<?php

declare(strict_types=1);

namespace TFGraphics\SmartImport\Support;

/**
 * Voluntary, admin-only support report flow for the Free edition.
 *
 * The destination is intentionally centralized and filterable. The UI never
 * renders the recipient address and diagnostics are opt-in and allowlisted.
 */
final class SupportReportController
{
    private const RECIPIENT = 'assistenza@tfgraphics.it';
    private const ACTION = 'tfsi_support_report_action';
    private const NONCE_FIELD = 'tfsi_support_nonce';
    private const RATE_LIMIT_SECONDS = 60;

    /** @var array<string,string> */
    private const TYPES = [
        'not_found' => 'Prodotto non trovato',
        'incomplete_data' => 'Dati incompleti',
        'wrong_data' => 'Dati errati',
        'wrong_images' => 'Immagini mancanti o errate',
        'provider_problem' => 'Problema con un provider',
        'import_problem' => 'Problema nell\'importazione',
        'other' => 'Altro',
    ];

    public static function register(): void
    {
        if (function_exists('add_action')) {
            add_action('admin_post_tfsi_support_report', [self::class, 'handle']);
        }
    }

    /** @return array<string,string> */
    public static function issueTypes(): array
    {
        if (! function_exists('__')) {
            return self::TYPES;
        }

        return [
            'not_found' => __('Prodotto non trovato', 'productgather'),
            'incomplete_data' => __('Dati incompleti', 'productgather'),
            'wrong_data' => __('Dati errati', 'productgather'),
            'wrong_images' => __('Immagini mancanti o errate', 'productgather'),
            'provider_problem' => __('Problema con un provider', 'productgather'),
            'import_problem' => __('Problema nell\'importazione', 'productgather'),
            'other' => __('Altro', 'productgather'),
        ];
    }

    public static function handle(): void
    {
        if (! current_user_can('manage_options')) {
            $result = ['status' => 'forbidden', 'accepted' => false];
        } elseif (! isset($_POST['tfsi_support_nonce'])
            || ! is_string($_POST['tfsi_support_nonce'])
            || false === wp_verify_nonce(
                sanitize_text_field(wp_unslash($_POST['tfsi_support_nonce'])),
                self::ACTION
            )) {
            $result = ['status' => 'invalid', 'accepted' => false];
        } else {
            // submit() retains its independent capability/nonce checks and
            // field-specific text, textarea, email and diagnostic allowlists.
            $result = self::submit(wp_unslash($_POST));
        }

        $url = function_exists('admin_url')
            ? admin_url('admin.php?page=tfsi_support')
            : 'admin.php?page=tfsi_support';
        if (function_exists('add_query_arg')) {
            $url = add_query_arg('tfsi_support_status', (string) ($result['status'] ?? 'failed'), $url);
        } else {
            $url .= '&tfsi_support_status=' . rawurlencode((string) ($result['status'] ?? 'failed'));
        }
        $url .= '#tfsi-support-report';

        if (function_exists('wp_safe_redirect')) {
            wp_safe_redirect($url);
            exit;
        }
    }

    /**
     * @param array<string,mixed> $post
     * @return array{status:string,accepted:bool}
     */
    public static function submit(array $post): array
    {
        if (! function_exists('current_user_can') || ! current_user_can('manage_options')) {
            return ['status' => 'forbidden', 'accepted' => false];
        }

        $nonce = self::text($post[self::NONCE_FIELD] ?? '');
        if (
            $nonce === ''
            || ! function_exists('wp_verify_nonce')
            || wp_verify_nonce($nonce, self::ACTION) === false
        ) {
            return ['status' => 'invalid', 'accepted' => false];
        }

        $rateKey = self::rateLimitKey();
        if ($rateKey !== '' && function_exists('get_transient') && get_transient($rateKey)) {
            return ['status' => 'rate_limited', 'accepted' => false];
        }

        $type = self::key($post['support_type'] ?? '');
        if (! isset(self::TYPES[$type])) {
            $type = 'other';
        }

        $description = self::textarea($post['support_description'] ?? '');
        $replyEmail = self::email($post['support_email'] ?? '');
        $query = self::text($post['support_query'] ?? '');
        $includeDiagnostics = ! empty($post['support_include_diagnostics']);

