/* ═══════════════════════════════════════════════════════════════
   PANEL ROUTES — server/src/routes/panel.js

     GET    /api/admin/panel/overview
     PATCH  /api/admin/panel/users/:id            role, is_active
     DELETE /api/admin/panel/users/:id/sessions   sign out everywhere

   Everything here is superadmin-only, enforced once at the top
   rather than per route — there's no read here that an ordinary
   admin should have either. Account records and live session
   counts are a different class of thing from content.

   Two rules run through the writes, both about not locking
   everyone out of the building:

     * nobody edits their own role or active flag, so a misclick
       can't demote the person making it;
     * the last active superadmin can't be demoted or disabled.

   Changing a role or disabling an account drops that person's
   live sessions immediately, the same way admin-cli.js does.
   Leaving a 30-day cookie valid after revoking the access it
   represents is the whole point of having the button.
   ═══════════════════════════════════════════════════════════════ */

import { Hono } from "hono";
import { requireAuth, requireRole, ROLES } from "../auth.js";

const panel = new Hono();

panel.use("*", requireAuth);
panel.use("*", requireRole("superadmin"));

const NO_STORE = { "Cache-Control": "no-store" };

/* The counts on the overview. Table name is a literal from this
   list, never anything off the wire. */
const CONTENT_TABLES = [
  ["Events", "events"],
  ["Organizations", "organizations"],
  ["People", "people"],
  ["Teams", "teams"],
  ["Awards", "awards"],
  ["Timeline entries", "timeline_entries"],
  ["Feedback", "feedback"],
];

/* ── GET /api/admin/panel/overview ─────────────────────────────── */

panel.get("/overview", (c) => {
  const db = c.get("db");

  const users = db
    .prepare(
      `SELECT u.id, u.email, u.name, u.role, u.is_active,
              u.created_at, u.last_login_at,
              (SELECT COUNT(*) FROM sessions s
                WHERE s.user_id = u.id
                  AND s.expires_at > datetime('now'))  AS sessions
         FROM admin_users u
        ORDER BY u.role DESC, u.email`,
    )
    .all();

  const content = CONTENT_TABLES.map(([label, table]) => ({
    label,
    count: count(db, table),
  }));

  return c.json(
    {
      system: {
        schemaVersion: db.prepare("PRAGMA user_version").get().user_version,
        dbPath: process.env.DB_PATH ?? null,
        nodeVersion: process.version,
        platform: `${process.platform} ${process.arch}`,
        uptimeSeconds: Math.round(process.uptime()),
        startedAt: new Date(Date.now() - process.uptime() * 1000).toISOString(),
        sessions: count(db, "sessions", "expires_at > datetime('now')"),
        roles: ROLES,
      },
      content,
      users,
    },
    200,
    NO_STORE,
  );
});

/* A table that hasn't been created yet shouldn't take the whole
   page down — the panel is where you go when something is wrong. */
function count(db, table, where) {
  try {
    const sql = `SELECT COUNT(*) AS n FROM ${table}${where ? ` WHERE ${where}` : ""}`;
    return db.prepare(sql).get().n;
  } catch {
    return null;
  }
}

/* ── PATCH /api/admin/panel/users/:id ───────────────────────────── */

panel.patch("/users/:id", async (c) => {
  const db = c.get("db");
  const me = c.get("user");

  const id = Number(c.req.param("id"));
  if (!Number.isInteger(id)) return c.json({ error: "Bad id." }, 400);

  if (id === me.id) {
    return c.json(
      { error: "You can't change your own role or access. Ask another superadmin." },
      403,
    );
  }

  let body;
  try {
    body = await c.req.json();
  } catch {
    return c.json({ error: "Expected a JSON body." }, 400);
  }

  const target = db
    .prepare("SELECT id, email, role, is_active FROM admin_users WHERE id = ?")
    .get(id);
  if (!target) return c.json({ error: "No such account." }, 404);

  const sets = [];
  const params = [];

  const losingSuper =
    target.role === "superadmin" &&
    ((body.role !== undefined && body.role !== "superadmin") ||
      (body.is_active !== undefined && Number(body.is_active) === 0));

  if (losingSuper && activeSupers(db) <= 1) {
    return c.json(
      { error: "That's the last active superadmin. Promote someone else first." },
      409,
    );
  }

  if (body.role !== undefined) {
    if (!ROLES.includes(body.role)) return c.json({ error: "Unknown role." }, 422);
    sets.push("role = ?");
    params.push(body.role);
  }

  if (body.is_active !== undefined) {
    sets.push("is_active = ?");
    params.push(Number(body.is_active) ? 1 : 0);
  }

  if (sets.length === 0) return c.json({ error: "Nothing to change." }, 400);

  const tx = db.transaction(() => {
    db.prepare(`UPDATE admin_users SET ${sets.join(", ")} WHERE id = ?`).run(
      ...params,
      id,
    );
    // Whatever changed, the access they're holding no longer
    // matches the row. Make them sign in again.
    db.prepare("DELETE FROM sessions WHERE user_id = ?").run(id);
  });
  tx();

  console.log(
    `account ${target.email} updated by ${me.email}: ${JSON.stringify(body)}`,
  );

  return c.json({ user: userRow(db, id) }, 200, NO_STORE);
});

/* ── DELETE /api/admin/panel/users/:id/sessions ─────────────────── */

panel.delete("/users/:id/sessions", (c) => {
  const db = c.get("db");
  const id = Number(c.req.param("id"));
  if (!Number.isInteger(id)) return c.json({ error: "Bad id." }, 400);

  const target = db.prepare("SELECT email FROM admin_users WHERE id = ?").get(id);
  if (!target) return c.json({ error: "No such account." }, 404);

  const { changes } = db.prepare("DELETE FROM sessions WHERE user_id = ?").run(id);

  console.log(
    `${changes} session(s) for ${target.email} revoked by ${c.get("user").email}`,
  );

  return c.json({ user: userRow(db, id), revoked: changes }, 200, NO_STORE);
});

function activeSupers(db) {
  return db
    .prepare(
      "SELECT COUNT(*) AS n FROM admin_users WHERE role = 'superadmin' AND is_active = 1",
    )
    .get().n;
}

function userRow(db, id) {
  return db
    .prepare(
      `SELECT u.id, u.email, u.name, u.role, u.is_active,
              u.created_at, u.last_login_at,
              (SELECT COUNT(*) FROM sessions s
                WHERE s.user_id = u.id
                  AND s.expires_at > datetime('now'))  AS sessions
         FROM admin_users u WHERE u.id = ?`,
    )
    .get(id);
}

export default panel;