rebuild branch

internal/api/handlers/claude/code_handlers.go

@@ -0,0 +1,237 @@
+// Package claude provides HTTP handlers for Claude API code-related functionality.
+// This package implements Claude-compatible streaming chat completions with sophisticated
+// client rotation and quota management systems to ensure high availability and optimal
+// resource utilization across multiple backend clients. It handles request translation
+// between Claude API format and the underlying Gemini backend, providing seamless
+// API compatibility while maintaining robust error handling and connection management.
+package claude
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/gin-gonic/gin"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/api/handlers"
+	. "github.com/router-for-me/CLIProxyAPI/v6/internal/constant"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/interfaces"
+	"github.com/router-for-me/CLIProxyAPI/v6/internal/registry"
+	"github.com/tidwall/gjson"
+)
+
+// ClaudeCodeAPIHandler contains the handlers for Claude API endpoints.
+// It holds a pool of clients to interact with the backend service.
+type ClaudeCodeAPIHandler struct {
+	*handlers.BaseAPIHandler
+}
+
+// NewClaudeCodeAPIHandler creates a new Claude API handlers instance.
+// It takes an BaseAPIHandler instance as input and returns a ClaudeCodeAPIHandler.
+//
+// Parameters:
+//   - apiHandlers: The base API handler instance.
+//
+// Returns:
+//   - *ClaudeCodeAPIHandler: A new Claude code API handler instance.
+func NewClaudeCodeAPIHandler(apiHandlers *handlers.BaseAPIHandler) *ClaudeCodeAPIHandler {
+	return &ClaudeCodeAPIHandler{
+		BaseAPIHandler: apiHandlers,
+	}
+}
+
+// HandlerType returns the identifier for this handler implementation.
+func (h *ClaudeCodeAPIHandler) HandlerType() string {
+	return Claude
+}
+
+// Models returns a list of models supported by this handler.
+func (h *ClaudeCodeAPIHandler) Models() []map[string]any {
+	// Get dynamic models from the global registry
+	modelRegistry := registry.GetGlobalRegistry()
+	return modelRegistry.GetAvailableModels("claude")
+}
+
+// ClaudeMessages handles Claude-compatible streaming chat completions.
+// This function implements a sophisticated client rotation and quota management system
+// to ensure high availability and optimal resource utilization across multiple backend clients.
+//
+// Parameters:
+//   - c: The Gin context for the request.
+func (h *ClaudeCodeAPIHandler) ClaudeMessages(c *gin.Context) {
+	// Extract raw JSON data from the incoming request
+	rawJSON, err := c.GetRawData()
+	// If data retrieval fails, return a 400 Bad Request error.
+	if err != nil {
+		c.JSON(http.StatusBadRequest, handlers.ErrorResponse{
+			Error: handlers.ErrorDetail{
+				Message: fmt.Sprintf("Invalid request: %v", err),
+				Type:    "invalid_request_error",
+			},
+		})
+		return
+	}
+
+	// Check if the client requested a streaming response.
+	streamResult := gjson.GetBytes(rawJSON, "stream")
+	if !streamResult.Exists() || streamResult.Type == gjson.False {
+		h.handleNonStreamingResponse(c, rawJSON)
+	} else {
+		h.handleStreamingResponse(c, rawJSON)
+	}
+}
+
+// ClaudeMessages handles Claude-compatible streaming chat completions.
+// This function implements a sophisticated client rotation and quota management system
+// to ensure high availability and optimal resource utilization across multiple backend clients.
+//
+// Parameters:
+//   - c: The Gin context for the request.
+func (h *ClaudeCodeAPIHandler) ClaudeCountTokens(c *gin.Context) {
+	// Extract raw JSON data from the incoming request
+	rawJSON, err := c.GetRawData()
+	// If data retrieval fails, return a 400 Bad Request error.
+	if err != nil {
+		c.JSON(http.StatusBadRequest, handlers.ErrorResponse{
+			Error: handlers.ErrorDetail{
+				Message: fmt.Sprintf("Invalid request: %v", err),
+				Type:    "invalid_request_error",
+			},
+		})
+		return
+	}
+
+	c.Header("Content-Type", "application/json")
+
+	alt := h.GetAlt(c)
+	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+
+	modelName := gjson.GetBytes(rawJSON, "model").String()
+
+	resp, errMsg := h.ExecuteCountWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, alt)
+	if errMsg != nil {
+		h.WriteErrorResponse(c, errMsg)
+		cliCancel(errMsg.Error)
+		return
+	}
+	_, _ = c.Writer.Write(resp)
+	cliCancel()
+}
+
+// ClaudeModels handles the Claude models listing endpoint.
