package config

import (
	"errors"
	"os"

	"go.wit.com/log"
	"google.golang.org/protobuf/proto"
)

// loads foo.proto from ~/.cache/<appname>/foo.pb
func LoadAppnameCache(pb proto.Message, appname string) error {
	protoname, err := GetProtobufName(pb) // defined in the foo.proto file
	if err != nil {
		return err
	}

	// Get ~/.cache/appname/protoname.text
	fullname := makeCacheFilename(appname, protoname)

	// get the current filename in the protobuf file
	curfilename, err := GetFilename(pb)
	if err != nil {
		return err
	}
	if curfilename == "" {
		// log.Printf("ConfigLoad() read in %s\n", fullname)
	}

	if !Exists(fullname) {
		SetFilename(pb, fullname)
		return os.ErrNotExist
	}

	err = loadPB(pb, fullname)
	if err != nil {
		return ErrMarshal
	}

	// If the cache file is new or has moved, this updates it to correct filename
	// (the filename is what is used by pb.Save()
	if curfilename != fullname {
		_, err := SetFilename(pb, fullname)
		if err != nil {
			log.Info("FILENAME COULD NOT BE SET old=", curfilename)
			log.Info("FILENAME COULD NOT BE SET new=", fullname)
			return errors.Join(err, errors.New("something is wrong in lib/config"))
		}
	}
	return nil
}