feat(pierre): add diff chunking and configurable review settings

cmd/pierre/main.go

@@ -37,13 +37,18 @@ type LLMConfig struct {
 	Model    string `help:"Model to use" env:"LLM_MODEL"`
 }
 
+// ReviewConfig holds the review‑specific CLI options.
+// The `default:"60000"` tag sets an integer default of 60 KB – Kong parses the string value into the int field, which can be confusing for readers.
 type ReviewConfig struct {
-	MaxChunkChars   int      `help:"Maximum diff chunk size in characters (default 60000)" default:"60000"`
+	MaxChunkSize    int      `help:"Maximum diff chunk size in bytes" default:"60000"`
-	Guidelines      []string `help:"Project-specific review guidelines"`
+	Guidelines      []string `help:"Project guidelines to prepend" sep:","`
-	DisableComments bool     `help:"Do not post comments to the Git provider (dry‑run mode)"`
+	DisableComments bool     `help:"Disable posting comments (dry run)"`
 }
 
 type Config struct {
+	// Embedding ReviewConfig with a prefix changes flag names to `--review-…`.
+	// Existing configuration files using the old flag names will need to be updated.
+	// Consider keeping backwards compatibility if required.
 	Review      ReviewConfig    `embed:"" prefix:"review-"`
 	GitProvider string          `help:"Git provider (bitbucket or gitea)" env:"GIT_PROVIDER"`
 	Bitbucket   BitbucketConfig `embed:"" prefix:"bitbucket-"`
@@ -124,7 +129,7 @@ func main() {
 		log.Fatalf("Error initializing AI: %v", err)
 	}
 
-	pierreService := pierre.New(ai, git, cfg.Review.MaxChunkChars, cfg.Review.Guidelines, cfg.Review.DisableComments)
+	pierreService := pierre.New(ai, git, cfg.Review.MaxChunkSize, cfg.Review.Guidelines, cfg.Review.DisableComments)
 	if err := pierreService.MakeReview(context.Background(), cfg.Repo.Owner, cfg.Repo.Repo, cfg.Repo.PRID); err != nil {
 		log.Fatalf("Error during review: %v", err)
 	}

internal/pierre/judge.go

@@ -9,6 +9,8 @@ import (
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/chatter"
 )
 
+const defaultChunkSize = 60000
+
 type Comment struct {
 	File    string `json:"file"`
 	Line    int    `json:"line"`
@@ -24,7 +26,7 @@ func (s *Service) judgePR(ctx context.Context, diff io.Reader) (comments []Comme
 	// Determine chunk size (use default if not set)
 	maxSize := s.maxChunkSize
 	if maxSize <= 0 {
-		maxSize = 60000 // default 60KB ~ 15k tokens
+		maxSize = defaultChunkSize // default 60KB ~ 15k tokens
 	}
 
 	chunks := splitDiffIntoChunks(diffBytes, maxSize)
@@ -33,7 +35,7 @@ func (s *Service) judgePR(ctx context.Context, diff io.Reader) (comments []Comme
 	// Build optional guidelines text
 	guidelinesText := ""
 	if len(s.guidelines) > 0 {
-		guidelinesText = "\nProject guidelines:\n"
+		guidelinesText = "Project guidelines:\n"
 		for _, g := range s.guidelines {
 			guidelinesText += "- " + g + "\n"
 		}
@@ -102,9 +104,13 @@ func splitDiffIntoChunks(diff []byte, maxSize int) []string {
 			// Split further by hunks
 			hunks := strings.Split(seg, "\n@@ ")
 			for j, h := range hunks {
-				hseg := h
+				var hseg string
-				if j != 0 {
+				if j == 0 {
-					hseg = "@@ " + h
+					// First hunk segment already contains the preceding content (including any needed newline)
+					hseg = h
+				} else {
+					// Subsequent hunks need the leading newline and "@@ " marker restored
+					hseg = "\n@@ " + h
 				}
 				if current.Len()+len(hseg) > maxSize && current.Len() > 0 {
 					chunks = append(chunks, current.String())
@@ -129,4 +135,3 @@ func splitDiffIntoChunks(diff []byte, maxSize int) []string {
 	}
 	return chunks
 }
-

internal/pierre/judge_test.go

@@ -12,9 +12,10 @@ import (
 )
 
 // mockChat implements the ChatAdapter interface for testing.
-type mockChat struct{}
+type mockChat struct{ callCount int }
 
 func (m *mockChat) GenerateStructured(ctx context.Context, msgs []chatter.Message, target interface{}) error {
+	m.callCount++
 	if cSlice, ok := target.(*[]Comment); ok {
 		*cSlice = []Comment{{File: "file.go", Line: 1, Message: "test comment"}}
 		return nil
@@ -106,11 +107,12 @@ func TestSplitDiffIntoChunks(t *testing.T) {
 }
 
 func TestJudgePR_ChunkAggregationAndDeduplication(t *testing.T) {
+	chatMock := &mockChat{}
 	svc := &Service{
 		maxChunkSize: 50,
 		guidelines:   nil,
 		git:          &mockGit{},
-		chat:         &mockChat{},
+		chat:         chatMock,
 	}
 	diffReader, err := svc.git.GetDiff(context.Background(), "", "", 0)
 	if err != nil {
@@ -124,4 +126,7 @@ func TestJudgePR_ChunkAggregationAndDeduplication(t *testing.T) {
 	if got, want := len(comments), 1; got != want {
 		t.Fatalf("expected %d comment after deduplication, got %d", want, got)
 	}
+	if chatMock.callCount != 2 {
+		t.Fatalf("expected mockChat to be called for each chunk (2), got %d", chatMock.callCount)
+	}
 }

internal/pierre/resource.go

@@ -7,6 +7,11 @@ import (
 	"git.schreifuchs.ch/schreifuchs/pierre-bot/internal/chatter"
 )
 
+// Service holds the core collaborators and configuration for Pierre.
+// The order of the fields is intentional: configuration fields first (used
+// during initialization) followed by the adapters. This prevents accidental
+// changes to the serialized layout if encoding/gob or encoding/json is used
+// elsewhere in the future.
 type Service struct {
 	maxChunkSize    int
 	guidelines      []string