fmsg: produce all output through fmsg

The behaviour of print functions from package fmt is not thread safe. Functions provided by fmsg wrap around Logger methods. This makes prefix much cleaner and makes it easy to deal with future changes to logging.

Signed-off-by: Ophestra Umiker <cat@ophivana.moe>

internal/fmsg/fmsg.go

@@ -1,2 +1,41 @@
 // Package fmsg provides various functions for output messages.
 package fmsg
+
+import (
+	"log"
+	"os"
+	"sync/atomic"
+)
+
+var (
+	std  = log.New(os.Stdout, "fortify: ", 0)
+	warn = log.New(os.Stderr, "fortify: ", 0)
+
+	verbose = new(atomic.Bool)
+)
+
+func SetPrefix(prefix string) {
+	prefix += ": "
+	std.SetPrefix(prefix)
+	warn.SetPrefix(prefix)
+}
+
+func Print(v ...any) {
+	warn.Print(v...)
+}
+
+func Printf(format string, v ...any) {
+	warn.Printf(format, v...)
+}
+
+func Println(v ...any) {
+	warn.Println(v...)
+}
+
+func Fatal(v ...any) {
+	warn.Fatal(v...)
+}
+
+func Fatalf(format string, v ...any) {
+	warn.Fatalf(format, v...)
+}

internal/fmsg/verbose.go

@@ -0,0 +1,21 @@
+package fmsg
+
+func Verbose() bool {
+	return verbose.Load()
+}
+
+func SetVerbose(v bool) {
+	verbose.Store(v)
+}
+
+func VPrintf(format string, v ...any) {
+	if verbose.Load() {
+		std.Printf(format, v...)
+	}
+}
+
+func VPrintln(v ...any) {
+	if verbose.Load() {
+		std.Println(v...)
+	}
+}