Changeset 0.13.1 (#65)

2026-02-25 23:56:27 +00:00
parent 8292a6efa8
commit 113b98ace4
24 changed files with 1565 additions and 24 deletions
--- a/server/tools/search/duckduckgo.go
+++ b/server/tools/search/duckduckgo.go
@@ -0,0 +1,152 @@
+package search
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+
+	"golang.org/x/net/html"
+)
+
+func init() {
+	RegisterProvider(&DuckDuckGo{})
+	// Default active provider — no API key needed
+	_ = SetActive("duckduckgo")
+}
+
+// DuckDuckGo implements Provider using DDG's HTML lite endpoint.
+// No API key required. Returns organic web results.
+type DuckDuckGo struct{}
+
+func (d *DuckDuckGo) Name() string { return "duckduckgo" }
+
+func (d *DuckDuckGo) Search(ctx context.Context, query string, maxResults int) ([]SearchResult, error) {
+	if maxResults <= 0 {
+		maxResults = 5
+	}
+	if maxResults > 10 {
+		maxResults = 10
+	}
+
+	endpoint := "https://html.duckduckgo.com/html/?q=" + url.QueryEscape(query)
+
+	req, err := http.NewRequestWithContext(ctx, "GET", endpoint, nil)
+	if err != nil {
+		return nil, fmt.Errorf("build request: %w", err)
+	}
+	req.Header.Set("User-Agent", "ChatSwitchboard/1.0 (Web Search Tool)")
+
+	client := &http.Client{Timeout: 10 * time.Second}
+	resp, err := client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("search request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("search returned HTTP %d", resp.StatusCode)
+	}
+
+	// Limit body read to 512KB
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 512*1024))
+	if err != nil {
+		return nil, fmt.Errorf("read response: %w", err)
+	}
+
+	return parseDDGHTML(string(body), maxResults), nil
+}
+
+// parseDDGHTML extracts search results from DuckDuckGo's HTML lite page.
+// Results are in <a class="result__a"> tags with snippets in <a class="result__snippet">.
+func parseDDGHTML(htmlContent string, maxResults int) []SearchResult {
+	doc, err := html.Parse(strings.NewReader(htmlContent))
+	if err != nil {
+		return nil
+	}
+
+	var results []SearchResult
+
+	// Walk the DOM looking for result blocks
+	var walk func(*html.Node)
+	walk = func(n *html.Node) {
+		if len(results) >= maxResults {
+			return
+		}
+
+		if n.Type == html.ElementNode && n.Data == "a" {
+			class := getAttr(n, "class")
+
+			if strings.Contains(class, "result__a") {
+				href := getAttr(n, "href")
+				title := textContent(n)
+				// DDG wraps URLs through a redirect; extract the actual URL
+				actualURL := extractDDGURL(href)
+				if actualURL != "" && title != "" {
+					results = append(results, SearchResult{
+						Title: strings.TrimSpace(title),
+						URL:   actualURL,
+					})
+				}
+			}
+
+			if strings.Contains(class, "result__snippet") {
+				snippet := strings.TrimSpace(textContent(n))
+				// Attach snippet to the most recent result
+				if len(results) > 0 && results[len(results)-1].Snippet == "" {
+					results[len(results)-1].Snippet = snippet
+				}
+			}
+		}
+
+		for c := n.FirstChild; c != nil; c = c.NextSibling {
+			walk(c)
+		}
+	}
+	walk(doc)
+
+	return results
+}
+
+// extractDDGURL extracts the actual URL from DDG's redirect wrapper.
+// DDG links look like: //duckduckgo.com/l/?uddg=https%3A%2F%2Fexample.com&rut=...
+func extractDDGURL(href string) string {
+	if strings.Contains(href, "uddg=") {
+		u, err := url.Parse(href)
+		if err != nil {
+			return href
+		}
+		uddg := u.Query().Get("uddg")
+		if uddg != "" {
+			return uddg
+		}
+	}
+	// Direct URL
+	if strings.HasPrefix(href, "http") {
+		return href
+	}
+	return ""
+}
+
+func getAttr(n *html.Node, key string) string {
+	for _, a := range n.Attr {
+		if a.Key == key {
+			return a.Val
+		}
+	}
+	return ""
+}
+
+func textContent(n *html.Node) string {
+	if n.Type == html.TextNode {
+		return n.Data
+	}
+	var sb strings.Builder
+	for c := n.FirstChild; c != nil; c = c.NextSibling {
+		sb.WriteString(textContent(c))
+	}
+	return sb.String()
+}