#pragma once

#include "mapbox/variant.hpp"

#include <map>
#include <memory>

namespace media {
namespace diagnostic {

using CounterVariant = mapbox::util::variant<
    vbl::baselong,
    vbl::CVBLString,
    SCounter
>;

struct CounterHolder {
public:
    CounterHolder() = default;

    explicit CounterHolder(CounterVariant val)
        : valid(true)
        , value(val) {
    }

    CounterVariant& Get() {
        VBL_ASSERT(valid);
        return value;
    }

    vbl::basebool valid{ false };

private:
    CounterVariant value;
};

using CounterMap = std::map<vbl::CVBLString, CounterHolder>;
using CounterMapPtr = std::shared_ptr<CounterMap>;

// IProvider represents a read-only interface for counter receiving.
class IProvider {
public:
    // Destroy.
    virtual ~IProvider() = default;

    // Returns the counter for the provided @p key.
    //
    // @remarks
    //  It is safe to modify received counter.
    virtual CounterHolder Get(const vbl::CVBLString& key) const = 0;

    // Returns all existing counters.
    //
    // @remarks
    //  It is safe to modify received counters.
    virtual CounterMap GetAll() const = 0;
};

} // diagnostic namespace
} // media namespace