feat: add teaching asset prompts

internal/teachingassets/service.go

@@ -0,0 +1,96 @@
+package teachingassets
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"sync/atomic"
+	"time"
+
+	"tutor/internal/ontology"
+	"tutor/internal/workflows"
+)
+
+type Service struct {
+	store         Store
+	ontology      *ontology.Service
+	imageModelKey string
+	ids           atomic.Uint64
+}
+
+func NewService(store Store, ontology *ontology.Service, imageModelKey string) *Service {
+	return &Service{
+		store:         store,
+		ontology:      ontology,
+		imageModelKey: imageModelKey,
+	}
+}
+
+func (s *Service) GeneratePrompt(input GenerateInput) (PromptCandidate, error) {
+	if strings.TrimSpace(input.ConceptID) == "" {
+		return PromptCandidate{}, errors.New("concept_id is required")
+	}
+	assetType := input.AssetType
+	if assetType == "" {
+		assetType = workflows.AssetDiagram
+	}
+
+	concept, err := s.findConcept(input.ConceptID)
+	if err != nil {
+		return PromptCandidate{}, err
+	}
+	if len(concept.Evidence) == 0 {
+		return PromptCandidate{}, errors.New("concept has no source evidence")
+	}
+
+	prompt := PromptCandidate{
+		ID:                          s.nextID("asset-prompt"),
+		Concept:                     concept.Concept,
+		AssetType:                   assetType,
+		Prompt:                      buildPrompt(concept.Concept, assetType),
+		SourceEvidence:              append([]workflows.EvidenceRef(nil), concept.Evidence...),
+		ModelKey:                    s.imageModelKey,
+		RequiresModelIDVerification: true,
+		ReviewState:                 ReviewCandidate,
+		CreatedAt:                   time.Now().UTC(),
+	}
+	return s.store.SavePrompt(prompt)
+}
+
+func (s *Service) Snapshot() Snapshot {
+	return s.store.Snapshot()
+}
+
+func (s *Service) findConcept(id string) (ontology.ConceptCandidate, error) {
+	if s.ontology == nil {
+		return ontology.ConceptCandidate{}, errors.New("ontology not configured")
+	}
+	snapshot := s.ontology.Snapshot()
+	for _, concept := range snapshot.Concepts {
+		if concept.Concept.ID == id {
+			return concept, nil
+		}
+	}
+	return ontology.ConceptCandidate{}, errors.New("concept not found")
+}
+
+func buildPrompt(concept workflows.ConceptRef, assetType workflows.AssetType) string {
+	switch assetType {
+	case workflows.AssetLessonSlice:
+		return "Create a concise slide-like lesson slice explaining " + concept.Label +
+			" for a backend developer interview, with one example and one pitfall."
+	case workflows.AssetWorksheet:
+		return "Create a worksheet for practicing " + concept.Label +
+			" with short prompts, answer space, and a rubric."
+	case workflows.AssetInterviewCard:
+		return "Create an interview explanation card for " + concept.Label +
+			" with definition, production tradeoff, and follow-up question."
+	default:
+		return "Create a clear technical diagram explaining " + concept.Label +
+			" for a backend developer interview, grounded in the provided source evidence."
+	}
+}
+
+func (s *Service) nextID(prefix string) string {
+	return fmt.Sprintf("%s-%d", prefix, s.ids.Add(1))
+}

internal/teachingassets/service_test.go

@@ -0,0 +1,39 @@
+package teachingassets
+
+import (
+	"testing"
+
+	"tutor/internal/ontology"
+	"tutor/internal/workflows"
+)
+
+func TestGeneratePromptKeepsLineageAndVerificationGuard(t *testing.T) {
+	onto := ontology.NewService(ontology.NewMemoryStore())
+	if _, err := onto.Ingest(ontology.IngestInput{
+		Title: "Backend notes",
+		Body:  "Idempotent API retries need transactions.",
+	}); err != nil {
+		t.Fatalf("Ingest error: %v", err)
+	}
+	service := NewService(NewMemoryStore(), onto, "gpt-image-v2")
+
+	prompt, err := service.GeneratePrompt(GenerateInput{
+		ConceptID: "http-idempotency",
+		AssetType: workflows.AssetDiagram,
+	})
+	if err != nil {
+		t.Fatalf("GeneratePrompt error: %v", err)
+	}
+	if prompt.ModelKey != "gpt-image-v2" {
+		t.Fatalf("ModelKey = %q", prompt.ModelKey)
+	}
+	if !prompt.RequiresModelIDVerification {
+		t.Fatal("expected model id verification guard")
+	}
+	if prompt.ReviewState != ReviewCandidate {
+		t.Fatalf("ReviewState = %q", prompt.ReviewState)
+	}
+	if len(prompt.SourceEvidence) == 0 {
+		t.Fatal("expected source evidence")
+	}
+}

internal/teachingassets/store.go

@@ -0,0 +1,49 @@
+package teachingassets
+
+import (
+	"sync"
+
+	"tutor/internal/workflows"
+)
+
+type Store interface {
+	SavePrompt(PromptCandidate) (PromptCandidate, error)
+	Snapshot() Snapshot
+}
+
+type MemoryStore struct {
+	mu      sync.RWMutex
+	prompts []PromptCandidate
+}
+
+func NewMemoryStore() *MemoryStore {
+	return &MemoryStore{}
+}
+
+func (s *MemoryStore) SavePrompt(prompt PromptCandidate) (PromptCandidate, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.prompts = append(s.prompts, clonePrompt(prompt))
+	return prompt, nil
+}
+
+func (s *MemoryStore) Snapshot() Snapshot {
+	s.mu.RLock()
+	defer s.mu.RUnlock()
+
+	return Snapshot{Prompts: clonePrompts(s.prompts)}
+}
+
+func clonePrompts(items []PromptCandidate) []PromptCandidate {
+	cloned := make([]PromptCandidate, len(items))
+	for i, item := range items {
+		cloned[i] = clonePrompt(item)
+	}
+	return cloned
+}
+
+func clonePrompt(prompt PromptCandidate) PromptCandidate {
+	prompt.SourceEvidence = append([]workflows.EvidenceRef(nil), prompt.SourceEvidence...)
+	return prompt
+}

internal/teachingassets/types.go

@@ -0,0 +1,34 @@
+package teachingassets
+
+import (
+	"time"
+
+	"tutor/internal/workflows"
+)
+
+type ReviewState string
+
+const (
+	ReviewCandidate ReviewState = "candidate"
+)
+
+type PromptCandidate struct {
+	ID                          string                  `json:"id"`
+	Concept                     workflows.ConceptRef    `json:"concept"`
+	AssetType                   workflows.AssetType     `json:"asset_type"`
+	Prompt                      string                  `json:"prompt"`
+	SourceEvidence              []workflows.EvidenceRef `json:"source_evidence"`
+	ModelKey                    string                  `json:"model_key"`
+	RequiresModelIDVerification bool                    `json:"requires_model_id_verification"`
+	ReviewState                 ReviewState             `json:"review_state"`
+	CreatedAt                   time.Time               `json:"created_at"`
+}
+
+type GenerateInput struct {
+	ConceptID string
+	AssetType workflows.AssetType
+}
+
+type Snapshot struct {
+	Prompts []PromptCandidate `json:"prompts"`
+}