package web

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

	"gitea.dooplex.hu/admin/felhom-hub/internal/store"
)

// handleDRRecipeDownload serves the assembled secret-free DR recipe for a customer as a JSON download
// (SPIKE-dr-recipe-2026-06-16). The recipe is PLAINTEXT because it carries NO secrets — only the
// reconstruction scaffolding (guest sizing, drive inventory, PVE storage, PBS coordinates, app
// inventory + storage bindings). Operator (dashboard-auth) only; no decrypt, nothing to redact.
func (s *Server) handleDRRecipeDownload(w http.ResponseWriter, r *http.Request, customerID string) {
	if r.Method != http.MethodGet {
		http.Error(w, "Method not allowed", http.StatusMethodNotAllowed)
		return
	}
	rec, err := s.store.GetDRRecipe(customerID)
	if err != nil {
		s.logger.Printf("[ERROR] DR-recipe lookup failed for %s: %v", customerID, err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	if rec == nil {
		http.Error(w, "No DR recipe for this customer yet (awaiting a host-report + controller report)", http.StatusNotFound)
		return
	}
	assembled, err := store.AssembleDRRecipe(rec)
	if err != nil {
		s.logger.Printf("[ERROR] DR-recipe assemble failed for %s: %v", customerID, err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	out, err := json.MarshalIndent(assembled, "", "  ")
	if err != nil {
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	w.Header().Set("Content-Disposition", "attachment; filename=\"dr-recipe-"+safeFilename(customerID)+".json\"")
	w.Write(out)
	s.logger.Printf("[INFO] DR-recipe downloaded for customer %s (v%d)", customerID, assembled.RecipeVersion)
}

// safeFilename keeps a customer id safe for a Content-Disposition filename (alnum/-/_ only).
func safeFilename(s string) string {
	out := make([]rune, 0, len(s))
	for _, r := range s {
		switch {
		case r >= 'a' && r <= 'z', r >= 'A' && r <= 'Z', r >= '0' && r <= '9', r == '-', r == '_':
			out = append(out, r)
		default:
			out = append(out, '_')
		}
	}
	if len(out) == 0 {
		return "customer"
	}
	return string(out)
}