import { redisClient } from '../config/database-factory';
import { 
  Pixel, 
  PixelChunk, 
  getChunkCoordinates, 
  getChunkKey, 
  getPixelKey,
  CANVAS_CONFIG 
} from '@gaplace/shared';
import { config } from '../config/env';

export class CanvasService {
  private readonly keyPrefix = config.redis.keyPrefix;

  async placePixel(canvasId: string, x: number, y: number, color: string, userId: string): Promise<boolean> {
    try {
      const { chunkX, chunkY } = getChunkCoordinates(x, y);
      const chunkKey = `${this.keyPrefix}canvas:${canvasId}:chunk:${getChunkKey(chunkX, chunkY)}`;
      const pixelKey = getPixelKey(x % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE, y % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE);
      
      // Simple approach without pipeline for better compatibility
      await redisClient.hSet(chunkKey, pixelKey, color);
      
      // Update chunk metadata
      await redisClient.hSet(`${chunkKey}:meta`, {
        lastModified: Date.now().toString(),
        lastUser: userId,
      });
      
      // Track user pixel count
      await redisClient.incr(`${this.keyPrefix}user:${userId}:pixels`);
      
      // Update canvas stats
      await redisClient.incr(`${this.keyPrefix}canvas:${canvasId}:totalPixels`);
      await redisClient.set(`${this.keyPrefix}canvas:${canvasId}:lastActivity`, Date.now().toString());
      
      return true;
    } catch (error) {
      console.error('Error placing pixel:', error);
      return false;
    }
  }

  async getChunk(canvasId: string, chunkX: number, chunkY: number): Promise<PixelChunk | null> {
    try {
      const chunkKey = `${this.keyPrefix}canvas:${canvasId}:chunk:${getChunkKey(chunkX, chunkY)}`;
      const [pixelData, metadata] = await Promise.all([
        redisClient.hGetAll(chunkKey),
        redisClient.hGetAll(`${chunkKey}:meta`)
      ]);

      if (Object.keys(pixelData).length === 0) {
        return null;
      }

      const pixels = new Map<string, string>();
      for (const [key, color] of Object.entries(pixelData)) {
        pixels.set(key, String(color));
      }

      return {
        chunkX,
        chunkY,
        pixels,
        lastModified: parseInt(metadata.lastModified || '0'),
      };
    } catch (error) {
      console.error('Error getting chunk:', error);
      return null;
    }
  }

  async getVisibleChunks(canvasId: string, startX: number, startY: number, endX: number, endY: number): Promise<PixelChunk[]> {
    const chunks: PixelChunk[] = [];
    
    const startChunkX = Math.floor(startX / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE);
    const startChunkY = Math.floor(startY / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE);
    const endChunkX = Math.floor(endX / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE);
    const endChunkY = Math.floor(endY / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE);

    const promises: Promise<PixelChunk | null>[] = [];
    
    for (let chunkX = startChunkX; chunkX <= endChunkX; chunkX++) {
      for (let chunkY = startChunkY; chunkY <= endChunkY; chunkY++) {
        promises.push(this.getChunk(canvasId, chunkX, chunkY));
      }
    }

    const results = await Promise.all(promises);
    
    for (const chunk of results) {
      if (chunk) {
        chunks.push(chunk);
      }
    }

    return chunks;
  }

  async getCanvasStats(canvasId: string): Promise<{
    totalPixels: number;
    lastActivity: number;
    activeUsers: number;
  }> {
    try {
      const [totalPixels, lastActivity, activeUsers] = await Promise.all([
        redisClient.get(`${this.keyPrefix}canvas:${canvasId}:totalPixels`),
        redisClient.get(`${this.keyPrefix}canvas:${canvasId}:lastActivity`),
        redisClient.sCard(`${this.keyPrefix}canvas:${canvasId}:activeUsers`)
      ]);

      return {
        totalPixels: parseInt(totalPixels || '0'),
        lastActivity: parseInt(lastActivity || '0'),
        activeUsers: activeUsers || 0,
      };
    } catch (error) {
      console.error('Error getting canvas stats:', error);
      return {
        totalPixels: 0,
        lastActivity: 0,
        activeUsers: 0,
      };
    }
  }

  async addActiveUser(canvasId: string, userId: string): Promise<void> {
    try {
      await redisClient.sAdd(`${this.keyPrefix}canvas:${canvasId}:activeUsers`, userId);
      // Set expiration to auto-remove inactive users
      await redisClient.expire(`${this.keyPrefix}canvas:${canvasId}:activeUsers`, 300); // 5 minutes
    } catch (error) {
      console.error('Error adding active user:', error);
    }
  }

  async removeActiveUser(canvasId: string, userId: string): Promise<void> {
    try {
      await redisClient.sRem(`${this.keyPrefix}canvas:${canvasId}:activeUsers`, userId);
    } catch (error) {
      console.error('Error removing active user:', error);
    }
  }

  async getActiveUsers(canvasId: string): Promise<string[]> {
    try {
      return await redisClient.sMembers(`${this.keyPrefix}canvas:${canvasId}:activeUsers`);
    } catch (error) {
      console.error('Error getting active users:', error);
      return [];
    }
  }
}