package loader

import (
	"context"
	"errors"
	"fmt"
	"galaxy/connector"
	mc "galaxy/model/client"
	"plugin"
	"time"

	"fyne.io/fyne/v2"
)

type ClientInit func(connector.UIConnector, fyne.App, mc.Settings) (mc.Client, error)

type loader struct {
	conn connector.Connector
	cli  mc.Client
}

func NewLoader(app fyne.App, conn connector.Connector) (*loader, error) {
	app.Storage().List()
	settings := mc.Settings{}
	cli, err := loadClientPlugin(conn, app, settings, "./client.so", "NewClient")
	if err != nil {
		return nil, err
	}
	l := &loader{
		conn: conn,
		cli:  cli,
	}
	return l, nil
}

func (l *loader) Run(ctx context.Context) error {
	final := make(chan struct{}, 1)
	go l.backgroundLoop(ctx, final)
	if err := l.cli.Run(); err != nil {
		return err
	}
	final <- struct{}{}
	return nil
}

func (l *loader) backgroundLoop(ctx context.Context, final <-chan struct{}) {
	t := time.NewTicker(time.Second * 5)
	for {
		select {
		case <-ctx.Done():
			l.cli.Shutdown()
			return
		case <-final:
			return
		case <-t.C:
			isGood := l.conn.CheckConnection()
			l.cli.OnConnection(isGood)
		}
	}
}

// loadClientPlugin loads a Client implementation from a shared object (.so) file at the specified path.
// It calls the constructor function by name, passing the necessary dependencies, and returns the initialized Client.
func loadClientPlugin(conn connector.UIConnector, app fyne.App, s mc.Settings, path, name string) (mc.Client, error) {
	if path == "" {
		return nil, errors.New("no plugin path given")
	}

	plug, err := plugin.Open(path)
	if err != nil {
		return nil, fmt.Errorf("open plugin %q: %w", path, err)
	}

	sym, err := plug.Lookup(name)
	if err != nil {
		return nil, fmt.Errorf("lookup symbol %q: %w", name, err)
	}

	initializerPtr, ok := sym.(*ClientInit)
	if !ok {
		return nil, fmt.Errorf("unexpected type %T; want %T", sym, initializerPtr)
	}

	return (*initializerPtr)(conn, app, s)
}