Add bounded structured-output repair

internal/usecase/repairer.go

@@ -0,0 +1,71 @@
+package usecase
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"strings"
+
+	"gitea.maximumdirect.net/eric/scriptorium/internal/domain"
+	"gitea.maximumdirect.net/eric/scriptorium/internal/llm"
+)
+
+type OutputRepairer interface {
+	Repair(ctx context.Context, req RepairRequest) (*domain.GenerateResponse, error)
+}
+
+type RepairRequest struct {
+	PreviousOutput   string
+	ValidationErrors []string
+	Target           domain.ModelTarget
+	Attempt          int
+	MaxAttempts      int
+	Mode             domain.ValidationMode
+}
+
+type defaultOutputRepairer struct {
+	llm llm.Client
+}
+
+func NewDefaultOutputRepairer(llmClient llm.Client) OutputRepairer {
+	return &defaultOutputRepairer{llm: llmClient}
+}
+
+func (r *defaultOutputRepairer) Repair(ctx context.Context, req RepairRequest) (*domain.GenerateResponse, error) {
+	if r.llm == nil {
+		return nil, errors.New("llm client is required for repair")
+	}
+
+	errs := "(none provided)"
+	if len(req.ValidationErrors) > 0 {
+		errs = strings.Join(req.ValidationErrors, "\n")
+	}
+
+	prompt := domain.RenderedPrompt{Messages: []domain.RenderedMessage{
+		{
+			Role:    "system",
+			Content: "You repair invalid JSON output. Return only corrected JSON. Do not include explanations or markdown code fences.",
+		},
+		{
+			Role: "user",
+			Content: fmt.Sprintf(
+				"Repair attempt %d of %d for validation mode %s.\n\nValidation errors:\n%s\n\nPrevious output:\n%s\n\nReturn only corrected JSON.",
+				req.Attempt,
+				req.MaxAttempts,
+				req.Mode,
+				errs,
+				req.PreviousOutput,
+			),
+		},
+	}}
+
+	resp, err := r.llm.Generate(ctx, domain.GenerateRequest{Prompt: prompt, Target: req.Target})
+	if err != nil {
+		return nil, err
+	}
+	if resp == nil {
+		return nil, errors.New("repair llm returned nil response")
+	}
+
+	return resp, nil
+}