import { promises as fs } from 'fs';
import * as path from 'path';
import * as zlib from 'zlib';
import { promisify } from 'util';

const gzip = promisify(zlib.gzip);

export interface GrokadeTemplateConfig {
  // Display settings
  scaleToFit?: boolean;
  optimizeForPixelArt?: boolean;
  centerCanvas?: boolean;
  customBackground?: string;
  
  // Loading settings
  showLoadingBar?: boolean;
  showLoadingText?: boolean;
  loadingBarColor?: string;
  clickToPlay?: boolean;
  fullscreenButton?: boolean;
  showScrollbars?: boolean;
  
  // Mobile settings
  mobileOptimized?: boolean;
  forceMobileFullscreen?: boolean;
  
  // Performance settings
  compressionEnabled?: boolean;
  maxFileSize?: number;
  maxTotalFiles?: number;
  maxFilenameLength?: number;
  
  // Security settings
  allowedFileTypes?: string[];
  httpsRequired?: boolean;
}

export class GrokadeTemplateManager {
  private readonly templatePath: string;
  private readonly defaultConfig: GrokadeTemplateConfig = {
    scaleToFit: true,
    optimizeForPixelArt: false,
    centerCanvas: true,
    customBackground: '#000000',
    showLoadingBar: true,
    showLoadingText: true,
    loadingBarColor: 'white',
    clickToPlay: false,
    fullscreenButton: true,
    showScrollbars: false,
    mobileOptimized: true,
    forceMobileFullscreen: true,
    compressionEnabled: true,
    maxFileSize: 200 * 1024 * 1024, // 200MB
    maxTotalFiles: 1000,
    maxFilenameLength: 240,
    allowedFileTypes: [
      '.html', '.js', '.css', '.wasm',
      '.jpg', '.jpeg', '.png', '.webp', '.svg',
      '.wav', '.ogg', '.mp3',
      '.glsl', '.vert', '.frag',
      '.json', '.txt'
    ],
    httpsRequired: true
  };

  constructor(templatePath: string) {
    this.templatePath = templatePath;
  }

  async applyTemplate(config: Partial<GrokadeTemplateConfig> = {}): Promise<void> {
    const finalConfig = { ...this.defaultConfig, ...config };
    
    try {
      await this.validateTemplate();
      await this.injectTemplateStyles(finalConfig);
      await this.setupLoadingIndicators(finalConfig);
      await this.configureCompression(finalConfig);
      await this.setupMobileSupport(finalConfig);
      await this.injectSecurityHeaders();
      await this.optimizeScaling(finalConfig);
    } catch (error) {
      console.error('Error applying template:', error);
      throw error;
    }
  }

  private async validateTemplate(): Promise<void> {
    const indexPath = path.join(this.templatePath, 'index.html');
    if (!await this.fileExists(indexPath)) {
      throw new Error('Template must contain an index.html file');
    }
  }

  private async injectTemplateStyles(config: GrokadeTemplateConfig): Promise<void> {
    const styles = `
      <style>
        html, body {
          background: ${config.customBackground};
          width: 100%;
          height: 100%;
          overflow: ${config.showScrollbars ? 'auto' : 'hidden'};
          padding: 0;
          margin: 0;
        }
        
        #gameContainer {
          background: transparent !important;
          position: absolute;
        }
        
        #gameContainer canvas {
          position: absolute;
        }
        
        #gameContainer canvas[data-pixel-art="true"] {
          position: absolute;
          image-rendering: optimizeSpeed;
          image-rendering: -webkit-crisp-edges;
          image-rendering: -moz-crisp-edges;
          image-rendering: -o-crisp-edges;
          image-rendering: crisp-edges;
          image-rendering: -webkit-optimize-contrast;
          image-rendering: optimize-contrast;
          image-rendering: pixelated;
          -ms-interpolation-mode: nearest-neighbor;
        }
        
        /* Loading container styles */
        #loading-container {
          display: ${config.showLoadingText || config.showLoadingBar ? 'flex' : 'none'};
          flex-direction: column;
          justify-content: center;
          align-items: center;
          position: absolute;
          top: 50%;
          left: 50%;
          transform: translate(-50%, -50%);
          z-index: 10;
          color: white;
          font-family: sans-serif;
          text-align: center;
        }
        
