gf_images_id.go

/*
GloFlow application and media management/publishing platform
Copyright (C) 2019 Ivan Trajkovic

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
*/

package gf_images_core

import (
	"fmt"
	"net/url"
	"time"
	"crypto/md5"
	"encoding/hex"
	"github.com/gloflow/gloflow/go/gf_core"
)

//---------------------------------------------------

type Gf_image_id string // DEPRECATED!! - switch to using GF_image_id fully
type GF_image_id = Gf_image_id
type GFimageID   = GF_image_id

//---------------------------------------------------
// CREATES_ID

func CreateIDfromURL(pImageURLstr string,
	pRuntimeSys *gf_core.RuntimeSys) (GFimageID, *gf_core.GFerror) {
	
	// urlparse() - used so that any possible url query parameters are not used in the 
	//              os.path.basename() result
	url, err := url.Parse(pImageURLstr)
	if err != nil {
		gfErr := gf_core.ErrorCreate("failed to parse image_url to create image ID",
			"url_parse_error",
			map[string]interface{}{"image_url_str": pImageURLstr,},
			err, "gf_images_core", pRuntimeSys)
		return "", gfErr
	}
	
	imageHostStr := url.Host
	imagePathStr := url.Path
	imageURIstr  := fmt.Sprintf("%s/%s", imageHostStr, imagePathStr)
	
	//-------------
	imageIDstr := CreateImageID(imageURIstr,
		pRuntimeSys)
	
	//-------------
	return imageIDstr, nil
}

//---------------------------------------------------
// CREATES_ID

func CreateImageID(pImageURIstr string,
	pRuntimeSys *gf_core.RuntimeSys) GFimageID {
	
	h := md5.New()
		
	currentUNIXtimeF := float64(time.Now().UnixNano())/1000000000.0
	h.Write([]byte(fmt.Sprint(currentUNIXtimeF)))
	h.Write([]byte(pImageURIstr))

	sum     := h.Sum(nil)
	hex_str := hex.EncodeToString(sum)
	
	gfImageIDstr := GFimageID(hex_str)
	return gfImageIDstr
}