init

2026-02-20 20:19:16 +05:30
commit 995c49518f
6 changed files with 861 additions and 0 deletions
--- a/.gitignore
+++ b/.gitignore
@@ -0,0 +1 @@
+*.sqlite*
--- a/README.md
+++ b/README.md
@@ -0,0 +1,118 @@
+# siliconpin_spider
+
+A Go-based web crawler with per-domain SQLite storage, robots.txt compliance,
+randomised polite delays, and Server-Sent Events (SSE) for real-time progress.
+
+---
+
+## Requirements
+
+| Tool | Notes |
+|------|-------|
+| Go 1.21+ | |
+| GCC | Required by `go-sqlite3` (CGO) |
+
+```bash
+# Ubuntu / Debian
+apt install gcc
+
+# macOS (Xcode CLI tools)
+xcode-select --install
+```
+
+---
+
+## Run
+
+```bash
+go mod tidy
+go run main.go
+# Server → http://localhost:8080
+```
+
+---
+
+## On startup
+
+- Creates **`siliconpin_spider.sqlite`** (domains registry)
+- Serves `./static/` at `/`
+- **Resumes** any crawls that were previously registered
+
+---
+
+## API
+
+### `POST /api/add_domain`
+
+Register a domain and immediately start crawling it.
+
+```bash
+curl -X POST http://localhost:8080/api/add_domain \
+  -H "Content-Type: application/json" \
+  -d '{"domain":"siliconpin.com","Crawl-delay":"20"}'
+```
+
+**Body fields**
+
+| Field | Required | Default | Notes |
+|-------|----------|---------|-------|
+| `domain` | ✅ | — | bare domain, scheme/www stripped automatically |
+| `Crawl-delay` | ❌ | `60` | seconds; actual delay is random in `[N, N*2]` |
+
+**Response `201`**
+
+```json
+{
+  "message":  "domain added, crawler started",
+  "domain":   "siliconpin.com",
+  "interval": 20,
+  "db_file":  "siliconpin.com.sqlite",
+  "sse":      "/api/sse/siliconpin.com"
+}
+```
+
+Creates **`siliconpin.com.sqlite`** with table:
+
+```
+urls(id, url UNIQUE, created_at, updated_at)
+```
+
+---
+
+### `GET /api/sse/{domain}`
+
+Stream crawl events for any registered domain as **Server-Sent Events**.
+
+```bash
+curl -N http://localhost:8080/api/sse/siliconpin.com
+curl -N http://localhost:8080/api/sse/cicdhosting.com
+```
+
+Each `data:` line is a JSON object:
+
+```
+data: {"event":"connected",  "data":{"domain":"siliconpin.com"}}
+data: {"event":"status",     "data":{"msg":"fetching robots.txt"}}
+data: {"event":"robots",     "data":{"disallowed":["/admin/"],"robots_delay":10,"effective_delay":20}}
+data: {"event":"waiting",    "data":{"url":"https://siliconpin.com/about","delay_s":27,"queue":4}}
+data: {"event":"fetching",   "data":{"url":"https://siliconpin.com/about"}}
+data: {"event":"saved",      "data":{"url":"…","status":200,"content_type":"text/html"}}
+data: {"event":"links_found","data":{"url":"…","found":12,"new":8,"queue_len":12}}
+data: {"event":"skipped",    "data":{"url":"…","reason":"robots.txt"}}
+data: {"event":"error",      "data":{"url":"…","msg":"…"}}
+data: {"event":"done",       "data":{"domain":"siliconpin.com","msg":"crawl complete"}}
+: keepalive
+```
+
+Multiple browser tabs / curl processes can listen to the **same** domain stream simultaneously.
