Feat Support tools and tools choice new fileds (#526)

* feat: support tools and tools choice new fileds

* fix: use value not pointers

chat.go

@@ -12,6 +12,7 @@ const (
 	ChatMessageRoleUser      = "user"
 	ChatMessageRoleAssistant = "assistant"
 	ChatMessageRoleFunction  = "function"
+	ChatMessageRoleTool      = "tool"
 )
 
 const chatCompletionsSuffix = "/chat/completions"
@@ -61,6 +62,12 @@ type ChatCompletionMessage struct {
 	Name string `json:"name,omitempty"`
 
 	FunctionCall *FunctionCall `json:"function_call,omitempty"`
+	ToolCalls    []ToolCall    `json:"tool_calls,omitempty"`
+}
+
+type ToolCall struct {
+	ID       string       `json:"id"`
+	Function FunctionCall `json:"function"`
 }
 
 type FunctionCall struct {
@@ -99,8 +106,33 @@ type ChatCompletionRequest struct {
 	// refs: https://platform.openai.com/docs/api-reference/chat/create#chat/create-logit_bias
 	LogitBias map[string]int `json:"logit_bias,omitempty"`
 	User      string         `json:"user,omitempty"`
+	// Deprecated: use Tools instead.
 	Functions []FunctionDefinition `json:"functions,omitempty"`
+	// Deprecated: use ToolChoice instead.
 	FunctionCall any    `json:"function_call,omitempty"`
+	Tools        []Tool `json:"tools,omitempty"`
+	// This can be either a string or an ToolChoice object.
+	ToolChoiche any `json:"tool_choice,omitempty"`
+}
+
+type ToolType string
+
+const (
+	ToolTypeFunction ToolType = "function"
+)
+
+type Tool struct {
+	Type     ToolType           `json:"type"`
+	Function FunctionDefinition `json:"function,omitempty"`
+}
+
+type ToolChoiche struct {
+	Type     ToolType     `json:"type"`
+	Function ToolFunction `json:"function,omitempty"`
+}
+
+type ToolFunction struct {
+	Name string `json:"name"`
 }
 
 type FunctionDefinition struct {
@@ -123,6 +155,7 @@ const (
 	FinishReasonStop          FinishReason = "stop"
 	FinishReasonLength        FinishReason = "length"
 	FinishReasonFunctionCall  FinishReason = "function_call"
+	FinishReasonToolCalls     FinishReason = "tool_calls"
 	FinishReasonContentFilter FinishReason = "content_filter"
 	FinishReasonNull          FinishReason = "null"
 )

chat_stream.go

@@ -9,6 +9,7 @@ type ChatCompletionStreamChoiceDelta struct {
 	Content      string        `json:"content,omitempty"`
 	Role         string        `json:"role,omitempty"`
 	FunctionCall *FunctionCall `json:"function_call,omitempty"`
+	ToolCalls    []ToolCall    `json:"tool_calls,omitempty"`
 }
 
 type ChatCompletionStreamChoice struct {