'use client';

import { useState } from 'react';
import useSWR, { mutate } from 'swr';
import NodeList from './NodeList';
import VMList from './VMList';
import LXCList from './LXCList';
import axios from 'axios';
import { SWRConfig } from 'swr';
import ConsolePanel from './ConsolePanel';

const POLL_INTERVAL = Number(process.env.NEXT_PUBLIC_API_POLL_INTERVAL || 30000);

/**
 * Fetch helper for SWR.
 * @param {string} url
 * @returns {Promise<{ data: *, error: string | null }>}
 */
async function fetchData(url) {


  try {
    const res = await axios.get(url);
    return res.data;
  } catch (err) {
    const status = err.response?.status || 'Unknown';
    const message = err.response?.data?.message || err.response?.data?.errors || err.message || String(err);
    throw new Error(`API error ${status}: ${message}`);
  }
}

/** @returns {import('react').ReactNode} */
export default function Dashboard() {
  const [activeTab, setActiveTab] = useState('nodes');
  const [activeConsole, setActiveConsole] = useState(null);
  const [powerActionStatus, setPowerActionStatus] = useState(null);

  /**
   * @param {string} node
   * @param {number} vmid
   * @param {string} type
   * @param {string} action
   */
  const handlePowerAction = async (node, vmid, type, action) => {
    setPowerActionStatus({ text: `${action.charAt(0).toUpperCase() + action.slice(1)}ing ${type === 'qemu' ? 'VM' : 'LXC'} ${vmid}...`, type: 'pending' });
    try {
      await axios.post('/api/power', { node, vmid, type, action });
      // Immediately refetch all data instead of waiting for polling interval
      await mutate('/api/nodes');
      await mutate('/api/vms');
      await mutate('/api/lxc');
      await mutate('/api/status');
      setPowerActionStatus({ text: `${action.charAt(0).toUpperCase() + action.slice(1)} successful`, type: 'success' });
    } catch (err) {
      setPowerActionStatus({ text: err.message || `${action.charAt(0).toUpperCase() + action.slice(1)} failed`, type: 'error' });
    }
  };

  const { data: nodesData, error: nodesError } = useSWR('/api/nodes', fetchData, {
    refreshInterval: POLL_INTERVAL,
  });
  const { data: vmsData, error: vmsError } = useSWR('/api/vms', fetchData, {
    refreshInterval: POLL_INTERVAL,
  });
  const { data: lxcData, error: lxcError } = useSWR('/api/lxc', fetchData, {
    refreshInterval: POLL_INTERVAL,
  });
  const { data: summaryData, error: summaryError } = useSWR('/api/status', fetchData, {
    refreshInterval: POLL_INTERVAL,
  });

  const nodes = nodesData?.data ?? [];
  const vms = vmsData?.data ?? [];
  const lxc = lxcData?.data ?? [];
  const summary = summaryData?.data ?? null;

  const tabs = [
    { id: 'nodes', label: 'Nodes' },
    { id: 'vms', label: 'VMs' },
    { id: 'lxc', label: 'LXCs' },
    ...(activeConsole ? [{ id: 'console', label: `Console: ${activeConsole.name}` }] : []),
  ];

  return (
    <div className="min-h-screen p-4 sm:p-6 lg:p-8">
      {/* Header */}
      <div className="mb-6 flex flex-col gap-4 sm:flex-row sm:items-end sm:justify-between">
        <div>
          <h1 className="text-2xl font-bold text-text-primary">Proxmox Monitor</h1>
          <p className="mt-1 text-sm text-text-secondary">
            {nodes.length} node{nodes.length !== 1 ? 's' : ''} • {summary?.runningVMs ?? 0} running • Updated{' '}
            {new Date().toLocaleTimeString()}
          </p>
        </div>
      </div>

      {/* Summary Cards */}
      {summary && !summaryError && (
        <div className="mb-6 grid gap-4 sm:grid-cols-4">
          <div className="rounded-xl border border-border-card bg-bg-card p-4">
            <div className="text-xs uppercase tracking-wider text-text-secondary">Nodes</div>
            <div className="mt-1 text-2xl font-bold text-text-primary">{summary.totalNodes}</div>
          </div>
          <div className="rounded-xl border border-border-card bg-bg-card p-4">
            <div className="text-xs uppercase tracking-wider text-text-secondary">Running VMs</div>
            <div className="mt-1 text-2xl font-bold text-status-green">{summary.runningVMs}</div>
          </div>
          <div className="rounded-xl border border-border-card bg-bg-card p-4">
            <div className="text-xs uppercase tracking-wider text-text-secondary">Stopped VMs</div>
            <div className="mt-1 text-2xl font-bold text-status-red">{summary.stoppedVMs}</div>
          </div>
          <div className="rounded-xl border border-border-card bg-bg-card p-4">
            <div className="text-xs uppercase tracking-wider text-text-secondary">Total Memory</div>
            <div className="mt-1 text-xl font-bold text-text-primary">
              {summary.totalMemory?.total
                ? `${(summary.totalMemory.used / (1024 ** 3)).toFixed(1)} / ${(summary.totalMemory.total / (1024 ** 3)).toFixed(1)} GB`
                : 'N/A'}
            </div>
          </div>
        </div>
      )}

      {(summaryError || nodesError) && (
        <div className="mb-6 rounded-xl border border-status-red/30 bg-status-red/10 p-4 text-sm text-status-red">
          {summaryError || nodesError}
        </div>
      )}

      {powerActionStatus && (
        <div className={`mb-6 rounded-xl border p-4 text-sm ${
          powerActionStatus.type === 'success' ? 'border-status-green/30 bg-status-green/10 text-status-green'
            : powerActionStatus.type === 'error' ? 'border-status-red/30 bg-status-red/10 text-status-red'
            : 'border-border-card bg-bg-card text-text-secondary'
        }`}>
          {powerActionStatus.text}
        </div>
      )}

      {/* Tab navigation */}
      <div className="mb-4 flex gap-2 border-b border-border-card">
        {tabs.map((tab) => (
          <button
            key={tab.id}
            onClick={() => setActiveTab(tab.id)}
            className={`px-4 py-2 text-sm font-medium transition-colors ${activeTab === tab.id
              ? 'border-b-2 border-accent text-text-primary'
              : 'text-text-secondary hover:text-text-primary'
              }`}
          >
            {tab.label}
          </button>
        ))}
      </div>

      {/* Tab content */}
      <div>
        {activeTab === 'nodes' && <NodeList nodes={nodes} />}
        {activeTab === 'vms' && <VMList vms={vms} onPowerAction={handlePowerAction} onOpenConsole={(vm) => { setActiveConsole(vm); setActiveTab('console'); }} />}
        {activeTab === 'lxc' && <LXCList lxc={lxc} onPowerAction={handlePowerAction} onOpenConsole={(lxc) => { setActiveConsole(lxc); setActiveTab('console'); }} />}
        {activeTab === 'console' && activeConsole && (
          <ConsolePanel vm={activeConsole} onClose={() => setActiveConsole(null)} />
        )}
      </div>

      {/* Footer */}
      <div className="mt-8 text-center text-xs text-text-secondary">
        Polling every {POLL_INTERVAL / 1000}s • Proxmox VE Monitor
      </div>
    </div>
  );
}