package lect78_impl.model;

import java.util.ArrayList;
import java.util.List;
import lect78_impl.model.Position;

/**
 * @overview A collection class that manages a set of tanks for a player
 * 
 * @attributes
 *  tanks       List<Tank>  List of tanks in the set
 *  currentIndex Integer    Index of the currently active tank
 *  maxTanks    Integer     Maximum number of tanks allowed
 *  owner       Player      The player who owns this tank set
 */
public class TankSet {
    private List<Tank> tanks;
    private int currentIndex;
    private int maxTanks;
    private Player owner;
    
    /**
     * @effects Creates an empty tank set with specified maximum capacity
     */
    public TankSet(Player owner, int maxTanks) {
        this.owner = owner;
        this.maxTanks = maxTanks;
        this.tanks = new ArrayList<>();
        this.currentIndex = 0;
    }
    
    /**
     * @effects Adds a tank to the set if space available
     * @return true if added successfully, false otherwise
     */
    public boolean addTank(Tank tank) {
        if (tanks.size() >= maxTanks) {
            return false;
        }
        
        tanks.add(tank);
        tank.setOwner(owner);
        return true;
    }
    
    /**
     * @effects Removes a tank from the set
     * @return true if removed successfully, false if tank not found
     */
    public boolean removeTank(Tank tank) {
        if (!tanks.contains(tank)) {
            return false;
        }
        
        int index = tanks.indexOf(tank);
        tanks.remove(tank);
        
        // Adjust current index if needed
        if (tanks.isEmpty()) {
            currentIndex = 0;
        } else if (currentIndex >= tanks.size()) {
            currentIndex = 0;
        } else if (index < currentIndex) {
            currentIndex--;
        }
        
        return true;
    }
    
    /**
     * @effects Removes a tank by its ID
     * @return true if removed successfully, false if ID not found
     */
    public boolean removeTankById(int tankId) {
        for (Tank tank : tanks) {
            if (tank.getId() == tankId) {
                return removeTank(tank);
            }
        }
        return false;
    }
    
    /**
     * @effects Gets the currently active tank
     * @return The active tank or null if set is empty
     */
    public Tank getActiveTank() {
        if (tanks.isEmpty()) {
            return null;
        }
        return tanks.get(currentIndex);
    }
    
    /**
     * @effects Switches to the next available tank
     * @return true if switched successfully, false if no other tanks
     */
    public boolean nextTank() {
        if (tanks.size() <= 1) {
            return false;
        }
        
        currentIndex = (currentIndex + 1) % tanks.size();
        return true;
    }
    
    /**
     * @effects Gets a tank by its ID
     * @return The tank or null if not found
     */
    public Tank getTankById(int id) {
        for (Tank tank : tanks) {
            if (tank.getId() == id) {
                return tank;
            }
        }
        return null;
    }
    
    /**
     * @effects Gets the number of tanks in the set
     */
    public int size() {
        return tanks.size();
    }
    
    /**
     * @effects Checks if the set is empty
     */
    public boolean isEmpty() {
        return tanks.isEmpty();
    }
    
    /**
     * @effects Gets all tanks in the set
     */
    public List<Tank> getAllTanks() {
        return new ArrayList<>(tanks); // Return a copy to prevent external modification
    }
    
    /**
     * @effects Gets all tanks at a specific position
     */
    public List<Tank> getTanksAt(Position pos) {
        List<Tank> result = new ArrayList<>();
        for (Tank tank : tanks) {
            if (tank.getPosition().equals(pos)) {
                result.add(tank);
            }
        }
        return result;
    }
}