<?php

declare(strict_types=1);

namespace Kiri\Di;

use Kiri\Di\Inject\Container;
use Kiri\Abstracts\Component;
use Kiri\Di\Inject\Skip;
use Psr\Container\ContainerInterface;
use ReflectionClass;
use ReflectionMethod;
use DirectoryIterator;
use Throwable;

class Scanner extends Component
{
	#[Container(ContainerInterface::class)]
	public ContainerInterface $container;

	/**
	 * @var array 已处理的文件路径列表
	 */
	public array $files = [];

	/**
	 * @var array 文件修改时间缓存
	 */
	private array $fileMtimes = [];

	/**
	 * @var bool|null OPcache可用性缓存
	 */
	private ?bool $hasOpcache = null;

	/**
	 * @var array 配置选项
	 */
	private array $config
		= [
			'skip_patterns'    => ['/vendor/', '/tests/', '/cache/', '/node_modules/'],
			'skip_directories' => [],
			'extensions'       => ['php'],
			'max_depth'        => 20,
			'follow_links'     => false,
			'cache_enabled'    => true,
			'cache_ttl'        => 3600,
			'debug'            => false,
		];

	/**
	 * 设置扫描器配置
	 */
	public function setConfig(array $config): void
	{
		$this->config = array_merge($this->config, $config);
	}

	/**
	 * 主扫描方法，支持缓存
	 */
	public function scan(string $path, ?string $cacheFile = null): void
	{
		if ($this->config['cache_enabled']) {
			$cacheFile = $cacheFile ?? $this->getDefaultCacheFile();
			if ($this->loadFromCache($cacheFile, $path)) {
				$this->processCachedFiles();
				return;
			}
		}

		$this->scanDirectory($path);

		if ($this->config['cache_enabled']) {
			$this->saveToCache($cacheFile);
		}
	}

	/**
	 * 扫描目录（替换原有的load_directory）
	 */
	private function scanDirectory(string $path, int $depth = 0): void
	{
		if ($depth > $this->config['max_depth']) {
			return;
		}

		try {
			$dir = new DirectoryIterator($path);
		} catch (Throwable $e) {
			$this->logError($e, ['path' => $path, 'action' => 'open_directory']);
			return;
		}

		foreach ($dir as $item) {
			if ($this->shouldSkipItem($item)) {
				continue;
			}

			$realPath = $item->getRealPath();

			if ($item->isDir()) {
				if ($this->shouldSkipDirectory($realPath)) {
					continue;
				}

				// 如果是符号链接且不跟随链接，则跳过
				if ($item->isLink() && !$this->config['follow_links']) {
					continue;
				}

				$this->scanDirectory($realPath, $depth + 1);
			} elseif ($item->isFile()) {
				$this->processFile($realPath);
			}
		}
	}

	/**
	 * 判断是否应该跳过该目录项
	 */
	private function shouldSkipItem(DirectoryIterator $item): bool
	{
		return $item->isDot() || str_starts_with($item->getFilename(), '.');
	}

	/**
	 * 判断是否应该跳过目录
	 */
	private function shouldSkipDirectory(string $path): bool
	{
		$path = rtrim($path, DIRECTORY_SEPARATOR) . DIRECTORY_SEPARATOR;

		// 检查配置文件中的跳过目录
		$skipDirs = array_merge(
			$this->config['skip_directories'],
			config('site.scanner.skip', [])
		);

		if (in_array($path, $skipDirs)) {
			return true;
		}

		// 检查跳过模式
		foreach ($this->config['skip_patterns'] as $pattern) {
			if (strpos($path, $pattern) !== false) {
				return true;
			}
		}

		return false;
	}

	/**
	 * 处理单个文件
	 */
	private function processFile(string $path): void
	{
		// 检查文件扩展名
		if (!in_array(pathinfo($path, PATHINFO_EXTENSION), $this->config['extensions'])) {
			return;
		}

		// 检查是否已处理
		if (in_array($path, $this->files)) {
			return;
		}

		// 检查文件是否需要重新处理（基于修改时间）
		if (!$this->shouldProcessFile($path)) {
			return;
		}

		$this->files[] = $path;

		try {
			$this->loadAndParseFile($path);
		} catch (Throwable $e) {
			$this->logError($e, [
				'file'   => $path,
				'action' => 'process_file'
			]);

