import { useEffect, useMemo, useState, type FormEvent } from "react";
import { Link } from "react-router-dom";
import { api, type AdminLink, type CurrentUser, type PortEntry, type ServerRecord } from "../api/client";
import { useSortable } from "../hooks/useSortable";
import SortableTh from "../components/SortableTh";
import { downloadCsv } from "../utils/csv";
import { guessAdminUrl, portOptionLabel } from "../utils/adminLinkUrl";
import { confirmDialog } from "../utils/dialogs";

interface LinkForm {
  serverId: number | "";
  label: string;
  url: string;
}

const emptyForm: LinkForm = { serverId: "", label: "", url: "" };

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

  const [links, setLinks] = useState<AdminLink[] | null>(null);
  const [servers, setServers] = useState<ServerRecord[] | null>(null);
  const [error, setError] = useState<string | null>(null);
  const [search, setSearch] = useState("");

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

  const [portOptions, setPortOptions] = useState<PortEntry[] | null>(null);
  const [portAddress, setPortAddress] = useState<string | null>(null);
  const [loadingPorts, setLoadingPorts] = useState(false);
  const [portPick, setPortPick] = useState("");

  function load() {
    api.servers.allLinks()
      .then((res) => setLinks(res.links))
      .catch((err) => setError(err instanceof Error ? err.message : String(err)));
  }

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

  // Once a server is picked in the add/edit form, offer to fill the URL from one of its own known
  // ports (agent-reported or already noted on its Ports card) instead of typing it out by hand.
  useEffect(() => {
    setPortPick("");
    if (form.serverId === "") {
      setPortOptions(null);
      setPortAddress(null);
      return;
    }
    const serverId = form.serverId;
    setLoadingPorts(true);
    Promise.all([api.servers.detail(serverId), api.servers.ports.list(serverId)])
      .then(([detail, portList]) => {
        setPortAddress(detail.server.hostname || detail.ipAddresses[0] || null);
        setPortOptions(portList.ports);
      })
      .catch(() => {
        setPortOptions(null);
        setPortAddress(null);
      })
      .finally(() => setLoadingPorts(false));
  }, [form.serverId]);

  function pickPort(key: string) {
    setPortPick(key);
    const entry = portOptions?.find((p) => `${p.protocol}:${p.port}` === key);
    if (!entry) return;
    const url = guessAdminUrl(portAddress, entry);
    setForm((f) => ({ ...f, url: url ?? f.url, label: f.label || entry.label || entry.agent?.process || "" }));
  }

  const filtered = useMemo(() => {
    if (!links) return [];
    const q = search.trim().toLowerCase();
    if (!q) return links;
    return links.filter((l) => [l.serverName, l.serverHostname, l.label, l.url].some((v) => (v ?? "").toLowerCase().includes(q)));
  }, [links, search]);

  const { sorted, sortKey, sortDir, requestSort } = useSortable(filtered, "serverName");

  function exportCsv() {
    downloadCsv(
      "admin-links.csv",
      ["Server", "Label", "URL"],
      (sorted ?? []).map((l) => [l.serverName, l.label, l.url]),
    );
  }

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

  function startEdit(link: AdminLink) {
    setEditing(link);
    setAdding(false);
    setForm({ serverId: link.serverId, label: link.label, url: link.url });
  }

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

  async function submit(e: FormEvent) {
    e.preventDefault();
    if (form.serverId === "") return;
    setError(null);
    setSaving(true);
    try {
      if (editing) {
        await api.servers.updateLink(editing.serverId, editing.id, { label: form.label, url: form.url });
      } else {
        await api.servers.addLink(form.serverId, { label: form.label, url: form.url });
      }
      cancelForm();
      load();
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    } finally {
      setSaving(false);
    }
  }

  async function remove(link: AdminLink) {
    if (!(await confirmDialog({ title: "Remove admin link", message: `Remove the "${link.label}" link from ${link.serverName}?`, confirmLabel: "Remove", danger: true }))) return;
    setError(null);
    try {
      await api.servers.removeLink(link.serverId, link.id);
      load();
    } catch (err) {
      setError(err instanceof Error ? err.message : String(err));
    }
  }

  const showForm = adding || editing;

  return (
    <>
      <h2 className="page-title mb-3">Admin Links</h2>
      <p className="text-secondary">
        Every admin bookmark added to a server's own page (Infrastructure → Servers → a server → Admin Links) — Dockge,
        Webmin, Cockpit, and the like — in one place, instead of visiting each server to find them.
      </p>
      {error && <div className="alert alert-danger">{error}</div>}

