import { useEffect, useState } from "react";
import { Link } from "react-router-dom";
import { api, type PrivacyOverview } from "../api/client";
import { formatDateTime } from "../utils/date";
import { formatAgo } from "../utils/duration";
import { readableError } from "../utils/errors";

const CHANNEL_LABELS = { gotify: "Gotify", ntfy: "ntfy", smtp: "email (SMTP)", webhook: "webhook" } as const;

/** SQLite timestamps ("2026-09-26 04:07:21") are UTC without a zone marker. */
function parseTime(value: string): Date {
  return new Date(value.includes("T") ? value : `${value.replace(" ", "T")}Z`);
}

export default function Privacy() {
  const [data, setData] = useState<PrivacyOverview | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [exporting, setExporting] = useState(false);

  useEffect(() => {
    api.privacy
      .overview()
      .then(setData)
      .catch((err) => setError(readableError(err)));
  }, []);

  async function download() {
    setExporting(true);
    setError(null);
    try {
      const blob = await api.privacy.exportOwnData();
      const url = URL.createObjectURL(blob);
      const a = document.createElement("a");
      a.href = url;
      a.download = "homelab-manager-my-data.json";
      a.click();
      URL.revokeObjectURL(url);
    } catch (err) {
      setError(readableError(err));
    } finally {
      setExporting(false);
    }
  }

  const retention = data?.retention;
  const outbound = data?.outbound;
  const enabledChannels = outbound ? (Object.keys(CHANNEL_LABELS) as (keyof typeof CHANNEL_LABELS)[]).filter((c) => outbound.channels[c].enabled) : [];

  return (
    <>
      <h2 className="page-title mb-3">Privacy</h2>
      <div className="card mb-3">
        <div className="card-body">
          Homelab Manager runs on your own server, and what it stores stays there unless it's listed under{" "}
          <a href="#where-it-goes">Where data goes</a>. It has no analytics or telemetry, loads no third-party scripts, fonts or
          trackers, and sets no tracking or advertising cookies. This page describes what it actually does and shows live values
          for this installation.
        </div>
      </div>
      {error && <div className="alert alert-danger">{error}</div>}

      {data && (
        <div className="card mb-3">
          <div className="card-header">
            <h3 className="card-title">About you</h3>
            <div className="card-actions">
              <button className="btn btn-sm btn-outline-primary" onClick={() => void download()} disabled={exporting}>
                {exporting ? "Preparing…" : "Download my data"}
              </button>
            </div>
          </div>
          <div className="card-body">
            <dl className="row mb-0">
              <dt className="col-sm-3">Name</dt>
              <dd className="col-sm-9">{data.me.user.name ?? "—"}</dd>
              <dt className="col-sm-3">Email</dt>
              <dd className="col-sm-9">{data.me.user.email ?? "—"}</dd>
              <dt className="col-sm-3">Role</dt>
              <dd className="col-sm-9">{data.me.user.role}</dd>
              <dt className="col-sm-3">Sign-in ID</dt>
              <dd className="col-sm-9 text-break">
                <code>{data.me.user.subject}</code>
              </dd>
              <dt className="col-sm-3">First signed in</dt>
              <dd className="col-sm-9">{formatDateTime(parseTime(data.me.user.createdAt))}</dd>
              <dt className="col-sm-3">Last signed in</dt>
              <dd className="col-sm-9">{data.me.user.lastLoginAt ? formatDateTime(parseTime(data.me.user.lastLoginAt)) : "—"}</dd>
              <dt className="col-sm-3">Recorded actions</dt>
              <dd className="col-sm-9">
                {data.me.auditEntries} change{data.me.auditEntries === 1 ? "" : "s"} you made are in the audit log under your name
              </dd>
            </dl>
            <div className="text-secondary small mt-2">
              Your name, email and sign-in ID come from Authentik and are refreshed each time you sign in.
            </div>
          </div>
          <div className="card-body border-top">
            <div className="fw-bold mb-2">Your active sign-ins</div>
            <div className="table-responsive">
              <table className="table table-sm table-vcenter mb-0">
                <thead>
                  <tr>
                    <th>From</th>
                    <th>Browser</th>
                    <th>Last active</th>
                    <th>Ends</th>
                  </tr>
                </thead>
                <tbody>
                  {data.me.sessions.map((s, i) => (
                    <tr key={i}>
                      <td>
                        {s.ip ?? "—"} {s.current && <span className="badge bg-green-lt text-green ms-1">this browser</span>}
                      </td>
                      <td className="text-secondary text-break">{s.userAgent ?? "—"}</td>
                      <td className="text-secondary">{formatAgo(s.lastAccess)}</td>
                      <td className="text-secondary">{s.expiresAt ? formatDateTime(new Date(s.expiresAt)) : "—"}</td>
                    </tr>
                  ))}
                  {data.me.sessions.length === 0 && (
                    <tr>
                      <td colSpan={4} className="text-secondary">
                        No active sign-ins found.
                      </td>
                    </tr>
                  )}
                </tbody>
              </table>
            </div>
            <div className="text-secondary small mt-2">
              “Download my data” gives you these details and every audit-log entry made under your account as a file — only yours.
            </div>
          </div>
        </div>
      )}

