licence-server/logger/web.go

package logger

import (
	"encoding/json"
	"fmt"
	"html/template"
	"net/http"
	"strconv"
	"strings"
	"time"
)

// Handler vraca ceo web sloj prijemnika (bez baze, bez spoljnih biblioteka).
func (s *Service) Handler() http.Handler {
	mux := http.NewServeMux()
	mux.HandleFunc("GET /", s.pageIndex)
	mux.HandleFunc("GET /uredjaj", s.pageDevice)
	mux.HandleFunc("GET /dnevnik.txt", s.pageRaw)
	mux.HandleFunc("GET /api/uredjaji", s.apiDevices)
	return s.withToken(mux)
}

// withToken je minimalna zastita kad web nije samo na 127.0.0.1. Token se
// prihvata iz ?t= ili iz zaglavlja X-Token; posle prvog uspesnog upita pamti se
// u kolacicu da linkovi ostanu kratki.
//
// Ovo NIJE zamena za nginx + TLS + lozinku - dnevnik sadrzi brojeve karata.
func (s *Service) withToken(next http.Handler) http.Handler {
	if s.cfg.Token == "" {
		return next
	}
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		ok := r.URL.Query().Get("t") == s.cfg.Token || r.Header.Get("X-Token") == s.cfg.Token
		if !ok {
			if c, err := r.Cookie("logger_token"); err == nil && c.Value == s.cfg.Token {
				ok = true
			}
		}
		if !ok {
			http.Error(w, "Pristup odbijen: nedostaje token.", http.StatusForbidden)
			return
		}
		http.SetCookie(w, &http.Cookie{
			Name: "logger_token", Value: s.cfg.Token, Path: "/",
			HttpOnly: true, SameSite: http.SameSiteLaxMode, MaxAge: 12 * 3600,
		})
		next.ServeHTTP(w, r)
	})
}

type deviceView struct {
	Key        string
	Naziv      string
	MAC        string
	IP         string
	FW         string
	Serijski   string
	Poznat     bool
	Tih        bool
	Vidjen     string
	Heartbeat  string
	Interval   int
	Paketa     uint64
	Linija     uint64
	Poslednja  string
	IzvornaIP  string
	PrviPutStr string
}

type indexData struct {
	Uredjaji   []deviceView
	Ukupno     int
	Paketa     uint64
	Heartbeata uint64
	Dnevnika   uint64
	Smece      uint64
	Greske     uint64
	DiskMB     string
	Fajlova    int
	UDP        string
	Port       int
	Dir        string
	Vreme      string
	Token      string
}

type deviceData struct {
	U      deviceView
	Linije []string
	Q      string
	N      int
	Dani   []string
	Vreme  string
	Token  string
	Nadjen bool
}

func (s *Service) view(d Device, now time.Time) deviceView {
	naziv := d.Name
	if naziv == "" {
		naziv = "(bez naziva)"
	}
	hb := "nikad"
	if !d.LastHeartbeat.IsZero() {
		hb = humanAgo(now.Sub(d.LastHeartbeat))
	}
	return deviceView{
		Key:        d.Key,
		Naziv:      naziv,
		MAC:        d.MAC,
		IP:         d.IP,
		FW:         d.FW,
		Serijski:   d.Serial,
		Poznat:     d.Identified,
		Tih:        s.reg.Stale(&d, now),
		Vidjen:     humanAgo(now.Sub(d.LastSeen)),
		Heartbeat:  hb,
		Interval:   s.reg.Interval(&d),
		Paketa:     d.LogPackets + d.Heartbeats,
		Linija:     d.LogLines,
		Poslednja:  d.LastLine,
		IzvornaIP:  d.SourceIP,
		PrviPutStr: d.FirstSeen.Format("02.01.2006. 15:04:05"),
	}
}