+// It returns a JSON response containing available Claude models and their specifications.
+//
+// Parameters:
+//   - c: The Gin context for the request.
+func (h *ClaudeCodeAPIHandler) ClaudeModels(c *gin.Context) {
+	c.JSON(http.StatusOK, gin.H{
+		"data": h.Models(),
+	})
+}
+
+// handleNonStreamingResponse handles non-streaming content generation requests for Claude models.
+// This function processes the request synchronously and returns the complete generated
+// response in a single API call. It supports various generation parameters and
+// response formats.
+//
+// Parameters:
+//   - c: The Gin context for the request
+//   - modelName: The name of the Gemini model to use for content generation
+//   - rawJSON: The raw JSON request body containing generation parameters and content
+func (h *ClaudeCodeAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSON []byte) {
+	c.Header("Content-Type", "application/json")
+	alt := h.GetAlt(c)
+	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+
+	modelName := gjson.GetBytes(rawJSON, "model").String()
+
+	resp, errMsg := h.ExecuteWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, alt)
+	if errMsg != nil {
+		h.WriteErrorResponse(c, errMsg)
+		cliCancel(errMsg.Error)
+		return
+	}
+	_, _ = c.Writer.Write(resp)
+	cliCancel()
+}
+
+// handleStreamingResponse streams Claude-compatible responses backed by Gemini.
+// It sets up SSE, selects a backend client with rotation/quota logic,
+// forwards chunks, and translates them to Claude CLI format.
+//
+// Parameters:
+//   - c: The Gin context for the request.
+//   - rawJSON: The raw JSON request body.
+func (h *ClaudeCodeAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON []byte) {
+	// Set up Server-Sent Events (SSE) headers for streaming response
+	// These headers are essential for maintaining a persistent connection
+	// and enabling real-time streaming of chat completions
+	c.Header("Content-Type", "text/event-stream")
+	c.Header("Cache-Control", "no-cache")
+	c.Header("Connection", "keep-alive")
+	c.Header("Access-Control-Allow-Origin", "*")
+
+	// Get the http.Flusher interface to manually flush the response.
+	// This is crucial for streaming as it allows immediate sending of data chunks
+	flusher, ok := c.Writer.(http.Flusher)
+	if !ok {
+		c.JSON(http.StatusInternalServerError, handlers.ErrorResponse{
+			Error: handlers.ErrorDetail{
+				Message: "Streaming not supported",
+				Type:    "server_error",
+			},
+		})
+		return
+	}
+
+	modelName := gjson.GetBytes(rawJSON, "model").String()
+
+	// Create a cancellable context for the backend client request
+	// This allows proper cleanup and cancellation of ongoing requests
+	cliCtx, cliCancel := h.GetContextWithCancel(h, c, context.Background())
+
+	dataChan, errChan := h.ExecuteStreamWithAuthManager(cliCtx, h.HandlerType(), modelName, rawJSON, "")
+	h.forwardClaudeStream(c, flusher, func(err error) { cliCancel(err) }, dataChan, errChan)
+	return
+}
+
+func (h *ClaudeCodeAPIHandler) forwardClaudeStream(c *gin.Context, flusher http.Flusher, cancel func(error), data <-chan []byte, errs <-chan *interfaces.ErrorMessage) {
+	for {
+		select {
+		case <-c.Request.Context().Done():
+			cancel(c.Request.Context().Err())
+			return
+		case chunk, ok := <-data:
+			if !ok {
+				flusher.Flush()
+				cancel(nil)
+				return
+			}
+
+			if bytes.HasPrefix(chunk, []byte("event:")) {
+				_, _ = c.Writer.Write([]byte("\n"))
+			}
+
+			_, _ = c.Writer.Write(chunk)
+			_, _ = c.Writer.Write([]byte("\n"))
+
+			flusher.Flush()
+		case errMsg, ok := <-errs:
+			if !ok {
+				continue
+			}
+			if errMsg != nil {
+				h.WriteErrorResponse(c, errMsg)
+				flusher.Flush()
+			}
+			var execErr error
+			if errMsg != nil {
+				execErr = errMsg.Error
+			}
+			cancel(execErr)
+			return
+		case <-time.After(500 * time.Millisecond):
+		}
+	}
+}