#pragma once

struct AppSystemInfo_t {
    const char* m_pModuleName;
    const char* m_pInterfaceName;
};

enum InitReturnVal_t {
    INIT_FAILED = 0,
    INIT_OK,

    INIT_LAST_VAL,
};

enum AppSystemTier_t {
    APP_SYSTEM_TIER0 = 0,
    APP_SYSTEM_TIER1,
    APP_SYSTEM_TIER2,
    APP_SYSTEM_TIER3,

    APP_SYSTEM_TIER_OTHER,
};

class IAppSystem {
   public:
    // Here's where the app systems get to learn about each other
    virtual bool Connect(CreateInterfaceFn factory) = 0;

    virtual void Disconnect() = 0;

    // Here's where systems can access other interfaces implemented by this
    // object Returns NULL if it doesn't implement the requested interface
    virtual void* QueryInterface(const char* pInterfaceName) = 0;

    // Init, shutdown
    virtual InitReturnVal_t Init() = 0;

    virtual void Shutdown() = 0;

    // Returns all dependent libraries
    virtual const AppSystemInfo_t* GetDependencies() = 0;

    // Returns the tier
    virtual AppSystemTier_t GetTier() = 0;

    // Reconnect to a particular interface
    virtual void Reconnect(CreateInterfaceFn factory,
                           const char* pInterfaceName) = 0;

    // Returns whether or not the app system is a singleton
    virtual bool IsSingleton() = 0;
};