GenAI interface (#2790)

* genai interface

* x

* x

* text to speech

* Re-add events package (#2761)

* Re-add events package

* run redis as a dep

* remove redis events

* fix: data race on event subscriber

* fix: data race in tests

* fix: store errors

* fix: lint issues

* feat: default stream

* Update file.go

---------

Co-authored-by: Brian Ketelsen <bketelsen@gmail.com>

* .

* copilot couldn't make it compile so I did

* copilot couldn't make it compile so I did

* x

---------

Co-authored-by: Brian Ketelsen <bketelsen@gmail.com>

genai/gemini/gemini.go

@@ -0,0 +1,161 @@
+package gemini
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+	"os"
+
+	"go-micro.dev/v5/genai"
+)
+
+// gemini implements the GenAI interface using Google Gemini 2.5 API.
+type gemini struct {
+	options genai.Options
+}
+
+func New(opts ...genai.Option) genai.GenAI {
+	var options genai.Options
+	for _, o := range opts {
+		o(&options)
+	}
+	if options.APIKey == "" {
+		options.APIKey = os.Getenv("GEMINI_API_KEY")
+	}
+	return &gemini{options: options}
+}
+
+func (g *gemini) Generate(prompt string, opts ...genai.Option) (*genai.Result, error) {
+	options := g.options
+	for _, o := range opts {
+		o(&options)
+	}
+	ctx := context.Background()
+
+	res := &genai.Result{Prompt: prompt, Type: options.Type}
+
+	endpoint := options.Endpoint
+	if endpoint == "" {
+		endpoint = "https://generativelanguage.googleapis.com/v1beta/models/"
+	}
+
+	var url string
+	var body map[string]interface{}
+
+	// Determine model to use
+	var model string
+	switch options.Type {
+	case "image":
+		if options.Model != "" {
+			model = options.Model
+		} else {
+			model = "gemini-2.5-pro-vision"
+		}
+		url = endpoint + model + ":generateContent?key=" + options.APIKey
+		body = map[string]interface{}{
+			"contents": []map[string]interface{}{
+				{"parts": []map[string]string{{"text": prompt}}},
+			},
+		}
+	case "audio":
+		if options.Model != "" {
+			model = options.Model
+		} else {
+			model = "gemini-2.5-pro"
+		}
+		url = endpoint + model + ":generateContent?key=" + options.APIKey
+		body = map[string]interface{}{
+			"contents": []map[string]interface{}{
+				{"parts": []map[string]string{{"text": prompt}}},
+			},
+			"response_mime_type": "audio/wav",
+		}
+	case "text":
+		fallthrough
+	default:
+		if options.Model != "" {
+			model = options.Model
+		} else {
+			model = "gemini-2.5-pro"
+		}
+		url = endpoint + model + ":generateContent?key=" + options.APIKey
+		body = map[string]interface{}{
+			"contents": []map[string]interface{}{
+				{"parts": []map[string]string{{"text": prompt}}},
+			},
+		}
+	}
+
+	b, _ := json.Marshal(body)
+	req, err := http.NewRequestWithContext(ctx, "POST", url, bytes.NewReader(b))
+	if err != nil {
+		return nil, err
+	}
+	req.Header.Set("Content-Type", "application/json")
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if options.Type == "audio" {
+		var result struct {
+			Candidates []struct {
+				Content struct {
+					Parts []struct {
+						InlineData struct {
+							Data []byte `json:"data"`
+						} `json:"inline_data"`
+					} `json:"parts"`
+				} `json:"content"`
+			} `json:"candidates"`
+		}
+		if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+			return nil, err
+		}
+		if len(result.Candidates) == 0 || len(result.Candidates[0].Content.Parts) == 0 {
+			return nil, fmt.Errorf("no audio returned")
+		}
+		res.Data = result.Candidates[0].Content.Parts[0].InlineData.Data
+		return res, nil
+	}
+
+	var result struct {
+		Candidates []struct {
+			Content struct {
+				Parts []struct {
+					Text string `json:"text"`
+				} `json:"parts"`
+			} `json:"content"`
+		} `json:"candidates"`
+	}
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, err
+	}
+	if len(result.Candidates) == 0 || len(result.Candidates[0].Content.Parts) == 0 {
+		return nil, fmt.Errorf("no candidates returned")
+	}
+	res.Text = result.Candidates[0].Content.Parts[0].Text
+	return res, nil
+}
+
+func (g *gemini) Stream(prompt string, opts ...genai.Option) (*genai.Stream, error) {
+	results := make(chan *genai.Result)
+	go func() {
+		defer close(results)
+		res, err := g.Generate(prompt, opts...)
+		if err != nil {
+			// Send error via Stream.Err, not channel
+			return
+		}
+		results <- res
+	}()
+	return &genai.Stream{Results: results}, nil
+}
+
+func init() {
+	genai.Register("gemini", New())
+}