package com.openosrs.client.engine;

import com.openosrs.client.core.ClientCore;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.concurrent.atomic.AtomicBoolean;

/**
 * PhysicsEngine - Handles game physics and movement calculations.
 */
class PhysicsEngine {
    private static final Logger logger = LoggerFactory.getLogger(PhysicsEngine.class);
    
    private final ClientCore clientCore;
    private final AtomicBoolean initialized = new AtomicBoolean(false);
    
    public PhysicsEngine(ClientCore clientCore) {
        this.clientCore = clientCore;
    }
    
    public void initialize() {
        if (initialized.get()) {
            logger.warn("PhysicsEngine already initialized");
            return;
        }
        
        logger.info("Initializing PhysicsEngine");
        
        try {
            // Initialize physics systems
            
            initialized.set(true);
            logger.info("PhysicsEngine initialized");
            
        } catch (Exception e) {
            logger.error("Failed to initialize PhysicsEngine", e);
            throw new RuntimeException("PhysicsEngine initialization failed", e);
        }
    }
    
    public void shutdown() {
        if (!initialized.get()) {
            return;
        }
        
        logger.info("Shutting down PhysicsEngine");
        
        try {
            // Cleanup physics resources
            
            initialized.set(false);
            logger.info("PhysicsEngine shutdown complete");
            
        } catch (Exception e) {
            logger.error("Error during PhysicsEngine shutdown", e);
        }
    }
    
    /**
     * Update physics simulation (called each game tick).
     */
    public void update() {
        if (!initialized.get()) {
            return;
        }
        
        try {
            // Update player movement
            updatePlayerMovement();
            
            // Update NPC movement
            updateNPCMovement();
            
            // Update object physics (falling items, etc.)
            updateObjectPhysics();
            
        } catch (Exception e) {
            logger.error("Error updating physics", e);
        }
    }
    
    private void updatePlayerMovement() {
        // Calculate player movement based on input and game state
        // This would handle walking, running, animations, etc.
    }
    
    private void updateNPCMovement() {
        // Update NPC positions and animations
        // This would handle NPC AI movement patterns
    }
    
    private void updateObjectPhysics() {
        // Handle physics for game objects
        // Falling items, projectiles, etc.
    }
    
    /**
     * Calculate path between two points.
     */
    public int[][] calculatePath(int startX, int startY, int endX, int endY) {
        // Simple pathfinding implementation
        // In a real implementation, this would use A* or similar algorithm
        
        logger.debug("Calculating path from ({}, {}) to ({}, {})", startX, startY, endX, endY);
        
        // For now, return a simple straight line path
        int deltaX = endX - startX;
        int deltaY = endY - startY;
        int steps = Math.max(Math.abs(deltaX), Math.abs(deltaY));
        
        if (steps == 0) {
            return new int[0][2];
        }
        
        int[][] path = new int[steps][2];
        for (int i = 0; i < steps; i++) {
            path[i][0] = startX + (deltaX * i / steps);
            path[i][1] = startY + (deltaY * i / steps);
        }
        
        return path;
    }
    
    /**
     * Check if a tile is walkable.
     */
    public boolean isWalkable(int x, int y, int plane) {
        // Check collision data, objects, etc.
        // For now, assume all tiles are walkable
        return true;
    }
    
    /**
     * Calculate distance between two points.
     */
    public double calculateDistance(int x1, int y1, int x2, int y2) {
        int dx = x2 - x1;
        int dy = y2 - y1;
        return Math.sqrt(dx * dx + dy * dy);
    }
    
    public boolean isInitialized() { return initialized.get(); }
}