/**
 * @file Express router for settings-related endpoints, providing system info, database statistics, hook status, and operations to clear data, re-import sessions, reinstall hooks, reset pricing, export data, and perform cleanup of stale sessions, plus the privacy controls (secret redaction, ignored folders), the push-ingest token, the daily database backup (server/lib/db-backup.js) and the opt-in retention + Compact (server/lib/db-retention.js). This allows the frontend to manage and maintain the agent monitoring system effectively.
 * @author Nguyễn Ngọc Trí Vĩ <vinnt@smartgift.vn>
 */

const { Router } = require("express");
const fs = require("fs");
const path = require("path");
const os = require("os");
const v8 = require("v8");
const { db, stmts, DB_PATH, DEFAULT_PRICING, applyIntroPricing } = require("../db");
const { getConnectionCount } = require("../websocket");
const { transcriptCache } = require("./hooks");
const { forgetHourly } = require("../lib/hourly-usage");

const router = Router();

const APP_VERSION = (() => {
  try {
    return require("../../package.json").version || "0.0.0";
  } catch {
    return "0.0.0";
  }
})();

const { getSettingsPath, getClaudeHome, setClaudeHome } = require("../lib/claude-home");
const { getCodexHome, setCodexHome } = require("../lib/codex-home");
const { envOwned, applySetting } = require("../lib/settings-env");
const privacy = require("../lib/privacy");
const dbBackup = require("../lib/db-backup");
const retention = require("../lib/db-retention");
const pushToken = require("../lib/push-token");
const pricingSync = require("../lib/pricing-sync");
const {
  EXPORT_FORMAT,
  EXPORT_VERSION,
  importExportBundle,
  exportableRun,
} = require("../lib/data-transfer");
const { sessionWhere, bySessionWhere, memberId } = require("../lib/scope");

function getDbSize() {
  try {
    const stat = fs.statSync(DB_PATH);
    return stat.size;
  } catch {
    return 0;
  }
}

// `req` scopes the counts to a server-mode member's own rows (sessions,
// agents, events, token usage); pricing is shared configuration, counted whole.
function getTableCounts(req) {
  const own = sessionWhere(req);
  const bySession = bySessionWhere(req);
  const count = (sql, w) => db.prepare(`${sql} WHERE ${w.where}`).get(...w.params).c;
  return {
    sessions: count("SELECT COUNT(*) as c FROM sessions", own),
    agents: count("SELECT COUNT(*) as c FROM agents", bySession),
    events: count("SELECT COUNT(*) as c FROM events", bySession),
    model_pricing: db.prepare("SELECT COUNT(*) as c FROM model_pricing").get().c,
    token_usage: count("SELECT COUNT(DISTINCT session_id) as c FROM token_usage", bySession),
  };
}

function getHookStatus() {
  try {
    if (!fs.existsSync(getSettingsPath())) {
      return { installed: false, path: getSettingsPath(), hooks: {} };
    }
    const raw = fs.readFileSync(getSettingsPath(), "utf8");
    const settings = JSON.parse(raw);
    // The enabled plugin runs the hooks from its own plugin.json, so
    // settings.json rightly holds none of ours (installHooks removes them).
    const { HOOK_TYPES: hookTypes, pluginProvidesHooks } = require("../../scripts/install-hooks");
    if (pluginProvidesHooks(settings)) {
      return {
        installed: true,
        source: "plugin",
        path: getSettingsPath(),
        hooks: Object.fromEntries(hookTypes.map((ht) => [ht, true])),
      };
    }
    const hooks = {};
    for (const ht of hookTypes) {
      const entries = settings.hooks?.[ht] || [];
      hooks[ht] = entries.some(
        (e) =>
          (e.command && e.command.includes("hook-handler.js")) ||
          (Array.isArray(e.hooks) &&
            e.hooks.some((h) => h.command && h.command.includes("hook-handler.js")))
      );
    }
    const installed = Object.values(hooks).every(Boolean);
    return { installed, path: getSettingsPath(), hooks };
  } catch {
    return { installed: false, path: getSettingsPath(), hooks: {} };
  }
}

// GET /api/settings/info — system info, db stats, hook status
router.get("/info", (req, res) => {
  const dbSize = getDbSize();
  const counts = getTableCounts(req);
  const hookStatus = getHookStatus();