      <div className="card mb-3">
        <div className="card-header">
          <h3 className="card-title">What is stored</h3>
        </div>
        <div className="table-responsive">
          <table className="table table-vcenter card-table">
            <thead>
              <tr>
                <th>What</th>
                <th>Contains</th>
                <th>Kept</th>
              </tr>
            </thead>
            <tbody>
              <tr>
                <td>Accounts</td>
                <td>Sign-in ID, email and name (from Authentik), role, first and last sign-in.</td>
                <td>Until an administrator removes the account from the database — the app can change roles but has no delete-account function.</td>
              </tr>
              <tr>
                <td>Sign-in sessions</td>
                <td>
                  Your sign-in ID, email and name, the ID token Authentik issued (needed to sign you out there), and the IP address and
                  browser name from the sign-in.
                </td>
                <td>7 days after sign-in, or until you sign out or an administrator ends the session.</td>
              </tr>
              <tr>
                <td>Audit log</td>
                <td>
                  Who changed what: your name (or email) as it was at the time, the action, what it was done to, and details of the change.
                  Also each time you sign in or out — with the IP address you came from — and when your account was first created.
                </td>
                <td>
                  {retention?.enabled
                    ? `Entries older than ${retention.retentionDays} days are deleted (checked every ${retention.intervalHours} h).`
                    : "Indefinitely — automatic deletion is off (Settings → Logs)."}{" "}
                  The name stays in old entries even if the account is removed.
                </td>
              </tr>
              <tr>
                <td>Diagnostic log</td>
                <td>Each call to a DNS provider or integration: which service, what operation, success or failure, how long it took, any error text. It isn't about people.</td>
                <td>
                  {retention?.enabled ? `Deleted after ${retention.retentionDays} days.` : "Indefinitely — automatic deletion is off."}
                </td>
              </tr>
              <tr>
                <td>Server reports</td>
                <td>
                  From each agent: hostname, IP addresses, CPU, memory and disk usage, listening ports with the program using them,
                  and cron/systemd tasks <em>including their commands</em> — which can contain sensitive text.
                </td>
                <td>The latest report; removed with the server.</td>
              </tr>
              <tr>
                <td>Secrets tracker</td>
                <td>Names, types, descriptions, expiry dates, notes, and a host to check for certificates. Never the secret values themselves.</td>
                <td>Until deleted.</td>
              </tr>
              <tr>
                <td>Integration, DNS and notification credentials</td>
                <td>
                  API tokens and passwords — including the Gotify/ntfy tokens, SMTP password and webhook secret — encrypted (AES-256-GCM) with a key held in
                  the server's environment, not in the database. (If that key isn't set, notification credentials are kept unencrypted and the server says so at startup.)
                </td>
                <td>Until deleted. Settings → Backup exports include them, encrypted with a passphrase you choose.</td>
              </tr>
              <tr>
                <td>Inventory</td>
                <td>IP addresses, cached DNS records, domain registrations, port notes, tags and maintenance windows.</td>
                <td>Until deleted.</td>
              </tr>
            </tbody>
          </table>
        </div>
      </div>

