Global code ovehaul - remove CAS and other, add 15 minute greet check

- Remove CAS, as it no longer works for us
- Remove other checks
- Implement 15 minute greet timeout check
- Fix chat logos
- Ditch thirdparty logger, use stdlib log facility wrapper for logging

internal/elog/format.go

@@ -0,0 +1,78 @@
+package elog
+
+// The value formatters: small conversions shared by the write path (which builds
+// path components) and the renderer (which builds inline fields). They are shared
+// by two topics, so they get a file of their own rather than living in one of them
+// and making the other look in the wrong place.
+
+import (
+	"strconv"
+	"strings"
+)
+
+// field renders "key=value", or empty when the value is empty. Empty fields are
+// omitted: a bare "username=@" is worse than nothing.
+//
+// It lives here rather than in render.go because sizeField, a formatter, is one of
+// its callers — and a helper two topics use belongs to neither.
+func field(key string, value string) string {
+	if value == "" {
+		return ""
+	}
+
+	return key + "=" + value
+}
+
+// joinFields drops empty fragments and joins the rest with single spaces.
+func joinFields(parts []string) string {
+	kept := make([]string, 0, len(parts))
+
+	for _, p := range parts {
+		if p != "" {
+			kept = append(kept, p)
+		}
+	}
+
+	return strings.Join(kept, " ")
+}
+
+// itoa renders an int64 for a path component or an inline field.
+func itoa(v int64) string {
+	return strconv.FormatInt(v, 10)
+}
+
+// itoaInt renders an int for a rendered field.
+func itoaInt(v int) string {
+	return strconv.Itoa(v)
+}
+
+// itoaFloat renders a float for a rendered field.
+func itoaFloat(v float64) string {
+	return strconv.FormatFloat(v, 'g', -1, 64)
+}
+
+// atUsername renders a username with the conventional @ prefix, or empty.
+func atUsername(name string) string {
+	if name == "" {
+		return ""
+	}
+
+	return "@" + name
+}
+
+// seconds renders a duration in seconds with its unit.
+func seconds(n int) string {
+	return itoaInt(n) + "s"
+}
+
+// sizeField renders a byte count, omitted when unknown. A size of 0 means
+// Telegram did not tell us, not that the file was empty.
+func sizeField(n int64) string {
+	if n <= 0 {
+		return ""
+	}
+
+	return field("size", itoa(n))
+}
+
+/* vim: set ft=go noet ai ts=4 sw=4 sts=4: */