import * as plugins from '../plugins.js';
import * as shared from './shared/index.js';
import * as appstate from '../appstate.js';

import {
  DeesElement,
  customElement,
  html,
  state,
  css,
  cssManager,
} from '@design.estate/dees-element';

@customElement('ops-view-overview')
export class OpsViewOverview extends DeesElement {
  @state()
  private statsState: appstate.IStatsState = {
    serverStats: null,
    emailStats: null,
    dnsStats: null,
    securityMetrics: null,
    lastUpdated: 0,
    isLoading: false,
    error: null,
  };

  constructor() {
    super();
    const subscription = appstate.statsStatePart
      .select((stateArg) => stateArg)
      .subscribe((statsState) => {
        this.statsState = statsState;
      });
    this.rxSubscriptions.push(subscription);
  }

  public static styles = [
    cssManager.defaultStyles,
    shared.viewHostCss,
    css`
      .statsGrid {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
        grid-gap: 16px;
        margin-bottom: 40px;
      }

      .statCard {
        background: #f8f9fa;
        border: 1px solid #e9ecef;
        border-radius: 8px;
        padding: 24px;
      }

      .statCard h3 {
        margin: 0 0 16px 0;
        font-size: 18px;
        font-weight: 600;
        color: #333;
      }

      .statValue {
        font-size: 32px;
        font-weight: 700;
        color: #2196F3;
        margin-bottom: 8px;
      }

      .statLabel {
        font-size: 14px;
        color: #666;
      }

      .chartGrid {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        grid-gap: 16px;
        margin-top: 32px;
      }

      .loadingMessage {
        text-align: center;
        padding: 40px;
        color: #666;
      }

      .errorMessage {
        background-color: #fee;
        border: 1px solid #fcc;
        border-radius: 4px;
        padding: 16px;
        color: #c00;
        margin: 16px 0;
      }
    `,
  ];

  public render() {
    return html`
      <ops-sectionheading>Overview</ops-sectionheading>
      
      ${this.statsState.isLoading ? html`
        <div class="loadingMessage">
          <dees-spinner></dees-spinner>
          <p>Loading statistics...</p>
        </div>
      ` : this.statsState.error ? html`
        <div class="errorMessage">
          Error loading statistics: ${this.statsState.error}
        </div>
      ` : html`
        <div class="statsGrid">
          ${this.statsState.serverStats ? html`
            <div class="statCard">
              <h3>Server Status</h3>
              <div class="statValue">${this.statsState.serverStats.uptime ? 'Online' : 'Offline'}</div>
              <div class="statLabel">Uptime: ${this.formatUptime(this.statsState.serverStats.uptime)}</div>
            </div>
            
            <div class="statCard">
              <h3>Connections</h3>
              <div class="statValue">${this.statsState.serverStats.activeConnections}</div>
              <div class="statLabel">Active connections</div>
            </div>

            <div class="statCard">
              <h3>Memory Usage</h3>
              <div class="statValue">${this.formatBytes(this.statsState.serverStats.memoryUsage.heapUsed)}</div>
              <div class="statLabel">of ${this.formatBytes(this.statsState.serverStats.memoryUsage.heapTotal)}</div>
            </div>

            <div class="statCard">
              <h3>CPU Usage</h3>
              <div class="statValue">${Math.round((this.statsState.serverStats.cpuUsage.user + this.statsState.serverStats.cpuUsage.system) / 2)}%</div>
              <div class="statLabel">Average load</div>
            </div>
          ` : ''}
        </div>

        ${this.statsState.emailStats ? html`
          <h2>Email Statistics</h2>
          <div class="statsGrid">
            <div class="statCard">
              <h3>Emails Sent</h3>
              <div class="statValue">${this.statsState.emailStats.sent}</div>
              <div class="statLabel">Total sent</div>
            </div>

            <div class="statCard">
              <h3>Emails Received</h3>
              <div class="statValue">${this.statsState.emailStats.received}</div>
              <div class="statLabel">Total received</div>
            </div>

            <div class="statCard">
              <h3>Failed Deliveries</h3>
              <div class="statValue">${this.statsState.emailStats.failed}</div>
              <div class="statLabel">Delivery failures</div>
            </div>

            <div class="statCard">
              <h3>Queued</h3>
              <div class="statValue">${this.statsState.emailStats.queued}</div>
              <div class="statLabel">In queue</div>
            </div>
          </div>
        ` : ''}

        ${this.statsState.dnsStats ? html`
          <h2>DNS Statistics</h2>
          <div class="statsGrid">
            <div class="statCard">
              <h3>DNS Queries</h3>
              <div class="statValue">${this.statsState.dnsStats.totalQueries}</div>
              <div class="statLabel">Total queries handled</div>
            </div>

            <div class="statCard">
              <h3>Cache Hit Rate</h3>
              <div class="statValue">${Math.round(this.statsState.dnsStats.cacheHitRate * 100)}%</div>
              <div class="statLabel">Cache efficiency</div>
            </div>
          </div>
        ` : ''}

        <div class="chartGrid">
          <dees-chart-area .label=${'Email Traffic (24h)'} .data=${[]}></dees-chart-area>
          <dees-chart-area .label=${'DNS Queries (24h)'} .data=${[]}></dees-chart-area>
          <dees-chart-log .label=${'Recent Events'} .data=${[]}></dees-chart-log>
          <dees-chart-log .label=${'Security Alerts'} .data=${[]}></dees-chart-log>
        </div>
      `}
    `;
  }

  private formatUptime(seconds: number): string {
    const days = Math.floor(seconds / 86400);
    const hours = Math.floor((seconds % 86400) / 3600);
    const minutes = Math.floor((seconds % 3600) / 60);
    
    if (days > 0) {
      return `${days}d ${hours}h ${minutes}m`;
    } else if (hours > 0) {
      return `${hours}h ${minutes}m`;
    } else {
      return `${minutes}m`;
    }
  }

  private formatBytes(bytes: number): string {
    const units = ['B', 'KB', 'MB', 'GB', 'TB'];
    let size = bytes;
    let unitIndex = 0;
    
    while (size >= 1024 && unitIndex < units.length - 1) {
      size /= 1024;
      unitIndex++;
    }
    
    return `${size.toFixed(1)} ${units[unitIndex]}`;
  }
}