feat: Refactor message handling and update dependencies

- Added required packages to go.mod: `github.com/Laisky/errors/v2 v2.0.1`, `github.com/stretchr/testify v1.8.3`, `github.com/davecgh/go-spew v1.1.1`, `github.com/pmezard/go-difflib v1.0.0`
- Increased the number of returned recordings to 100 in `relay-utils.go`
- Refactored and simplified code in `relay-aiproxy.go` for improved message retrieval and error handling
- Added new test file `relay_test.go` and various test cases for different message types
- Modified functions in `group.go` and `relay.go` for improved functionality

controller/relay.go

@@ -1,13 +1,14 @@
 package controller
 
 import (
-	"errors"
+	"encoding/json"
 	"fmt"
 	"net/http"
 	"one-api/common"
 	"strconv"
 	"strings"
 
+	"github.com/Laisky/errors/v2"
 	"github.com/gin-gonic/gin"
 )
 
@@ -92,6 +93,8 @@ func (r *GeneralOpenAIRequest) MessagesLen() int {
 		return len(msgs)
 	case []VisionMessage:
 		return len(msgs)
+	case []map[string]any:
+		return len(msgs)
 	default:
 		return 0
 	}
@@ -99,46 +102,24 @@ func (r *GeneralOpenAIRequest) MessagesLen() int {
 
 // TextMessages returns messages as []Message
 func (r *GeneralOpenAIRequest) TextMessages() (messages []Message, err error) {
-	switch msgs := r.Messages.(type) {
-	case []any:
-		messages = make([]Message, 0, len(msgs))
-		for _, msg := range msgs {
-			if m, ok := msg.(Message); ok {
-				messages = append(messages, m)
-			} else {
-				err = fmt.Errorf("invalid message type")
-				return
-			}
-		}
-	case []Message:
-		messages = msgs
-	default:
-		return nil, errors.New("invalid message type")
+	if blob, err := json.Marshal(r.Messages); err != nil {
+		return nil, errors.Wrap(err, "marshal messages failed")
+	} else if err := json.Unmarshal(blob, &messages); err != nil {
+		return nil, errors.Wrap(err, "unmarshal messages failed")
+	} else {
+		return messages, nil
 	}
-
-	return
 }
 
 // VisionMessages returns messages as []VisionMessage
 func (r *GeneralOpenAIRequest) VisionMessages() (messages []VisionMessage, err error) {
-	switch msgs := r.Messages.(type) {
-	case []any:
-		messages = make([]VisionMessage, 0, len(msgs))
-		for _, msg := range msgs {
-			if m, ok := msg.(VisionMessage); ok {
-				messages = append(messages, m)
-			} else {
-				err = fmt.Errorf("invalid message type")
-				return
-			}
-		}
-	case []VisionMessage:
-		messages = msgs
-	default:
-		return nil, errors.New("invalid message type")
+	if blob, err := json.Marshal(r.Messages); err != nil {
+		return nil, errors.Wrap(err, "marshal vision messages failed")
+	} else if err := json.Unmarshal(blob, &messages); err != nil {
+		return nil, errors.Wrap(err, "unmarshal vision messages failed")
+	} else {
+		return messages, nil
 	}
-
-	return
 }
 
 func (r GeneralOpenAIRequest) ParseInput() []string {