel.split(path.sep)[0] !== ".." && !path.isAbsolute(rel);
}

/**
 * Server mode: whether `dir` is, lies inside, or contains the folder of a
 * workspace this member does not own (another user's, or the host's) — for any
 * tool. A member's workspace may not overlap another's, or its git and file
 * views would reach that user's files.
 */
function folderTakenByOther(req, dir) {
  const uid = memberId(req);
  if (uid == null) return false;
  const path = require("node:path");
  const mine = path.resolve(dir);
  const related = (a, b) => {
    const rel = path.relative(a, b);
    return rel === "" || (rel.split(path.sep)[0] !== ".." && !path.isAbsolute(rel));
  };
  return sql("SELECT cwd FROM lanes WHERE owner_id IS NULL OR owner_id != ?")
    .all(uid)
    .some((r) => typeof r.cwd === "string" && (related(r.cwd, mine) || related(mine, r.cwd)));
}

/**
 * Server mode: whether a non-admin may name `dir` — only inside one of their
 * own workspaces' folders, compared by real path so a symlink in their folder
 * cannot point the check elsewhere. An analyst's GET too (a path is read with
 * the dashboard's rights, see `ownFolder`). Always true for an admin.
 */
function insideOwnWorkspace(req, dir) {
  const u = req?.user;
  if (!u || u.role === "admin") return true;
  return insideLanes(
    sql("SELECT id FROM lanes WHERE owner_id = ?")
      .all(u.id)
      .map((r) => r.id),
    dir
  );
}

/**
 * Server mode: Express middleware for the config readers (`/cc-config`,
 * `/codex-config`) — a non-admin's `?cwd=` (an analyst's GET included) must be
 * inside one of THEIR OWN workspaces, else 403 EFOLDER. A caller-chosen
 * folder is a path the dashboard reads as itself: under S3, with
 * CAP_DAC_READ_SEARCH, one planted link (`/tmp/a/.claude -> /`) made it a
 * whole-machine read. An admin, and local mode, pass.
 */
function ownCwdQuery(req, res, next) {
  const asked = typeof req.query?.cwd === "string" && req.query.cwd;
  if (!asked || !req.user || req.user.role === "admin") return next();
  const own = sql("SELECT id FROM lanes WHERE owner_id = ?")
    .all(req.user.id)
    .map((r) => r.id);
  if (require("node:path").isAbsolute(asked) && insideLanes(own, asked)) return next();
  res.status(403).json({
    error: { code: "EFOLDER", message: "that folder is not one of your workspaces" },
  });
}

function insideLanes(ids, dir) {
  const path = require("node:path");
  const lanesLib = require("./lanes");
  const real = lanesLib.canonicalCwd(dir);
  return ids.some((id) => {
    const cwd = lanesLib.getLane(id)?.cwd;
    if (!cwd) return false;
    const rel = path.relative(cwd, real);
    return rel === "" || (rel.split(path.sep)[0] !== ".." && !path.isAbsolute(rel));
  });
}

module.exports = {
  insideOwnWorkspace,
  ownCwdQuery,
  folderTakenByOther,
  scopeGuard,
  broadcastAudience,
  audienceIncludes,
  sessionOwners,
  PATH_RULES,
  canSeeRowSession,
  canSeeRunRow,
  folderAllowed,
  ownFolder,
  memberId,
  ownerFor,
  sessionWhere,
  bySessionWhere,
  laneWhere,
  canSeeLane,
  canSeeSession,
  canSeeAgent,
  canSeeRun,
  visibleLaneIds,
};