// IPlugin: interface all monitoring agent plugins must implement.

#pragma once

#include <cstdint>

// Plugin interface implemented by every dynamically loaded monitoring plugin.

// Lifecycle contract:

//   1. The registry calls create() (exported from the shared library) to obtain a pointer.

//   2. The plugin is used via this interface.

//   3. The registry calls destroy() on the plugin before calling dlclose().

//      Calling any virtual method after dlclose() is undefined behaviour.

class IPlugin {

public:

  virtual ~IPlugin() = default;

  // Returns the plugin's human-readable name (stable pointer into the plugin's DSO).

  virtual const char* name() const = 0;

  // Collects a metric sample; may block briefly while querying the OS.

  // Returns: raw metric value; negative on error.

  virtual int64_t collect() = 0;

  // Releases all plugin resources.

  // Must be called before the host calls dlclose() on this plugin's library.

  virtual void destroy() = 0;

};