+
+---
+
+## Crawl behaviour
+
+1. Fetches `robots.txt`; respects `Disallow` paths and `Crawl-delay`
+   - If `robots.txt` specifies a higher delay than you set, the higher value wins
+2. BFS queue – same-host HTML links only
+3. Random delay between requests: **`interval` → `interval × 2`** seconds
+4. Skips already-visited URLs (checked against the domain's SQLite)
+5. On restart, existing domains resume from where they left off (unvisited URLs are re-queued from the start URL; already saved URLs are skipped)
--- a/go.mod
+++ b/go.mod
@@ -0,0 +1,5 @@
+module siliconpin_spider
+
+go 1.21
+
+require github.com/mattn/go-sqlite3 v1.14.22
--- a/go.sum
+++ b/go.sum
@@ -0,0 +1,2 @@
+github.com/mattn/go-sqlite3 v1.14.22 h1:2gZY6PC6kBnID23Tichd1K+Z0oS6nE/XwU+Vz/5o4kU=
+github.com/mattn/go-sqlite3 v1.14.22/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
--- a/main.go
+++ b/main.go
@@ -0,0 +1,597 @@
+package main
+
+import (
+	"bufio"
+	"database/sql"
+	"encoding/json"
+	"fmt"
+	"io"
+	"log"
+	"math/rand"
+	"net/http"
+	"net/url"
+	"os"
+	"regexp"
+	"strings"
+	"sync"
+	"time"
+
+	_ "github.com/mattn/go-sqlite3"
+)
+
+// ─────────────────────────────────────────────────────────────────
+//  Global state
+// ─────────────────────────────────────────────────────────────────
+
+const mainDBFile = "siliconpin_spider.sqlite"
+
+var mainDB *sql.DB
+
+// per-domain SSE brokers
+var (
+	brokersMu sync.RWMutex
+	brokers   = map[string]*Broker{}
+)
+
+// per-domain DB connections (kept open)
+var (
+	domainDBsMu sync.RWMutex
+	domainDBs   = map[string]*sql.DB{}
+)
+
+// guard against duplicate crawlers
+var (
+	crawlersMu sync.Mutex
+	crawlers   = map[string]bool{}
+)
+
+// ─────────────────────────────────────────────────────────────────
+//  SSE Broker  – fan-out to multiple subscribers per domain
+// ─────────────────────────────────────────────────────────────────
+
+type Broker struct {
+	mu      sync.Mutex
+	clients map[chan string]struct{}
+}
+
+func newBroker() *Broker {
+	return &Broker{clients: make(map[chan string]struct{})}
+}
+
+func (b *Broker) subscribe() chan string {
+	ch := make(chan string, 64)
+	b.mu.Lock()
+	b.clients[ch] = struct{}{}
+	b.mu.Unlock()
+	return ch
+}
+
+func (b *Broker) unsubscribe(ch chan string) {
+	b.mu.Lock()
+	delete(b.clients, ch)
+	b.mu.Unlock()
+}
+
+func (b *Broker) publish(msg string) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	for ch := range b.clients {
+		select {
+		case ch <- msg:
+		default: // slow client – drop message
+		}
+	}
+}
+
+func getBroker(domain string) *Broker {
+	brokersMu.RLock()
+	br, ok := brokers[domain]
+	brokersMu.RUnlock()
+	if ok {
+		return br
+	}
+	brokersMu.Lock()
+	defer brokersMu.Unlock()
+	if br, ok = brokers[domain]; ok {
+		return br
+	}
+	br = newBroker()
+	brokers[domain] = br
+	return br
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  SSE event helper
+// ─────────────────────────────────────────────────────────────────
+
+type sseEvent struct {
+	Event string      `json:"event"`
+	Data  interface{} `json:"data"`
+}
+
+func emit(br *Broker, event string, data interface{}) {
+	payload, _ := json.Marshal(sseEvent{Event: event, Data: data})
+	br.publish(string(payload))
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  Database helpers
+// ─────────────────────────────────────────────────────────────────
+
+func initMainDB() {
+	var err error
+	mainDB, err = sql.Open("sqlite3", mainDBFile+"?_journal=WAL&_busy_timeout=5000")
+	if err != nil {
+		log.Fatalf("open main DB: %v", err)
+	}
+	_, err = mainDB.Exec(`
+		CREATE TABLE IF NOT EXISTS domains (
+			id         INTEGER  PRIMARY KEY AUTOINCREMENT,
+			domain     TEXT     NOT NULL UNIQUE,
+			interval   INTEGER  NOT NULL DEFAULT 60,
+			created_at DATETIME NOT NULL,
+			updated_at DATETIME NOT NULL
+		)`)
+	if err != nil {
