import { create } from 'zustand';
import { devtools } from 'zustand/middleware';
import { CANVAS_CONFIG, COLORS } from '@gaplace/shared';

interface PixelData {
  x: number;
  y: number;
  color: string;
  timestamp?: number;
  userId?: string;
  username?: string;
}

interface PixelInfo {
  color: string;
  userId?: string;
  username?: string;
  timestamp?: number;
}

interface Chunk {
  chunkX: number;
  chunkY: number;
  pixels: Map<string, PixelInfo>; // key: "x,y", value: pixel info
  isLoaded: boolean;
  lastModified: number;
}

interface Viewport {
  x: number;
  y: number;
  width: number;
  height: number;
  zoom: number;
}

interface CanvasState {
  // Canvas data
  canvasId: string;
  chunks: Map<string, Chunk>; // key: "chunkX,chunkY"
  
  // Viewport
  viewport: Viewport;
  
  // Tools
  selectedColor: string;
  selectedTool: 'pixel' | 'fill' | 'eyedropper';
  brushSize: number;
  
  // UI state
  isLoading: boolean;
  isPanning: boolean;
  showGrid: boolean;
  showCursors: boolean;
  
  // User presence
  activeUsers: string[];
  userCursors: Map<string, { x: number; y: number; username: string; color: string }>;
  
  // Stats
  totalPixels: number;
  userPixels: number;
  
  // Actions
  setCanvasId: (id: string) => void;
  setPixel: (x: number, y: number, color: string, userId?: string, username?: string) => void;
  loadChunk: (chunkX: number, chunkY: number, pixels: PixelData[]) => void;
  setViewport: (viewport: Partial<Viewport>) => void;
  setZoom: (zoom: number, centerX?: number, centerY?: number) => void;
  pan: (deltaX: number, deltaY: number) => void;
  setSelectedColor: (color: string) => void;
  setSelectedTool: (tool: 'pixel' | 'fill' | 'eyedropper') => void;
  setBrushSize: (size: number) => void;
  setUserCursor: (userId: string, x: number, y: number, username: string, color: string) => void;
  removeUserCursor: (userId: string) => void;
  setActiveUsers: (users: string[]) => void;
  setStats: (totalPixels: number, userPixels?: number) => void;
  getPixelAt: (x: number, y: number) => string | null;
  getPixelInfo: (x: number, y: number) => PixelInfo | null;
  getChunkKey: (chunkX: number, chunkY: number) => string;
  getPixelKey: (x: number, y: number) => string;
  getChunkCoordinates: (x: number, y: number) => { chunkX: number; chunkY: number };
}

export const useCanvasStore = create<CanvasState>()(
  devtools(
    (set, get) => ({
      // Initial state
      canvasId: 'default',
      chunks: new Map(),
      viewport: {
        x: 0,
        y: 0,
        width: 1920,
        height: 1080,
        zoom: 1,
      },
      selectedColor: COLORS.PALETTE[0],
      selectedTool: 'pixel',
      brushSize: 1,
      isLoading: false,
      isPanning: false,
      showGrid: true,
      showCursors: true,
      activeUsers: [],
      userCursors: new Map(),
      totalPixels: 0,
      userPixels: 0,

      // Actions
      setCanvasId: (id) => set({ canvasId: id }),

      setPixel: (x, y, color, userId, username) => {
        const state = get();
        const { chunkX, chunkY } = state.getChunkCoordinates(x, y);
        const chunkKey = state.getChunkKey(chunkX, chunkY);
        const pixelKey = state.getPixelKey(
          x % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE,
          y % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE
        );

        const chunks = new Map(state.chunks);
        let chunk = chunks.get(chunkKey);

        if (!chunk) {
          chunk = {
            chunkX,
            chunkY,
            pixels: new Map(),
            isLoaded: true,
            lastModified: Date.now(),
          };
        }

        const pixelInfo: PixelInfo = {
          color,
          userId,
          username,
          timestamp: Date.now()
        };

        chunk.pixels.set(pixelKey, pixelInfo);
        chunk.lastModified = Date.now();
        chunks.set(chunkKey, chunk);

        set({ chunks });
      },

      loadChunk: (chunkX, chunkY, pixels) => {
        const state = get();
        const chunkKey = state.getChunkKey(chunkX, chunkY);
        const chunks = new Map(state.chunks);