			// 如果是语法错误，可以选择抛出或记录
			if ($e instanceof \ParseError) {
				throw $e;
			}
		}
	}

	/**
	 * 判断文件是否需要处理
	 */
	private function shouldProcessFile(string $path): bool
	{
		if (!file_exists($path)) {
			return false;
		}

		$mtime = filemtime($path);

		// 如果没有缓存过修改时间，或者文件已更新，则需要处理
		if (!isset($this->fileMtimes[$path]) || $this->fileMtimes[$path] < $mtime) {
			$this->fileMtimes[$path] = $mtime;
			return true;
		}

		return false;
	}

	/**
	 * 加载并解析文件
	 */
	private function loadAndParseFile(string $path): void
	{
		// OPcache优化
		$this->optimizeWithOpcache($path);

		// 加载文件
		require_once $path;

		// 尝试从文件内容提取类名（更准确）
		$class = $this->extractClassNameFromFile($path);

		if ($class && class_exists($class)) {
			$this->analyzeClass($class);
		}
	}

	/**
	 * 使用OPcache优化文件
	 */
	private function optimizeWithOpcache(string $path): void
	{
		if ($this->hasOpcache === null) {
			$this->hasOpcache = function_exists('opcache_invalidate')
								&& function_exists('opcache_compile_file');
		}

		if ($this->hasOpcache) {
			try {
				opcache_invalidate($path, true);
				opcache_compile_file($path);
			} catch (Throwable $e) {
				// 静默处理OPcache错误，不影响主要功能
				if ($this->config['debug']) {
					$this->logError($e, [
						'file'   => $path,
						'action' => 'opcache_optimize'
					]);
				}
			}
		}
	}

	/**
	 * 从文件内容提取完整的类名（命名空间+类名）
	 */
	private function extractClassNameFromFile(string $path): ?string
	{
		$content = @file_get_contents($path);
		if (!$content) {
			return null;
		}

		$tokens     = token_get_all($content);
		$namespace  = '';
		$class      = '';
		$classToken = false;

		foreach ($tokens as $token) {
			if (is_array($token)) {
				if ($token[0] === T_NAMESPACE) {
					$namespace  = '';
					$collecting = true;
				} elseif ($collecting && $token[0] === T_STRING) {
					$namespace .= $token[1];
				} elseif ($collecting && $token[0] === T_NS_SEPARATOR) {
					$namespace .= '\\';
				} elseif ($collecting && $token[0] === T_WHITESPACE) {
					// 忽略空白
				} else {
					$collecting = false;
				}

				if ($token[0] === T_CLASS || $token[0] === T_INTERFACE || $token[0] === T_TRAIT) {
					$classToken = true;
				} elseif ($classToken && $token[0] === T_STRING) {
					$class = $token[1];
					break;
				}
			} else {
				if ($token === ';' || $token === '{') {
					$collecting = false;
				}
			}
		}

		if (!$class) {
			return null;
		}

		return $namespace ? $namespace . '\\' . $class : $class;
	}

	/**
	 * 分析类及其方法
	 */
	private function analyzeClass(string $class): void
	{
		try {
			$reflect = $this->container->getReflectionClass($class);

			if (!$reflect->isInstantiable() ||
				$reflect->isTrait() ||
				$reflect->isEnum() ||
				$reflect->isInterface()) {
				return;
			}

			// 检查跳过注解
			if ($this->shouldSkipClass($reflect)) {
				return;
			}

			// 分析类的方法
			$this->analyzeClassMethods($reflect, $class);

		} catch (Throwable $e) {
			$this->logError($e, [
				'class'  => $class,
				'action' => 'analyze_class'
			]);
		}
	}

	/**
	 * 判断是否应该跳过该类
	 */
	private function shouldSkipClass(ReflectionClass $reflect): bool
	{
		$attributes = array_map(
			fn($attr) => $attr->getName(),
			$reflect->getAttributes()
		);

		return in_array(Skip::class, $attributes, true) ||
			   in_array(\Attribute::class, $attributes, true);
	}