+		log.Fatalf("create domains table: %v", err)
+	}
+	log.Printf("Main DB ready: %s", mainDBFile)
+}
+
+func openDomainDB(domain string) (*sql.DB, error) {
+	domainDBsMu.RLock()
+	db, ok := domainDBs[domain]
+	domainDBsMu.RUnlock()
+	if ok {
+		return db, nil
+	}
+
+	db, err := sql.Open("sqlite3", domain+".sqlite?_journal=WAL&_busy_timeout=5000")
+	if err != nil {
+		return nil, err
+	}
+	_, err = db.Exec(`
+		CREATE TABLE IF NOT EXISTS urls (
+			id         INTEGER  PRIMARY KEY AUTOINCREMENT,
+			url        TEXT     NOT NULL UNIQUE,
+			created_at DATETIME NOT NULL,
+			updated_at DATETIME NOT NULL
+		)`)
+	if err != nil {
+		db.Close()
+		return nil, err
+	}
+
+	domainDBsMu.Lock()
+	domainDBs[domain] = db
+	domainDBsMu.Unlock()
+	return db, nil
+}
+
+func insertURL(db *sql.DB, rawURL string) (bool, error) {
+	now := time.Now().UTC().Format(time.RFC3339)
+	res, err := db.Exec(
+		`INSERT OR IGNORE INTO urls (url, created_at, updated_at) VALUES (?, ?, ?)`,
+		rawURL, now, now,
+	)
+	if err != nil {
+		return false, err
+	}
+	n, _ := res.RowsAffected()
+	return n > 0, nil
+}
+
+func isURLKnown(db *sql.DB, rawURL string) bool {
+	var c int
+	db.QueryRow(`SELECT COUNT(1) FROM urls WHERE url = ?`, rawURL).Scan(&c)
+	return c > 0
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  robots.txt  (minimal, single-pass parser)
+// ─────────────────────────────────────────────────────────────────
+
+type robotsRules struct {
+	disallowed []string
+	crawlDelay int // 0 = not set
+}
+
+func fetchRobots(domain string) *robotsRules {
+	rules := &robotsRules{}
+	client := &http.Client{Timeout: 15 * time.Second}
+	resp, err := client.Get("https://" + domain + "/robots.txt")
+	if err != nil || resp.StatusCode != 200 {
+		return rules
+	}
+	defer resp.Body.Close()
+
+	inSection := false
+	scanner := bufio.NewScanner(resp.Body)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		lower := strings.ToLower(line)
+
+		if strings.HasPrefix(lower, "user-agent:") {
+			agent := strings.TrimSpace(line[len("user-agent:"):])
+			inSection = agent == "*" ||
+				strings.EqualFold(agent, "siliconpin_spider")
+			continue
+		}
+		if !inSection {
+			continue
+		}
+		switch {
+		case strings.HasPrefix(lower, "disallow:"):
+			p := strings.TrimSpace(line[len("disallow:"):])
+			if p != "" {
+				rules.disallowed = append(rules.disallowed, p)
+			}
+		case strings.HasPrefix(lower, "crawl-delay:"):
+			fmt.Sscanf(strings.TrimSpace(line[len("crawl-delay:"):]), "%d", &rules.crawlDelay)
+		}
+	}
+	return rules
+}
+
+func (r *robotsRules) allowed(path string) bool {
+	for _, d := range r.disallowed {
+		if strings.HasPrefix(path, d) {
+			return false
+		}
+	}
+	return true
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  Link extractor  – same-host HTML links only
+// ─────────────────────────────────────────────────────────────────
+
+var hrefRe = regexp.MustCompile(`(?i)href=["']([^"'#][^"']*)["']`)
+
+func extractLinks(base *url.URL, body string) []string {
+	seen := map[string]bool{}
+	var links []string
+	for _, m := range hrefRe.FindAllStringSubmatch(body, -1) {
+		href := strings.TrimSpace(m[1])
+		parsed, err := url.Parse(href)
+		if err != nil {
+			continue
+		}
+		resolved := base.ResolveReference(parsed)
+		resolved.Fragment = ""
+		resolved.RawQuery = ""
+		if resolved.Scheme != "http" && resolved.Scheme != "https" {
+			continue
+		}
+		if !strings.EqualFold(resolved.Hostname(), base.Hostname()) {
+			continue
+		}
+		s := resolved.String()
+		if !seen[s] {
+			seen[s] = true
+			links = append(links, s)
+		}
+	}
+	return links
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  Crawler goroutine
+// ─────────────────────────────────────────────────────────────────
+
+func crawlDomain(domain string, intervalSec int) {
+	log.Printf("[%s] crawler started (base interval %ds)", domain, intervalSec)
