import { useEffect, useState, type FormEvent } from "react";
import { Link } from "react-router-dom";
import {
  api,
  type AgentPortRow,
  type CurrentUser,
  type PortForward,
  type PortForwardInput,
  type ServerRecord,
} from "../api/client";
import { useSortable } from "../hooks/useSortable";
import SortableTh from "../components/SortableTh";
import { usePagination } from "../hooks/usePagination";
import Pagination from "../components/Pagination";
import { downloadCsv } from "../utils/csv";
import { formatAgo } from "../utils/duration";

const emptyForm: PortForwardInput = {
  label: "",
  externalPort: 0,
  protocol: "tcp",
  serverId: null,
  destination: "",
  internalPort: null,
  source: "",
  comment: "",
};

export default function Ports({ user }: { user: CurrentUser }) {
  const canEdit = user.role === "admin" || user.role === "operator";

  const [agentPorts, setAgentPorts] = useState<AgentPortRow[] | null>(null);
  const [reportingServers, setReportingServers] = useState(0);
  const [totalServers, setTotalServers] = useState(0);
  const [agentError, setAgentError] = useState<string | null>(null);

  const [servers, setServers] = useState<ServerRecord[] | null>(null);
  const [forwards, setForwards] = useState<PortForward[] | null>(null);
  const [forwardError, setForwardError] = useState<string | null>(null);

  const [editing, setEditing] = useState<PortForward | null>(null);
  const [adding, setAdding] = useState(false);
  const [form, setForm] = useState<PortForwardInput>(emptyForm);
  const [saving, setSaving] = useState(false);

  function loadAgentPorts() {
    api.ports
      .agent()
      .then((res) => {
        setAgentPorts(res.ports);
        setReportingServers(res.reportingServers);
        setTotalServers(res.totalServers);
      })
      .catch((err) => setAgentError(err instanceof Error ? err.message : String(err)));
  }

  function loadForwards() {
    api.ports.forwards
      .list()
      .then((res) => setForwards(res.forwards))
      .catch((err) => setForwardError(err instanceof Error ? err.message : String(err)));
  }

  useEffect(() => {
    loadAgentPorts();
    loadForwards();
    api.servers
      .list()
      .then((res) => setServers(res.servers))
      .catch(() => {});
  }, []);

  const { sorted: sortedAgentPorts, sortKey: agentSortKey, sortDir: agentSortDir, requestSort: requestAgentSort } = useSortable(
    agentPorts,
    "serverName",
  );
  const { pageItems: agentPageItems, page: agentPage, setPage: setAgentPage, pageCount: agentPageCount, totalCount: agentTotalCount } = usePagination(
    sortedAgentPorts,
  );

  const { sorted: sortedForwards, sortKey: forwardSortKey, sortDir: forwardSortDir, requestSort: requestForwardSort } = useSortable(
    forwards,
    "externalPort",
  );

  function exportAgentCsv() {
    downloadCsv(
      "agent-reported-ports.csv",
      ["Server", "Hostname", "Protocol", "Port", "Addresses", "Process", "Local only"],
      (sortedAgentPorts ?? []).map((p) => [
        p.serverName,
        p.serverHostname ?? "",
        p.protocol,
        p.port,
        p.addresses.join(", "),
        p.process ?? "",
        p.localOnly ? "yes" : "no",
      ]),
    );
  }

  function exportForwardsCsv() {
    downloadCsv(
      "port-forwards.csv",
      ["Label", "External port", "Protocol", "Server", "Destination", "Internal port", "Source", "Comment"],
      (sortedForwards ?? []).map((f) => [
        f.label,
        f.externalPort,
        f.protocol,
        f.serverName ?? "",
        f.destination ?? "",
        f.internalPort ?? "",
        f.source ?? "",
        f.comment ?? "",
      ]),
    );
  }

  function startAdd() {
    setAdding(true);
    setEditing(null);
    setForm(emptyForm);
  }

  function startEdit(fwd: PortForward) {
    setEditing(fwd);
    setAdding(false);
    setForm({
      label: fwd.label,
      externalPort: fwd.externalPort,
      protocol: fwd.protocol,
      serverId: fwd.serverId,
      destination: fwd.destination ?? "",
      internalPort: fwd.internalPort,
      source: fwd.source ?? "",
      comment: fwd.comment ?? "",
    });
  }

  function cancelForm() {
    setAdding(false);
    setEditing(null);
    setForm(emptyForm);
  }

  async function submit(e: FormEvent) {
    e.preventDefault();
    setForwardError(null);
    setSaving(true);
    try {
      if (editing) {
        await api.ports.forwards.update(editing.id, form);
      } else {
        await api.ports.forwards.create(form);
      }
      cancelForm();
      loadForwards();
    } catch (err) {
      setForwardError(err instanceof Error ? err.message : String(err));
    } finally {
      setSaving(false);
    }
  }

