package peer

import (
	"encoding/json"
	"io"
	"log"
	"net/http"
	"net/url"
	"time"
	"vppn/m"
)

func (r *Router) pollHub() {
	u, err := url.Parse(r.conf.HubAddress)
	if err != nil {
		log.Fatalf("Failed to parse hub address %s: %v", r.conf.HubAddress, err)
	}
	u.Path = "/peer/fetch-state/"

	client := &http.Client{Timeout: 8 * time.Second}

	req := &http.Request{
		Method: http.MethodGet,
		URL:    u,
		Header: http.Header{},
	}
	req.SetBasicAuth("", r.conf.APIKey)

	// TODO: Before we start polling, load state from the file system.
	r._pollHub(client, req)

	for range time.Tick(32 * time.Second) {
		r._pollHub(client, req)
	}
}

func (r *Router) _pollHub(client *http.Client, req *http.Request) {
	var state m.NetworkState

	log.Printf("Fetching peer state from %s...", r.conf.HubAddress)
	resp, err := client.Do(req)
	if err != nil {
		log.Printf("Failed to fetch peer state: %v", err)
		return
	}
	body, err := io.ReadAll(resp.Body)
	_ = resp.Body.Close()
	if err != nil {
		log.Printf("Failed to read body from hub: %v", err)
		return
	}

	if err := json.Unmarshal(body, &state); err != nil {
		log.Printf("Failed to unmarshal response from hub: %v", err)
		return
	}

	for i := range r.conns {
		if r.conns[i] != nil {
			r.conns[i].UpdatePeer(peerUpdate{PeerIP: byte(i), Peer: state.Peers[i]})
		}
	}
}