+	br := getBroker(domain)
+
+	db, err := openDomainDB(domain)
+	if err != nil {
+		emit(br, "error", map[string]string{"msg": "DB error: " + err.Error()})
+		return
+	}
+
+	// ── robots.txt ──────────────────────────────────────────────
+	emit(br, "status", map[string]string{"msg": "fetching robots.txt"})
+	robots := fetchRobots(domain)
+
+	// robots.txt crawl-delay overrides our setting if higher
+	if robots.crawlDelay > intervalSec {
+		intervalSec = robots.crawlDelay
+		now := time.Now().UTC().Format(time.RFC3339)
+		mainDB.Exec(`UPDATE domains SET interval=?, updated_at=? WHERE domain=?`,
+			intervalSec, now, domain)
+	}
+	emit(br, "robots", map[string]interface{}{
+		"disallowed":      robots.disallowed,
+		"robots_delay":    robots.crawlDelay,
+		"effective_delay": intervalSec,
+	})
+
+	// ── BFS queue ───────────────────────────────────────────────
+	startURL := "https://" + domain + "/"
+	queue := []string{startURL}
+
+	httpClient := &http.Client{
+		Timeout: 30 * time.Second,
+		CheckRedirect: func(req *http.Request, via []*http.Request) error {
+			if len(via) >= 5 {
+				return fmt.Errorf("too many redirects")
+			}
+			return nil
+		},
+	}
+
+	for len(queue) > 0 {
+		// Re-read interval in case it was updated via API
+		var cur int
+		if err := mainDB.QueryRow(`SELECT interval FROM domains WHERE domain=?`, domain).Scan(&cur); err == nil && cur > 0 {
+			intervalSec = cur
+		}
+
+		target := queue[0]
+		queue = queue[1:]
+
+		if isURLKnown(db, target) {
+			continue
+		}
+
+		// robots check
+		parsed, err := url.Parse(target)
+		if err != nil {
+			continue
+		}
+		if !robots.allowed(parsed.Path) {
+			emit(br, "skipped", map[string]string{"url": target, "reason": "robots.txt"})
+			continue
+		}
+
+		// random delay: [interval, interval*2] seconds
+		delaySec := intervalSec + rand.Intn(intervalSec+1)
+		delay := time.Duration(delaySec) * time.Second
+		emit(br, "waiting", map[string]interface{}{
+			"url":     target,
+			"delay_s": delaySec,
+			"queue":   len(queue),
+		})
+		time.Sleep(delay)
+
+		// fetch
+		emit(br, "fetching", map[string]string{"url": target})
+		resp, err := httpClient.Get(target)
+		if err != nil {
+			emit(br, "error", map[string]string{"url": target, "msg": err.Error()})
+			log.Printf("[%s] fetch error %s: %v", domain, target, err)
+			continue
+		}
+
+		ct := resp.Header.Get("Content-Type")
+		isHTML := strings.Contains(ct, "text/html")
+
+		var bodyStr string
+		if isHTML {
+			raw, _ := io.ReadAll(io.LimitReader(resp.Body, 5<<20)) // 5 MB cap
+			bodyStr = string(raw)
+		}
+		resp.Body.Close()
+
+		inserted, _ := insertURL(db, target)
+		if inserted {
+			emit(br, "saved", map[string]interface{}{
+				"url":          target,
+				"status":       resp.StatusCode,
+				"content_type": ct,
+			})
+			log.Printf("[%s] saved: %s", domain, target)
+		}
+
+		// discover links
+		if isHTML && resp.StatusCode == 200 {
+			links := extractLinks(parsed, bodyStr)
+			newCount := 0
+			for _, link := range links {
+				if !isURLKnown(db, link) {
+					queue = append(queue, link)
+					newCount++
+				}
+			}
+			emit(br, "links_found", map[string]interface{}{
+				"url":       target,
+				"found":     len(links),
+				"new":       newCount,
+				"queue_len": len(queue),
+			})
+		}
+	}
+
+	emit(br, "done", map[string]string{"domain": domain, "msg": "crawl complete"})
+	log.Printf("[%s] crawl complete", domain)
+
+	crawlersMu.Lock()
+	delete(crawlers, domain)
+	crawlersMu.Unlock()
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  HTTP handlers
+// ─────────────────────────────────────────────────────────────────
+
+func sanitizeDomain(raw string) string {
+	raw = strings.TrimSpace(raw)
+	raw = strings.TrimPrefix(raw, "https://")
+	raw = strings.TrimPrefix(raw, "http://")
+	raw = strings.TrimPrefix(raw, "www.")
