Initial release

1 files changed, 49 insertions, 0 deletions

diff --git a/internal/logger/logger.go b/internal/logger/logger.go
new file mode 100644
index 0000000..e0f6598
--- /dev/null
+++ b/internal/logger/logger.go
@@ -0,0 +1,49 @@
+// Package logger provides a minimal levelled logger for Shiv.
+// Output is gated behind a verbose flag set at startup via Init.
+// Only fatal startup messages use Always — everything else is verbose.
+package logger
+
+import (
+	"fmt"
+	"io"
+	"os"
+	"time"
+)
+
+var verbose bool
+
+// Init configures the logger. Call once at startup.
+func Init(isVerbose bool) {
+	verbose = isVerbose
+}
+
+// Always logs a message that is always shown regardless of verbose flag.
+// Use sparingly — only for critical startup/shutdown messages.
+func Always(format string, args ...any) {
+	log(os.Stdout, "INFO", format, args...)
+}
+
+// Info logs a message only when verbose mode is enabled.
+func Info(format string, args ...any) {
+	if verbose {
+		log(os.Stdout, "INFO", format, args...)
+	}
+}
+
+// Error logs an error that is always shown.
+func Error(format string, args ...any) {
+	log(os.Stderr, "ERR ", format, args...)
+}
+
+// Debug logs a message only when verbose mode is enabled.
+func Debug(format string, args ...any) {
+	if verbose {
+		log(os.Stdout, "DBG ", format, args...)
+	}
+}
+
+func log(w io.Writer, level, format string, args ...any) {
+	timestamp := time.Now().Format("15:04:05.000")
+	msg := fmt.Sprintf(format, args...)
+	fmt.Fprintf(w, "[shiv] %s %s %s\n", timestamp, level, msg)
+}