mv cmd/generate/mailstuff/ lib/mailstuff/ # and supporting

1 files changed, 38 insertions, 0 deletions

diff --git a/lib/mailstuff/mbox.go b/lib/mailstuff/mbox.go
new file mode 100644
index 0000000..8700c24
--- /dev/null
+++ b/lib/mailstuff/mbox.go
@@ -0,0 +1,38 @@
+package mailstuff
+
+import (
+	"bytes"
+	"io"
+	"net/mail"
+)
+
+func ReadMBox(r io.Reader) ([]*mail.Message, error) {
+	rest, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	const terminator = "\nFrom "
+
+	var parts [][]byte
+	for {
+		pos := bytes.Index(rest, []byte(terminator))
+		if pos < 0 {
+			parts = append(parts, rest)
+			break
+		}
+		parts = append(parts, rest[:pos+1])
+		rest = rest[pos+1:]
+	}
+
+	ret := make([]*mail.Message, len(parts))
+	for i := range len(parts) {
+		msg, err := mail.ReadMessage(bytes.NewReader(parts[i]))
+		if err != nil {
+			return nil, err
+		}
+		ret[i] = msg
+	}
+
+	return ret, nil
+}