feat: Поиск - with it on the assistant searches DuckDuckGo itself and answers from what it found; without it, it cannot. «Думал N сек.»

internal/server/search.go

@@ -0,0 +1,128 @@
+package server
+
+import (
+	"context"
+	"encoding/json"
+	"errors"
+	"html"
+	"io"
+	"net/http"
+	"net/url"
+	"regexp"
+	"strings"
+	"time"
+)
+
+// Web search for the assistant, when the user turned «Поиск» on: DuckDuckGo's
+// plain pages, no key and nothing to install. The light page first, the
+// HTML one if that fails; DuckDuckGo turns away too many requests from one
+// address, and then the assistant is told so.
+
+type searchResult struct {
+	Title   string `json:"title"`
+	URL     string `json:"url"`
+	Snippet string `json:"snippet"`
+}
+
+var (
+	reLiteLink    = regexp.MustCompile(`(?s)<a[^>]+href="([^"]+)"[^>]*class='result-link'[^>]*>(.*?)</a>`)
+	reLiteSnippet = regexp.MustCompile(`(?s)<td class='result-snippet'>(.*?)</td>`)
+	reHTMLLink    = regexp.MustCompile(`(?s)<a[^>]+class="result__a"[^>]+href="([^"]+)"[^>]*>(.*?)</a>`)
+	reHTMLSnippet = regexp.MustCompile(`(?s)<a[^>]+class="result__snippet"[^>]*>(.*?)</a>`)
+	reTags        = regexp.MustCompile(`<[^>]+>`)
+)
+
+// text is a bit of a results page as plain text.
+func text(s string) string {
+	return strings.Join(strings.Fields(html.UnescapeString(reTags.ReplaceAllString(s, ""))), " ")
+}
+
+// realURL takes DuckDuckGo's redirect (/l/?uddg=…) back to the address.
+func realURL(h string) string {
+	h = html.UnescapeString(h)
+	if strings.HasPrefix(h, "//") {
+		h = "https:" + h
+	}
+	if u, err := url.Parse(h); err == nil {
+		if t := u.Query().Get("uddg"); t != "" {
+			return t
+		}
+	}
+	return h
+}
+
+// parseDDG reads the results of the light or the HTML page.
+func parseDDG(page string) []searchResult {
+	links, snips := reLiteLink.FindAllStringSubmatch(page, -1), reLiteSnippet.FindAllStringSubmatch(page, -1)
+	if len(links) == 0 {
+		links, snips = reHTMLLink.FindAllStringSubmatch(page, -1), reHTMLSnippet.FindAllStringSubmatch(page, -1)
+	}
+	var out []searchResult
+	for i, l := range links {
+		r := searchResult{Title: text(l[2]), URL: realURL(l[1])}
+		if i < len(snips) {
+			r.Snippet = text(snips[i][1])
+		}
+		// Ads lead back through DuckDuckGo itself: left out.
+		if strings.Contains(r.URL, "duckduckgo.com/y.js") || r.Title == "" {
+			continue
+		}
+		out = append(out, r)
+	}
+	return out
+}
+
+var searchClient = &http.Client{Timeout: 15 * time.Second}
+
+// webSearch asks DuckDuckGo for q: up to n results.
+func webSearch(ctx context.Context, q string, n int) ([]searchResult, error) {
+	var last error
+	for _, base := range []string{"https://lite.duckduckgo.com/lite/?q=", "https://html.duckduckgo.com/html/?q="} {
+		req, _ := http.NewRequestWithContext(ctx, http.MethodGet, base+url.QueryEscape(q), nil)
+		req.Header.Set("User-Agent", "Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0 Safari/537.36")
+		req.Header.Set("Accept-Language", "ru,en;q=0.8")
+		resp, err := searchClient.Do(req)
+		if err != nil {
+			last = err
+			continue
+		}
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 2<<20))
+		resp.Body.Close()
+		rs := parseDDG(string(b))
+		if resp.StatusCode == http.StatusOK && len(rs) > 0 {
+			if len(rs) > n {
+				rs = rs[:n]
+			}
+			return rs, nil
+		}
+		if resp.StatusCode == http.StatusOK {
+			last = errors.New("ничего не нашлось")
+		} else {
+			last = errors.New("поисковик не ответил (" + resp.Status + "), возможно, временно ограничил запросы")
+		}
+	}
+	return nil, last
+}
+
+// POST /api/panel/ai/search - {q}: the results, for a user with the
+// assistant on (the «Поиск» switch is the page's: it lets the model ask).
+func (s *Server) handleAISearch(w http.ResponseWriter, r *http.Request) {
+	a := s.currentAdmin(r)
+	if on, _ := s.db.GetConfig(aiUserKey(a.ID)); on != "1" {
+		writeJSON(w, map[string]any{"ok": false, "error": "ассистент выключен в профиле"})
+		return
+	}
+	var in struct {
+		Q string `json:"q"`
+	}
+	if err := json.NewDecoder(http.MaxBytesReader(w, r.Body, 4<<10)).Decode(&in); err != nil || strings.TrimSpace(in.Q) == "" {
+		writeJSON(w, map[string]any{"ok": false, "error": "пустой запрос"})
+		return
+	}
+	rs, err := webSearch(r.Context(), strings.TrimSpace(in.Q), 6)
+	if err != nil {
+		writeJSON(w, map[string]any{"ok": false, "error": err.Error()})
+		return
+	}
+	writeJSON(w, map[string]any{"ok": true, "data": rs})
+}