feat: add logs

cmd/pierre/main.go

@@ -3,8 +3,10 @@ package main
 import (
 	"context"
 	"log"
+	"log/slog"
 	"os"
 	"path/filepath"
+	"strings"
 
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/chatter"
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/gitadapters/bitbucket"
@@ -46,6 +48,7 @@ type ReviewConfig struct {
 }
 
 type Config struct {
+	LogLevel string `help:"Log verbosity: debug, info, warn, error"`
 	// Deprecated flags (no prefix). Retained for backward compatibility.
 	// These will be mapped to the embedded ReviewConfig if provided.
 	MaxChunkSize    int      `help:"Deprecated: use --review-max-chunk-size"`
@@ -65,6 +68,7 @@ type Config struct {
 }
 
 func main() {
+
 	cfg := &Config{}
 	home, err := os.UserHomeDir()
 	if err != nil {
@@ -81,6 +85,23 @@ func main() {
 		kong.Configuration(kongyaml.Loader, "config.yaml", defaultConfig),
 	)
 
+	// Configure global slog logger based on the --log-level flag
+	lvl := slog.LevelInfo
+	switch strings.ToLower(cfg.LogLevel) {
+	case "debug":
+		lvl = slog.LevelDebug
+	case "info":
+		lvl = slog.LevelInfo
+	case "warn":
+		lvl = slog.LevelWarn
+	case "error":
+		lvl = slog.LevelError
+	}
+	// Logs are sent to stderr so that stdout can be safely piped.
+	// The review output (fmt.Printf) stays on stdout unchanged.
+	logger := slog.New(slog.NewTextHandler(os.Stderr, &slog.HandlerOptions{Level: lvl}))
+	slog.SetDefault(logger)
+
 	// Backwards compatibility: map deprecated flag values (if any) to the embedded ReviewConfig.
 	if cfg.MaxChunkSize != 0 {
 		cfg.Review.MaxChunkSize = cfg.MaxChunkSize