        #loading-text {
          display: ${config.showLoadingText ? 'block' : 'none'};
          margin-bottom: 10px;
        }
      </style>
    `;

    try {
      const indexPath = path.join(this.templatePath, 'index.html');
      let html = await fs.readFile(indexPath, 'utf8');
      
      // Replace existing styles or add new ones
      if (html.includes('</head>')) {
        html = html.replace('</head>', `${styles}</head>`);
      } else {
        html = `<html><head>${styles}</head>${html}</html>`;
      }
      
      await fs.writeFile(indexPath, html);
    } catch (error) {
      console.error('Error injecting template styles:', error);
      throw error;
    }
  }

  private async setupLoadingIndicators(config: GrokadeTemplateConfig): Promise<void> {
    if (!config.showLoadingBar && !config.showLoadingText) {
      return;
    }

    try {
      const indexPath = path.join(this.templatePath, 'index.html');
      let html = await fs.readFile(indexPath, 'utf8');
      
      const loadingContainer = `
        <div id="loading-container">
          ${config.showLoadingText ? '<div id="loading-text">Loading...</div>' : ''}
        </div>
      `;
      
      // Add loading container to the body
      if (html.includes('<body>')) {
        html = html.replace('<body>', `<body>${loadingContainer}`);
      }
      
      // Modify the createUnityInstance function to handle loading progress
      const progressHandlerScript = `
        function progressHandler(progress) {
          var percent = progress * 100 + '%';
          canvas.style.background = 'linear-gradient(to right, ${config.loadingBarColor}, ${config.loadingBarColor} ' + percent + ', transparent ' + percent + ', transparent) no-repeat center';
          canvas.style.backgroundSize = '100% 1rem';
          
          // Update loading text if available
          var loadingText = document.getElementById('loading-text');
          if (loadingText) {
            loadingText.textContent = 'Loading... ' + Math.round(progress * 100) + '%';
          }
        }
      `;
      
      // Add progress handler to the existing JavaScript
      if (html.includes('createUnityInstance')) {
        // Add progress handler before createUnityInstance
        html = html.replace(/createUnityInstance\(/g, 
          `${progressHandlerScript}\n    createUnityInstance(`);
        
        // Add progressHandler to createUnityInstance parameters if not already there
        if (!html.includes('progressHandler')) {
          html = html.replace(/createUnityInstance\(([^,]+),\s*([^,)]+)/, 
            'createUnityInstance($1, $2, progressHandler');
        }
        
        // Hide loading container when the game is loaded
        html = html.replace(/createUnityInstance\([^)]+\).then\(function\s*\(([^)]+)\)/g, 
          `createUnityInstance(canvas, config, progressHandler).then(function($1) {
            // Hide loading container
            var loadingContainer = document.getElementById('loading-container');
            if (loadingContainer) {
              loadingContainer.style.display = 'none';
            }
          `);
      }
      
      await fs.writeFile(indexPath, html);
    } catch (error) {
      console.error('Error setting up loading indicators:', error);
      throw error;
    }
  }

  private async optimizeScaling(config: GrokadeTemplateConfig): Promise<void> {
    try {
      const indexPath = path.join(this.templatePath, 'index.html');
      let html = await fs.readFile(indexPath, 'utf8');
      
      // Ensure we have a canvas with data-pixel-art attribute
      if (html.includes('<canvas') && !html.includes('data-pixel-art')) {
        html = html.replace(/<canvas([^>]+)>/g, 
          `<canvas$1 data-pixel-art="${config.optimizeForPixelArt}">`);
      }
      
      // Add scaling functionality
      const scalingScript = `
        var scaleToFit = ${config.scaleToFit};
        
        function onResize() {
          var container = canvas.parentElement;
          var w;
          var h;

          if (scaleToFit) {
            w = window.innerWidth;
            h = window.innerHeight;

            var r = canvas.height / canvas.width;

            if (w * r > window.innerHeight) {
              w = Math.min(w, Math.ceil(h / r));
            }
            h = Math.floor(w * r);
          } else {
            w = canvas.width;
            h = canvas.height;
          }

          container.style.width = canvas.style.width = w + "px";
          container.style.height = canvas.style.height = h + "px";
          container.style.top = Math.floor((window.innerHeight - h) / 2) + "px";
          container.style.left = Math.floor((window.innerWidth - w) / 2) + "px";
          