  // Advanced SQLite info
  const pragmas = {
    journal_mode: db.pragma("journal_mode", { simple: true }),
    synchronous: db.pragma("synchronous", { simple: true }),
    auto_vacuum: db.pragma("auto_vacuum", { simple: true }),
    encoding: db.pragma("encoding", { simple: true }),
    foreign_keys: db.pragma("foreign_keys", { simple: true }),
    busy_timeout: db.pragma("busy_timeout", { simple: true }),
  };

  // Recent activity load (events in last 5, 15, 60 minutes)
  const ownEvents = bySessionWhere(req);
  const getCount = (ms) => {
    const d = new Date(Date.now() - ms).toISOString();
    return db
      .prepare(`SELECT COUNT(*) as c FROM events WHERE created_at > ? AND ${ownEvents.where}`)
      .get(d, ...ownEvents.params).c;
  };

  const load_stats = {
    m5: getCount(5 * 60 * 1000),
    m15: getCount(15 * 60 * 1000),
    h1: getCount(60 * 60 * 1000),
  };

  // A developer (server mode) gets the numbers, never a path of the host's:
  // the transcript cache is keyed by EVERY user's transcript path (their
  // folders, their session ids), and the DB/settings paths are the host's.
  const developer = memberId(req) != null;
  const cache = transcriptCache.stats();
  res.json({
    db: {
      path: developer ? null : DB_PATH,
      size: dbSize,
      counts,
      pragmas,
      load_stats,
    },
    hooks: developer ? { installed: hookStatus.installed } : hookStatus,
    server: {
      version: APP_VERSION,
      uptime: process.uptime(),
      node_version: process.version,
      platform: process.platform,
      ws_connections: getConnectionCount(),
      // heapTotal is only what V8 has grown the heap to SO FAR, so used/total
      // sits at 70-90% on a perfectly healthy process. heapLimit is the ceiling
      // the process actually dies at — the denominator a "heap used %" needs.
      memory: { ...process.memoryUsage(), heapLimit: v8.getHeapStatistics().heap_size_limit },
      cpu_load: os.loadavg(),
      arch: os.arch(),
      total_mem: os.totalmem(),
      free_mem: os.freemem(),
      cpus: os.cpus().length,
    },
    transcript_cache: developer ? { ...cache, keys: undefined } : cache,
  });
});

// POST /api/settings/clear-data — delete all sessions, agents, events, tokens
router.post("/clear-data", (_req, res) => {
  const counts = getTableCounts();
  // foreign_keys cannot change inside a transaction, so it is turned off
  // around one: all of it lands, or none of it (a crash midway used to leave
  // events without sessions).
  db.pragma("foreign_keys = OFF");
  try {
    db.transaction(clearAll)();
  } finally {
    db.pragma("foreign_keys = ON");
  }
  res.json({ ok: true, cleared: counts });
});

function clearAll() {
  db.prepare("DELETE FROM token_usage").run();
  db.prepare("DELETE FROM token_usage_hourly").run();
  forgetHourly();
  db.prepare("DELETE FROM events").run();
  db.prepare("DELETE FROM agents").run();
  db.prepare("DELETE FROM sessions").run();
  // What the Codex/Antigravity/Cursor polls have read: kept, it would stop them
  // ever importing those sessions again (and bring one back half, on its next write).
  db.prepare("DELETE FROM codex_rollouts").run();
  db.prepare("DELETE FROM antigravity_conversations").run();
  db.prepare("DELETE FROM cursor_transcripts").run();
  // Fired alerts reference the cleared sessions — wipe the feed too. Alert
  // *rules* survive: they're user configuration, like model_pricing.
  db.prepare("DELETE FROM alert_events").run();
  // Webhook delivery log is an audit trail of those fired alerts — wipe it too.
  // Webhook *targets* survive, like alert rules and pricing.
  db.prepare("DELETE FROM webhook_deliveries").run();
  // Workflow runs belong to the sessions; with foreign keys off they would
  // not cascade and stay as orphans.
  db.prepare("DELETE FROM workflows").run();
  // session_snapshots survive: a snapshot is a frozen copy the user chose to
  // keep, like alert rules — deleted only from Settings → Snapshots & reports.
  // report_definitions and report_runs survive too: a definition is user
  // configuration and a run's files are reports already delivered — removed
  // only from Settings → Snapshots & reports.
}