      {canEdit && showForm && (
        <div className="card mb-3">
          <div className="card-header">
            <h3 className="card-title">{editing ? `Edit "${editing.label}"` : "Add an admin link"}</h3>
          </div>
          <form onSubmit={submit}>
            <div className="card-body row g-3">
              <div className="col-md-3">
                <label className="form-label">Server</label>
                <select
                  className="form-select"
                  required
                  disabled={!!editing}
                  value={form.serverId}
                  onChange={(e) => setForm({ ...form, serverId: e.target.value ? Number(e.target.value) : "" })}
                >
                  <option value="" disabled>
                    — choose a server —
                  </option>
                  {(servers ?? []).map((s) => (
                    <option key={s.id} value={s.id}>
                      {s.name}
                    </option>
                  ))}
                </select>
                {editing && <div className="form-hint">Remove and re-add to move it to a different server.</div>}
              </div>
              <div className="col-md-3">
                <label className="form-label">Label</label>
                <input
                  className="form-control"
                  required
                  maxLength={60}
                  placeholder="e.g. Dockge, Webmin, Cockpit"
                  value={form.label}
                  onChange={(e) => setForm({ ...form, label: e.target.value })}
                />
              </div>
              <div className="col-md-6">
                <label className="form-label">URL</label>
                <input
                  type="url"
                  className="form-control"
                  required
                  placeholder="http://10.0.0.5:5001"
                  value={form.url}
                  onChange={(e) => setForm({ ...form, url: e.target.value })}
                />
              </div>
              {form.serverId !== "" && (
                <div className="col-12">
                  <label className="form-label">Fill from a known port (optional)</label>
                  <select
                    className="form-select"
                    style={{ maxWidth: 460 }}
                    value={portPick}
                    disabled={loadingPorts || !portOptions?.length}
                    onChange={(e) => pickPort(e.target.value)}
                  >
                    <option value="">
                      {loadingPorts
                        ? "Loading this server's ports…"
                        : portOptions?.length
                          ? "— pick a port to fill in the URL above —"
                          : "No known ports for this server yet"}
                    </option>
                    {portOptions?.map((p) => (
                      <option key={`${p.protocol}:${p.port}`} value={`${p.protocol}:${p.port}`}>
                        {portOptionLabel(p)}
                      </option>
                    ))}
                  </select>
                  {portOptions && portOptions.length > 0 && !portAddress && (
                    <div className="form-hint">
                      This server has no known hostname or IP yet, so picking a port won't fill in an address —
                      see its Ports card under Infrastructure → Servers.
                    </div>
                  )}
                </div>
              )}
            </div>
            <div className="card-footer d-flex gap-2">
              <button type="submit" className="btn btn-primary" disabled={saving}>
                {editing ? "Save changes" : "Add link"}
              </button>
              <button type="button" className="btn" onClick={cancelForm}>
                Cancel
              </button>
            </div>
          </form>
        </div>
      )}

      <div className="card">
        <div className="card-header">
          <input
            className="form-control"
            style={{ maxWidth: 280 }}
            placeholder="Search server, label, URL…"
            value={search}
            onChange={(e) => setSearch(e.target.value)}
          />
          <div className="card-actions">
            {canEdit && !showForm && (
              <button className="btn btn-primary btn-sm" onClick={startAdd}>
                Add link
              </button>
            )}
            <button className="btn btn-sm btn-outline-secondary" onClick={exportCsv} disabled={!sorted?.length}>
              Export CSV
            </button>
          </div>
        </div>
        <div className="table-responsive">
          <table className="table table-vcenter card-table">
            <thead>
              <tr>
                <SortableTh<AdminLink> label="Server" sortKeyName="serverName" activeKey={sortKey} direction={sortDir} onSort={requestSort} />
                <SortableTh<AdminLink> label="Label" sortKeyName="label" activeKey={sortKey} direction={sortDir} onSort={requestSort} />
                <th>URL</th>
                {canEdit && <th className="w-1">Actions</th>}
              </tr>
            </thead>
            <tbody>
              {(sorted ?? []).map((l) => (
                <tr key={l.id}>
                  <td>
                    <Link to={`/servers/${l.serverId}`}>{l.serverName}</Link>
                    {l.serverHostname && <div className="text-secondary small">{l.serverHostname}</div>}
                  </td>
                  <td>{l.label}</td>
                  <td>
                    <a href={l.url} target="_blank" rel="noopener noreferrer">
                      {l.url}
                    </a>
                  </td>
                  {canEdit && (
                    <td>
                      <div className="btn-list flex-nowrap">
                        <button className="btn btn-sm" onClick={() => startEdit(l)}>
                          Edit
                        </button>
                        <button className="btn btn-sm btn-outline-danger" onClick={() => remove(l)}>
                          Delete
                        </button>
                      </div>
                    </td>
                  )}
                </tr>
              ))}
              {links !== null && links.length === 0 && (
                <tr>
                  <td colSpan={canEdit ? 4 : 3} className="text-secondary text-center">
                    No admin links added yet.
                  </td>
                </tr>
              )}
              {links !== null && links.length > 0 && (sorted ?? []).length === 0 && (
                <tr>
                  <td colSpan={canEdit ? 4 : 3} className="text-secondary text-center">
                    Nothing matches "{search}".
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </div>
      </div>
    </>
  );
}