feat(chat): 完善 Chat Completions 兼容层

apps/api/internal/clients/gemini.go

@@ -70,15 +70,185 @@ func geminiBody(request Request) map[string]any {
 		return map[string]any{"contents": contents}
 	}
 	prompt := firstNonEmptyPrompt(request.Body, "")
-	if prompt == "" {
-		prompt = textFromMessages(request.Body)
+	if prompt != "" {
+		return map[string]any{
+			"contents": []any{map[string]any{
+				"role":  "user",
+				"parts": []any{map[string]any{"text": prompt}},
+			}},
+		}
 	}
-	return map[string]any{
-		"contents": []any{map[string]any{
-			"role":  "user",
-			"parts": []any{map[string]any{"text": prompt}},
-		}},
+	body := map[string]any{"contents": geminiContentsFromMessages(request.Body)}
+	if tools := geminiToolsFromOpenAITools(request.Body["tools"]); len(tools) > 0 {
+		body["tools"] = tools
 	}
+	contents, _ := body["contents"].([]any)
+	if len(contents) > 0 {
+		return body
+	}
+	return map[string]any{"contents": []any{map[string]any{
+		"role":  "user",
+		"parts": []any{map[string]any{"text": textFromMessages(request.Body)}},
+	}}}
+}
+
+func geminiContentsFromMessages(body map[string]any) []any {
+	normalized := NormalizeChatCompletionRequestBody(body)
+	messages, _ := normalized["messages"].([]any)
+	contents := make([]any, 0, len(messages))
+	toolNames := map[string]string{}
+	for _, rawMessage := range messages {
+		message, _ := rawMessage.(map[string]any)
+		if len(message) == 0 {
+			continue
+		}
+		role := stringFromAny(message["role"])
+		if role == "tool" {
+			toolCallID := stringFromAny(message["tool_call_id"])
+			name := toolNames[toolCallID]
+			if name == "" {
+				name = toolCallID
+			}
+			if name == "" {
+				name = "tool"
+			}
+			contents = append(contents, map[string]any{
+				"role": "user",
+				"parts": []any{map[string]any{"functionResponse": map[string]any{
+					"name":     name,
+					"response": geminiFunctionResponsePayload(message["content"]),
+				}}},
+			})
+			continue
+		}
+		parts := geminiTextParts(message["content"])
+		if role == "assistant" {
+			for _, rawToolCall := range toolCallsSlice(message["tool_calls"]) {
+				toolCall, _ := rawToolCall.(map[string]any)
+				function, _ := toolCall["function"].(map[string]any)
+				name := stringFromAny(function["name"])
+				if name == "" {
+					continue
+				}
+				if id := stringFromAny(toolCall["id"]); id != "" {
+					toolNames[id] = name
+				}
+				parts = append(parts, map[string]any{"functionCall": map[string]any{
+					"name": name,
+					"args": geminiFunctionArgs(function["arguments"]),
+				}})
+			}
+		}
+		if len(parts) == 0 {
+			continue
+		}
+		contents = append(contents, map[string]any{
+			"role":  geminiRole(role),
+			"parts": parts,
+		})
+	}
+	return contents
+}
+
+func geminiRole(role string) string {
+	if role == "assistant" {
+		return "model"
+	}
+	return "user"
+}
+
+func geminiTextParts(content any) []any {
+	parts := make([]any, 0)
+	switch typed := content.(type) {
+	case string:
+		if strings.TrimSpace(typed) != "" {
+			parts = append(parts, map[string]any{"text": typed})
+		}
+	case []any:
+		for _, rawPart := range typed {
+			part, _ := rawPart.(map[string]any)
+			if text := stringFromAny(firstPresent(part["text"], part["content"])); strings.TrimSpace(text) != "" {
+				parts = append(parts, map[string]any{"text": text})
+			}
+		}
+	}
+	return parts
+}
+
+func toolCallsSlice(value any) []any {
+	switch typed := value.(type) {
+	case []any:
+		return typed
+	case map[string]any:
+		return []any{typed}
+	default:
+		return nil
+	}
+}
+
+func geminiFunctionArgs(value any) map[string]any {
+	if value == nil {
+		return map[string]any{}
+	}
+	if args, ok := value.(map[string]any); ok {
+		return args
+	}
+	if text, ok := value.(string); ok {
+		if strings.TrimSpace(text) == "" {
+			return map[string]any{}
+		}
+		var args map[string]any
+		if err := json.Unmarshal([]byte(text), &args); err == nil {
+			return args
+		}
+		return map[string]any{"arguments": text}
+	}
+	return map[string]any{"arguments": value}
+}
+
+func geminiFunctionResponsePayload(value any) map[string]any {
+	if payload, ok := value.(map[string]any); ok {
+		return payload
+	}
+	if text, ok := value.(string); ok {
+		var payload map[string]any
+		if err := json.Unmarshal([]byte(text), &payload); err == nil {
+			return payload
+		}
+		return map[string]any{"content": text}
+	}
+	if value == nil {
+		return map[string]any{}
+	}
+	return map[string]any{"content": value}
+}
+
+func geminiToolsFromOpenAITools(value any) []any {
+	tools, ok := value.([]any)
+	if !ok || len(tools) == 0 {
+		return nil
+	}
+	declarations := make([]any, 0, len(tools))
+	for _, rawTool := range tools {
+		tool, _ := rawTool.(map[string]any)
+		function, _ := tool["function"].(map[string]any)
+		name := stringFromAny(function["name"])
+		if name == "" {
+			continue
+		}
+		declaration := map[string]any{"name": name}
+		if description := stringFromAny(function["description"]); description != "" {
+			declaration["description"] = description
+		}
+		if parameters, ok := function["parameters"]; ok {
+			declaration["parameters"] = parameters
+		}
+		declarations = append(declarations, declaration)
+	}
+	if len(declarations) == 0 {
+		return nil
+	}
+	return []any{map[string]any{"functionDeclarations": declarations}}
 }
 
 func geminiResult(request Request, raw map[string]any) map[string]any {