      <div className="card mb-3" id="where-it-goes">
        <div className="card-header">
          <h3 className="card-title">Where data goes</h3>
        </div>
        <div className="card-body">
          <ul className="mb-0">
            <li className="mb-2">
              <strong>Authentik</strong> — you sign in there. The app receives your name, email and sign-in ID; it never sees your password.
            </li>
            <li className="mb-2">
              <strong>Your integrations</strong>
              {outbound && outbound.integrationTypes.length > 0 ? ` (${outbound.integrationTypes.join(", ")})` : ""} — API calls to systems
              you configured, to read status and, when someone with permission asks, to act (start a VM, run a template…).
            </li>
            <li className="mb-2">
              <strong>DNS providers</strong>
              {outbound && outbound.dnsProviderTypes.length > 0 ? ` (${outbound.dnsProviderTypes.join(", ")})` : ""} — zones and records are read
              from, and changed at, the provider.
            </li>
            <li className="mb-2">
              <strong>Notifications</strong> —{" "}
              {enabledChannels.length === 0 ? (
                "no channel is switched on, so no alerts leave the server."
              ) : (
                <>
                  alerts are sent to{" "}
                  {enabledChannels
                    .map((c) => `${CHANNEL_LABELS[c]}${outbound!.channels[c].host ? ` (${outbound!.channels[c].host})` : ""}`)
                    .join(", ")}
                  . They can mention server names, addresses, domain names and secret names. If a channel points at a public service such as
                  ntfy.sh, that service sees the text.
                </>
              )}
            </li>
            <li className="mb-2">
              <strong>Domain registries</strong> — the {outbound?.domainsTracked ?? 0} domain name{outbound?.domainsTracked === 1 ? "" : "s"} tracked
              on the Domains page are sent to IANA and each registry's RDAP or WHOIS server to read the expiry date. Nothing but the names.
            </li>
            <li className="mb-2">
              <strong>Certificate checks</strong> — for {outbound?.tlsCertificateChecks ?? 0} secret{outbound?.tlsCertificateChecks === 1 ? "" : "s"} with
              a host to check, the app connects to that host to read its certificate.
            </li>
            <li className="mb-2">
              <strong>Skatteverket</strong> — only when an admin clicks "Import from Skatteverket" under Settings → Names, the app asks
              Skatteverket's open name statistics for the most common given names. The request carries a sex and a birth year, nothing about you
              or your servers.
            </li>
            <li className="mb-2">
              <strong>Servers and agents</strong> — {outbound?.serversWithAgent ?? 0} of {outbound?.servers ?? 0} servers have reported in. Agents push
              their reports to the app; the app doesn't connect out to them, apart from port scans, which run only when an operator starts one
              and only against private addresses.
            </li>
            <li>
              <strong>Nothing else.</strong> No telemetry, no update checks, no crash reports, no third-party analytics.
            </li>
          </ul>
        </div>
      </div>

      <div className="row row-cards mb-3">
        <div className="col-lg-6">
          <div className="card h-100">
            <div className="card-header">
              <h3 className="card-title">In your browser</h3>
            </div>
            <div className="card-body">
              <ul className="mb-0">
                <li className="mb-2">
                  One <strong>session cookie</strong>: scripts on the page can't read it, it's restricted from cross-site requests, it's marked secure over
                  HTTPS, and it lasts 7 days.
                </li>
                <li className="mb-2">
                  One <strong>saved preference</strong> in this browser: whether you chose light or dark mode.
                </li>
                <li>If you install the app to your device, it stores no pages or data for offline use.</li>
              </ul>
            </div>
          </div>
        </div>
        <div className="col-lg-6">
          <div className="card h-100">
            <div className="card-header">
              <h3 className="card-title">Who can see what</h3>
            </div>
            <div className="card-body">
              <ul className="mb-0">
                <li className="mb-2">Everyone signed in: the inventory and status pages, including server, IP, domain and secret-name details.</li>
                <li className="mb-2">Operators and admins: also the audit log — who did what, and who signed in from where.</li>
                <li>Admins only: the user list, everyone's active sign-ins (with IP and browser), the diagnostic log and settings.</li>
              </ul>
            </div>
          </div>
        </div>
      </div>

      <div className="card">
        <div className="card-header">
          <h3 className="card-title">Removing or limiting data</h3>
        </div>
        <div className="card-body">
          <ul className="mb-0">
            <li className="mb-2">
              <strong>Sign out</strong> to end your session now. Administrators can also end anyone's on the <Link to="/sessions">Sessions</Link> page.
            </li>
            <li className="mb-2">
              <strong>Audit and diagnostic logs</strong> can be deleted automatically after a set number of days under Settings → Logs
              {retention ? ` — currently ${retention.enabled ? `on, ${retention.retentionDays} days` : "off"}` : ""}.
            </li>
            <li className="mb-2">
              <strong>Your account</strong> can only be removed by an administrator deleting it from the database; the app doesn't do that
              itself. Old audit entries keep your name until the log is purged.
            </li>
            <li>
              <strong>A copy of your data</strong> is the “Download my data” button above.
            </li>
          </ul>
        </div>
      </div>
    </>
  );
}