feat(inference): 实现文生图与图片编辑 API 调用，新增管线与编辑 HTTP 端点，JWT 认证中间件

- inference.go: GenerateImages 改为 API 优先（callImageGenAPI），无 key 回退 mock；新增 EditImages/callImageEditAPI（multipart 上传编辑）；提取 parseImageResponse 共享响应解析 - handler/generate.go: POST /api/v1/generate 触发生成管线，返回 base64 图片 - handler/edit.go: POST /api/v1/images/edit 图片编辑端点 - mildware/auth.go: JWT Bearer token 认证中间件 - main.go: 路由拆分公开/认证组，generate 与 images/edit 需鉴权
2026-05-24 22:47:43 +08:00
parent 5e54591b1f
commit 0a9a923d55
5 changed files with 412 additions and 21 deletions
@@ -4,10 +4,18 @@ import (
 	"bytes"
 	"context"
 	"crypto/rand"
+	"encoding/base64"
+	"encoding/json"
 	"fmt"
 	"image"
 	"image/color"
 	"image/png"
+	"io"
+	"log"
+	"mime/multipart"
+	"net/http"
+	"strconv"
+	"strings"

 	"gen2d/internal/config"
 )
@@ -20,37 +28,201 @@ func InitImageGenConfig(cfg config.ImageGenConfig) {
 	imgCfg = cfg
 }

-// GenerateImages 调用 AI 推理 API 生成图片。
-// MVP 阶段返回 mock 占位图。
-func GenerateImages(ctx context.Context, prompt string, params AssetParams) ([]GeneratedImage, error) {
-	size := params.Resolution
-	if size <= 0 {
-		size = 64
-	}
+// ======================== 文生图 API 调用层 ========================

+// imageGenRequest OpenAI 兼容的文生图请求体。
+type imageGenRequest struct {
+	Model          string  `json:"model"`
+	Prompt         string  `json:"prompt"`
+	N              int     `json:"n,omitempty"`
+	Size           string  `json:"size,omitempty"`
+	ResponseFormat string  `json:"response_format,omitempty"`
+	Steps          int     `json:"steps,omitempty"`
+	CFGScale       float64 `json:"cfg_scale,omitempty"`
+}
+
+// imageGenResponse OpenAI 兼容的文生图响应体。
+type imageGenResponse struct {
+	Data []struct {
+		URL     string `json:"url"`
+		B64JSON string `json:"b64_json"`
+	} `json:"data"`
+}
+
+// GenerateImages 调用 AI 推理 API 生成图片，未配置 API key 时回退到 mock。
+func GenerateImages(ctx context.Context, prompt string, params AssetParams) ([]GeneratedImage, error) {
 	count := 1
 	if params.Frames.Directions > 0 && params.Frames.FramesPerDirection > 0 {
 		count = params.Frames.Directions * params.Frames.FramesPerDirection
 	}

