import { useState } from "react";
import { useMutation, useQuery, useQueryClient } from "@tanstack/react-query";
import { Network as NetworkIcon, Plus, Trash2, Eraser } from "lucide-react";
import { toast } from "sonner";
import { Badge, Button, Card, Input, Spinner } from "@/components/ui";
import { ConfirmDialog } from "@/components/ui/ConfirmDialog";
import { networksApi, type NetworkInfo } from "@/api/networks";
import { apiErrorMessage } from "@/api/client";
import { useAuthStore } from "@/store/auth";

const selectClass =
  "w-full rounded-lg border border-slate-300 bg-white px-3 py-2 text-sm dark:border-slate-600 dark:bg-slate-800";

export function Networks() {
  const isAdmin = useAuthStore((s) => s.user?.role === "admin");
  const qc = useQueryClient();
  const { data, isLoading } = useQuery({
    queryKey: ["networks"],
    queryFn: networksApi.list,
    refetchInterval: 10000,
  });
  const [creating, setCreating] = useState(false);
  const [toDelete, setToDelete] = useState<NetworkInfo | null>(null);
  const invalidate = () => qc.invalidateQueries({ queryKey: ["networks"] });

  const prune = useMutation({
    mutationFn: networksApi.prune,
    onSuccess: (r) => {
      const n = r.NetworksDeleted?.length ?? 0;
      toast.success(n ? `Pruned ${n} network(s)` : "No unused networks");
      invalidate();
    },
    onError: (e) => toast.error(apiErrorMessage(e)),
  });
  const remove = useMutation({
    mutationFn: (id: string) => networksApi.remove(id),
    onSuccess: () => {
      toast.success("Network deleted");
      setToDelete(null);
      invalidate();
    },
    onError: (e) => toast.error(apiErrorMessage(e)),
  });

  if (isLoading) return <Spinner />;

  return (
    <div className="space-y-4">
      {isAdmin && (
        <div className="flex flex-wrap justify-end gap-2">
          <Button variant="outline" onClick={() => prune.mutate()} loading={prune.isPending}>
            <Eraser className="h-4 w-4" /> Prune unused
          </Button>
          <Button onClick={() => setCreating(true)}>
            <Plus className="h-4 w-4" /> Create network
          </Button>
        </div>
      )}

      <Card className="overflow-x-auto p-0">
        <table className="w-full text-left text-sm">
          <thead className="border-b border-slate-200 text-xs uppercase text-slate-500 dark:border-slate-700">
            <tr>
              <th className="px-4 py-2">Name</th>
              <th className="px-4 py-2">Driver</th>
              <th className="px-4 py-2">Scope</th>
              <th className="px-4 py-2">Subnet</th>
              <th className="px-4 py-2">In use</th>
              {isAdmin && <th className="px-4 py-2"></th>}
            </tr>
          </thead>
          <tbody className="divide-y divide-slate-100 dark:divide-slate-700">
            {data?.map((n) => (
              <tr key={n.id}>
                <td className="px-4 py-2">
                  <div className="flex items-center gap-2">
                    <NetworkIcon className="h-4 w-4 text-slate-400" />
                    <span className="font-medium">{n.name}</span>
                    {n.is_default && <Badge>default</Badge>}
                    {n.stack && <Badge>{n.stack}</Badge>}
                    {n.internal && <span className="text-xs text-slate-400">internal</span>}
                  </div>
                </td>
                <td className="px-4 py-2 text-slate-500">{n.driver}</td>
                <td className="px-4 py-2 text-slate-500">{n.scope}</td>
                <td className="px-4 py-2 font-mono text-xs text-slate-500">{n.subnet ?? "—"}</td>
                <td className="px-4 py-2">
                  {n.in_use ? (
                    <span title={n.containers.join(", ")} className="text-slate-600 dark:text-slate-300">
                      {n.containers.length} container{n.containers.length > 1 ? "s" : ""}
                    </span>
                  ) : (
                    <span className="text-slate-400">—</span>
                  )}
                </td>
                {isAdmin && (
                  <td className="px-4 py-2 text-right">
                    {!n.is_default && (
                      <button
                        title={n.in_use ? "In use — disconnect containers first" : "Delete"}
                        onClick={() => setToDelete(n)}
                        className="rounded-lg p-1.5 hover:bg-slate-100 dark:hover:bg-slate-700"
                      >
                        <Trash2 className="h-4 w-4 text-red-500" />
                      </button>
                    )}
                  </td>
                )}
              </tr>
            ))}
            {data?.length === 0 && (
              <tr>
                <td colSpan={6} className="px-4 py-8 text-center text-sm text-slate-500">
                  No networks.
                </td>
              </tr>
            )}
          </tbody>
        </table>
      </Card>

