1 files changed, 72 insertions, 0 deletions
diff --git a/internal/feed/template/funcs.go b/internal/feed/template/funcs.go
new file mode 100644
index 0000000..300b9ca
--- /dev/null
+++ b/internal/feed/template/funcs.go
@@ -0,0 +1,72 @@
+package template
+
+import (
+	"fmt"
+	html "html/template"
+	"strconv"
+	"strings"
+
+	"github.com/Necoro/feed2imap-go/pkg/log"
+)
+
+// dict creates a map out of the passed in key/value pairs.
+func dict(v ...interface{}) map[string]interface{} {
+	dict := make(map[string]interface{})
+	lenv := len(v)
+	for i := 0; i < lenv; i += 2 {
+		key := v[i].(string)
+		if i+1 >= lenv {
+			dict[key] = ""
+			continue
+		}
+		dict[key] = v[i+1]
+	}
+	return dict
+}
+
+// join takes a separator and a list of strings and puts the former in between each pair of the latter.
+func join(sep string, parts []string) string {
+	return strings.Join(parts, sep)
+}
+
+// lastUrlPart returns the last part of a URL string
+func lastUrlPart(url string) string {
+	split := strings.Split(url, "/")
+	return split[len(split)-1]
+}
+
+// byteCount receives an integer as a string, that is interpreted as a size in bytes.
+// This size is then equipped with the corresponding unit:
+//
+func byteCount(str string) string {
+	var b uint64
+	if str != "" {
+		var err error
+		if b, err = strconv.ParseUint(str, 10, 64); err != nil {
+			log.Printf("Cannot convert '%s' to byte count: %s", str, err)
+		}
+	}
+
+	const unit = 1024
+	if b < unit {
+		return fmt.Sprintf("%d B", b)
+	}
+	div, exp := uint64(unit), 0
+	for n := b / unit; n >= unit; n /= unit {
+		div *= unit
+		exp++
+	}
+	return fmt.Sprintf("%.1f %cB", float64(b)/float64(div), "KMGTPE"[exp])
+}
+
+func _html(s string) html.HTML {
+	return html.HTML(s)
+}
+
+var funcMap = map[string]interface{}{
+	"dict":        dict,
+	"join":        join,
+	"lastUrlPart": lastUrlPart,
+	"byteCount":   byteCount,
+	"html":        _html,
+}