// humanAgo pise razmak vremena na srpskom, kratko.
func humanAgo(d time.Duration) string {
	switch {
	case d < 2*time.Second:
		return "upravo sada"
	case d < time.Minute:
		return fmt.Sprintf("pre %d s", int(d.Seconds()))
	case d < time.Hour:
		return fmt.Sprintf("pre %d min", int(d.Minutes()))
	case d < 48*time.Hour:
		return fmt.Sprintf("pre %d h", int(d.Hours()))
	default:
		return fmt.Sprintf("pre %d dana", int(d.Hours()/24))
	}
}

func (s *Service) pageIndex(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.NotFound(w, r)
		return
	}
	now := s.now()
	devs := s.reg.Snapshot(now)
	views := make([]deviceView, 0, len(devs))
	for _, d := range devs {
		views = append(views, s.view(d, now))
	}
	bytes, files := s.store.Usage()
	data := indexData{
		Uredjaji:   views,
		Ukupno:     len(views),
		Paketa:     s.stats.Packets.Load(),
		Heartbeata: s.stats.Heartbeat.Load(),
		Dnevnika:   s.stats.LogPkts.Load(),
		Smece:      s.stats.Garbage.Load(),
		Greske:     s.stats.WriteErrs.Load(),
		DiskMB:     fmt.Sprintf("%.1f", float64(bytes)/(1<<20)),
		Fajlova:    files,
		UDP:        fmt.Sprintf("%s:%d", orAll(s.cfg.UDPHost), s.cfg.UDPPort),
		Port:       s.cfg.UDPPort,
		Dir:        s.cfg.Dir,
		Vreme:      now.Format("02.01.2006. 15:04:05"),
		Token:      s.cfg.Token,
	}
	render(w, tmplIndex, data)
}

func (s *Service) pageDevice(w http.ResponseWriter, r *http.Request) {
	key := SanitizeSegment(r.URL.Query().Get("k"))
	q := r.URL.Query().Get("q")
	if len(q) > 200 {
		q = q[:200]
	}
	n := 200
	if v := r.URL.Query().Get("n"); v != "" {
		if x, err := strconv.Atoi(v); err == nil && x > 0 && x <= 5000 {
			n = x
		}
	}
	now := s.now()
	data := deviceData{Q: q, N: n, Vreme: now.Format("02.01.2006. 15:04:05"), Token: s.cfg.Token}
	if d, ok := s.reg.Get(key); ok {
		data.U = s.view(d, now)
		data.Nadjen = true
	} else {
		// Uredjaj moze postojati samo na disku (posle restarta prijemnika).
		data.U = deviceView{Key: key, Naziv: "(nije se javio od pokretanja prijemnika)"}
	}
	lines, err := s.store.Tail(key, n, q)
	if err != nil {
		lines = []string{"Greska pri citanju dnevnika: " + err.Error()}
	}
	data.Linije = lines
	data.Dani = s.store.Days(key)
	render(w, tmplDevice, data)
}

// pageRaw daje isti sadrzaj kao stranica, ali kao cist tekst - za curl sa
// servera i za lepljenje u prepisku.
func (s *Service) pageRaw(w http.ResponseWriter, r *http.Request) {
	key := SanitizeSegment(r.URL.Query().Get("k"))
	n := 500
	if v := r.URL.Query().Get("n"); v != "" {
		if x, err := strconv.Atoi(v); err == nil && x > 0 && x <= 5000 {
			n = x
		}
	}
	lines, err := s.store.Tail(key, n, r.URL.Query().Get("q"))
	if err != nil {
		http.Error(w, "Greska: "+err.Error(), http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "text/plain; charset=utf-8")
	w.Write([]byte(strings.Join(lines, "\n") + "\n"))
}

func (s *Service) apiDevices(w http.ResponseWriter, r *http.Request) {
	now := s.now()
	devs := s.reg.Snapshot(now)
	out := make([]map[string]any, 0, len(devs))
	for _, d := range devs {
		out = append(out, map[string]any{
			"kljuc":          d.Key,
			"naziv":          d.Name,
			"mac":            d.MAC,
			"ip":             d.IP,
			"izvorna_ip":     d.SourceIP,
			"fw":             d.FW,
			"serijski":       d.Serial,
			"identifikovan":  d.Identified,
			"tih":            s.reg.Stale(&d, now),
			"interval_sek":   s.reg.Interval(&d),
			"poslednji_put":  d.LastSeen.Format(time.RFC3339),
			"heartbeata":     d.Heartbeats,
			"paketa_dnevnik": d.LogPackets,
			"linija":         d.LogLines,
		})
	}
	w.Header().Set("Content-Type", "application/json; charset=utf-8")
	enc := json.NewEncoder(w)
	enc.SetIndent("", "  ")
	enc.Encode(map[string]any{"uredjaji": out, "vreme": now.Format(time.RFC3339)})
}

