Composite.cpp

#include <iostream>
#include <vector>
#include <string>
#include <memory>
#include <algorithm>

// Component Interface
class FileSystemItem {
public:
    virtual ~FileSystemItem() = default;

    virtual void print(int indent = 0) const = 0;
    virtual size_t getSize() const = 0;

    virtual void add(std::shared_ptr<FileSystemItem> item) {
        throw std::runtime_error("Operation not supported on Leaf nodes.");
    }
};

// Leaf Node (File)
class File : public FileSystemItem {
private:
    std::string name;
    size_t size;

public:
    File(std::string name, size_t size) 
        : name(std::move(name)), size(size) {}

    void print(int indent = 0) const override {
        std::string padding(indent, ' ');
        std::cout << padding << "- File: " << name << " (" << size << " KB)\n";
    }

    size_t getSize() const override {
        return size;
    }
};

// Composite Node (Directory)
class Directory : public FileSystemItem {
private:
    std::string name;
    std::vector<std::shared_ptr<FileSystemItem>> children;

public:
    explicit Directory(std::string name) : name(std::move(name)) {}

    void add(std::shared_ptr<FileSystemItem> item) override {
        children.push_back(std::move(item));
    }

    void print(int indent = 0) const override {
        std::string padding(indent, ' ');
        std::cout << padding << "+ Directory: " << name << "/\n";

        for (const auto& child : children) {
            child->print(indent + 4);
        }
    }

    size_t getSize() const override {
        size_t total = 0;
        for (const auto& child : children) {
            total += child->getSize();
        }
        return total;
    }
};

int main() {
    auto root = std::make_shared<Directory>("Root");

    auto file1 = std::make_shared<File>("config.json", 12);
    auto file2 = std::make_shared<File>("index.html", 45);

    root->add(file1);
    root->add(file2);

    auto subDir = std::make_shared<Directory>("images");
    auto img1 = std::make_shared<File>("logo.png", 250);
    auto img2 = std::make_shared<File>("banner.jpg", 1024);

    subDir->add(img1);
    subDir->add(img2);

    root->add(subDir);

    root->print();

    std::cout << "\nTotal Root Directory Size: " << root->getSize() << " KB\n";

    return 0;
}