// POST /api/settings/reimport — re-import legacy sessions from ~/.claude/
router.post("/reimport", async (_req, res) => {
  try {
    const { importAllSessions } = require("../../scripts/import-history");
    const dbModule = require("../db");
    const result = await importAllSessions(dbModule);
    res.json({ ok: true, ...result });
  } catch (err) {
    res.status(500).json({
      error: { code: "IMPORT_FAILED", message: err.message },
    });
  }
});

// POST /api/settings/reinstall-hooks — reinstall Claude Code hooks
router.post("/reinstall-hooks", (_req, res) => {
  try {
    const { installHooks } = require("../../scripts/install-hooks");
    const success = installHooks(true);
    const hookStatus = getHookStatus();
    res.json({ ok: success, hooks: hookStatus });
  } catch (err) {
    res.status(500).json({
      error: { code: "HOOK_INSTALL_FAILED", message: err.message },
    });
  }
});

// GET/POST/DELETE /api/settings/codex-hooks — AgentHub's hooks in Codex's
// `$CODEX_HOME/hooks.json`: status, install (or reinstall), remove. Only ever
// on a click; Codex itself asks the user to trust them (server/lib/codex-hooks.js).
const codexHooks = require("../lib/codex-hooks");
const { sameOriginGuard } = require("../lib/same-origin");
function codexHooksRoute(fn) {
  return (_req, res) => {
    try {
      res.json(fn());
    } catch (err) {
      const client = ["EBADJSON", "EUNSUPPORTED", "EFOREIGN"].includes(err.code);
      res.status(client ? 400 : 500).json({
        error: { code: client ? err.code : "ESAVE", message: err.message },
      });
    }
  };
}
router.get("/codex-hooks", codexHooksRoute(codexHooks.status));
// Writing makes Codex run a command (once trusted), so no other site may ask.
router.post("/codex-hooks", sameOriginGuard, codexHooksRoute(codexHooks.install));
router.delete("/codex-hooks", sameOriginGuard, codexHooksRoute(codexHooks.remove));

// GET/POST/DELETE /api/settings/antigravity-hooks — AgentHub's named hook in
// `~/.gemini/config/hooks.json` (server/lib/antigravity-hooks.js). agy runs it
// with no trust step, so the write routes refuse another site the same way.
const antigravityHooks = require("../lib/antigravity-hooks");
router.get("/antigravity-hooks", codexHooksRoute(antigravityHooks.status));
router.post("/antigravity-hooks", sameOriginGuard, codexHooksRoute(antigravityHooks.install));
router.delete("/antigravity-hooks", sameOriginGuard, codexHooksRoute(antigravityHooks.remove));

// GET/PUT /api/settings/autostart — start the dashboard at boot/login through
// the per-user service (server/lib/autostart.js). Off by default; a PUT only
// enables or disables the unit, it never starts or stops the server.
const autostart = require("../lib/autostart");
router.get("/autostart", (_req, res) => res.json(autostart.status()));
router.put("/autostart", sameOriginGuard, (req, res) => {
  if (typeof req.body?.enabled !== "boolean") {
    return res
      .status(400)
      .json({ error: { code: "EBADVALUE", message: "`enabled` must be a boolean" } });
  }
  try {
    res.json(autostart.setEnabled(req.body.enabled));
  } catch (err) {
    const status = { EUNAVAILABLE: 400, EFOREIGN: 409 }[err.code] || 500;
    res.status(status).json({ error: { code: err.code || "ESERVICE", message: err.message } });
  }
});

// GET/PUT /api/settings/tray — AgentHub's icon in the OS status area
// (server/lib/tray.js). On by default; a PUT starts or stops the icon process.
const tray = require("../lib/tray");
router.get("/tray", (_req, res) => res.json(tray.status()));
router.put("/tray", sameOriginGuard, (req, res) => {
  if (typeof req.body?.enabled !== "boolean") {
    return res
      .status(400)
      .json({ error: { code: "EBADVALUE", message: "`enabled` must be a boolean" } });
  }
  res.json(tray.setEnabled(req.body.enabled));
});

