refactor: refactor MCP tool registration and pagination handling (#86)

- Add documentation for MCP tool constants and tool registration
- Use configurable default values for pagination arguments in user organization queries
- Introduce registerTools helper to streamline MCP tool registration
- Refactor pagination argument parsing into a reusable getIntArg function
- Add descriptive logging for tool handler execution
- Improve code organization for defining and registering MCP tools

Signed-off-by: appleboy <appleboy.tw@gmail.com>

Reviewed-on: https://gitea.com/gitea/gitea-mcp/pulls/86
Co-authored-by: appleboy <appleboy.tw@gmail.com>
Co-committed-by: appleboy <appleboy.tw@gmail.com>

operation/user/user.go

@@ -15,68 +15,94 @@ import (
 )
 
 const (
+	// GetMyUserInfoToolName is the unique tool name used for MCP registration and lookup of the get_my_user_info command.
 	GetMyUserInfoToolName = "get_my_user_info"
-	GetUserOrgsToolName   = "get_user_orgs"
+	// GetUserOrgsToolName is the unique tool name used for MCP registration and lookup of the get_user_orgs command.
+	GetUserOrgsToolName = "get_user_orgs"
+
+	// defaultPage is the default starting page number used for paginated organization listings.
+	defaultPage = 1
+	// defaultPageSize is the default number of organizations per page for paginated queries.
+	defaultPageSize = 100
 )
 
+// Tool is the MCP tool manager instance for registering all MCP tools in this package.
 var Tool = tool.New()
 
 var (
+	// GetMyUserInfoTool is the MCP tool for retrieving the current user's info.
+	// It is registered with a specific name and a description string.
 	GetMyUserInfoTool = mcp.NewTool(
 		GetMyUserInfoToolName,
 		mcp.WithDescription("Get my user info"),
 	)
 
+	// GetUserOrgsTool is the MCP tool for listing organizations for the authenticated user.
+	// It supports pagination via "page" and "pageSize" arguments with default values specified above.
 	GetUserOrgsTool = mcp.NewTool(
 		GetUserOrgsToolName,
 		mcp.WithDescription("Get organizations associated with the authenticated user"),
-		mcp.WithNumber("page", mcp.Description("page number"), mcp.DefaultNumber(1)),
-		mcp.WithNumber("pageSize", mcp.Description("page size"), mcp.DefaultNumber(100)),
+		mcp.WithNumber("page", mcp.Description("page number"), mcp.DefaultNumber(defaultPage)),
+		mcp.WithNumber("pageSize", mcp.Description("page size"), mcp.DefaultNumber(defaultPageSize)),
 	)
 )
 
+// init registers all MCP tools in Tool at package initialization.
+// This function ensures the handler functions are registered before server usage.
 func init() {
-	Tool.RegisterRead(server.ServerTool{
-		Tool:    GetMyUserInfoTool,
-		Handler: GetUserInfoFn,
-	})
-
-	Tool.RegisterRead(server.ServerTool{
-		Tool:    GetUserOrgsTool,
-		Handler: GetUserOrgsFn,
-	})
+	registerTools()
 }
 
+// registerTools registers all local MCP tool definitions and their handler functions.
+// To add new functionality, append your tool/handler pair to the tools slice below.
+func registerTools() {
+	tools := []server.ServerTool{
+		{Tool: GetMyUserInfoTool, Handler: GetUserInfoFn},
+		{Tool: GetUserOrgsTool, Handler: GetUserOrgsFn},
+	}
+	for _, t := range tools {
+		Tool.RegisterRead(t)
+	}
+}
+
+// getIntArg parses an integer argument from the MCP request arguments map.
+// Returns def if missing, not a number, or less than 1. Used for pagination arguments.
+func getIntArg(req mcp.CallToolRequest, name string, def int) int {
+	val, ok := req.GetArguments()[name].(float64)
+	if !ok || val < 1 {
+		return def
+	}
+	return int(val)
+}
+
+// GetUserInfoFn is the handler for "get_my_user_info" MCP tool requests.
+// Logs invocation, fetches current user info from gitea, wraps result for MCP.
 func GetUserInfoFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-	log.Debugf("Called GetUserInfoFn")
+	log.Debugf("[User] Called GetUserInfoFn")
 	user, _, err := gitea.Client().GetMyUserInfo()
 	if err != nil {
 		return to.ErrorResult(fmt.Errorf("get user info err: %v", err))
 	}
-
 	return to.TextResult(user)
 }
 
+// GetUserOrgsFn is the handler for "get_user_orgs" MCP tool requests.
+// Logs invocation, pulls validated pagination arguments from request,
+// performs Gitea organization listing, and wraps the result for MCP.
 func GetUserOrgsFn(ctx context.Context, req mcp.CallToolRequest) (*mcp.CallToolResult, error) {
-	log.Debugf("Called GetUserOrgsFn")
-	page, ok := req.GetArguments()["page"].(float64)
-	if !ok || page < 1 {
-		page = 1
-	}
-	pageSize, ok := req.GetArguments()["pageSize"].(float64)
-	if !ok || pageSize < 1 {
-		pageSize = 100
-	}
+	log.Debugf("[User] Called GetUserOrgsFn")
+	page := getIntArg(req, "page", defaultPage)
+	pageSize := getIntArg(req, "pageSize", defaultPageSize)
+
 	opt := gitea_sdk.ListOrgsOptions{
 		ListOptions: gitea_sdk.ListOptions{
-			Page:     int(page),
-			PageSize: int(pageSize),
+			Page:     page,
+			PageSize: pageSize,
 		},
 	}
 	orgs, _, err := gitea.Client().ListMyOrgs(opt)
 	if err != nil {
 		return to.ErrorResult(fmt.Errorf("get user orgs err: %v", err))
 	}
-
 	return to.TextResult(orgs)
 }