        $lines = [
            __('ProductGather Free — segnalazione volontaria', 'productgather'),
            '',
            __('Tipo: ', 'productgather') . \TFGraphics\SmartImport\Admin\Presentation\UiTranslations::translate(self::TYPES[$type]),
        ];

        if ($description !== '') {
            $lines[] = __('Nota facoltativa:', 'productgather');
            $lines[] = $description;
        }

        if ($query !== '') {
            $lines[] = '';
            $lines[] = __('Ricerca interessata (mostrata all’utente prima dell’invio):', 'productgather');
            $lines[] = $query;
        }

        if ($includeDiagnostics) {
            $lines[] = '';
            $lines[] = __('Diagnostica tecnica autorizzata dall’utente:', 'productgather');
            foreach (self::diagnostics($post) as $label => $value) {
                if ($value !== '') {
                    $lines[] = \TFGraphics\SmartImport\Admin\Presentation\UiTranslations::translate($label) . ': ' . $value;
                }
            }
        }

        $subject = '[ProductGather Free] ' . \TFGraphics\SmartImport\Admin\Presentation\UiTranslations::translate(self::TYPES[$type]);
        $headers = [];
        if ($replyEmail !== '') {
            $headers[] = 'Reply-To: ' . $replyEmail;
        }

        $accepted = function_exists('wp_mail')
            ? (bool) wp_mail(self::recipient(), $subject, implode("\n", $lines), $headers)
            : false;

        if ($rateKey !== '' && function_exists('set_transient')) {
            set_transient($rateKey, 1, self::RATE_LIMIT_SECONDS);
        }

        return ['status' => $accepted ? 'sent' : 'failed', 'accepted' => $accepted];
    }

    public static function recipient(): string
    {
        $recipient = self::RECIPIENT;
        if (function_exists('apply_filters')) {
            $recipient = (string) apply_filters('tfsi_support_recipient', $recipient);
        }

        return self::email($recipient);
    }

    /**
     * Only a strict allowlist is accepted. Secrets, cookies, tokens, nonces,
     * sessions, customer/order data and arbitrary headers are never read.
     *
     * @param array<string,mixed> $post
     * @return array<string,string>
     */
    public static function diagnostics(array $post): array
    {
        $wooVersion = defined('WC_VERSION') ? (string) WC_VERSION : '';
        if ($wooVersion === '' && function_exists('WC')) {
            try {
                $woo = WC();
                if (is_object($woo) && isset($woo->version)) {
                    $wooVersion = (string) $woo->version;
                }
            } catch (\Throwable) {
                $wooVersion = '';
            }
        }

        return [
            'Plugin version' => defined('TFSI_VERSION') ? (string) TFSI_VERSION : '',
            'Build' => defined('TFSI_BUILD') ? (string) TFSI_BUILD : '',
            'WordPress' => function_exists('get_bloginfo') ? (string) get_bloginfo('version') : '',
            'WooCommerce' => $wooVersion,
            'PHP' => PHP_VERSION,
            'Locale' => function_exists('determine_locale') ? (string) determine_locale() : '',
            'Area' => self::text($post['support_area'] ?? ''),
            'Trace ID' => self::text($post['support_trace_id'] ?? ''),
            'Tipo ricerca' => self::text($post['support_search_type'] ?? ''),
            'Provider tentati' => self::text($post['support_providers'] ?? ''),
            'Stato provider' => self::text($post['support_provider_status'] ?? ''),
            'Codici errore' => self::text($post['support_error_codes'] ?? ''),
            'Tempi essenziali' => self::text($post['support_timings'] ?? ''),
        ];
    }

    private static function rateLimitKey(): string
    {
        if (! function_exists('get_current_user_id')) {
            return '';
        }

        $userId = (int) get_current_user_id();
        return $userId > 0 ? 'tfsi_support_report_' . $userId : '';
    }

    private static function text(mixed $value): string
    {
        $value = is_scalar($value) ? (string) $value : '';
        if (function_exists('sanitize_text_field')) {
            return trim((string) sanitize_text_field($value));
        }

        return trim((string) preg_replace('/[\x00-\x1F\x7F]/u', '', $value));
    }

    private static function textarea(mixed $value): string
    {
        $value = is_scalar($value) ? (string) $value : '';
        if (function_exists('sanitize_textarea_field')) {
            return trim((string) sanitize_textarea_field($value));
        }

        return trim((string) preg_replace('/<[^>]*>/', '', $value));
    }

    private static function email(mixed $value): string
    {
        $value = is_scalar($value) ? trim((string) $value) : '';
        if ($value === '') {
            return '';
        }
        if (function_exists('sanitize_email')) {
            return (string) sanitize_email($value);
        }

        return filter_var($value, FILTER_VALIDATE_EMAIL) ? $value : '';
    }

    private static function key(mixed $value): string
    {
        $value = is_scalar($value) ? (string) $value : '';
        if (function_exists('sanitize_key')) {
            return (string) sanitize_key($value);
        }

        return strtolower((string) preg_replace('/[^a-z0-9_\-]/i', '', $value));
    }
}