// POST /api/settings/quit — Quit AgentHub (server/lib/quit.js): kill every
// lane pane, then stop this server once the answer is out. It stays stopped
// (the bootstrap starts none) until a server starts again — `agenthub start`,
// or boot/login through an enabled autostart unit.
const quit = require("../lib/quit");
router.post("/quit", sameOriginGuard, (_req, res) => {
  quit.markQuit();
  const runs = require("../lib/pty-run");
  let killed = 0;
  for (const run of runs.listRuns()) if (runs.killRun(run.id)) killed++;
  res.on("finish", () => quit.stopServer());
  res.json({ ok: true, killed });
});

// POST /api/settings/uninstall {confirm: true} — Uninstall AgentHub
// (scripts/uninstall.js) in a detached worker, because it stops this server.
// Under systemd it starts in a scope of its own, outside the unit's cgroup —
// an older unit still on KillMode=control-group would reap it mid-run; launchd
// leaves it alone (AbandonProcessGroup).
// Never in server mode — a shared dashboard is removed from the host's shell.
router.post("/uninstall", sameOriginGuard, (req, res) => {
  if (require("../lib/auth").isServerMode()) {
    return res.status(403).json({
      error: { code: "ESERVERMODE", message: "Run `agenthub uninstall` on the host instead" },
    });
  }
  if (req.body?.confirm !== true) {
    return res
      .status(400)
      .json({ error: { code: "ECONFIRM", message: "`confirm: true` is required" } });
  }
  const script = path.join(__dirname, "..", "..", "scripts", "uninstall.js");
  const svc = require("../../scripts/service-manager");
  const argv = [process.execPath, script, "--yes"];
  const [cmd, ...args] =
    svc.kind === "systemd" && svc.systemctlAvailable()
      ? ["systemd-run", "--user", "--scope", "--quiet", "--collect", "--", ...argv]
      : argv;
  require("child_process")
    .spawn(cmd, args, {
      cwd: os.tmpdir(), // never the plugin root, which it deletes
      detached: true,
      stdio: "ignore",
      env: process.env,
    })
    .unref();
  res.status(202).json({ ok: true, log: require("../../scripts/uninstall").logPath() });
});

// POST /api/settings/reset-pricing — reset pricing to defaults. The seed is
// Claude's; a model priced by the automatic sync (an OpenAI one, from Codex
// sessions) is fetched back at once, waiting at most RESET_SYNC_MS for it.
// `{scope: "claude"}` (the Claude tab's button) resets only `claude-…` rows,
// so another vendor's edits and a custom router row survive it.
const RESET_SYNC_MS = 3000;
router.post("/reset-pricing", async (req, res) => {
  if (req.body?.scope === "claude") {
    db.prepare("DELETE FROM model_pricing WHERE model_pattern LIKE 'claude-%'").run();
    db.prepare("DELETE FROM model_pricing_dismissed WHERE model_pattern LIKE 'claude-%'").run();
  } else {
    db.prepare("DELETE FROM model_pricing").run();
    db.prepare("DELETE FROM model_pricing_dismissed").run();
  }

  const seedPricing = db.prepare(
    "INSERT OR IGNORE INTO model_pricing (model_pattern, display_name, input_per_mtok, output_per_mtok, cache_read_per_mtok, cache_write_per_mtok, cache_write_1h_per_mtok, fast_input_per_mtok, fast_output_per_mtok) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"
  );
  for (const [pattern, name, inp, out, cr, cw, cw1h, fin, fout] of DEFAULT_PRICING) {
    seedPricing.run(pattern, name, inp, out, cr, cw, cw1h, fin, fout);
  }
  // Re-apply time-limited intro rates (e.g. Sonnet 5) — the seed above only
  // carries standard rates, so without this a reset silently drops the promo.
  applyIntroPricing(db);
  if (pricingSync.syncEnabled()) {
    // The rows just deleted include current models nobody has used yet; the
    // cached list counts as applied, so without this they wait for tomorrow.
    pricingSync.invalidate();
    await Promise.race([
      pricingSync.syncPricing(db),
      new Promise((r) => setTimeout(r, RESET_SYNC_MS).unref()),
    ]);
  }

  const pricing = stmts.listPricing.all();
  res.json({ ok: true, pricing });
});

