initial handleMcpTool method

- validate flags with inputSchema

Author: burmudar

cmd/src/mcp.go

@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"strings"
 
 	"github.com/sourcegraph/src-cli/internal/mcp"
 )
@@ -47,6 +48,33 @@ func mcpMain(args []string) error {
 }
 
 func handleMcpTool(tool *mcp.ToolDef, args []string) error {
-	fmt.Printf("handling tool %q args: %+v", tool.Name, args)
+	fs, vars, err := buildArgFlagSet(tool)
+	if err != nil {
+		return err
+	}
+
+	if err := fs.Parse(args); err != nil {
+		return err
+	}
+
+	inputSchema := tool.InputSchema
+
+	for _, reqName := range inputSchema.Required {
+		if vars[reqName] == nil {
+			return fmt.Errorf("no value provided for required flag --%s", reqName)
+		}
+	}
+
+	if len(args) < len(inputSchema.Required) {
+		return fmt.Errorf("not enough arguments provided - the following flags are required:\n%s", strings.Join(inputSchema.Required, "\n"))
+	}
+
+	derefFlagValues(vars)
+
+	fmt.Println("Flags")
+	for name, val := range vars {
+		fmt.Printf("--%s=%v\n", name, val)
+	}
+
 	return nil
 }

cmd/src/mcp_args.go

@@ -3,6 +3,7 @@ package main
 import (
 	"flag"
 	"fmt"
+	"reflect"
 	"strings"
 )
 
@@ -21,6 +22,19 @@ func (s *strSliceFlag) String() string {
 	return strings.Join(s.vals, ",")
 }
 
+func derefFlagValues(vars map[string]any) {
+	for k, v := range vars {
+		rfl := reflect.ValueOf(v)
+		if rfl.Kind() == reflect.Pointer {
+			vv := rfl.Elem().Interface()
+			if slice, ok := vv.(strSliceFlag); ok {
+				vv = slice.vals
+			}
+			vars[k] = vv
+		}
+	}
+}
+
 func buildArgFlagSet(tool *MCPToolDef) (*flag.FlagSet, map[string]any, error) {
 	fs := flag.NewFlagSet(tool.Name(), flag.ContinueOnError)
 	flagVars := map[string]any{}