	/**
	 * 分析类的方法
	 */
	private function analyzeClassMethods(ReflectionClass $reflect, string $class): void
	{
		foreach ($reflect->getMethods(ReflectionMethod::IS_PUBLIC) as $method) {
			// 跳过静态方法和继承的方法
			if ($method->isStatic() || $method->getDeclaringClass()->getName() !== $class) {
				continue;
			}

			$this->processMethodAttributes($method, $class);
		}
	}

	/**
	 * 处理方法上的注解
	 */
	private function processMethodAttributes(ReflectionMethod $method, string $class): void
	{
		foreach ($method->getAttributes() as $attribute) {
			$attributeName = $attribute->getName();

			if (!class_exists($attributeName)) {
				continue;
			}

			try {
				$instance = $attribute->newInstance();

				if (method_exists($instance, 'dispatch')) {
					$instance->dispatch($class, $method->getName());
				}
			} catch (Throwable $e) {
				$this->logError($e, [
					'class'     => $class,
					'method'    => $method->getName(),
					'attribute' => $attributeName,
					'action'    => 'process_attribute'
				]);
			}
		}
	}

	/**
	 * 缓存相关方法
	 */
	private function getDefaultCacheFile(): string
	{
		$cacheDir = sys_get_temp_dir() . '/kiri-scanner-cache/';
		if (!is_dir($cacheDir)) {
			mkdir($cacheDir, 0755, true);
		}

		$projectHash = md5(__DIR__);
		return $cacheDir . 'scanner_' . $projectHash . '.json';
	}

	/**
	 * 从缓存加载
	 */
	private function loadFromCache(string $cacheFile, string $path): bool
	{
		if (!file_exists($cacheFile)) {
			return false;
		}

		// 检查缓存是否过期
		if (filemtime($cacheFile) + $this->config['cache_ttl'] < time()) {
			return false;
		}

		// 检查目录是否有更新
		if ($this->hasDirectoryChanged($path, $cacheFile)) {
			return false;
		}

		$data = json_decode(file_get_contents($cacheFile), true);
		if (!is_array($data) || !isset($data['files'], $data['mtimes'])) {
			return false;
		}

		$this->files      = $data['files'];
		$this->fileMtimes = $data['mtimes'];

		return true;
	}

	/**
	 * 检查目录是否有更新
	 */
	private function hasDirectoryChanged(string $path, string $cacheFile): bool
	{
		$cacheMtime = filemtime($cacheFile);

		// 简单的实现：检查目录本身和一级子目录
		$dirIterator = new DirectoryIterator($path);
		foreach ($dirIterator as $item) {
			if ($item->isDot()) {
				continue;
			}

			$itemPath = $item->getRealPath();
			if (filemtime($itemPath) > $cacheMtime) {
				return true;
			}
		}

		return false;
	}

	/**
	 * 保存到缓存
	 */
	private function saveToCache(string $cacheFile): void
	{
		$data = [
			'files'     => $this->files,
			'mtimes'    => $this->fileMtimes,
			'timestamp' => time(),
			'version'   => '1.0'
		];

		file_put_contents($cacheFile, json_encode($data, JSON_PRETTY_PRINT));

		// 清理旧缓存文件
		$this->cleanupOldCacheFiles(dirname($cacheFile));
	}

	/**
	 * 清理旧的缓存文件
	 */
	private function cleanupOldCacheFiles(string $cacheDir): void
	{
		$files = glob($cacheDir . '/scanner_*.json');
		$now   = time();

		foreach ($files as $file) {
			if (filemtime($file) + (7 * 24 * 3600) < $now) { // 清理7天前的缓存
				unlink($file);
			}
		}
	}

	/**
	 * 处理缓存的文件（批量处理，避免重复加载）
	 */
	private function processCachedFiles(): void
	{
		foreach ($this->files as $file) {
			if ($this->shouldProcessFile($file)) {
				$this->loadAndParseFile($file);
			}
		}
	}

	/**
	 * 错误记录方法
	 */
	private function logError(Throwable $e, array $context = []): void
	{
		json_log($e, $context);
	}

	/**
	 * 重置扫描器状态
	 */
	public function reset(): void
	{
		$this->files      = [];
		$this->fileMtimes = [];
		$this->hasOpcache = null;
	}
}