<?php

declare(strict_types=1);

namespace Sarcio\WordPress;

final class Usage
{
    private const CACHE_SEC = 300;
    private const TRANSIENT = 'sarcio_usage';

    /**
     * @return array{billingUrl:string,creditsAvailable:int,creditsPercent:int,creditsUsed:float,draftsIncluded:int,draftsPercent:int,draftsUsed:int,planName:string,resetsAt:string,state:string}|null
     */
    public static function get(): ?array
    {
        $siteKey = (string) Options::get('site_key');
        $secret = (string) Options::get('sidecar_key');
        if ($siteKey === '' || $secret === '') {
            return null;
        }
        $cached = get_transient(self::TRANSIENT);
        if (is_array($cached) && ($cached['siteKey'] ?? '') === $siteKey) {
            return $cached['usage'] ?? null;
        }
        $response = wp_remote_get(
            sprintf('%s/api/sites/%s/usage', Options::apiUrl(), rawurlencode($siteKey)),
            [
                'headers' => ['Authorization' => 'Bearer ' . $secret],
                'redirection' => 0,
                'timeout' => 4,
            ],
        );
        $usage = null;
        if (!is_wp_error($response) && (int) wp_remote_retrieve_response_code($response) === 200) {
            $usage = self::parse(json_decode((string) wp_remote_retrieve_body($response), true));
        }
        set_transient(self::TRANSIENT, ['siteKey' => $siteKey, 'usage' => $usage], self::CACHE_SEC);
        return $usage;
    }

    public static function forget(): void
    {
        delete_transient(self::TRANSIENT);
    }

    /**
     * @return array{billingUrl:string,creditsAvailable:int,creditsPercent:int,creditsUsed:float,draftsIncluded:int,draftsPercent:int,draftsUsed:int,planName:string,resetsAt:string,state:string}|null
     */
    public static function parse(mixed $body): ?array
    {
        if (!is_array($body) || !isset($body['draftsUsed'], $body['draftsIncluded'], $body['creditsUsed'], $body['creditsAvailable'])) {
            return null;
        }
        $state = (string) ($body['state'] ?? 'ok');
        return [
            'billingUrl' => esc_url_raw((string) ($body['billingUrl'] ?? '')),
            'creditsAvailable' => (int) $body['creditsAvailable'],
            'creditsPercent' => max(0, min(100, (int) ($body['creditsPercent'] ?? 0))),
            'creditsUsed' => (float) $body['creditsUsed'],
            'draftsIncluded' => (int) $body['draftsIncluded'],
            'draftsPercent' => max(0, min(100, (int) ($body['draftsPercent'] ?? 0))),
            'draftsUsed' => (int) $body['draftsUsed'],
            'planName' => sanitize_text_field((string) ($body['planName'] ?? '')),
            'resetsAt' => sanitize_text_field((string) ($body['resetsAt'] ?? '')),
            'state' => in_array($state, ['near', 'ok', 'reached'], true) ? $state : 'ok',
        ];
    }
}