Initial Bitbucket→GitHub migration commit, based on release v2.0.0.

util.go

@@ -0,0 +1,117 @@
+/*
+	Copyright © 2014–2019 Thomas Michael Edwards. All rights reserved.
+	Use of this source code is governed by a Simplified BSD License which
+	can be found in the LICENSE file.
+*/
+
+package main
+
+import (
+	"path/filepath"
+	"regexp"
+	"strings"
+)
+
+func mediaTypeFromFilename(filename string) string {
+	return mediaTypeFromExt(normalizedFileExt(filename))
+}
+
+func mediaTypeFromExt(ext string) string {
+	var mediaType string
+	switch ext {
+	// AUDIO NOTES:
+	//
+	// The preferred media type for WAVE audio is `audio/wave`, however,
+	// some browsers only recognize `audio/wav`, requiring its use instead.
+	case "aac", "flac", "ogg", "wav":
+		mediaType = "audio/" + ext
+	case "mp3":
+		mediaType = "audio/mpeg"
+	case "m4a":
+		mediaType = "audio/mp4"
+	case "oga", "opus":
+		mediaType = "audio/ogg"
+	case "wave":
+		mediaType = "audio/wav"
+	case "weba":
+		mediaType = "audio/webm"
+
+	// FONT NOTES:
+	//
+	// (ca. 2017) The IANA deprecated the various font subtypes of the
+	// "application" type in favor of the new "font" type.  While the
+	// standards were new at that point, many browsers had long accepted
+	// such media types due to existing use in the wild—erroneous at
+	// that point or not.
+	//     otf   : application/font-sfnt  → font/otf
+	//     ttf   : application/font-sfnt  → font/ttf
+	//     woff  : application/font-woff  → font/woff
+	//     woff2 : application/font-woff2 → font/woff2
+	case "otf", "ttf", "woff", "woff2":
+		mediaType = "font/" + ext
+
+	// IMAGE NOTES:
+	case "gif", "jpeg", "png", "tiff", "webp":
+		mediaType = "image/" + ext
+	case "jpg":
+		mediaType = "image/jpeg"
+	case "svg":
+		mediaType = "image/svg+xml"
+	case "tif":
+		mediaType = "image/tiff"
+
+	// METADATA NOTES:
+	//
+	// Name aside, WebVTT files are generic media cue metadata files
+	// that may be used with either `<audio>` or `<video>` elements.
+	case "vtt": // WebVTT (Web Video Text Tracks)
+		mediaType = "text/vtt"
+
+	// VIDEO NOTES:
+	case "mp4", "webm":
+		mediaType = "video/" + ext
+	case "ogv":
+		mediaType = "video/ogg"
+	}
+
+	return mediaType
+}
+
+func normalizedFileExt(filename string) string {
+	ext := filepath.Ext(filename)
+	if ext == "" {
+		return ext
+	}
+	return strings.ToLower(ext[1:])
+}
+
+func slugify(original string) string {
+	// TODO: Maybe expand this to include non-ASCII alphas?
+	invalidRe := regexp.MustCompile(`[^[:word:]-]`)
+	return strings.ToLower(invalidRe.ReplaceAllLiteralString(original, "-"))
+}
+
+func stringSliceContains(haystack []string, needle string) bool {
+	if len(haystack) > 0 {
+		for _, val := range haystack {
+			if val == needle {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+func stringSliceDelete(haystack []string, needle string) []string {
+	if len(haystack) > 0 {
+		for i, val := range haystack {
+			if val == needle {
+				copy(haystack[i:], haystack[i+1:])
+				haystack[len(haystack)-1] = ""
+				haystack = haystack[:len(haystack)-1]
+				break
+			}
+		}
+	}
+	return haystack
+}