  async function remove(fwd: PortForward) {
    if (!confirm(`Delete port opening "${fwd.label}"?`)) return;
    setForwardError(null);
    try {
      await api.ports.forwards.remove(fwd.id);
      loadForwards();
    } catch (err) {
      setForwardError(err instanceof Error ? err.message : String(err));
    }
  }

  const showForm = adding || editing;

  return (
    <>
      <h2 className="page-title mb-3">Ports</h2>

      <div className="row g-3 mb-3">
        <div className="col-12">
          <div className="card">
            <div className="card-header">
              <h3 className="card-title">Ports reported by agents</h3>
              <div className="card-actions">
                <span className="text-secondary me-3">
                  {reportingServers} of {totalServers} server{totalServers !== 1 ? "s" : ""} reporting
                </span>
                <button className="btn btn-sm btn-outline-secondary" onClick={exportAgentCsv} disabled={!sortedAgentPorts?.length}>
                  Export CSV
                </button>
                <button className="btn btn-sm btn-outline-secondary" onClick={loadAgentPorts}>
                  Refresh
                </button>
              </div>
            </div>
            {agentError && <div className="alert alert-danger m-3">{agentError}</div>}
            <div className="table-responsive">
              <table className="table table-vcenter card-table">
                <thead>
                  <tr>
                    <SortableTh<AgentPortRow> label="Server" sortKeyName="serverName" activeKey={agentSortKey} direction={agentSortDir} onSort={requestAgentSort} />
                    <SortableTh<AgentPortRow> label="Protocol" sortKeyName="protocol" activeKey={agentSortKey} direction={agentSortDir} onSort={requestAgentSort} />
                    <SortableTh<AgentPortRow> label="Port" sortKeyName="port" activeKey={agentSortKey} direction={agentSortDir} onSort={requestAgentSort} />
                    <th>Address</th>
                    <th>Process</th>
                    <SortableTh<AgentPortRow> label="Last report" sortKeyName="lastSeenAt" activeKey={agentSortKey} direction={agentSortDir} onSort={requestAgentSort} />
                  </tr>
                </thead>
                <tbody>
                  {(agentPageItems ?? []).map((p) => (
                    <tr key={`${p.serverId}-${p.protocol}-${p.port}`}>
                      <td>
                        <Link to={`/servers/${p.serverId}`}>{p.serverName}</Link>
                        {p.serverHostname && <div className="text-secondary small">{p.serverHostname}</div>}
                      </td>
                      <td className="text-uppercase text-secondary">{p.protocol}</td>
                      <td>{p.port}</td>
                      <td className="text-secondary">
                        {p.addresses.join(", ")}
                        {p.localOnly && <span className="badge bg-secondary-lt text-secondary ms-2">local only</span>}
                      </td>
                      <td className="text-secondary">{p.process ?? "—"}</td>
                      <td className="text-secondary">{p.lastSeenAt ? formatAgo(p.lastSeenAt) : "—"}</td>
                    </tr>
                  ))}
                  {agentPorts !== null && agentPorts.length === 0 && (
                    <tr>
                      <td colSpan={6} className="text-secondary text-center">
                        No servers have reported listening ports yet.
                      </td>
                    </tr>
                  )}
                </tbody>
              </table>
            </div>
            <Pagination page={agentPage} pageCount={agentPageCount} totalCount={agentTotalCount} onPageChange={setAgentPage} />
          </div>
        </div>
      </div>

