Add prompt reference template functions

internal/framework/prompt/render.go

@@ -4,6 +4,9 @@ import (
 	"bytes"
 	"fmt"
 	"strings"
+	"text/template"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
 )
 
 // RenderUserSystem renders the system and user prompt pair for promptID.
@@ -16,20 +19,105 @@ func RenderUserSystem(promptID string, data any) (system string, user string, me
 	return compiled.RenderUserSystem(data)
 }
 
+// RenderUserSystemWithReferences renders the system and user prompt pair for promptID with reference template functions.
+func RenderUserSystemWithReferences(promptID string, data any, references contracts.ReferenceSet) (system string, user string, metadata Metadata, err error) {
+	trimmedID := strings.TrimSpace(promptID)
+	compiled, ok := promptRegistry[trimmedID]
+	if !ok {
+		return "", "", Metadata{}, fmt.Errorf("unknown prompt id %q", promptID)
+	}
+	return compiled.RenderUserSystemWithReferences(data, references)
+}
+
 // RenderUserSystem renders the bundle's system and user prompts.
 func (b *Bundle) RenderUserSystem(data any) (system string, user string, metadata Metadata, err error) {
+	return b.RenderUserSystemWithReferences(data, contracts.ReferenceSet{})
+}
+
+// RenderUserSystemWithReferences renders the bundle's system and user prompts with reference template functions.
+func (b *Bundle) RenderUserSystemWithReferences(data any, references contracts.ReferenceSet) (system string, user string, metadata Metadata, err error) {
 	if b == nil {
 		return "", "", Metadata{}, fmt.Errorf("prompt bundle must not be nil")
 	}
+	systemTmpl, userTmpl, err := b.renderTemplates(references)
+	if err != nil {
+		return "", "", Metadata{}, err
+	}
 	var systemBuf bytes.Buffer
-	if err := b.systemTmpl.Execute(&systemBuf, data); err != nil {
+	if err := systemTmpl.Execute(&systemBuf, data); err != nil {
 		return "", "", Metadata{}, fmt.Errorf("render system prompt %q: %w", b.metadata.PromptID, err)
 	}
 
 	var userBuf bytes.Buffer
-	if err := b.userTmpl.Execute(&userBuf, data); err != nil {
+	if err := userTmpl.Execute(&userBuf, data); err != nil {
 		return "", "", Metadata{}, fmt.Errorf("render user prompt %q: %w", b.metadata.PromptID, err)
 	}
 
 	return strings.TrimSpace(systemBuf.String()), strings.TrimSpace(userBuf.String()), b.metadata, nil
 }
+
+func (b *Bundle) renderTemplates(references contracts.ReferenceSet) (*template.Template, *template.Template, error) {
+	funcs := b.referenceFuncs(references)
+	systemTmpl, err := b.systemTmpl.Clone()
+	if err != nil {
+		return nil, nil, fmt.Errorf("clone system prompt %q: %w", b.metadata.PromptID, err)
+	}
+	userTmpl, err := b.userTmpl.Clone()
+	if err != nil {
+		return nil, nil, fmt.Errorf("clone user prompt %q: %w", b.metadata.PromptID, err)
+	}
+	systemTmpl.Funcs(funcs)
+	userTmpl.Funcs(funcs)
+	return systemTmpl, userTmpl, nil
+}
+
+func (b *Bundle) referenceFuncs(references contracts.ReferenceSet) template.FuncMap {
+	return template.FuncMap{
+		"hardening": func() string { return sharedHardening },
+		"hasreference": func(slotName string) (bool, error) {
+			items, _, err := b.referenceItems(slotName, references)
+			if err != nil {
+				return false, err
+			}
+			for _, item := range items {
+				if len(item.Content) > 0 {
+					return true, nil
+				}
+			}
+			return false, nil
+		},
+		"reference": func(slotName string) (string, error) {
+			items, slot, err := b.referenceItems(slotName, references)
+			if err != nil {
+				return "", err
+			}
+			if len(items) == 0 {
+				return "", nil
+			}
+			if len(items) > 1 && !slot.Multiple {
+				return "", fmt.Errorf("reference slot %q has %d bound items but does not allow multiple", slot.Name, len(items))
+			}
+			parts := make([]string, 0, len(items))
+			for _, item := range items {
+				parts = append(parts, string(item.Content))
+			}
+			return strings.Join(parts, "\n"), nil
+		},
+	}
+}
+
+func (b *Bundle) referenceItems(slotName string, references contracts.ReferenceSet) ([]contracts.ReferenceItem, contracts.ReferenceSlot, error) {
+	slotName = strings.TrimSpace(slotName)
+	slot, ok := b.referenceSlots[slotName]
+	if !ok {
+		return nil, contracts.ReferenceSlot{}, fmt.Errorf("reference slot %q is not declared", slotName)
+	}
+	if len(references.Slots) == 0 {
+		return nil, slot, nil
+	}
+	resolved, ok := references.Slots[slotName]
+	if !ok {
+		return nil, slot, nil
+	}
+	return append([]contracts.ReferenceItem(nil), resolved.Items...), slot, nil
+}