Codex first iteration

internal/tools/tool.go

@@ -0,0 +1,57 @@
+package tools
+
+import (
+	"context"
+	"errors"
+	"net/http"
+	"sort"
+	"sync"
+)
+
+type Definition struct{ Key, Name, Description string }
+type Tool interface {
+	Definition() Definition
+	StudentHandler() http.Handler
+}
+type InstructorTool interface{ InstructorHandler() http.Handler }
+type Runner interface{ Run(context.Context) error }
+
+var ErrNotFound = errors.New("tool not found")
+
+type Registry struct {
+	mu    sync.RWMutex
+	tools map[string]Tool
+}
+
+func NewRegistry() *Registry { return &Registry{tools: make(map[string]Tool)} }
+func (r *Registry) Register(t Tool) error {
+	if t == nil || t.Definition().Key == "" {
+		return errors.New("tool key is required")
+	}
+	r.mu.Lock()
+	defer r.mu.Unlock()
+	if _, ok := r.tools[t.Definition().Key]; ok {
+		return errors.New("duplicate tool key")
+	}
+	r.tools[t.Definition().Key] = t
+	return nil
+}
+func (r *Registry) Get(key string) (Tool, error) {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	t, ok := r.tools[key]
+	if !ok {
+		return nil, ErrNotFound
+	}
+	return t, nil
+}
+func (r *Registry) List() []Tool {
+	r.mu.RLock()
+	defer r.mu.RUnlock()
+	out := make([]Tool, 0, len(r.tools))
+	for _, t := range r.tools {
+		out = append(out, t)
+	}
+	sort.Slice(out, func(i, j int) bool { return out[i].Definition().Name < out[j].Definition().Name })
+	return out
+}