// Package plugin defines the plugin system for the Orca framework.
//
// All extensions to the framework (skills, tools, LLM drivers, etc.)
// are implemented as plugins that implement the Plugin interface.
// The kernel manages plugin lifecycle: load, init, start, stop, shutdown.
package plugin

import "github.com/orca/orca/pkg/bus"

// PluginState represents the current lifecycle state of a plugin.
type PluginState int

const (
	StateUnknown     PluginState = iota
	StateRegistered
	StateInitialized
	StateRunning
	StateStopped
	StateError
)

func (ps PluginState) String() string {
	switch ps {
	case StateUnknown:
		return "unknown"
	case StateRegistered:
		return "registered"
	case StateInitialized:
		return "initialized"
	case StateRunning:
		return "running"
	case StateStopped:
		return "stopped"
	case StateError:
		return "error"
	default:
		return "unknown"
	}
}

// PluginHost is the interface that the kernel provides to plugins.
//
// Plugins receive a PluginHost reference during Init() to interact
// with the framework: publishing/subscribing to messages, discovering
// other plugins, and accessing shared resources.
type PluginHost interface {
	Bus() bus.MessageBus
	GetPlugin(name string) (Plugin, bool)
	ListPlugins() []Plugin
}

// Plugin defines the interface that all Orca plugins must implement.
type Plugin interface {
	Name() string
	Version() string
	Init(host PluginHost) error
	Shutdown() error
}