// GET /api/settings/export — export all data as JSON. Same document as ever,
// but written as it is read: `events` alone is GBs on a long-lived install,
// and one `.all()` + `res.json` held it in memory twice (past V8's string
// limit). Events go out in keyset pages, waiting for the socket to drain.
const EXPORT_PAGE = 500;
router.get("/export", async (req, res) => {
  res.setHeader("Content-Type", "application/json");
  res.setHeader(
    "Content-Disposition",
    `attachment; filename="agent-monitor-export-${new Date().toISOString().slice(0, 10)}.json"`
  );
  let gone = false;
  req.on("close", () => (gone = true));
  const write = async (chunk) => {
    if (!res.write(chunk)) await new Promise((r) => res.once("drain", r));
  };
  const field = (name, value) => `,${JSON.stringify(name)}:${JSON.stringify(value)}`;
  try {
    await write(
      `{"format":${JSON.stringify(EXPORT_FORMAT)},"version":${EXPORT_VERSION}` +
        field("exported_at", new Date().toISOString())
    );
    await write(
      field("sessions", db.prepare("SELECT * FROM sessions ORDER BY started_at DESC").all())
    );
    await write(field("agents", db.prepare("SELECT * FROM agents ORDER BY started_at DESC").all()));
    await write(`,"events":[`);
    const first = db.prepare(
      `SELECT * FROM events ORDER BY created_at DESC, id DESC LIMIT ${EXPORT_PAGE}`
    );
    const next = db.prepare(
      `SELECT * FROM events WHERE created_at < ? OR (created_at = ? AND id < ?)
       ORDER BY created_at DESC, id DESC LIMIT ${EXPORT_PAGE}`
    );
    let page = first.all();
    let sep = "";
    while (page.length && !gone) {
      await write(sep + page.map((e) => JSON.stringify(e)).join(","));
      sep = ",";
      const last = page[page.length - 1];
      page = next.all(last.created_at, last.created_at, last.id);
    }
    await write("]");
    await write(field("token_usage", db.prepare("SELECT * FROM token_usage").all()));
    await write(field("workflows", db.prepare("SELECT * FROM workflows").all()));
    await write(
      field(
        "dashboard_runs",
        db.prepare("SELECT * FROM dashboard_runs ORDER BY started_at DESC").all().map(exportableRun)
      )
    );
    await write(
      field("alert_rules", db.prepare("SELECT * FROM alert_rules ORDER BY created_at ASC").all())
    );
    await write(field("model_pricing", stmts.listPricing.all()) + "}");
    res.end();
  } catch (err) {
    console.warn("export failed:", err.message);
    res.destroy(err);
  }
});

// POST /api/settings/import — restore a file written by GET /export, uploaded
// as multipart `file`. Non-destructive (data-transfer.js: a session already
// here is skipped whole, nothing is overwritten). The whole file is parsed in
// memory, hence the size cap; a bad file is answered without echoing its text.
// ponytail: one JSON.parse of the whole bundle; stream-parse if backups outgrow 512 MB.
const IMPORT_MAX_BYTES = 512 * 1024 * 1024;
router.post("/import", sameOriginGuard, (req, res) => {
  const multer = require("multer");
  const upload = multer({
    dest: os.tmpdir(),
    limits: { files: 1, fileSize: IMPORT_MAX_BYTES, fields: 8 },
  }).single("file");
  upload(req, res, (uploadErr) => {
    const file = req.file;
    const done = (status, body) => {
      if (file) fs.rm(file.path, { force: true }, () => {});
      res.status(status).json(body);
    };
    if (uploadErr) {
      const tooBig = uploadErr.code === "LIMIT_FILE_SIZE";
      return done(tooBig ? 413 : 400, {
        error: {
          code: tooBig ? "FILE_TOO_LARGE" : "BAD_UPLOAD",
          message: tooBig ? "the backup is larger than 512 MB" : uploadErr.message,
        },
      });
    }
    if (!file) {
      return done(400, { error: { code: "NO_FILE", message: "attach the export as `file`" } });
    }
    let bundle;
    try {
      bundle = JSON.parse(fs.readFileSync(file.path, "utf8"));
    } catch {
      return done(400, {
        error: { code: "INVALID_FORMAT", message: "Not a valid export file (not JSON)." },
      });
    }
    try {
      const counts = importExportBundle(db, bundle);
      done(200, {
        ok: true,
        source: file.originalname,
        format: bundle.format ?? null,
        ...counts,
      });
    } catch (err) {
      if (err.code === "INVALID_FORMAT") {
        return done(400, { error: { code: err.code, message: err.message } });
      }
      console.warn("import failed:", err.message);
      done(500, { error: { code: "IMPORT_FAILED", message: err.message } });
    }
  });
});

