feat: 添加基础通道实现和请求处理逻辑

internal/channel/base_channel.go

@@ -0,0 +1,122 @@
+package channel
+
+import (
+	"bytes"
+	"compress/gzip"
+	"fmt"
+	"gpt-load/internal/models"
+	"gpt-load/internal/response"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"github.com/gin-gonic/gin"
+	"github.com/sirupsen/logrus"
+)
+
+// RequestModifier defines a function that can modify the upstream request,
+// for example, by adding authentication headers.
+type RequestModifier func(req *http.Request, apiKey *models.APIKey)
+
+// BaseChannel provides a foundation for specific channel implementations.
+type BaseChannel struct {
+	Name       string
+	BaseURL    *url.URL
+	HTTPClient *http.Client
+}
+
+// ProcessRequest handles the generic logic of creating, sending, and handling an upstream request.
+func (ch *BaseChannel) ProcessRequest(c *gin.Context, apiKey *models.APIKey, modifier RequestModifier) error {
+	// 1. Create the upstream request
+	req, err := ch.createUpstreamRequest(c, apiKey, modifier)
+	if err != nil {
+		response.Error(c, http.StatusInternalServerError, "Failed to create upstream request")
+		return fmt.Errorf("create upstream request failed: %w", err)
+	}
+
+	// 2. Send the request
+	resp, err := ch.HTTPClient.Do(req)
+	if err != nil {
+		response.Error(c, http.StatusServiceUnavailable, "Upstream service unavailable")
+		return fmt.Errorf("upstream request failed: %w", err)
+	}
+	defer resp.Body.Close()
+
+	// 3. Handle non-200 status codes
+	if resp.StatusCode != http.StatusOK {
+		errorMsg := ch.getErrorMessage(resp)
+		response.Error(c, resp.StatusCode, errorMsg)
+		return fmt.Errorf("upstream returned status %d: %s", resp.StatusCode, errorMsg)
+	}
+
+	// 4. Stream the successful response back to the client
+	for key, values := range resp.Header {
+		for _, value := range values {
+			c.Header(key, value)
+		}
+	}
+	c.Status(http.StatusOK)
+	_, err = io.Copy(c.Writer, resp.Body)
+	if err != nil {
+		logrus.Errorf("Failed to copy response body to client: %v", err)
+		return fmt.Errorf("copy response body failed: %w", err)
+	}
+
+	return nil
+}
+
+func (ch *BaseChannel) createUpstreamRequest(c *gin.Context, apiKey *models.APIKey, modifier RequestModifier) (*http.Request, error) {
+	targetURL := *ch.BaseURL
+	targetURL.Path = c.Param("path")
+
+	body, err := io.ReadAll(c.Request.Body)
+	if err != nil {
+		return nil, fmt.Errorf("failed to read request body: %w", err)
+	}
+	c.Request.Body = io.NopCloser(bytes.NewBuffer(body))
+
+	req, err := http.NewRequestWithContext(c.Request.Context(), c.Request.Method, targetURL.String(), bytes.NewBuffer(body))
+	if err != nil {
+		return nil, fmt.Errorf("failed to create new request: %w", err)
+	}
+
+	req.Header = c.Request.Header.Clone()
+	req.Host = ch.BaseURL.Host
+
+	// Apply the channel-specific modifications
+	if modifier != nil {
+		modifier(req, apiKey)
+	}
+
+	return req, nil
+}
+
+func (ch *BaseChannel) getErrorMessage(resp *http.Response) string {
+	bodyBytes, err := io.ReadAll(resp.Body)
+	if err != nil {
+		return fmt.Sprintf("HTTP %d (failed to read error body: %v)", resp.StatusCode, err)
+	}
+
+	var errorMessage string
+	if resp.Header.Get("Content-Encoding") == "gzip" {
+		reader, gErr := gzip.NewReader(bytes.NewReader(bodyBytes))
+		if gErr != nil {
+			return string(bodyBytes)
+		}
+		defer reader.Close()
+		uncompressedBytes, rErr := io.ReadAll(reader)
+		if rErr != nil {
+			return fmt.Sprintf("gzip read error: %v", rErr)
+		}
+		errorMessage = string(uncompressedBytes)
+	} else {
+		errorMessage = string(bodyBytes)
+	}
+
+	if strings.TrimSpace(errorMessage) == "" {
+		return fmt.Sprintf("HTTP %d: %s", resp.StatusCode, http.StatusText(resp.StatusCode))
+	}
+
+	return errorMessage
+}

internal/channel/channel.go

@@ -10,5 +10,5 @@ import (
 type ChannelProxy interface {
 	// Handle takes a context, an API key, and the original request,
 	// then forwards the request to the upstream service.
-	Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group)
+	Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group) error
 }

internal/channel/gemini_channel.go

@@ -1,55 +1,50 @@
 package channel
 
 import (
+	"encoding/json"
 	"fmt"
 	"gpt-load/internal/models"
 	"net/http"
-	"net/http/httputil"
 	"net/url"
 
