Refactor command parsing and building

pkg/backends/vllm/vllm.go

@@ -142,3 +142,31 @@ func (o *VllmServerOptions) BuildCommandArgs() []string {
 	}
 	return backends.BuildCommandArgs(o, multipleFlags)
 }
+
+// ParseVllmCommand parses a vLLM serve command string into VllmServerOptions
+// Supports multiple formats:
+// 1. Full command: "vllm serve --model MODEL_NAME --other-args"
+// 2. Full path: "/usr/local/bin/vllm serve --model MODEL_NAME"
+// 3. Serve only: "serve --model MODEL_NAME --other-args"
+// 4. Args only: "--model MODEL_NAME --other-args"
+// 5. Multiline commands with backslashes
+func ParseVllmCommand(command string) (*VllmServerOptions, error) {
+	executableNames := []string{"vllm"}
+	subcommandNames := []string{"serve"}
+	multiValuedFlags := map[string]bool{
+		"middleware":      true,
+		"api_key":         true,
+		"allowed_origins": true,
+		"allowed_methods": true,
+		"allowed_headers": true,
+		"lora_modules":    true,
+		"prompt_adapters": true,
+	}
+
+	var vllmOptions VllmServerOptions
+	if err := backends.ParseCommand(command, executableNames, subcommandNames, multiValuedFlags, &vllmOptions); err != nil {
+		return nil, err
+	}
+
+	return &vllmOptions, nil
+}