Refactor codebase, introduce relaymode package, update constants and improve consistency

- Refactor constant definitions and organization
- Clean up package level variables and functions
- Introduce new `relaymode` and `apitype` packages for constant definitions
- Refactor and simplify code in several packages including `openai`, `relay/channel/baidu`, `relay/util`, `relay/controller`, `relay/channeltype`
- Add helper functions in `relay/channeltype` package to convert channel type constants to corresponding API type constants
- Remove deprecated functions such as `ResponseText2Usage` from `relay/channel/openai/helper.go`
- Modify code in `relay/util/validation.go` and related files to use new `validator.ValidateTextRequest` function
- Rename `util` package to `relaymode` and update related imports in several packages

middleware/distributor.go

@@ -2,14 +2,16 @@ package middleware
 
 import (
 	"fmt"
-	"github.com/songquanpeng/one-api/common"
-	"github.com/songquanpeng/one-api/common/logger"
-	"github.com/songquanpeng/one-api/model"
 	"net/http"
 	"strconv"
 	"strings"
 
 	"github.com/gin-gonic/gin"
+	"github.com/songquanpeng/one-api/common/config"
+	"github.com/songquanpeng/one-api/common/logger"
+	"github.com/songquanpeng/one-api/model"
+	"github.com/songquanpeng/one-api/relay/billing/ratio"
+	"github.com/songquanpeng/one-api/relay/channeltype"
 )
 
 type ModelRequest struct {
@@ -35,42 +37,16 @@ func Distribute() func(c *gin.Context) {
 				abortWithMessage(c, http.StatusBadRequest, "无效的渠道 Id")
 				return
 			}
-			if channel.Status != common.ChannelStatusEnabled {
+			if channel.Status != model.ChannelStatusEnabled {
 				abortWithMessage(c, http.StatusForbidden, "该渠道已被禁用")
 				return
 			}
 		} else {
-			// Select a channel for the user
-			var modelRequest ModelRequest
-			err := common.UnmarshalBodyReusable(c, &modelRequest)
+			requestModel := c.GetString("request_model")
+			var err error
+			channel, err = model.CacheGetRandomSatisfiedChannel(userGroup, requestModel, false)
 			if err != nil {
-				abortWithMessage(c, http.StatusBadRequest, fmt.Sprintf("无效的请求: %+v", err))
-				return
-			}
-			if strings.HasPrefix(c.Request.URL.Path, "/v1/moderations") {
-				if modelRequest.Model == "" {
-					modelRequest.Model = "text-moderation-stable"
-				}
-			}
-			if strings.HasSuffix(c.Request.URL.Path, "embeddings") {
-				if modelRequest.Model == "" {
-					modelRequest.Model = c.Param("model")
-				}
-			}
-			if strings.HasPrefix(c.Request.URL.Path, "/v1/images/generations") {
-				if modelRequest.Model == "" {
-					modelRequest.Model = "dall-e-2"
-				}
-			}
-			if strings.HasPrefix(c.Request.URL.Path, "/v1/audio/transcriptions") || strings.HasPrefix(c.Request.URL.Path, "/v1/audio/translations") {
-				if modelRequest.Model == "" {
-					modelRequest.Model = "whisper-1"
-				}
-			}
-			requestModel = modelRequest.Model
-			channel, err = model.CacheGetRandomSatisfiedChannel(userGroup, modelRequest.Model, false)
-			if err != nil {
-				message := fmt.Sprintf("当前分组 %s 下对于模型 %s 无可用渠道", userGroup, modelRequest.Model)
+				message := fmt.Sprintf("当前分组 %s 下对于模型 %s 无可用渠道", userGroup, requestModel)
 				if channel != nil {
 					logger.SysError(fmt.Sprintf("渠道不存在：%d", channel.Id))
 					message = "数据库一致性已被破坏，请联系管理员"
@@ -85,17 +61,18 @@ func Distribute() func(c *gin.Context) {
 }
 
 func SetupContextForSelectedChannel(c *gin.Context, channel *model.Channel, modelName string) {
+	// one channel could relates to multiple groups,
+	// and each groud has individual ratio,
 	// set minimal group ratio as channel_ratio
 	var minimalRatio float64 = -1
 	for _, grp := range strings.Split(channel.Group, ",") {
-		v := common.GetGroupRatio(grp)
+		v := ratio.GetGroupRatio(grp)
 		if minimalRatio < 0 || v < minimalRatio {
 			minimalRatio = v
 		}
 	}
 	logger.Info(c.Request.Context(), fmt.Sprintf("set channel %s ratio to %f", channel.Name, minimalRatio))
 	c.Set("channel_ratio", minimalRatio)
-
 	c.Set("channel", channel.Type)
 	c.Set("channel_id", channel.Id)
 	c.Set("channel_name", channel.Name)
@@ -105,19 +82,19 @@ func SetupContextForSelectedChannel(c *gin.Context, channel *model.Channel, mode
 	c.Set("base_url", channel.GetBaseURL())
 	// this is for backward compatibility
 	switch channel.Type {
-	case common.ChannelTypeAzure:
-		c.Set(common.ConfigKeyAPIVersion, channel.Other)
-	case common.ChannelTypeXunfei:
-		c.Set(common.ConfigKeyAPIVersion, channel.Other)
-	case common.ChannelTypeGemini:
-		c.Set(common.ConfigKeyAPIVersion, channel.Other)
-	case common.ChannelTypeAIProxyLibrary:
-		c.Set(common.ConfigKeyLibraryID, channel.Other)
-	case common.ChannelTypeAli:
-		c.Set(common.ConfigKeyPlugin, channel.Other)
+	case channeltype.Azure:
+		c.Set(config.KeyAPIVersion, channel.Other)
+	case channeltype.Xunfei:
+		c.Set(config.KeyAPIVersion, channel.Other)
+	case channeltype.Gemini:
+		c.Set(config.KeyAPIVersion, channel.Other)
+	case channeltype.AIProxyLibrary:
+		c.Set(config.KeyLibraryID, channel.Other)
+	case channeltype.Ali:
+		c.Set(config.KeyPlugin, channel.Other)
 	}
 	cfg, _ := channel.LoadConfig()
 	for k, v := range cfg {
-		c.Set(common.ConfigKeyPrefix+k, v)
+		c.Set(config.KeyPrefix+k, v)
 	}
 }