+	raw = strings.TrimRight(raw, "/")
+	return raw
+}
+
+var domainRe = regexp.MustCompile(`^[a-zA-Z0-9]([a-zA-Z0-9\-]{0,61}[a-zA-Z0-9])?(\.[a-zA-Z]{2,})+$`)
+
+func isValidDomain(d string) bool { return domainRe.MatchString(d) }
+
+// POST /api/add_domain
+func addDomainHandler(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodPost {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	var body struct {
+		Domain     string `json:"domain"`
+		CrawlDelay string `json:"Crawl-delay"`
+	}
+	w.Header().Set("Content-Type", "application/json")
+
+	if err := json.NewDecoder(r.Body).Decode(&body); err != nil {
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "invalid JSON"})
+		return
+	}
+	if body.Domain == "" {
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "domain is required"})
+		return
+	}
+
+	domain := sanitizeDomain(body.Domain)
+	if !isValidDomain(domain) {
+		w.WriteHeader(http.StatusBadRequest)
+		json.NewEncoder(w).Encode(map[string]string{"error": "invalid domain"})
+		return
+	}
+
+	interval := 60
+	if body.CrawlDelay != "" {
+		fmt.Sscanf(body.CrawlDelay, "%d", &interval)
+		if interval <= 0 {
+			interval = 60
+		}
+	}
+
+	now := time.Now().UTC().Format(time.RFC3339)
+	_, err := mainDB.Exec(
+		`INSERT INTO domains (domain,interval,created_at,updated_at) VALUES (?,?,?,?)
+		 ON CONFLICT(domain) DO UPDATE SET interval=excluded.interval, updated_at=excluded.updated_at`,
+		domain, interval, now, now,
+	)
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		json.NewEncoder(w).Encode(map[string]string{"error": "db error"})
+		return
+	}
+
+	if _, err := openDomainDB(domain); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		json.NewEncoder(w).Encode(map[string]string{"error": "domain DB init failed"})
+		return
+	}
+
+	// start crawler if not already running
+	crawlersMu.Lock()
+	if !crawlers[domain] {
+		crawlers[domain] = true
+		go crawlDomain(domain, interval)
+	}
+	crawlersMu.Unlock()
+
+	w.WriteHeader(http.StatusCreated)
+	json.NewEncoder(w).Encode(map[string]interface{}{
+		"message":  "domain added, crawler started",
+		"domain":   domain,
+		"interval": interval,
+		"db_file":  domain + ".sqlite",
+		"sse":      "/api/sse/" + domain,
+	})
+}
+
+// GET /api/sse/{domain}
+func sseHandler(w http.ResponseWriter, r *http.Request) {
+	rawDomain := strings.TrimPrefix(r.URL.Path, "/api/sse/")
+	domain := sanitizeDomain(rawDomain)
+	if !isValidDomain(domain) {
+		http.Error(w, "invalid domain", http.StatusBadRequest)
+		return
+	}
+
+	flusher, ok := w.(http.Flusher)
+	if !ok {
+		http.Error(w, "streaming not supported", http.StatusInternalServerError)
+		return
+	}
+
+	w.Header().Set("Content-Type", "text/event-stream")
+	w.Header().Set("Cache-Control", "no-cache")
+	w.Header().Set("Connection", "keep-alive")
+	w.Header().Set("X-Accel-Buffering", "no") // nginx: disable proxy buffering
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+
+	br := getBroker(domain)
+	ch := br.subscribe()
+	defer br.unsubscribe(ch)
+
+	log.Printf("[SSE] client connected → %s", domain)
+
+	// send immediate connected event
+	fmt.Fprintf(w, "data: {\"event\":\"connected\",\"data\":{\"domain\":%q}}\n\n", domain)
+	flusher.Flush()
+
+	ticker := time.NewTicker(25 * time.Second)
+	defer ticker.Stop()
+
+	for {
+		select {
+		case <-r.Context().Done():
+			log.Printf("[SSE] client disconnected → %s", domain)
+			return
+		case msg := <-ch:
+			fmt.Fprintf(w, "data: %s\n\n", msg)
+			flusher.Flush()
+		case <-ticker.C:
