feat: add Google GenAI API

model/genai.go

@@ -0,0 +1,120 @@
+package model
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+)
+
+const (
+	ModelGemini15Flash = "models/gemini-1.5-flash"
+)
+
+type Text struct {
+	Text string `json:"text"`
+}
+
+type Content struct {
+	Parts []Text `json:"parts"`
+	Role  string `json:"role,omitempty"`
+}
+
+func (c *Content) String() string {
+	sb := strings.Builder{}
+	for _, p := range c.Parts {
+		sb.WriteString(p.Text)
+	}
+	return sb.String()
+}
+
+type Candidate struct {
+	Content      Content `json:"content"`
+	FinishReason string  `json:"finishReason"`
+	Index        int     `json:"index"`
+}
+
+// GenAI is Goole API format
+type GenAI struct {
+	model    string `json:"-"`
+	Protocol `json:"-"`
+	// request only
+	Contents          []Content `json:"contents,omitempty"`
+	SystemInstruction *Content  `json:"systemInstruction,omitempty"`
+	GenerationConfig  struct {
+		Temperature      float32 `json:"temperature,omitempty"`
+		ResponseMimeType string  `json:"responseMimeType,omitempty"`
+		TopP             float32 `json:"topP,omitempty"`
+		MaxOutputTokens  int     `json:"maxOutputTokens,omitempty"`
+	} `json:"generationConfig"`
+	// callback only
+	Candidates []Candidate `json:"candidates,omitempty"`
+}
+
+// NewGenAI use temp 0.7, topp 0.9, maxn 4096 if you don't know the meaning.
+func NewGenAI(model string, temp, topp float32, maxn uint) *GenAI {
+	opai := new(GenAI)
+	opai.model = model
+	opai.GenerationConfig.Temperature = temp
+	opai.GenerationConfig.ResponseMimeType = "text/plain"
+	opai.GenerationConfig.TopP = topp
+	opai.GenerationConfig.MaxOutputTokens = int(maxn)
+	return opai
+}
+
+func (opai *GenAI) API(api, key string) string {
+	return fmt.Sprintf("%s/%s:generateContent?key=%s", api, opai.model, key)
+}
+
+func (*GenAI) Header(_ string, h http.Header) {
+	h.Add("Content-Type", "application/json")
+}
+
+func (opai *GenAI) Body() *bytes.Buffer {
+	w := bytes.NewBuffer(make([]byte, 0, 8192))
+	err := json.NewEncoder(w).Encode(opai)
+	if err != nil {
+		panic(err)
+	}
+	return w
+}
+
+func (opai *GenAI) Parse(body io.Reader) error {
+	return json.NewDecoder(body).Decode(&opai)
+}
+
+func (opai *GenAI) Output() string {
+	if len(opai.Candidates) == 0 {
+		return ""
+	}
+	return opai.Candidates[0].Content.String()
+}
+
+func (opai *GenAI) OutputRaw() string {
+	return opai.Output()
+}
+
+func (opai *GenAI) System(prompt string) Protocol {
+	opai.SystemInstruction = &Content{
+		Parts: []Text{{prompt}},
+	}
+	return opai
+}
+
+func (opai *GenAI) User(prompt string) Protocol {
+	opai.Contents = append(opai.Contents, Content{
+		Parts: []Text{{prompt}},
+		Role:  "user",
+	})
+	return opai
+}
+
+func (opai *GenAI) Assistant(prompt string) Protocol {
+	opai.Contents = append(opai.Contents, Content{
+		Parts: []Text{{prompt}},
+		Role:  "model",
+	})
+	return opai
+}