package engine

import (
	"fmt"

	"robotfs/config"
	"robotfs/pkg/fs"
	"robotfs/pkg/meta/redis_lua"
	"robotfs/pkg/storage"
)

type Engine struct {
	FileSystem *fs.FileSystem
}

func NewEngine() *Engine {
	return &Engine{}
}

func (e *Engine) Start() error {
	cfg := config.GetConfig()

	meta, err := e.initMetaStore(cfg)
	if err != nil {
		return err
	}

	store, err := e.initStorage(cfg)
	if err != nil {
		return err
	}

	e.FileSystem = fs.NewFileSystem(
		meta,
		store,
		cfg.GetString("robotfs.data_path"),
	)

	return nil
}

func (e *Engine) initMetaStore(cfg config.Configuration) (*redis_lua.RedisLuaStore, error) {
	meta := redis_lua.NewRedisLuaStore()
	if err := meta.Initialize(cfg, "redis."); err != nil {
		return nil, fmt.Errorf("initialize meta store failed: %v", err)
	}

	return meta, nil
}

func (e *Engine) initStorage(cfg config.Configuration) (*storage.Storage, error) {
	store := storage.NewStorage()
	if err := store.Initialize(cfg, "s3."); err != nil {
		return nil, fmt.Errorf("initialize s3 config failed: %v", err)
	}

	return store, nil
}

func (e *Engine) Stop() {
	// Stop filesystem manager.
	e.FileSystem.Shutdown()
}