func orAll(h string) string {
	if h == "" {
		return "0.0.0.0"
	}
	return h
}

func render(w http.ResponseWriter, t *template.Template, data any) {
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := t.Execute(w, data); err != nil {
		http.Error(w, "Greska pri prikazu: "+err.Error(), http.StatusInternalServerError)
	}
}

const cssCommon = `
body{font-family:system-ui,Segoe UI,Arial,sans-serif;margin:0;background:#f4f6f8;color:#1c2733}
header{background:#12354f;color:#fff;padding:12px 18px;display:flex;gap:16px;align-items:baseline;flex-wrap:wrap}
header h1{font-size:18px;margin:0}
header a{color:#9fd3ff;text-decoration:none}
main{padding:16px 18px;max-width:1200px}
table{border-collapse:collapse;width:100%;background:#fff;box-shadow:0 1px 2px rgba(0,0,0,.12)}
th,td{padding:7px 10px;text-align:left;border-bottom:1px solid #e3e8ee;font-size:14px;vertical-align:top}
th{background:#eef2f6;font-weight:600}
tr.tih td{background:#ffe9e9}
.znak{display:inline-block;padding:1px 7px;border-radius:9px;font-size:12px;font-weight:600}
.ok{background:#d6f5dd;color:#0f6b2b}
.lose{background:#ffd2d2;color:#a11}
.nepoznat{background:#ffeccc;color:#8a5300}
.mali{color:#5a6b7b;font-size:12px}
pre{background:#0f1b26;color:#dbe7f0;padding:12px;border-radius:4px;overflow:auto;font-size:13px;line-height:1.45;max-height:70vh}
form.pretraga{margin:12px 0;display:flex;gap:8px;flex-wrap:wrap}
input,select{padding:6px 8px;border:1px solid #c6d0da;border-radius:4px;font-size:14px}
button{padding:6px 14px;border:0;border-radius:4px;background:#12354f;color:#fff;font-size:14px;cursor:pointer}
.prazno{padding:24px;background:#fff;color:#5a6b7b}
`

var tmplIndex = template.Must(template.New("index").Parse(`<!doctype html>
<html lang="sr"><head><meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<meta http-equiv="refresh" content="10">
<title>Prijemnik dijagnostike — TERMINIA</title>
<style>` + cssCommon + `</style></head>
<body>
<header><h1>Prijemnik dijagnostike</h1>
<span class="mali">UDP {{.UDP}} · dnevnici: {{.Dir}} ({{.DiskMB}} MB / {{.Fajlova}} fajlova)</span>
<span class="mali">osveženo {{.Vreme}}</span></header>
<main>
<p class="mali">Uređaja: <b>{{.Ukupno}}</b> · primljeno paketa: {{.Paketa}}
(heartbeat {{.Heartbeata}}, dnevnik {{.Dnevnika}}, odbačeno {{.Smece}}) · greške upisa: {{.Greske}}</p>
{{if .Uredjaji}}
<table>
<tr><th>Uređaj</th><th>MAC</th><th>IP</th><th>FW</th><th>Stanje</th><th>Poslednji put</th><th>Heartbeat</th><th>Linija</th><th>Poslednja linija</th></tr>
{{range .Uredjaji}}
<tr {{if .Tih}}class="tih"{{end}}>
<td><a href="/uredjaj?k={{.Key}}{{if $.Token}}&amp;t={{$.Token}}{{end}}"><b>{{.Naziv}}</b></a>
{{if not .Poznat}}<br><span class="znak nepoznat">nepoznat uređaj</span>
<span class="mali">FW stariji od 0.13.4 — prepoznat samo po adresi {{.IzvornaIP}}</span>{{end}}</td>
<td>{{if .MAC}}{{.MAC}}{{else}}<span class="mali">—</span>{{end}}</td>
<td>{{if .IP}}{{.IP}}{{else}}{{.IzvornaIP}}{{end}}</td>
<td>{{if .FW}}{{.FW}}{{else}}<span class="mali">—</span>{{end}}</td>
<td>{{if .Tih}}<span class="znak lose">tih</span>{{else}}<span class="znak ok">javlja se</span>{{end}}</td>
<td>{{.Vidjen}}</td>
<td>{{.Heartbeat}}<br><span class="mali">interval ~{{.Interval}} s</span></td>
<td>{{.Linija}}</td>
<td class="mali">{{.Poslednja}}</td>
</tr>
{{end}}
</table>
<p class="mali">Crveno = uređaj nije poslao ništa duže od 3× svog intervala javljanja.</p>
{{else}}
<div class="prazno">Nijedan uređaj se još nije javio.<br><br>
Na uređaju: <b>Podešavanja → Servis</b> → <code>svcLogHost</code> = <code>&lt;IP servera&gt;:{{.Port}}</code>,
uključi „Šalji dnevnik rada na server", heartbeat npr. 60 s.</div>
{{end}}
</main></body></html>`))

