<?php

namespace app\flow\strategies;

use app\flow\context\ProcessContext;
use app\flow\nodes\ProcessNodeInterface;

/**
 * 策略抽象基类
 */
abstract class AbstractStrategy implements ProcessStrategyInterface
{
    /**
     * 策略配置
     */
    protected array $config = [];

    /**
     * 策略执行阶段
     */
    protected string $phase = 'before';

    public function __construct(array $config = [])
    {
        $this->config = array_merge($this->config, $config);
    }

    /**
     * 执行策略
     */
    public function execute(ProcessContext $context, ProcessNodeInterface $node): ProcessContext
    {
        if (!$this->isApplicable($context, $node)) {
            return $context;
        }
        return $this->doExecute($context, $node);
    }

    /**
     * 具体执行逻辑，由子类实现
     */
    abstract protected function doExecute(ProcessContext $context, ProcessNodeInterface $node): ProcessContext;

    /**
     * 获取策略执行阶段
     */
    public function getPhase(): string
    {
        return $this->phase;
    }

    /**
     * 设置执行阶段
     */
    public function setPhase(string $phase): self
    {
        $this->phase = $phase;
        return $this;
    }

    /**
     * 判断策略是否适用
     * 默认总是适用
     */
    public function isApplicable(ProcessContext $context, ProcessNodeInterface $node): bool
    {
        return true;
    }

    /**
     * 获取配置
     */
    protected function getConfig(string $key, mixed $default = null): mixed
    {
        return $this->config[$key] ?? $default;
    }
}