package mcp

import (
	"encoding/json"
	"log"
)

// extractUCPAgentMeta checks whether the JSON arguments carry a "meta" key with
// a nested "ucp-agent.profile" (the UCP-Agent profile advertisement, a sibling
// of the real arguments per the UCP spec). If present it logs the profile for
// observability and strips "meta" so it does not leak into the tool's argument
// namespace. When absent it returns the arguments unchanged — a no-op for tools
// that don't speak UCP.
func extractUCPAgentMeta(arguments json.RawMessage) json.RawMessage {
	if len(arguments) == 0 {
		return arguments
	}
	var obj map[string]json.RawMessage
	if err := json.Unmarshal(arguments, &obj); err != nil {
		return arguments
	}
	metaRaw, hasMeta := obj["meta"]
	if !hasMeta {
		return arguments
	}
	var meta struct {
		UCPAgent *struct {
			Profile string `json:"profile"`
		} `json:"ucp-agent"`
	}
	if err := json.Unmarshal(metaRaw, &meta); err == nil && meta.UCPAgent != nil && meta.UCPAgent.Profile != "" {
		log.Printf("ucp-agent: profile=%s", meta.UCPAgent.Profile)
	}
	delete(obj, "meta")
	cleaned, err := json.Marshal(obj)
	if err != nil {
		return arguments
	}
	return cleaned
}