directory delta compression logic implemented

TODO

@@ -0,0 +1,18 @@
+process
+1. create symlinks in gallery
+2. create full-size photos/videos in gallery
+3. create thumbnails in gallery
+4. create directory index.html:s in gallery for changed directories and where doesn't exist
+5. delete old redundant gallery files (those that don't exist)
+
+backlog
+- make full-size and thumbnail creation concurrent
+- print progress indicator
+
+architecture
+- use thumbnails as master in output directory
+- create symlinks and full-size pics before full-screen version
+
+hotfixes
+- how to quickly check emptiness of directory?
+- TODO go through all the todo stuff

gogallery.go

@@ -43,7 +43,7 @@ func parseArgs() (inputDirectory string, outputDirectory string) {
 		os.Exit(1)
 	}
 
-	if isEmpty(flag.Args()[0]) {
+	if isEmptyDir(flag.Args()[0]) {
 		fmt.Fprintf(os.Stderr, "%s: Input directory is empty: %s\n", os.Args[0], flag.Args()[0])
 		os.Exit(1)
 	}
@@ -52,15 +52,16 @@ func parseArgs() (inputDirectory string, outputDirectory string) {
 }
 
 type file struct {
-	name      string
-	modTime   time.Time
-	thumbnail string
+	name    string
+	path    string
+	modTime time.Time
+	exists  bool
 }
 
 type directory struct {
 	name           string
+	path           string
 	modTime        time.Time
-	thumbnail      string
 	subdirectories []directory
 	files          []file
 }
@@ -71,7 +72,7 @@ func checkError(e error) {
 	}
 }
 
-func isEmpty(directory string) (isEmpty bool) {
+func isEmptyDir(directory string) (isEmpty bool) {
 	list, err := ioutil.ReadDir(directory)
 	checkError(err)
 
@@ -81,28 +82,81 @@ func isEmpty(directory string) (isEmpty bool) {
 	return false
 }
 
-func discoverAsIs(outputDirectory string) (asIs directory) {
-	asIs.name = filepath.Base(outputDirectory)
+func isMediaFile(filename string) (isMedia bool) {
+	//TODO fix add strings.toLower() once goimport stops removing it
+	switch filepath.Ext(filename) {
+	case ".jpg", ".jpeg", ".heic", ".png", ".gif", ".tif":
+		return true
+	case ".cr2", ".raw", ".arw":
+		return true
+	case ".mp4", ".mov", ".3gp", ".avi", ".mts", ".m4v", ".mpg":
+		return true
+	default:
+		return false
+	}
+}
 
-	list, err := ioutil.ReadDir(outputDirectory)
+func recurseDirectory(thisDirectory string, relativeDirectory string) (root directory) {
+	root.name = filepath.Base(thisDirectory)
+	asIsStat, _ := os.Stat(thisDirectory)
+	root.modTime = asIsStat.ModTime()
+	root.path = relativeDirectory
+
+	list, err := ioutil.ReadDir(thisDirectory)
 	checkError(err)
 
 	for _, entry := range list {
 		if entry.IsDir() {
-			asIs.subdirectories = append(asIs.subdirectories, directory{name: entry.Name(), modTime: entry.ModTime()})
+			if !isEmptyDir(filepath.Join(thisDirectory, entry.Name())) {
+				root.subdirectories = append(root.subdirectories, recurseDirectory(filepath.Join(thisDirectory, entry.Name()), filepath.Join(relativeDirectory, entry.Name())))
+			}
 		} else {
-			asIs.files = append(asIs.files, file{name: entry.Name(), modTime: entry.ModTime()})
+			if isMediaFile(entry.Name()) {
+				root.files = append(root.files, file{name: entry.Name(), modTime: entry.ModTime(), path: filepath.Join(relativeDirectory, entry.Name()), exists: false})
+			}
+		}
+	}
+
+	return (root)
+}
+
+func compareDirectories(source *directory, gallery *directory, changes *int) {
+	for i, inputFile := range source.files {
+		for j, outputFile := range gallery.files {
+			// TODO what if modtimes are exact same as expected
+			if inputFile.name == outputFile.name && outputFile.modTime.After(inputFile.modTime) {
+				source.files[i].exists = true
+				gallery.files[j].exists = true
+				*changes--
+			}
+		}
+	}
+
+	for k, inputDir := range source.subdirectories {
+		for l, outputDir := range gallery.subdirectories {
+			if inputDir.name == outputDir.name {
+				compareDirectories(&(gallery.subdirectories[l]), &(source.subdirectories[k]), changes)
+			}
 		}
 	}
+}
+
+func countFiles(source directory, inputChanges int) (outputChanges int) {
+	outputChanges = inputChanges + len(source.files)
+
+	for _, dir := range source.subdirectories {
+		outputChanges = countFiles(dir, outputChanges)
+	}
 
-	return (asIs)
-	//fmt.Println(root)
+	return outputChanges
 }
 
 func main() {
 	var inputDirectory string
 	var outputDirectory string
-	var asIs directory
+	var gallery directory
+	var source directory
+	var changes int
 
 	outputDirectory, inputDirectory = parseArgs()
 
@@ -112,6 +166,9 @@ func main() {
 	fmt.Println("Creating static gallery in:", outputDirectory)
 	fmt.Println("")
 
-	asIs = discoverAsIs(outputDirectory)
-	fmt.Println("As-is: ", asIs)
+	gallery = recurseDirectory(outputDirectory, "")
+	source = recurseDirectory(inputDirectory, "")
+	changes = countFiles(source, 0)
+	compareDirectories(&source, &gallery, &changes)
+	fmt.Println(changes, "new pictures to update")
 }