package client;

import (
	"git.xdrm.io/schastsp/client/keyset"
	"fmt"
	"path/filepath"
	"errors"
	"os"
)


type config struct {
	path string // absolute configuration file path
}

/* (1) Constructor
*
* @dir<string>						Dir path
* @name<string>						file name
*
---------------------------------------------------------*/
func Config(dir string, name string) (*config, error) {

	inst := new(config);

	/* (1) Build full path */
	absoluteDir, err := filepath.Abs(dir);
	if err != nil { return nil, err; }

	basename := filepath.Base(name);
	fullpath := fmt.Sprintf("%s/%s", absoluteDir, basename);


	/* (2) Check directory */
	if info, err := os.Stat(absoluteDir); err != nil {

		// Unknown error
		if !os.IsNotExist(err) { return nil, err }

		// not exists -> try to create dir
		err2 := os.MkdirAll(absoluteDir, 0755);
		if err2 != nil { return nil, err2 }

	// fail if not a directory
	} else if !info.Mode().IsDir() {
		return nil, errors.New("Configuration dir is not a directory");
	}


	/* (3) Check file */
	info, err := os.Stat(fullpath);
	if err != nil {

		// Unknown error
		if !os.IsNotExist(err) { return nil, err }

		// File does not exist -> try to create file
		_, err2 := os.Create(fullpath);
		if err2 != nil { return nil, err2 }


	// fail if exists but not regular file
	} else if !info.Mode().IsRegular() {
		return nil, errors.New("Configuration file is not a regular file");
	}

	inst.path = fullpath

	return inst, nil

}


/* (2) Fetches a keyset from a file
*
* @ks<*keyset.T>					Set to fetch into
*
* @return err<error>				Fetching error
* 									NIL on error
*
---------------------------------------------------------*/
func (c config) Fetch(ks *keyset.T) (err error) {

	/* (1) Open file */
	file, err := os.Open(c.path)
	if err != nil { return err }

	/* (2) Defer close */
	defer file.Close()

	/* (3) Fetch from file */
	err = ks.Fetch(file);
	if err != nil { return err }

	return nil

}


/* (3) Stores a keyset into file
*
* @ks<*keyset.T>					Set to store
*
* @return err<error>				Storage error
* 									NIL on error
*
---------------------------------------------------------*/
func (c config) Store(ks *keyset.T) error {

	/* (1) Open file */
	file, err := os.OpenFile(c.path, os.O_RDWR|os.O_CREATE, 0755);
	if err != nil { return err }

	/* (2) Defer close */
	defer file.Close()

	/* (3) Store into file */
	err = ks.Store(file)
	if err != nil { return err }

	return nil

}