// The two editable home directories share one shape: GET answers the value and
// whether the real environment set it (`env_owned` — then a saved value is
// overridden again at the next start), PUT validates, applies and persists
// (server/lib/settings-env.js). EBADHOME = too broad, INVALID_PATH = any other
// bad path, 500 ESAVE = the settings file could not be written.
function homeRoutes(route, key, field, get, set) {
  router.get(route, (_req, res) => {
    res.json({ [field]: get(), env_owned: envOwned.has(key) });
  });
  // A home decides which config a pane runs (CODEX_HOME: MCP servers, notify
  // commands), so no other site may set one.
  router.put(route, sameOriginGuard, (req, res) => {
    const newPath = req.body && req.body.path;
    if (!newPath || typeof newPath !== "string") {
      return res.status(400).json({
        error: { code: "INVALID_PATH", message: "path is required and must be a string" },
      });
    }
    let resolved;
    try {
      resolved = set(newPath);
    } catch (err) {
      // A bad path is 400; anything else (the settings file unwritable) is ours.
      const bad = err.code === "EBADHOME" || err.code === "INVALID_PATH";
      return res.status(bad ? 400 : 500).json({
        error: { code: bad ? err.code : "ESAVE", message: err.message },
      });
    }
    res.json({ ok: true, [field]: resolved, env_owned: envOwned.has(key) });
  });
}

// GET/PUT /api/settings/claude-home
homeRoutes("/claude-home", "CLAUDE_HOME", "claude_home", getClaudeHome, setClaudeHome);
// GET/PUT /api/settings/codex-home — a session's AI Proxy layer is written
// into the current home at its spawn, so a move needs no repair here.
homeRoutes("/codex-home", "CODEX_HOME", "codex_home", getCodexHome, setCodexHome);

// GET/PUT /api/settings/privacy — opt-in secret redaction of stored payloads
// and the folders whose hooks are dropped (server/lib/privacy.js). Both persist
// to the settings file; one the environment set is `env_owned` and refused.
function privacyState() {
  return {
    redact_secrets: privacy.redactionEnabled(),
    ignore_cwd: privacy.ignoredCwds(),
    env_owned: {
      redact_secrets: envOwned.has(privacy.REDACT_KEY),
      ignore_cwd: envOwned.has(privacy.IGNORE_KEY),
    },
  };
}
router.get("/privacy", (_req, res) => res.json(privacyState()));
router.put("/privacy", sameOriginGuard, (req, res) => {
  const body = req.body || {};
  const fail = (status, code, message) => res.status(status).json({ error: { code, message } });
  const writes = [];
  if (body.redact_secrets !== undefined) {
    if (typeof body.redact_secrets !== "boolean")
      return fail(400, "INVALID_INPUT", "redact_secrets must be a boolean");
    writes.push([privacy.REDACT_KEY, body.redact_secrets ? "1" : "0"]);
  }
  if (body.ignore_cwd !== undefined) {
    let list;
    try {
      list = privacy.validateIgnoreList(body.ignore_cwd);
    } catch (err) {
      return fail(400, err.code || "EBADPATH", err.message);
    }
    writes.push([privacy.IGNORE_KEY, list.join(path.delimiter)]);
  }
  const owned = writes.find(([k]) => envOwned.has(k));
  if (owned) return fail(409, "EENVOWNED", `${owned[0]} is set by the environment`);
  try {
    for (const [k, v] of writes) applySetting(k, v);
  } catch (err) {
    return fail(500, "ESAVE", err.message);
  }
  res.json({ ok: true, ...privacyState() });
});

