package api

import (
	"encoding/json"
	"log"

	"crypto-miner-server/internal/atlas"
)

func (h *WSHub) handleAgentFleetTorrentGossip(senderID string, payload json.RawMessage) {
	if !h.serverPolicySnapshot().FleetTorrentEnabled {
		return
	}
	var body struct {
		Records []atlas.FleetGossipRecord `json:"records"`
	}
	if err := json.Unmarshal(payload, &body); err != nil || len(body.Records) == 0 {
		return
	}
	records := atlas.NormalizeFleetGossipRecords(body.Records)
	if len(records) == 0 {
		return
	}
	h.relayFleetTorrentGossip(senderID, records)
}

func (h *WSHub) relayFleetTorrentGossip(senderID string, records []atlas.FleetGossipRecord) {
	out := Message{
		Type: "fleet_torrent_gossip",
		Payload: mustMarshal(map[string]interface{}{
			"records":         records,
			"source_agent_id": senderID,
		}),
	}
	h.mu.RLock()
	defer h.mu.RUnlock()
	for id, ac := range h.agents {
		if id == senderID || ac == nil {
			continue
		}
		if err := ac.SendJSON(out); err != nil {
			log.Printf("[fleet-torrent] relay to %s: %v", id, err)
		}
	}
}

// subnetPrimarySeederHint elects one primary seeder per /24 when fleet torrent is enabled.
func (h *WSHub) subnetPrimarySeederHint(agentID, clientIP, role string) string {
	if !h.serverPolicySnapshot().FleetTorrentEnabled {
		return ""
	}
	if role != "seeder" {
		return ""
	}
	subnet := subnetPrefix24(clientIP)
	if subnet == "" {
		return ""
	}
	pick := h.electSubnetPrimarySeeder(subnet)
	if pick == "" {
		return agentID
	}
	return pick
}

func (h *WSHub) electSubnetPrimarySeeder(subnet string) string {
	if subnet == "" {
		return ""
	}
	h.mu.RLock()
	defer h.mu.RUnlock()
	var bestID string
	for id, tel := range h.agentLiveTelemetry {
		role, _ := tel["fleet_role"].(string)
		if role != "seeder" {
			continue
		}
		ip := h.agentIPLocked(id)
		if subnetPrefix24(ip) != subnet {
			continue
		}
		if bestID == "" || id < bestID {
			bestID = id
		}
	}
	return bestID
}

func (h *WSHub) isSubnetPrimarySeeder(agentID, clientIP string) bool {
	if agentID == "" {
		return false
	}
	subnet := subnetPrefix24(clientIP)
	if subnet == "" {
		return false
	}
	pick := h.electSubnetPrimarySeeder(subnet)
	if pick == "" {
		return true
	}
	return pick == agentID
}