+			fmt.Fprintf(w, ": keepalive\n\n")
+			flusher.Flush()
+		}
+	}
+}
+
+// ─────────────────────────────────────────────────────────────────
+//  main
+// ─────────────────────────────────────────────────────────────────
+
+func main() {
+	rand.Seed(time.Now().UnixNano()) //nolint:staticcheck
+
+	if err := os.MkdirAll("static", 0o755); err != nil {
+		log.Fatalf("mkdir static: %v", err)
+	}
+
+	initMainDB()
+	defer mainDB.Close()
+
+	// Resume any domains already in the DB from a previous run
+	rows, err := mainDB.Query(`SELECT domain, interval FROM domains`)
+	if err == nil {
+		defer rows.Close()
+		for rows.Next() {
+			var d string
+			var iv int
+			if rows.Scan(&d, &iv) == nil {
+				crawlersMu.Lock()
+				if !crawlers[d] {
+					crawlers[d] = true
+					go crawlDomain(d, iv)
+				}
+				crawlersMu.Unlock()
+			}
+		}
+	}
+
+	mux := http.NewServeMux()
+	mux.Handle("/", http.FileServer(http.Dir("./static")))
+	mux.HandleFunc("/api/add_domain", addDomainHandler)
+	mux.HandleFunc("/api/sse/", sseHandler)
+
+	port := ":8080"
+	log.Printf("siliconpin_spider listening on %s", port)
+	log.Fatal(http.ListenAndServe(port, mux))
+}
--- a/static/index.html
+++ b/static/index.html
@@ -0,0 +1,138 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8"/>
+<meta name="viewport" content="width=device-width,initial-scale=1"/>
+<title>SiliconPin Spider</title>
+<style>
+  *{box-sizing:border-box;margin:0;padding:0}
+  body{font-family:'Segoe UI',sans-serif;background:#0f1117;color:#e0e0e0;min-height:100vh;padding:32px 20px}
+  h1{color:#58a6ff;font-size:1.8rem;margin-bottom:4px}
+  .sub{color:#8b949e;font-size:.9rem;margin-bottom:32px}
+  .card{background:#161b22;border:1px solid #30363d;border-radius:10px;padding:24px;max-width:680px;margin-bottom:24px}
+  h2{font-size:1rem;color:#cdd9e5;margin-bottom:16px}
+  label{display:block;font-size:.82rem;color:#8b949e;margin-bottom:4px}
+  input{width:100%;padding:8px 12px;background:#0d1117;border:1px solid #30363d;border-radius:6px;color:#e0e0e0;font-size:.92rem;outline:none;transition:border .2s}
+  input:focus{border-color:#58a6ff}
+  .row{display:flex;gap:12px;margin-bottom:14px}
+  .row>div{flex:1}
+  button{padding:9px 22px;background:#238636;border:none;border-radius:6px;color:#fff;font-size:.9rem;cursor:pointer;transition:background .2s}
+  button:hover{background:#2ea043}
+  #log{background:#0d1117;border:1px solid #30363d;border-radius:8px;padding:16px;height:340px;overflow-y:auto;font-size:.8rem;font-family:monospace;margin-top:12px}
+  .ev{padding:3px 0;border-bottom:1px solid #1c2128;display:flex;gap:8px;align-items:flex-start}
+  .ev:last-child{border-bottom:none}
+  .badge{font-size:.7rem;padding:2px 7px;border-radius:12px;white-space:nowrap;font-weight:600}
+  .connected{background:#1f4e79;color:#79c0ff}
+  .status   {background:#2d333b;color:#cdd9e5}
+  .robots   {background:#3b2300;color:#f0883e}
+  .waiting  {background:#1c2a1e;color:#56d364}
+  .fetching {background:#172033;color:#79c0ff}
+  .saved    {background:#0d2818;color:#56d364}
+  .links_found{background:#1f2d3d;color:#a5d6ff}
+  .skipped  {background:#2d2d00;color:#e3b341}
+  .error    {background:#3d0000;color:#f85149}
+  .done     {background:#1f4e2c;color:#56d364}
+  .keepalive{background:#2d333b;color:#484f58;font-style:italic}
+  .ev-body{word-break:break-all;color:#cdd9e5}
+  .status-dot{width:8px;height:8px;border-radius:50%;background:#484f58;display:inline-block;margin-right:6px;flex-shrink:0;margin-top:4px}
