package moduleadapter

import (
	"encoding/json"
	"net/http"

	"github.com/jackc/pgx/v5/pgxpool"
)

type registerRequest struct {
	ModuleName     string `json:"module_name"`
	ObjectType     string `json:"object_type"`
	RetentionClass string `json:"retention_class"`
	CallbackURL    string `json:"callback_url"`
}

// RegisterHandler ist die REST-Schnittstelle (Ticket-Technikvorgabe), über
// die ein Modul einen Objekttyp registriert (Akzeptanzkriterium 1).
// POST /register mit JSON-Body {module_name, object_type, callback_url}.
func RegisterHandler(pool *pgxpool.Pool) http.HandlerFunc {
	return func(w http.ResponseWriter, r *http.Request) {
		if r.Method != http.MethodPost {
			http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
			return
		}
		var req registerRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			http.Error(w, "ungültiger request-body: "+err.Error(), http.StatusBadRequest)
			return
		}
		if req.ModuleName == "" || req.ObjectType == "" || req.RetentionClass == "" || req.CallbackURL == "" {
			http.Error(w, "module_name, object_type, retention_class und callback_url sind pflichtfelder", http.StatusBadRequest)
			return
		}

		reg, err := Register(r.Context(), pool, req.ModuleName, req.ObjectType, req.RetentionClass, req.CallbackURL)
		if err != nil {
			http.Error(w, err.Error(), http.StatusInternalServerError)
			return
		}

		w.Header().Set("Content-Type", "application/json")
		w.WriteHeader(http.StatusOK)
		_ = json.NewEncoder(w).Encode(reg)
	}
}