// GET/PUT /api/settings/backup, POST /api/settings/backup/run — the daily
// database backup (server/lib/db-backup.js). The folder, hour and count persist
// to the settings file; one the environment set is `env_owned` and refused. A
// run answers 202 at once (a large database takes tens of seconds) and the
// page polls GET while `running`.
function backupState() {
  const cfg = dbBackup.backupConfig();
  let files = [];
  let dir_error = null;
  if (cfg.dir) {
    try {
      files = dbBackup.listBackups(cfg.dir);
    } catch (err) {
      dir_error = err.message;
    }
  }
  return {
    ...cfg,
    running: dbBackup.isRunning(),
    last: dbBackup.lastResult(),
    files,
    dir_error,
    env_owned: Object.fromEntries(
      Object.entries(dbBackup.KEYS).map(([field, key]) => [field, envOwned.has(key)])
    ),
  };
}
router.get("/backup", (_req, res) => res.json(backupState()));
router.put("/backup", sameOriginGuard, (req, res) => {
  const body = req.body || {};
  const fail = (code, message) => res.status(400).json({ error: { code, message } });
  const writes = [];
  if (body.dir !== undefined) {
    if (typeof body.dir !== "string") return fail("INVALID_PATH", "dir must be a string");
    let dir = "";
    if (body.dir.trim()) {
      try {
        dir = dbBackup.validateBackupDir(body.dir);
      } catch (err) {
        return fail(err.code || "INVALID_PATH", err.message);
      }
    }
    writes.push([dbBackup.KEYS.dir, dir]);
  }
  for (const [field, lo, hi] of [
    ["hour", 0, 23],
    ["keep", 1, 365],
  ]) {
    if (body[field] === undefined) continue;
    const n = body[field];
    if (!Number.isInteger(n) || n < lo || n > hi) {
      return fail("INVALID_INPUT", `${field} must be a whole number from ${lo} to ${hi}`);
    }
    writes.push([dbBackup.KEYS[field], String(n)]);
  }
  const owned = writes.find(([k]) => envOwned.has(k));
  if (owned) {
    return res
      .status(409)
      .json({ error: { code: "EENVOWNED", message: `${owned[0]} is set by the environment` } });
  }
  try {
    for (const [k, v] of writes) applySetting(k, v);
  } catch (err) {
    return res.status(500).json({ error: { code: "ESAVE", message: err.message } });
  }
  res.json({ ok: true, ...backupState() });
});
router.post("/backup/run", sameOriginGuard, (_req, res) => {
  if (!dbBackup.backupConfig().dir) {
    return res
      .status(400)
      .json({ error: { code: "ENOBACKUPDIR", message: "choose a backup folder first" } });
  }
  dbBackup.runBackup().catch(() => {}); // the outcome is `last` in GET
  res.status(202).json({ ok: true, ...backupState() });
});

// GET/POST/DELETE /api/settings/push-token — the token for POST
// /api/hooks/ingest-batch (server/lib/push-token.js). GET never returns it;
// POST makes a new one (the old one stops working) and returns it this once.
router.get("/push-token", (_req, res) => res.json(pushToken.pushTokenStatus()));
function pushTokenWrite(fn) {
  return (_req, res) => {
    try {
      const token = fn();
      res.json({ ok: true, ...(token && { token }), ...pushToken.pushTokenStatus() });
    } catch (err) {
      const owned = err.code === "EENVOWNED";
      res
        .status(owned ? 409 : 500)
        .json({ error: { code: owned ? err.code : "ESAVE", message: err.message } });
    }
  };
}
router.post("/push-token", sameOriginGuard, pushTokenWrite(pushToken.rotatePushToken));
router.delete("/push-token", sameOriginGuard, pushTokenWrite(pushToken.revokePushToken));

// GET/PUT /api/settings/retention, POST /api/settings/compact — database size
// upkeep (server/lib/db-retention.js). Retention is OFF by default: `days` 0
// turns it off, 1–3650 makes the hourly maintenance purge finished sessions
// older than that, the manual purge's rule. It persists to the settings file;
// one the environment set is `env_owned` and refused. Compact (a full VACUUM
// in a worker) answers 202 and the page polls GET while `compacting`.
function retentionState() {
  let space = null;
  try {
    space = retention.spaceInfo(db);
  } catch {
    /* pragma unavailable: the card shows no numbers */
  }
  return {
    ...retention.retentionConfig(),
    max_days: retention.MAX_DAYS,
    env_owned: { days: envOwned.has(retention.KEYS.days) },
    last_run: retention.lastMaintenance(),
    space,
    db_size: getDbSize(),
    compacting: retention.isCompacting(),
    last_compact: retention.lastCompactResult(),
  };
}
router.get("/retention", (_req, res) => res.json(retentionState()));
router.put("/retention", sameOriginGuard, (req, res) => {
  const days = req.body?.days;
  if (!Number.isInteger(days) || days < 0 || days > retention.MAX_DAYS) {
    return res.status(400).json({
      error: {
        code: "INVALID_INPUT",
        message: `days must be a whole number from 0 (off) to ${retention.MAX_DAYS}`,
      },
    });
  }
  if (envOwned.has(retention.KEYS.days)) {
    return res.status(409).json({
      error: { code: "EENVOWNED", message: `${retention.KEYS.days} is set by the environment` },
    });
  }
  try {
    applySetting(retention.KEYS.days, days === 0 ? "" : String(days));
  } catch (err) {
    return res.status(500).json({ error: { code: "ESAVE", message: err.message } });
  }
  res.json({ ok: true, ...retentionState() });
});
router.post("/compact", sameOriginGuard, (req, res) => {
  if (req.body?.confirm !== true) {
    return res.status(400).json({
      error: { code: "ECONFIRM", message: "compacting needs confirm: true" },
    });
  }
  retention.runCompact().catch(() => {}); // the outcome is `last_compact` in GET
  res.status(202).json({ ok: true, ...retentionState() });
});