+  .status-dot.live{background:#56d364;animation:pulse 1.5s infinite}
+  @keyframes pulse{0%,100%{opacity:1}50%{opacity:.4}}
+  .conn-row{display:flex;align-items:center;gap:8px;margin-bottom:8px}
+</style>
+</head>
+<body>
+<h1>🕷 SiliconPin Spider</h1>
+<p class="sub">Polite web crawler — respects robots.txt · random delay · SSE live feed</p>
+
+<div class="card">
+  <h2>Add domain</h2>
+  <div class="row">
+    <div>
+      <label>Domain</label>
+      <input id="domain" placeholder="siliconpin.com" value=""/>
+    </div>
+    <div>
+      <label>Crawl-delay (s)</label>
+      <input id="delay" placeholder="20" value="20" style="max-width:100px"/>
+    </div>
+  </div>
+  <button onclick="addDomain()">Add &amp; Crawl</button>
+  <div id="addResult" style="margin-top:10px;font-size:.82rem;color:#8b949e"></div>
+</div>
+
+<div class="card">
+  <h2>Live SSE stream</h2>
+  <div class="conn-row">
+    <span class="status-dot" id="dot"></span>
+    <input id="sseDomain" placeholder="siliconpin.com" style="flex:1"/>
+    <button onclick="connectSSE()">Connect</button>
+    <button onclick="clearLog()" style="background:#30363d">Clear</button>
+  </div>
+  <div id="log"><span style="color:#484f58">— events will appear here —</span></div>
+</div>
+
+<script>
+let es = null;
+
+async function addDomain() {
+  const domain = document.getElementById('domain').value.trim();
+  const delay  = document.getElementById('delay').value.trim();
+  if (!domain) { alert('Domain is required'); return; }
+  const res = await fetch('/api/add_domain', {
+    method: 'POST',
+    headers: {'Content-Type':'application/json'},
+    body: JSON.stringify({domain, 'Crawl-delay': delay})
+  });
+  const data = await res.json();
+  const el = document.getElementById('addResult');
+  if (res.ok) {
+    el.style.color = '#56d364';
+    el.textContent = `✓ ${data.message} — SSE: ${data.sse}`;
+    document.getElementById('sseDomain').value = domain;
+  } else {
+    el.style.color = '#f85149';
+    el.textContent = `✗ ${data.error}`;
+  }
+}
+
+function connectSSE() {
+  const domain = document.getElementById('sseDomain').value.trim();
+  if (!domain) { alert('Enter a domain'); return; }
+  if (es) { es.close(); }
+  document.getElementById('dot').className = 'status-dot live';
+  es = new EventSource('/api/sse/' + domain);
+  es.onmessage = function(e) { appendEvent(e.data); };
+  es.onerror   = function()  {
+    appendRaw('keepalive','connection error / closed');
+    document.getElementById('dot').className = 'status-dot';
+  };
+}
+
+function appendEvent(raw) {
+  let obj;
+  try { obj = JSON.parse(raw); } catch(e) { appendRaw('status', raw); return; }
+  const event = obj.event || 'status';
+  const data  = typeof obj.data === 'object' ? JSON.stringify(obj.data) : String(obj.data);
+  appendRaw(event, data);
+}
+
+function appendRaw(event, text) {
+  const log = document.getElementById('log');
+  if (log.querySelector('span')) log.innerHTML = '';
+  const div = document.createElement('div');
+  div.className = 'ev';
+  div.innerHTML = `<span class="badge ${event}">${event}</span><span class="ev-body">${escHtml(text)}</span>`;
+  log.appendChild(div);
+  log.scrollTop = log.scrollHeight;
+}
+
+function clearLog() {
+  document.getElementById('log').innerHTML = '<span style="color:#484f58">— cleared —</span>';
+}
+
+function escHtml(s) {
+  return s.replace(/&/g,'&amp;').replace(/</g,'&lt;').replace(/>/g,'&gt;');
+}
+</script>
+</body>
+</html>