        const pixelMap = new Map<string, PixelInfo>();
        pixels.forEach((pixel) => {
          const localX = pixel.x % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
          const localY = pixel.y % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
          const pixelKey = state.getPixelKey(localX, localY);
          pixelMap.set(pixelKey, {
            color: pixel.color,
            userId: pixel.userId,
            username: pixel.username,
            timestamp: pixel.timestamp
          });
        });

        const chunk: Chunk = {
          chunkX,
          chunkY,
          pixels: pixelMap,
          isLoaded: true,
          lastModified: Date.now(),
        };

        chunks.set(chunkKey, chunk);
        set({ chunks });
      },

      setViewport: (newViewport) => {
        const state = get();
        set({
          viewport: { ...state.viewport, ...newViewport },
        });
      },

      setZoom: (zoom, centerX, centerY) => {
        const state = get();
        const clampedZoom = Math.max(CANVAS_CONFIG.MIN_ZOOM, Math.min(CANVAS_CONFIG.MAX_ZOOM, zoom));
        
        let newViewport = { ...state.viewport, zoom: clampedZoom };

        // If center point is provided, zoom towards that point
        if (centerX !== undefined && centerY !== undefined) {
          const BASE_PIXEL_SIZE = 32;
          const currentPixelSize = BASE_PIXEL_SIZE * state.viewport.zoom;
          const newPixelSize = BASE_PIXEL_SIZE * clampedZoom;
          
          // Calculate what canvas coordinate is at the center point
          const canvasCenterX = (centerX + state.viewport.x) / currentPixelSize;
          const canvasCenterY = (centerY + state.viewport.y) / currentPixelSize;
          
          // Calculate new viewport to keep same canvas point at center
          newViewport.x = canvasCenterX * newPixelSize - centerX;
          newViewport.y = canvasCenterY * newPixelSize - centerY;
        }

        set({ viewport: newViewport });
      },

      pan: (deltaX, deltaY) => {
        const state = get();
        set({
          viewport: {
            ...state.viewport,
            x: state.viewport.x + deltaX,
            y: state.viewport.y + deltaY,
          },
        });
      },

      setSelectedColor: (color) => set({ selectedColor: color }),
      setSelectedTool: (tool) => set({ selectedTool: tool }),
      setBrushSize: (size) => set({ brushSize: Math.max(1, Math.min(10, size)) }),

      setUserCursor: (userId, x, y, username, color) => {
        const state = get();
        const userCursors = new Map(state.userCursors);
        userCursors.set(userId, { x, y, username, color });
        set({ userCursors });
      },

      removeUserCursor: (userId) => {
        const state = get();
        const userCursors = new Map(state.userCursors);
        userCursors.delete(userId);
        set({ userCursors });
      },

      setActiveUsers: (users) => set({ activeUsers: users }),
      setStats: (totalPixels, userPixels) => set({ 
        totalPixels, 
        ...(userPixels !== undefined && { userPixels }) 
      }),

      getPixelAt: (x, y) => {
        const state = get();
        const { chunkX, chunkY } = state.getChunkCoordinates(x, y);
        const chunkKey = state.getChunkKey(chunkX, chunkY);
        const chunk = state.chunks.get(chunkKey);

        if (!chunk) return null;

        const localX = x % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
        const localY = y % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
        const pixelKey = state.getPixelKey(localX, localY);

        return chunk.pixels.get(pixelKey)?.color || null;
      },

      getPixelInfo: (x, y) => {
        const state = get();
        const { chunkX, chunkY } = state.getChunkCoordinates(x, y);
        const chunkKey = state.getChunkKey(chunkX, chunkY);
        const chunk = state.chunks.get(chunkKey);

        if (!chunk) return null;

        const localX = x % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
        const localY = y % CANVAS_CONFIG.DEFAULT_CHUNK_SIZE;
        const pixelKey = state.getPixelKey(localX, localY);

        return chunk.pixels.get(pixelKey) || null;
      },

      getChunkKey: (chunkX, chunkY) => `${chunkX},${chunkY}`,
      getPixelKey: (x, y) => `${x},${y}`,
      getChunkCoordinates: (x, y) => ({
        chunkX: Math.floor(x / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE),
        chunkY: Math.floor(y / CANVAS_CONFIG.DEFAULT_CHUNK_SIZE),
      }),
    }),
    { name: 'canvas-store' }
  )
);