package watchers

import (
	"fmt"
	"sync"

	"git.sharkk.net/Sky/Moonshark/core/logger"
	"git.sharkk.net/Sky/Moonshark/core/routers"
	"git.sharkk.net/Sky/Moonshark/core/runner"
)

// Global watcher manager instance
var (
	globalManager     *WatcherManager
	globalManagerOnce sync.Once
)

// GetWatcherManager returns the global watcher manager, creating it if needed
func GetWatcherManager(adaptive bool) *WatcherManager {
	globalManagerOnce.Do(func() {
		globalManager = NewWatcherManager(adaptive)
	})
	return globalManager
}

// WatchDirectory creates a new directory watcher and registers it with the manager
func WatchDirectory(config DirectoryWatcherConfig, manager *WatcherManager) (*Watcher, error) {
	dirWatcher, err := NewDirectoryWatcher(config)
	if err != nil {
		return nil, fmt.Errorf("failed to create directory watcher: %w", err)
	}

	manager.AddWatcher(dirWatcher)

	// Create a wrapper Watcher that implements the old interface
	w := &Watcher{
		dir:      config.Dir,
		dirWatch: dirWatcher,
		manager:  manager,
	}

	logger.Debug("Started watching directory: %s", config.Dir)
	return w, nil
}

// Watcher is a compatibility wrapper that maintains the old API
type Watcher struct {
	dir      string
	dirWatch *DirectoryWatcher
	manager  *WatcherManager
}

// Close unregisters the watcher from the manager
func (w *Watcher) Close() error {
	w.manager.RemoveWatcher(w.dir)
	return nil
}

// WatchLuaRouter sets up a watcher for a LuaRouter's routes directory; also updates
// the LuaRunner so that the state can be rebuilt
func WatchLuaRouter(router *routers.LuaRouter, runner *runner.Runner, routesDir string) (*Watcher, error) {
	manager := GetWatcherManager(true)

	runnerRefresh := func() error {
		logger.Debug("Refreshing LuaRunner state due to file change")
		runner.NotifyFileChanged("")
		return nil
	}

	combinedCallback := combineCallbacks(router.Refresh, runnerRefresh)

	config := DirectoryWatcherConfig{
		Dir:       routesDir,
		Callback:  combinedCallback,
		Recursive: true,
	}

	watcher, err := WatchDirectory(config, manager)
	if err != nil {
		return nil, err
	}

	logger.Info("Started watching Lua routes directory: %s", routesDir)
	return watcher, nil
}

// WatchStaticRouter sets up a watcher for a StaticRouter's root directory
func WatchStaticRouter(router *routers.StaticRouter, staticDir string) (*Watcher, error) {
	manager := GetWatcherManager(true)

	config := DirectoryWatcherConfig{
		Dir:       staticDir,
		Callback:  router.Refresh,
		Recursive: true,
	}

	watcher, err := WatchDirectory(config, manager)
	if err != nil {
		return nil, err
	}

	logger.Info("Started watching static files directory: %s", staticDir)
	return watcher, nil
}

// WatchLuaModules sets up watchers for Lua module directories
func WatchLuaModules(luaRunner *runner.Runner, libDirs []string) ([]*Watcher, error) {
	manager := GetWatcherManager(true)
	watchers := make([]*Watcher, 0, len(libDirs))

	for _, dir := range libDirs {
		// Create a directory-specific callback
		dirCopy := dir // Capture for closure

		callback := func() error {
			logger.Debug("Detected changes in Lua module directory: %s", dirCopy)

			if err := luaRunner.RefreshStates(); err != nil {
				logger.Warning("Error reloading modules: %v", err)
			}

			return nil
		}

		config := DirectoryWatcherConfig{
			Dir:       dir,
			Callback:  callback,
			Recursive: true,
		}

		watcher, err := WatchDirectory(config, manager)
		if err != nil {
			// Clean up already created watchers
			for _, w := range watchers {
				w.Close()
			}
			return nil, err
		}

		watchers = append(watchers, watcher)
		logger.Info("Started watching Lua modules directory: %s", dir)
	}

	return watchers, nil
}

// ShutdownWatcherManager closes the global watcher manager if it exists
func ShutdownWatcherManager() {
	if globalManager != nil {
		globalManager.Close()
		globalManager = nil
	}
}

// combineCallbacks creates a single callback function from multiple callbacks
func combineCallbacks(callbacks ...func() error) func() error {
	return func() error {
		for _, callback := range callbacks {
			if err := callback(); err != nil {
				return err
			}
		}
		return nil
	}
}