 	"github.com/gin-gonic/gin"
-	"github.com/sirupsen/logrus"
 )
-
-const GeminiBaseURL = "https://generativelanguage.googleapis.com"
-
 type GeminiChannel struct {
-	BaseURL *url.URL
+	BaseChannel
+}
+
+type GeminiChannelConfig struct {
+	BaseURL string `json:"base_url"`
 }
 
 func NewGeminiChannel(group *models.Group) (*GeminiChannel, error) {
-	baseURL, err := url.Parse(GeminiBaseURL)
-	if err != nil {
-		return nil, err // Should not happen with a constant
+	var config GeminiChannelConfig
+	if err := json.Unmarshal([]byte(group.Config), &config); err != nil {
+		return nil, fmt.Errorf("failed to unmarshal channel config: %w", err)
 	}
-	return &GeminiChannel{BaseURL: baseURL}, nil
+	if config.BaseURL == "" {
+		return nil, fmt.Errorf("base_url is required for gemini channel")
+	}
+
+	baseURL, err := url.Parse(config.BaseURL)
+	if err != nil {
+		return nil, fmt.Errorf("failed to parse base_url: %w", err)
+	}
+
+	return &GeminiChannel{
+		BaseChannel: BaseChannel{
+			Name:       "gemini",
+			BaseURL:    baseURL,
+			HTTPClient: &http.Client{},
+		},
+	}, nil
 }
 
-func (ch *GeminiChannel) Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group) {
-	proxy := httputil.NewSingleHostReverseProxy(ch.BaseURL)
-
-	proxy.Director = func(req *http.Request) {
-		// Gemini API key is passed as a query parameter
-		originalPath := c.Param("path")
-		newPath := fmt.Sprintf("%s?key=%s", originalPath, apiKey.KeyValue)
-
-		req.URL.Scheme = ch.BaseURL.Scheme
-		req.URL.Host = ch.BaseURL.Host
-		req.URL.Path = newPath
-		req.Host = ch.BaseURL.Host
-		// Remove the Authorization header if it was passed by the client
-		req.Header.Del("Authorization")
+func (ch *GeminiChannel) Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group) error {
+	modifier := func(req *http.Request, key *models.APIKey) {
+		q := req.URL.Query()
+		q.Set("key", key.KeyValue)
+		req.URL.RawQuery = q.Encode()
 	}
-
-	proxy.ModifyResponse = func(resp *http.Response) error {
-		// Log the response, etc.
-		return nil
-	}
-
-	proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
-		logrus.Errorf("Proxy error to Gemini: %v", err)
-		// Handle error, maybe update key status
-	}
-
-	proxy.ServeHTTP(c.Writer, c.Request)
+	return ch.ProcessRequest(c, apiKey, modifier)
 }

internal/channel/openai_channel.go

@@ -2,17 +2,15 @@ package channel
 
 import (
 	"encoding/json"
+	"fmt"
 	"gpt-load/internal/models"
 	"net/http"
-	"net/http/httputil"
 	"net/url"
 
 	"github.com/gin-gonic/gin"
-	"github.com/sirupsen/logrus"
 )
-
 type OpenAIChannel struct {
-	BaseURL *url.URL
+	BaseChannel
 }
 
 type OpenAIChannelConfig struct {
@@ -22,34 +20,29 @@ type OpenAIChannelConfig struct {
 func NewOpenAIChannel(group *models.Group) (*OpenAIChannel, error) {
 	var config OpenAIChannelConfig
 	if err := json.Unmarshal([]byte(group.Config), &config); err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to unmarshal channel config: %w", err)
 	}
+	if config.BaseURL == "" {
+		return nil, fmt.Errorf("base_url is required for openai channel")
+	}
+
 	baseURL, err := url.Parse(config.BaseURL)
 	if err != nil {
-		return nil, err
+		return nil, fmt.Errorf("failed to parse base_url: %w", err)
 	}
-	return &OpenAIChannel{BaseURL: baseURL}, nil
+
+	return &OpenAIChannel{
+		BaseChannel: BaseChannel{
+			Name:       "openai",
+			BaseURL:    baseURL,
+			HTTPClient: &http.Client{},
+		},
+	}, nil
 }
 
-func (ch *OpenAIChannel) Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group) {
-	proxy := httputil.NewSingleHostReverseProxy(ch.BaseURL)
-	proxy.Director = func(req *http.Request) {
-		req.URL.Scheme = ch.BaseURL.Scheme
-		req.URL.Host = ch.BaseURL.Host
-		req.URL.Path = c.Param("path")
-		req.Host = ch.BaseURL.Host
-		req.Header.Set("Authorization", "Bearer "+apiKey.KeyValue)
+func (ch *OpenAIChannel) Handle(c *gin.Context, apiKey *models.APIKey, group *models.Group) error {
+	modifier := func(req *http.Request, key *models.APIKey) {
+		req.Header.Set("Authorization", "Bearer "+key.KeyValue)
 	}
-
-	proxy.ModifyResponse = func(resp *http.Response) error {
-		// Log the response, etc.
-		return nil
-	}
-
-	proxy.ErrorHandler = func(w http.ResponseWriter, r *http.Request, err error) {
-		logrus.Errorf("Proxy error: %v", err)
-		// Handle error, maybe update key status
-	}
-
-	proxy.ServeHTTP(c.Writer, c.Request)
+	return ch.ProcessRequest(c, apiKey, modifier)
 }