// POST /api/settings/cleanup — abandon stale sessions, purge old data.
// `purge_days` is a whole number ≥ 1 (0.1 days would purge almost everything);
// `dry_run: true` answers the same counts and changes nothing.
router.post("/cleanup", (req, res) => {
  const { abandon_hours, purge_days } = req.body;
  const dryRun = req.body.dry_run === true;
  if (purge_days !== undefined && purge_days !== null) {
    if (!Number.isInteger(purge_days) || purge_days < 1) {
      return res.status(400).json({
        error: {
          code: "INVALID_PURGE_DAYS",
          message: "purge_days must be a whole number of days, 1 or more",
        },
      });
    }
  }
  const result = { abandoned: 0, purged_sessions: 0, purged_events: 0, purged_agents: 0 };
  if (dryRun) result.dry_run = true;
  // A dry run abandons nothing, so the purge below would not see the sessions a
  // real run abandons first and then purges; it adds them back from this list.
  let wouldAbandon = [];

  if (abandon_hours && typeof abandon_hours === "number" && abandon_hours > 0) {
    // Mark active sessions with no recent events as abandoned
    const cutoff = new Date(Date.now() - abandon_hours * 3600 * 1000).toISOString();
    const stale = db
      .prepare(
        `SELECT s.id, s.started_at FROM sessions s
         WHERE s.status = 'active'
           AND s.started_at < ?
           AND NOT EXISTS (
             SELECT 1 FROM events e WHERE e.session_id = s.id AND e.created_at > ?
           )`
      )
      .all(cutoff, cutoff);

    const abandon = db.prepare(
      "UPDATE sessions SET status = 'abandoned', ended_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now') WHERE id = ?"
    );
    if (dryRun) {
      result.abandoned = stale.length;
      wouldAbandon = stale;
    } else {
      // Also complete any lingering agents
      const complete = db.prepare(
        "UPDATE agents SET status = 'completed', ended_at = strftime('%Y-%m-%dT%H:%M:%fZ', 'now') WHERE session_id = ? AND status IN ('waiting','working')"
      );
      db.transaction(() => {
        for (const row of stale) {
          abandon.run(row.id);
          complete.run(row.id);
        }
      })();
      result.abandoned = stale.length;
    }
  }

  if (purge_days && typeof purge_days === "number" && purge_days > 0) {
    const cutoff = new Date(Date.now() - purge_days * 86400 * 1000).toISOString();
    // Only purge completed/error/abandoned sessions, never active
    const toDelete = retention.purgeableBefore(db, cutoff);

    if (dryRun) {
      // Exactly the ids the real run deletes: those already purgeable, plus
      // the stale ones it abandons first that are also older than the cutoff.
      const ids = [
        ...toDelete.map((r) => r.id),
        ...wouldAbandon.filter((r) => r.started_at < cutoff).map((r) => r.id),
      ];
      Object.assign(result, retention.countSessionIds(db, ids));
      return res.json({ ok: true, ...result });
    }

    // One transaction; the deletion itself is shared with the automatic
    // retention (server/lib/db-retention.js).
    const ids = toDelete.map((r) => r.id);
    const purged = db.transaction(() => retention.purgeSessionIds(db, ids))();
    Object.assign(result, purged, { purged_sessions: ids.length });
  }

  res.json({ ok: true, ...result });
});

module.exports = router;