Merge pull request #6 from eSlider/feat/produktor-search

feat(search): add produktor SearXNG JSON client

search/client.go

@@ -0,0 +1,148 @@
+// Package search provides a client for the produktor SearXNG instance
+// at https://search.produktor.io.
+package search
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"time"
+)
+
+const DefaultBaseURL = "https://search.produktor.io"
+
+// Client queries the produktor SearXNG instance.
+type Client struct {
+	BaseURL    string
+	HTTPClient *http.Client
+}
+
+// NewClient returns a client with sensible defaults.
+func NewClient() *Client {
+	return &Client{
+		BaseURL: DefaultBaseURL,
+		HTTPClient: &http.Client{
+			Timeout: 30 * time.Second,
+		},
+	}
+}
+
+// Options are optional SearXNG query parameters.
+type Options struct {
+	Categories string // e.g. "general", "images"
+	Engines    string // e.g. "duckduckgo,wikipedia"
+	Language   string // e.g. "en", "de"
+	Page       int    // 1-based page number
+	SafeSearch int    // 0=off, 1=moderate, 2=strict
+}
+
+// Result is one search hit.
+type Result struct {
+	URL           string   `json:"url"`
+	Title         string   `json:"title"`
+	Content       string   `json:"content"`
+	Engine        string   `json:"engine"`
+	Engines       []string `json:"engines"`
+	Score         float64  `json:"score"`
+	Category      string   `json:"category"`
+	PublishedDate *string  `json:"publishedDate"`
+	Thumbnail     string   `json:"thumbnail"`
+}
+
+// Response is the JSON envelope from /search?format=json.
+type Response struct {
+	Query               string     `json:"query"`
+	Results             []Result   `json:"results"`
+	Suggestions         []string   `json:"suggestions"`
+	Answers             []any      `json:"answers"`
+	Corrections         []any      `json:"corrections"`
+	Infoboxes           []any      `json:"infoboxes"`
+	UnresponsiveEngines [][]string `json:"unresponsive_engines"`
+}
+
+// Search runs a query and decodes the JSON response.
+func (c *Client) Search(ctx context.Context, query string, opts *Options) (*Response, error) {
+	if strings.TrimSpace(query) == "" {
+		return nil, fmt.Errorf("search: empty query")
+	}
+
+	base := strings.TrimRight(c.baseURL(), "/")
+	u, err := url.Parse(base + "/search")
+	if err != nil {
+		return nil, fmt.Errorf("search: parse url: %w", err)
+	}
+
+	q := u.Query()
+	q.Set("q", query)
+	q.Set("format", "json")
+	if opts != nil {
+		if opts.Categories != "" {
+			q.Set("categories", opts.Categories)
+		}
+		if opts.Engines != "" {
+			q.Set("engines", opts.Engines)
+		}
+		if opts.Language != "" {
+			q.Set("language", opts.Language)
+		}
+		if opts.Page > 0 {
+			q.Set("pageno", fmt.Sprintf("%d", opts.Page))
+		}
+		if opts.SafeSearch > 0 {
+			q.Set("safesearch", fmt.Sprintf("%d", opts.SafeSearch))
+		}
+	}
+	u.RawQuery = q.Encode()
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, u.String(), nil)
+	if err != nil {
+		return nil, fmt.Errorf("search: new request: %w", err)
+	}
+	req.Header.Set("Accept", "application/json")
+	req.Header.Set("User-Agent", "go-produktor-search/1.0")
+
+	resp, err := c.httpClient().Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("search: request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := io.ReadAll(io.LimitReader(resp.Body, 10<<20))
+	if err != nil {
+		return nil, fmt.Errorf("search: read body: %w", err)
+	}
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("search: HTTP %d: %s", resp.StatusCode, truncate(string(body), 200))
+	}
+
+	var out Response
+	if err := json.Unmarshal(body, &out); err != nil {
+		return nil, fmt.Errorf("search: decode json: %w", err)
+	}
+	return &out, nil
+}
+
+func (c *Client) baseURL() string {
+	if c.BaseURL != "" {
+		return c.BaseURL
+	}
+	return DefaultBaseURL
+}
+
+func (c *Client) httpClient() *http.Client {
+	if c.HTTPClient != nil {
+		return c.HTTPClient
+	}
+	return http.DefaultClient
+}
+
+func truncate(s string, n int) string {
+	if len(s) <= n {
+		return s
+	}
+	return s[:n] + "..."
+}