      {creating && (
        <CreateNetworkDialog onDone={() => { setCreating(false); invalidate(); }} onCancel={() => setCreating(false)} />
      )}
      {toDelete && (
        <ConfirmDialog
          title={`Delete network “${toDelete.name}”?`}
          message={
            toDelete.in_use
              ? "This network is in use; Docker will refuse unless containers are disconnected first."
              : "This cannot be undone."
          }
          confirmLabel="Delete network"
          danger
          busy={remove.isPending}
          onConfirm={() => remove.mutate(toDelete.id)}
          onCancel={() => setToDelete(null)}
        />
      )}
    </div>
  );
}

function CreateNetworkDialog({ onDone, onCancel }: { onDone: () => void; onCancel: () => void }) {
  const [form, setForm] = useState({
    name: "",
    driver: "bridge",
    subnet: "",
    gateway: "",
    internal: false,
    attachable: true,
  });
  const set = (k: string, v: unknown) => setForm((f) => ({ ...f, [k]: v }));

  const create = useMutation({
    mutationFn: () =>
      networksApi.create({
        name: form.name,
        driver: form.driver,
        subnet: form.subnet.trim() || null,
        gateway: form.gateway.trim() || null,
        internal: form.internal,
        attachable: form.attachable,
      }),
    onSuccess: () => { toast.success("Network created"); onDone(); },
    onError: (e) => toast.error(apiErrorMessage(e)),
  });

  return (
    <div className="fixed inset-0 z-50 flex items-center justify-center bg-black/50 p-4" onClick={onCancel}>
      <div
        className="w-full max-w-md rounded-xl border border-slate-200 bg-card p-5 shadow-xl dark:border-slate-700 dark:bg-card-dark"
        onClick={(e) => e.stopPropagation()}
      >
        <h2 className="mb-3 text-lg font-semibold">Create network</h2>
        <div className="space-y-3">
          <label className="block space-y-1">
            <span className="text-xs font-medium text-slate-500">Name</span>
            <Input value={form.name} onChange={(e) => set("name", e.target.value)} placeholder="my-net" />
          </label>
          <label className="block space-y-1">
            <span className="text-xs font-medium text-slate-500">Driver</span>
            <select className={selectClass} value={form.driver} onChange={(e) => set("driver", e.target.value)}>
              <option value="bridge">bridge</option>
              <option value="macvlan">macvlan</option>
              <option value="ipvlan">ipvlan</option>
              <option value="overlay">overlay</option>
            </select>
          </label>
          <div className="grid grid-cols-2 gap-3">
            <label className="space-y-1">
              <span className="text-xs font-medium text-slate-500">Subnet (optional)</span>
              <Input value={form.subnet} onChange={(e) => set("subnet", e.target.value)} placeholder="172.20.0.0/16" />
            </label>
            <label className="space-y-1">
              <span className="text-xs font-medium text-slate-500">Gateway (optional)</span>
              <Input value={form.gateway} onChange={(e) => set("gateway", e.target.value)} placeholder="172.20.0.1" />
            </label>
          </div>
          <div className="flex gap-4">
            <label className="flex items-center gap-2 text-sm">
              <input type="checkbox" checked={form.internal} onChange={(e) => set("internal", e.target.checked)} className="h-4 w-4" />
              Internal (no external access)
            </label>
            <label className="flex items-center gap-2 text-sm">
              <input type="checkbox" checked={form.attachable} onChange={(e) => set("attachable", e.target.checked)} className="h-4 w-4" />
              Attachable
            </label>
          </div>
        </div>
        <div className="mt-4 flex justify-end gap-2">
          <Button variant="outline" onClick={onCancel}>Cancel</Button>
          <Button onClick={() => create.mutate()} loading={create.isPending} disabled={!form.name.trim()}>
            Create
          </Button>
        </div>
      </div>
    </div>
  );
}