Initial commit: DeepRes Go backend — bot + worker + embed service

internal/research/embed/embed.go

@@ -0,0 +1,105 @@
+package embed
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"math"
+	"net/http"
+	"time"
+)
+
+type EmbedClient struct {
+	baseURL string
+	client  *http.Client
+	model   string
+}
+
+type EmbedRequest struct {
+	Model string   `json:"model"`
+	Input []string `json:"input"`
+}
+
+type EmbedResponse struct {
+	Data []struct {
+		Embedding []float32 `json:"embedding"`
+	} `json:"data"`
+}
+
+func NewEmbedClient(baseURL string) *EmbedClient {
+	return &EmbedClient{
+		baseURL: baseURL,
+		client:  &http.Client{Timeout: 30 * time.Second},
+		model:   "intfloat/e5-small-v2",
+	}
+}
+
+func (c *EmbedClient) Embed(ctx context.Context, texts []string) ([][]float32, error) {
+	if len(texts) == 0 {
+		return [][]float32{}, nil
+	}
+	if len(texts) > 100 {
+		return nil, fmt.Errorf("batch too large: %d > 100", len(texts))
+	}
+
+	body := EmbedRequest{
+		Model: c.model,
+		Input: texts,
+	}
+	payload, err := json.Marshal(body)
+	if err != nil {
+		return nil, fmt.Errorf("marshal embed request: %w", err)
+	}
+
+	req, err := http.NewRequestWithContext(ctx, "POST", c.baseURL+"/v1/embeddings", bytes.NewReader(payload))
+	if err != nil {
+		return nil, fmt.Errorf("embed request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := c.client.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("embed call: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		bodyBytes, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("embed service returned %d: %s", resp.StatusCode, string(bodyBytes))
+	}
+
+	respBody, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return nil, fmt.Errorf("read embed response: %w", err)
+	}
+
+	var er EmbedResponse
+	if err := json.Unmarshal(respBody, &er); err != nil {
+		return nil, fmt.Errorf("parse embed response: %w", err)
+	}
+	if len(er.Data) != len(texts) {
+		return nil, fmt.Errorf("embed mismatch: expected %d embeddings, got %d", len(texts), len(er.Data))
+	}
+
+	result := make([][]float32, len(er.Data))
+	for i, d := range er.Data {
+		result[i] = d.Embedding
+	}
+	return result, nil
+}
+
+// CosineSimilarity вычисляет косинусную близость между двумя векторами
+func CosineSimilarity(a, b []float32) float32 {
+	var dot, normA, normB float64
+	for i := range a {
+		dot += float64(a[i]) * float64(b[i])
+		normA += float64(a[i]) * float64(a[i])
+		normB += float64(b[i]) * float64(b[i])
+	}
+	if normA == 0 || normB == 0 {
+		return 0
+	}
+	return float32(dot / (math.Sqrt(normA) * math.Sqrt(normB)))
+}