#include <boost/shared_ptr.hpp>
#include <iostream>
#include <vector>
#include <string>

class DownloadObject {
public:
    DownloadObject(std::string uri, int priority)
        :uri_(uri), pri_(priority) {}
    virtual void downloadCompleted() = 0;
    virtual ~DownloadObject() {}
private:
    std::string uri_;
    int pri_;
};

class Downloader {
public:
    void download(DownloadObject *d) {
        // ダウンロード開始
        objs_.push_back(d);
        // ダウンロード完了したとして。。
        for (std::vector<DownloadObject *>::iterator i(objs_.begin());
            i != objs_.end();
            ++i)
            (*i)->downloadCompleted();
    }
    std::vector<DownloadObject *> objs_;
};

class Content;
typedef boost::shared_ptr<Content> ContentSp;

class Cache;
typedef boost::shared_ptr<Cache> CacheSp;

class Cache {
public:
    static Cache &getInstance() { 
        static CacheSp cache_;
        if (!cache_) {
            cache_.reset(new Cache);
        }
        return *cache_.get();
    }
    void addContent(const ContentSp& c) {
        contents_.push_back(c);
    }
private:
    std::vector<ContentSp> contents_;
};

class Content:public DownloadObject {
public:
    static ContentSp create(std::string uri, int priority) {
        ContentSp s(new Content(uri, priority));
        s->setSp(s);
        return s;
    }
    virtual ~Content() { std::cout << "Destroyed" << std::endl; }
    virtual void downloadCompleted() {
        std::cout << "downloadCompleted" << std::endl;
        Cache::getInstance().addContent(self_);
    }
private:
    Content(std::string uri, int priority)
        :DownloadObject(uri, priority)
        { std::cout << "Created" << std::endl; }
    void setSp(const ContentSp &sp) { self_ = sp; }
    ContentSp self_;
};

int main()
{
    std::cout << "Test started" << std::endl;
    {
        ContentSp sp = Content::create("hoge", 1);
        Downloader d;
        d.download(sp.get());
    }
    std::cout << "Test finished" << std::endl;
}