var tmplDevice = template.Must(template.New("device").Parse(`<!doctype html>
<html lang="sr"><head><meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1">
<title>{{.U.Naziv}} — dnevnik</title>
<style>` + cssCommon + `</style></head>
<body>
<header><h1>{{.U.Naziv}}</h1>
<span class="mali">{{if .U.MAC}}{{.U.MAC}} · {{end}}{{if .U.FW}}FW {{.U.FW}} · {{end}}{{if .U.IP}}{{.U.IP}}{{end}}</span>
<a href="/{{if .Token}}?t={{.Token}}{{end}}">&larr; svi uređaji</a>
<span class="mali">{{.Vreme}}</span></header>
<main>
{{if .Nadjen}}
<p class="mali">
{{if .U.Tih}}<span class="znak lose">tih</span>{{else}}<span class="znak ok">javlja se</span>{{end}}
· poslednji paket {{.U.Vidjen}} · heartbeat {{.U.Heartbeat}} (interval ~{{.U.Interval}} s)
· linija dnevnika: {{.U.Linija}} · prvi put viđen {{.U.PrviPutStr}}
{{if not .U.Poznat}}<br><span class="znak nepoznat">nepoznat uređaj</span>
identifikovan samo po izvornoj adresi {{.U.IzvornaIP}} — paket nije imao zaglavlje (FW stariji od 0.13.4){{end}}
</p>
{{else}}
<p class="mali">Uređaj se nije javio od pokretanja prijemnika — prikazano je ono što je ostalo na disku.</p>
{{end}}
<form class="pretraga" method="get" action="/uredjaj">
<input type="hidden" name="k" value="{{.U.Key}}">
{{if .Token}}<input type="hidden" name="t" value="{{.Token}}">{{end}}
<input type="text" name="q" value="{{.Q}}" placeholder="pretraga po tekstu (npr. stampac)" size="40">
<select name="n">
<option value="100" {{if eq .N 100}}selected{{end}}>100 linija</option>
<option value="200" {{if eq .N 200}}selected{{end}}>200 linija</option>
<option value="500" {{if eq .N 500}}selected{{end}}>500 linija</option>
<option value="2000" {{if eq .N 2000}}selected{{end}}>2000 linija</option>
</select>
<button type="submit">Prikaži</button>
</form>
<p class="mali">Dani sa dnevnikom: {{if .Dani}}{{range .Dani}}{{.}} {{end}}{{else}}nema zapisa{{end}}
· <a href="/dnevnik.txt?k={{.U.Key}}&amp;n={{.N}}&amp;q={{.Q}}{{if .Token}}&amp;t={{.Token}}{{end}}">preuzmi kao tekst</a></p>
{{if .Linije}}<pre>{{range .Linije}}{{.}}
{{end}}</pre>{{else}}<div class="prazno">Nema linija za zadate uslove.</div>{{end}}
</main></body></html>`))