package platform

import (
	"net/http"
	"strings"
)

// Old frozen receipts remain readable. Old whole-snapshot/ownership writers may
// not edit a migrated tree, even when their old client has not seen the barrier.
func (s *service) guardLegacyCanonicalRequest(w http.ResponseWriter, r *http.Request, project, account string) (bool, error) {
	if r.PathValue("material") == "" {
		return false, nil
	}
	path := r.URL.Path
	legacy := strings.HasSuffix(path, "/canvas")
	if r.Method != http.MethodGet {
		for _, part := range []string{"/canvas/subgraphs", "/canvas/connections", "/canvas/transactions", "/canvas/operations"} {
			legacy = legacy || strings.Contains(path, part)
		}
	}
	if !legacy {
		return false, nil
	}
	tx, err := s.db.BeginTx(r.Context(), nil)
	if err != nil {
		return false, err
	}
	defer tx.Rollback()
	if _, _, err = lockMaterial(r.Context(), tx, project, r.PathValue("workspace"), r.PathValue("material"), account); err != nil {
		return false, err
	}
	root, err := canonicalRoot(r.Context(), tx, project, r.PathValue("workspace"), r.PathValue("material"))
	if err != nil {
		return false, err
	}
	if root == "" {
		return false, nil
	}
	reply(w, 409, response{"error": "canonical_write_required", "root_id": root, "model_path": "canvas/model"})
	return true, nil
}