package web

// S2 offsite connectivity: the read-only /offsite registry page (doc 06 §8 S2 "hub UI shows the
// peer registry"). Read-only by design — add/remove stay on the admin API; UI mutations arrive
// with tunnel health (S3/S6). Peers render neutral (no health state exists yet — nothing to
// except on, so no status colors).

import (
	"database/sql"
	"net/http"
)

// truncateMiddle shortens a long opaque value (pubkeys) for table display, keeping both ends —
// the full value always rides the title attribute.
func truncateMiddle(s string, keep int) string {
	if len(s) <= 2*keep+1 {
		return s
	}
	return s[:keep] + "…" + s[len(s)-keep:]
}

// offsitePeerRow is the per-peer view model.
type offsitePeerRow struct {
	Pubkey      string
	PubkeyShort string
	AssignedIP  string // with /32
	HostID      string // "" = unbound
	Note        string
	CreatedAt   string
}

// handleOffsite renders the offsite registry: the endpoint card + the peer table.
func (s *Server) handleOffsite(w http.ResponseWriter, r *http.Request) {
	data := map[string]interface{}{
		"HasEndpoint": false,
	}

	ep, err := s.store.GetWGEndpoint()
	if err != nil && err != sql.ErrNoRows {
		s.logger.Printf("[ERROR] offsite: endpoint read: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	if ep != nil {
		data["HasEndpoint"] = true
		data["Endpoint"] = map[string]interface{}{
			"DNSName":           ep.DNSName,
			"WGPort":            ep.WGPort,
			"ServerPubkey":      ep.ServerPubkey,
			"ServerPubkeyShort": truncateMiddle(ep.ServerPubkey, 10),
			"TunnelSubnet":      ep.TunnelSubnet,
			"PBSTunnelIP":       ep.PBSTunnelIP,
		}
	}

	peers, err := s.store.ListWGPeers()
	if err != nil {
		s.logger.Printf("[ERROR] offsite: peer list: %v", err)
		http.Error(w, "Internal error", http.StatusInternalServerError)
		return
	}
	rows := make([]offsitePeerRow, 0, len(peers))
	for _, p := range peers {
		rows = append(rows, offsitePeerRow{
			Pubkey:      p.Pubkey,
			PubkeyShort: truncateMiddle(p.Pubkey, 10),
			AssignedIP:  p.AssignedIP + "/32",
			HostID:      p.HostID,
			Note:        p.Note,
			CreatedAt:   p.CreatedAt,
		})
	}
	data["Peers"] = rows

	if err := s.templates.ExecuteTemplate(w, "offsite.html", data); err != nil {
		s.logger.Printf("[ERROR] offsite.html template: %v", err)
	}
}