-	images := make([]GeneratedImage, count)
-	for i := 0; i < count; i++ {
-		data, err := generateMockImage(size, i)
-		if err != nil {
-			return nil, fmt.Errorf("generate mock image %d: %w", i, err)
+	if imgCfg.APIKey != "" {
+		return callImageGenAPI(ctx, prompt, count)
+	}
+
+	size := params.Resolution
+	if size <= 0 {
+		size = 64
+	}
+	log.Println("[inference] ImageGen API key not configured, using mock")
+	return generateMockImages(size, count)
+}
+
+// callImageGenAPI 调用 OpenAI 兼容的 Images API，返回生成的图片。
+func callImageGenAPI(ctx context.Context, prompt string, count int) ([]GeneratedImage, error) {
+	reqBody := imageGenRequest{
+		Model:          imgCfg.Model,
+		Prompt:         prompt,
+		N:              count,
+		Size:           fmt.Sprintf("%dx%d", imgCfg.Width, imgCfg.Height),
+		ResponseFormat: "b64_json",
+	}
+	if imgCfg.Steps > 0 {
+		reqBody.Steps = imgCfg.Steps
+	}
+	if imgCfg.CFGScale > 0 {
+		reqBody.CFGScale = imgCfg.CFGScale
+	}
+
+	body, err := json.Marshal(reqBody)
+	if err != nil {
+		return nil, fmt.Errorf("marshal request: %w", err)
+	}
+
+	url := strings.TrimRight(imgCfg.BaseURL, "/")
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, bytes.NewReader(body))
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("Authorization", "Bearer "+imgCfg.APIKey)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("send request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return nil, fmt.Errorf("image gen api error %d: %s", resp.StatusCode, string(b))
+	}
+
+	return parseImageResponse(ctx, resp.Body)
+}
+
+// ======================== 图片编辑 API ========================
+
+// EditImages 调用图片编辑 API，基于已有图片和文本提示词生成修改后的图片。
+func EditImages(ctx context.Context, imageData []byte, prompt string, count int) ([]GeneratedImage, error) {
+	if imgCfg.APIKey == "" {
+		return nil, fmt.Errorf("image edit API key not configured")
+	}
+	return callImageEditAPI(ctx, imageData, prompt, count)
+}
+
+// callImageEditAPI 调用 OpenAI 兼容的 Images Edits API（multipart/form-data）。
+func callImageEditAPI(ctx context.Context, imageData []byte, prompt string, count int) ([]GeneratedImage, error) {
+	var buf bytes.Buffer
+	writer := multipart.NewWriter(&buf)
+
+	part, err := writer.CreateFormFile("image", "image.png")
+	if err != nil {
+		return nil, fmt.Errorf("create form file: %w", err)
+	}
+	if _, err := part.Write(imageData); err != nil {
+		return nil, fmt.Errorf("write image data: %w", err)
+	}
+
+	writer.WriteField("prompt", prompt)
+	writer.WriteField("model", imgCfg.Model)
+	writer.WriteField("n", strconv.Itoa(count))
+	writer.WriteField("size", fmt.Sprintf("%dx%d", imgCfg.Width, imgCfg.Height))
+	writer.WriteField("response_format", "b64_json")
+
+	if err := writer.Close(); err != nil {
+		return nil, fmt.Errorf("close multipart writer: %w", err)
+	}
+
+	url := strings.Replace(strings.TrimRight(imgCfg.BaseURL, "/"), "generations", "edits", 1)
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, url, &buf)
+	if err != nil {
+		return nil, fmt.Errorf("create request: %w", err)
+	}
+	req.Header.Set("Content-Type", writer.FormDataContentType())
+	req.Header.Set("Authorization", "Bearer "+imgCfg.APIKey)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("send request: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		b, _ := io.ReadAll(io.LimitReader(resp.Body, 4096))
+		return nil, fmt.Errorf("image edit api error %d: %s", resp.StatusCode, string(b))
+	}
+
+	return parseImageResponse(ctx, resp.Body)
+}
+
+// parseImageResponse 解析 OpenAI 兼容的图片生成/编辑响应体。
+func parseImageResponse(ctx context.Context, r io.Reader) ([]GeneratedImage, error) {
+	var genResp imageGenResponse
+	if err := json.NewDecoder(r).Decode(&genResp); err != nil {
+		return nil, fmt.Errorf("decode response: %w", err)
+	}
+
+	images := make([]GeneratedImage, 0, len(genResp.Data))
+	for i, d := range genResp.Data {
+		var data []byte
+		switch {
+		case d.B64JSON != "":
+			var err error
+			data, err = base64.StdEncoding.DecodeString(d.B64JSON)
+			if err != nil {
+				return nil, fmt.Errorf("decode base64 image %d: %w", i, err)
+			}
+		case d.URL != "":
+			var err error
+			data, err = downloadImage(ctx, d.URL)
+			if err != nil {
+				return nil, fmt.Errorf("download image %d: %w", i, err)
+			}
+		default:
+			return nil, fmt.Errorf("image %d: no data or url in response", i)
 		}
-		images[i] = GeneratedImage{
+		images = append(images, GeneratedImage{
 			Data:   data,
-			Width:  size,
-			Height: size,
+			Width:  imgCfg.Width,
+			Height: imgCfg.Height,
 			Format: "png",
-		}
+		})
 	}
 	return images, nil
 }

+// downloadImage 从 URL 下载图片数据。
+func downloadImage(ctx context.Context, url string) ([]byte, error) {
+	req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
+	if err != nil {
+		return nil, fmt.Errorf("create download request: %w", err)
+	}
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, fmt.Errorf("download: %w", err)
+	}
+	defer resp.Body.Close()
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("download status %d", resp.StatusCode)
+	}
+	return io.ReadAll(resp.Body)
+}
+
+// ======================== 质检 ========================
+
 // QualityChecker 质检函数，可替换用于测试。
-// 签名：(ctx, images, style) → (pass, reason, error)
 var QualityChecker = defaultCheckQuality

 // CheckQuality 调用当前 QualityChecker。
@@ -82,11 +254,30 @@ func AlwaysFailQualityChecker() func(context.Context, []GeneratedImage, map[stri
 	}
 }

-// generateMockImage 生成一张带随机色块的 PNG 占位图
+// ======================== Mock 回退 ========================
+
+// generateMockImages 批量生成 mock PNG 占位图。
+func generateMockImages(size, count int) ([]GeneratedImage, error) {
+	images := make([]GeneratedImage, count)
+	for i := 0; i < count; i++ {
+		data, err := generateMockImage(size, i)
+		if err != nil {
+			return nil, fmt.Errorf("generate mock image %d: %w", i, err)
+		}
+		images[i] = GeneratedImage{
+			Data:   data,
+			Width:  size,
+			Height: size,
+			Format: "png",
+		}
+	}
+	return images, nil
+}
+
+// generateMockImage 生成一张带随机色块的 PNG 占位图。
 func generateMockImage(size int, seed int) ([]byte, error) {
 	img := image.NewRGBA(image.Rect(0, 0, size, size))

-	// 用 seed 生成不同颜色
 	r := uint8((seed*47 + 13) % 256)
 	g := uint8((seed*83 + 37) % 256)
 	b := uint8((seed*61 + 71) % 256)
@@ -104,7 +295,7 @@ func generateMockImage(size int, seed int) ([]byte, error) {
 	return buf.Bytes(), nil
 }

-// generateRandomBytes 用于生成随机数据（备用）
+// generateRandomBytes 用于生成随机数据（备用）。
 func generateRandomBytes(n int) ([]byte, error) {
 	b := make([]byte, n)
 	_, err := rand.Read(b)