feat(sync): full code sync from release

backend/internal/service/sora_upstream_forwarder.go

@@ -0,0 +1,149 @@
+package service
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+	"time"
+
+	"github.com/Wei-Shaw/sub2api/internal/pkg/logger"
+	"github.com/gin-gonic/gin"
+)
+
+// forwardToUpstream 将请求 HTTP 透传到上游 Sora 服务（用于 apikey 类型账号）。
+// 上游地址为 account.GetBaseURL() + "/sora/v1/chat/completions"，
+// 使用 account.GetCredential("api_key") 作为 Bearer Token。
+// 支持流式和非流式响应的直接透传。
+func (s *SoraGatewayService) forwardToUpstream(
+	ctx context.Context,
+	c *gin.Context,
+	account *Account,
+	body []byte,
+	clientStream bool,
+	startTime time.Time,
+) (*ForwardResult, error) {
+	apiKey := account.GetCredential("api_key")
+	if apiKey == "" {
+		s.writeSoraError(c, http.StatusBadGateway, "upstream_error", "Sora apikey account missing api_key credential", clientStream)
+		return nil, fmt.Errorf("sora apikey account %d missing api_key", account.ID)
+	}
+
+	baseURL := account.GetBaseURL()
+	if baseURL == "" {
+		s.writeSoraError(c, http.StatusBadGateway, "upstream_error", "Sora apikey account missing base_url", clientStream)
+		return nil, fmt.Errorf("sora apikey account %d missing base_url", account.ID)
+	}
+	// 校验 scheme 合法性（仅允许 http/https）
+	if !strings.HasPrefix(baseURL, "http://") && !strings.HasPrefix(baseURL, "https://") {
+		s.writeSoraError(c, http.StatusBadGateway, "upstream_error", "Sora apikey base_url must start with http:// or https://", clientStream)
+		return nil, fmt.Errorf("sora apikey account %d invalid base_url scheme: %s", account.ID, baseURL)
+	}
+	upstreamURL := strings.TrimRight(baseURL, "/") + "/sora/v1/chat/completions"
+
+	// 构建上游请求
+	upstreamReq, err := http.NewRequestWithContext(ctx, http.MethodPost, upstreamURL, bytes.NewReader(body))
+	if err != nil {
+		s.writeSoraError(c, http.StatusInternalServerError, "api_error", "Failed to create upstream request", clientStream)
+		return nil, fmt.Errorf("create upstream request: %w", err)
+	}
+
+	upstreamReq.Header.Set("Content-Type", "application/json")
+	upstreamReq.Header.Set("Authorization", "Bearer "+apiKey)
+
+	// 透传客户端的部分请求头
+	for _, header := range []string{"Accept", "Accept-Encoding"} {
+		if v := c.GetHeader(header); v != "" {
+			upstreamReq.Header.Set(header, v)
+		}
+	}
+
+	logger.LegacyPrintf("service.sora", "[ForwardUpstream] account=%d url=%s", account.ID, upstreamURL)
+
+	// 获取代理 URL
+	proxyURL := ""
+	if account.ProxyID != nil && account.Proxy != nil {
+		proxyURL = account.Proxy.URL()
+	}
+
+	// 发送请求
+	resp, err := s.httpUpstream.Do(upstreamReq, proxyURL, account.ID, account.Concurrency)
+	if err != nil {
+		s.writeSoraError(c, http.StatusBadGateway, "upstream_error", "Failed to connect to upstream Sora service", clientStream)
+		return nil, &UpstreamFailoverError{
+			StatusCode: http.StatusBadGateway,
+		}
+	}
+	defer func() {
+		_ = resp.Body.Close()
+	}()
+
+	// 错误响应处理
+	if resp.StatusCode >= 400 {
+		respBody, _ := io.ReadAll(io.LimitReader(resp.Body, 64*1024))
+
+		if s.shouldFailoverUpstreamError(resp.StatusCode) {
+			return nil, &UpstreamFailoverError{
+				StatusCode:      resp.StatusCode,
+				ResponseBody:    respBody,
+				ResponseHeaders: resp.Header.Clone(),
+			}
+		}
+
+		// 非转移错误，直接透传给客户端
+		c.Status(resp.StatusCode)
+		for key, values := range resp.Header {
+			for _, v := range values {
+				c.Writer.Header().Add(key, v)
+			}
+		}
+		if _, err := c.Writer.Write(respBody); err != nil {
+			return nil, fmt.Errorf("write upstream error response: %w", err)
+		}
+		return nil, fmt.Errorf("upstream error: %d", resp.StatusCode)
+	}
+
+	// 成功响应 — 直接透传
+	c.Status(resp.StatusCode)
+	for key, values := range resp.Header {
+		lower := strings.ToLower(key)
+		// 透传内容相关头部
+		if lower == "content-type" || lower == "transfer-encoding" ||
+			lower == "cache-control" || lower == "x-request-id" {
+			for _, v := range values {
+				c.Writer.Header().Add(key, v)
+			}
+		}
+	}
+
+	// 流式复制响应体
+	if flusher, ok := c.Writer.(http.Flusher); ok && clientStream {
+		buf := make([]byte, 4096)
+		for {
+			n, readErr := resp.Body.Read(buf)
+			if n > 0 {
+				if _, err := c.Writer.Write(buf[:n]); err != nil {
+					return nil, fmt.Errorf("stream upstream response write: %w", err)
+				}
+				flusher.Flush()
+			}
+			if readErr != nil {
+				break
+			}
+		}
+	} else {
+		if _, err := io.Copy(c.Writer, resp.Body); err != nil {
+			return nil, fmt.Errorf("copy upstream response: %w", err)
+		}
+	}
+
+	duration := time.Since(startTime)
+	return &ForwardResult{
+		RequestID: resp.Header.Get("x-request-id"),
+		Model:     "", // 由调用方填充
+		Stream:    clientStream,
+		Duration:  duration,
+	}, nil
+}