<?php

declare(strict_types=1);

namespace Kiri\Di;

class HotReloadState
{
	private const int MAX_AGE_SECONDS = 30;

	public function store(array $changedFiles): void
	{
		$payload = [
			'timestamp' => time(),
			'changed_files' => $changedFiles
			                   |> array_filter(...)
			                   |> (fn($x) => array_map([$this, 'normalizePath'], $x))
			                   |> array_unique(...)
			                   |> array_values(...),
		];

		$directory = dirname($this->getFilePath());
		if (!is_dir($directory)) {
			mkdir($directory, 0755, true);
		}

		file_put_contents($this->getFilePath(), json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES));
	}

	public function consume(): array
	{
		return $this->peek();
	}

	public function peek(): array
	{
		$file = $this->getFilePath();
		if (!file_exists($file)) {
			return [];
		}

		$data = json_decode((string)file_get_contents($file), true);
		if (!is_array($data)) {
			return [];
		}

		$timestamp = (int)($data['timestamp'] ?? 0);
		if ($timestamp < 1 || (time() - $timestamp) > self::MAX_AGE_SECONDS) {
			return [];
		}

		$files = is_array($data['changed_files'] ?? null) ? $data['changed_files'] : [];
		return array_map([$this, 'normalizePath'], $files)
		       |> array_unique(...)
		       |> array_values(...);
	}

	private function getFilePath(): string
	{
		$basePath = $this->normalizePath($_SERVER['PWD'] ?? APP_PATH ?? getcwd());
		$runtimePath = defined('APP_PATH')
			? rtrim(str_replace('\\', '/', APP_PATH), '/') . '/storage/.kiri-hot-reload/'
			: sys_get_temp_dir() . '/kiri-hot-reload/';

		return $runtimePath . md5($basePath) . '.json';
	}

	private function normalizePath(string $path): string
	{
		$resolved = realpath($path) ?: $path;
		return str_replace('\\', '/', $resolved);
	}
}