          // Ensure focus for keyboard inputs
          window.focus();
        }
        
        window.addEventListener('resize', onResize);
        onResize();
      `;
      
      // Add scaling script after canvas setup
      if (html.includes('createUnityInstance') && !html.includes('onResize')) {
        // Add resize handler at the appropriate location
        html = html.replace(/createUnityInstance\([^)]+\).then\(function\s*\(([^)]+)\)\s*\{/g, 
          `createUnityInstance(canvas, config, progressHandler).then(function($1) {
            canvas = $1.Module.canvas;
            ${scalingScript}
          `);
      }
      
      await fs.writeFile(indexPath, html);
    } catch (error) {
      console.error('Error optimizing scaling:', error);
      throw error;
    }
  }

  private async setupMobileSupport(config: GrokadeTemplateConfig): Promise<void> {
    if (!config.mobileOptimized) {
      return;
    }
    
    try {
      const indexPath = path.join(this.templatePath, 'index.html');
      let html = await fs.readFile(indexPath, 'utf8');
      
      // Add mobile viewport meta tag
      if (html.includes('<head>') && !html.includes('viewport')) {
        const viewportMeta = `
          <meta name="viewport" content="width=device-width, height=device-height, initial-scale=1.0, user-scalable=no, shrink-to-fit=yes">
        `;
        html = html.replace('<head>', `<head>${viewportMeta}`);
      }
      
      // Add mobile detection code
      const mobileScript = `
        if (/iPhone|iPad|iPod|Android/i.test(navigator.userAgent)) {
          // Mobile device detected
          ${config.forceMobileFullscreen ? `
          // Request fullscreen on first touch
          document.addEventListener('touchstart', function() {
            if (document.documentElement.requestFullscreen) {
              document.documentElement.requestFullscreen();
            } else if (document.documentElement.webkitRequestFullscreen) {
              document.documentElement.webkitRequestFullscreen();
            }
          }, { once: true });
          ` : ''}
        }
      `;
      
      // Add mobile detection script
      if (html.includes('<script>') && !html.includes('iPhone|iPad|iPod|Android')) {
        html = html.replace('</script>', `${mobileScript}</script>`);
      } else {
        html = html.replace('</body>', `<script>${mobileScript}</script></body>`);
      }
      
      await fs.writeFile(indexPath, html);
    } catch (error) {
      console.error('Error setting up mobile support:', error);
      throw error;
    }
  }

  private async injectSecurityHeaders(): Promise<void> {
    // These headers would typically be set by the server, but we'll document them here
    const headers = {
      'Content-Security-Policy': "default-src 'self' https: data: 'unsafe-inline' 'unsafe-eval'",
      'X-Frame-Options': 'SAMEORIGIN',
      'X-Content-Type-Options': 'nosniff',
      'Referrer-Policy': 'strict-origin-when-cross-origin'
    };

    // Add a comment in the HTML documenting required headers
    const headerComment = `
      <!-- 
      Required Security Headers:
      ${Object.entries(headers).map(([key, value]) => `${key}: ${value}`).join('\n')}
      -->
    `;

    const indexPath = path.join(this.templatePath, 'index.html');
    let html = await fs.readFile(indexPath, 'utf-8');
    html = html.replace('<!DOCTYPE html>', `<!DOCTYPE html>\n${headerComment}`);
    await fs.writeFile(indexPath, html, 'utf-8');
  }

  private async configureCompression(config: GrokadeTemplateConfig): Promise<void> {
    if (!config.compressionEnabled) return;

    // Add compression configuration
    const compressionScript = `
      <script>
        window.GrokadeCompression = {
          enabled: true,
          async decompressData(data) {
            // Handle compressed data using WebAssembly
            return data;
          }
        };
      </script>
    `;

    const indexPath = path.join(this.templatePath, 'index.html');
    let html = await fs.readFile(indexPath, 'utf-8');
    html = html.replace('</head>', `${compressionScript}\n</head>`);
    await fs.writeFile(indexPath, html, 'utf-8');
  }

  private async fileExists(filePath: string): Promise<boolean> {
    try {
      await fs.access(filePath);
      return true;
    } catch {
      return false;
    }
  }
}