<?php

namespace App\Services\Tool;

use Illuminate\Support\Str;

/**
 * Tool 执行调度器，负责超时/结果截断等基础防护。
 */
class ToolExecutor
{
    public function __construct(
        private readonly ToolRegistry $registry,
        private ?int $timeoutSeconds = null,
        private ?int $maxResultBytes = null,
    ) {
        $this->timeoutSeconds = $this->timeoutSeconds ?? (int) config('agent.tools.timeout_seconds', 15);
        $this->maxResultBytes = $this->maxResultBytes ?? (int) config('agent.tools.result_max_bytes', 4096);
    }

    public function execute(ToolCall $call): ToolResult
    {
        $tool = $this->registry->get($call->name);

        if (! $tool) {
            return new ToolResult(
                $call->runId,
                $call->parentRunId,
                $call->toolCallId,
                $call->name,
                'FAILED',
                '',
                'TOOL_NOT_FOUND'
            );
        }

        $started = microtime(true);

        try {
            $result = $tool->execute($call->arguments);
            $output = is_string($result) ? $result : json_encode($result, JSON_UNESCAPED_UNICODE);
        } catch (\Throwable $exception) {
            return new ToolResult(
                $call->runId,
                $call->parentRunId,
                $call->toolCallId,
                $call->name,
                'FAILED',
                '',
                Str::limit($exception->getMessage(), 200)
            );
        }

        $duration = microtime(true) - $started;
        $truncated = false;

        if ($this->maxResultBytes > 0 && strlen($output) > $this->maxResultBytes) {
            $output = substr($output, 0, $this->maxResultBytes);
            $truncated = true;
        }

        if ($this->timeoutSeconds > 0 && $duration > $this->timeoutSeconds) {
            return new ToolResult(
                $call->runId,
                $call->parentRunId,
                $call->toolCallId,
                $call->name,
                'TIMEOUT',
                $output,
                'TOOL_TIMEOUT',
                $truncated
            );
        }

        return new ToolResult(
            $call->runId,
            $call->parentRunId,
            $call->toolCallId,
            $call->name,
            'SUCCESS',
            $output,
            null,
            $truncated
        );
    }
}