      {canEdit && showForm && (
        <div className="card mb-3">
          <div className="card-header">
            <h3 className="card-title">{editing ? `Edit "${editing.label}"` : "Add a manual port opening"}</h3>
          </div>
          <form onSubmit={submit}>
            <div className="card-body row g-3">
              <div className="col-md-3">
                <label className="form-label">Label</label>
                <input
                  className="form-control"
                  required
                  placeholder="Plex remote access"
                  value={form.label}
                  onChange={(e) => setForm({ ...form, label: e.target.value })}
                />
              </div>
              <div className="col-md-2">
                <label className="form-label">External port</label>
                <input
                  type="number"
                  className="form-control"
                  required
                  min={1}
                  max={65535}
                  value={form.externalPort || ""}
                  onChange={(e) => setForm({ ...form, externalPort: Number(e.target.value) })}
                />
              </div>
              <div className="col-md-2">
                <label className="form-label">Protocol</label>
                <select
                  className="form-select"
                  value={form.protocol}
                  onChange={(e) => setForm({ ...form, protocol: e.target.value as "tcp" | "udp" })}
                >
                  <option value="tcp">TCP</option>
                  <option value="udp">UDP</option>
                </select>
              </div>
              <div className="col-md-2">
                <label className="form-label">Internal port</label>
                <input
                  type="number"
                  className="form-control"
                  min={1}
                  max={65535}
                  placeholder="if different"
                  value={form.internalPort ?? ""}
                  onChange={(e) => setForm({ ...form, internalPort: e.target.value ? Number(e.target.value) : null })}
                />
              </div>
              <div className="col-md-3">
                <label className="form-label">Server (optional)</label>
                <select
                  className="form-select"
                  value={form.serverId ?? ""}
                  onChange={(e) => setForm({ ...form, serverId: e.target.value ? Number(e.target.value) : null })}
                >
                  <option value="">— none —</option>
                  {(servers ?? []).map((s) => (
                    <option key={s.id} value={s.id}>
                      {s.name}
                    </option>
                  ))}
                </select>
              </div>
              <div className="col-md-3">
                <label className="form-label">Destination</label>
                <input
                  className="form-control"
                  placeholder="IP/host, if not a tracked server"
                  value={form.destination ?? ""}
                  onChange={(e) => setForm({ ...form, destination: e.target.value })}
                />
              </div>
              <div className="col-md-3">
                <label className="form-label">Source</label>
                <input
                  className="form-control"
                  placeholder="Home router, OPNsense, Cloudflare Tunnel…"
                  value={form.source ?? ""}
                  onChange={(e) => setForm({ ...form, source: e.target.value })}
                />
              </div>
              <div className="col-md-3">
                <label className="form-label">Comment</label>
                <input
                  className="form-control"
                  value={form.comment ?? ""}
                  onChange={(e) => setForm({ ...form, comment: e.target.value })}
                />
              </div>
            </div>
            <div className="card-footer d-flex gap-2">
              <button type="submit" className="btn btn-primary" disabled={saving}>
                {editing ? "Save changes" : "Add port opening"}
              </button>
              <button type="button" className="btn" onClick={cancelForm}>
                Cancel
              </button>
            </div>
          </form>
        </div>
      )}

      <div className="card">
        <div className="card-header">
          <h3 className="card-title">Manual port openings</h3>
          <p className="text-secondary mb-0 me-auto">
            Router port forwards, edge firewall rules, cloud security groups — anything opened further out on the
            network that this app can't see on its own.
          </p>
          <div className="card-actions">
            {canEdit && !showForm && (
              <button className="btn btn-primary btn-sm" onClick={startAdd}>
                Add port opening
              </button>
            )}
            <button className="btn btn-sm btn-outline-secondary" onClick={exportForwardsCsv} disabled={!sortedForwards?.length}>
              Export CSV
            </button>
          </div>
        </div>
        {forwardError && <div className="alert alert-danger m-3">{forwardError}</div>}
        <div className="table-responsive">
          <table className="table table-vcenter card-table">
            <thead>
              <tr>
                <SortableTh<PortForward> label="Label" sortKeyName="label" activeKey={forwardSortKey} direction={forwardSortDir} onSort={requestForwardSort} />
                <SortableTh<PortForward>
                  label="External port"
                  sortKeyName="externalPort"
                  activeKey={forwardSortKey}
                  direction={forwardSortDir}
                  onSort={requestForwardSort}
                />
                <th>Destination</th>
                <SortableTh<PortForward> label="Source" sortKeyName="source" activeKey={forwardSortKey} direction={forwardSortDir} onSort={requestForwardSort} />
                <th>Comment</th>
                {canEdit && <th className="w-1">Actions</th>}
              </tr>
            </thead>
            <tbody>
              {(sortedForwards ?? []).map((f) => (
                <tr key={f.id}>
                  <td>{f.label}</td>
                  <td>
                    <span className="text-uppercase text-secondary me-1">{f.protocol}</span>
                    {f.externalPort}
                    {f.internalPort && f.internalPort !== f.externalPort && (
                      <span className="text-secondary"> → {f.internalPort}</span>
                    )}
                  </td>
                  <td className="text-secondary">
                    {f.serverId ? <Link to={`/servers/${f.serverId}`}>{f.serverName}</Link> : f.destination || "—"}
                    {f.serverId && f.destination && <div className="small">{f.destination}</div>}
                  </td>
                  <td className="text-secondary">{f.source ?? "—"}</td>
                  <td className="text-secondary">{f.comment ?? "—"}</td>
                  {canEdit && (
                    <td>
                      <div className="btn-list flex-nowrap">
                        <button className="btn btn-sm" onClick={() => startEdit(f)}>
                          Edit
                        </button>
                        <button className="btn btn-sm btn-outline-danger" onClick={() => remove(f)}>
                          Delete
                        </button>
                      </div>
                    </td>
                  )}
                </tr>
              ))}
              {forwards !== null && forwards.length === 0 && (
                <tr>
                  <td colSpan={canEdit ? 6 : 5} className="text-secondary text-center">
                    No manual port openings recorded yet.
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </div>
      </div>
    </>
  );
}