<?php
namespace JVBase\integrations;

if (!defined('ABSPATH')) {
	exit;
}

class RateLimits {
	protected array $history = [];
	protected int $maxHistory = 100;
	protected array $limits = [
		'per_second'	=> 2,
		'per_minute'	=> 30,
		'per_hour'		=> 1000
	];

	protected string $key;

	public function __construct(string $key, array $limits = []) {
		$this->key = sanitize_title($key);
		//Allow custom limits
		foreach ($limits as $interval => $limit) {
			$key = match($interval) {
				'second', 'per_second','s' 	=> 'per_second',
				'minute', 'per_minute', 'm' => 'per_minute',
				'hour', 'per_hour', 'h'		=> 'per_hour',
				default => false
			};
			if (!$key) {
				error_log('Attempted to add custom limit: '.$interval.' for key '.$key);
				continue;
			}
			$this->limits[$key] = (int)$limit;
		}

		$this->getHistory();
		add_action('shutdown', [$this, 'saveHistory']);
	}
		protected function getHistory():void
		{
			$stored = get_transient(BASE.$this->key.'_limits');
			if (!$stored) {
				$stored = [];
			}
			$this->history = $stored;
		}
		public function recordRequest(string $endpoint = 'base'):void
		{
			if (!array_key_exists($endpoint, $this->history)) {
				$this->history[$endpoint] = [];
			}

			$this->history[$endpoint][] = time();
			$this->checkHistorySize();
		}
		public function saveHistory():void
		{
			set_transient(BASE.$this->key.'_limits', $this->history);
		}
		protected function checkHistorySize():void
		{
			foreach ($this->history as $endpoint => $history) {
				if (count($history) > $this->maxHistory) {
					$this->history[$endpoint] = array_slice($this->history[$endpoint], -$this->maxHistory);
				}
			}
		}

	public function checkRateLimit(string $endpoint = 'base'):bool
	{
		if (!array_key_exists($endpoint, $this->history)) {
			return true;
		}

		$now = time();

		$this->cleanHistory($now);
		$counts = [
			'per_second'	=> 0,
			'per_minute'	=> 0,
			'per_hour'		=> count($this->history)
		];

		foreach ($this->history[$endpoint]??[] as $timestamp) {
			if ($now - $timestamp <=1) $counts['per_second']++;
			if ($now - $timestamp <=60) $counts['per_minute']++;
		}

		foreach ($this->limits as $interval => $limit) {
			if ($counts[$interval] >= $limit) return false;
		}
		return true;
	}

	protected function cleanHistory($now):void
	{
		$this->history = array_map(function ($endpointHistory) use ($now) {
			return array_filter($endpointHistory, function($timestamp) use ($now) {
				return ($now - $timestamp) < 3600; //Keep last hour
			});
		}, $this->history);
	}
}