<?php

namespace App\Services\Whatsapp;

use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;

class WhatsappCloudClient
{
    public function isConfigured()
    {
        return trim((string) config('whatsapp.token')) !== ''
            && trim((string) config('whatsapp.phone_number_id')) !== '';
    }

    /**
     * Malaysia MSISDN for Graph API, e.g. 60193450165.
     *
     * @return string|null
     */
    public function normalizeMsisdn($raw)
    {
        $digits = preg_replace('/\D+/', '', (string) $raw);
        if ($digits === '') {
            return null;
        }

        if (strpos($digits, '60') === 0) {
            return $digits;
        }

        if (strpos($digits, '0') === 0) {
            return '60' . substr($digits, 1);
        }

        return '60' . $digits;
    }

    /**
     * @param string $to
     * @param string $templateName
     * @param string $lang
     * @param array<int,string> $bodyParams
     * @return \Illuminate\Http\Client\Response
     */
    public function sendTemplate($to, $templateName, $lang, array $bodyParams = [])
    {
        $payload = [
            'messaging_product' => 'whatsapp',
            'to' => $to,
            'type' => 'template',
            'template' => [
                'name' => $templateName,
                'language' => ['code' => $lang],
            ],
        ];

        if (count($bodyParams) > 0) {
            $payload['template']['components'] = [[
                'type' => 'body',
                'parameters' => array_map(function ($text) {
                    return [
                        'type' => 'text',
                        'text' => $this->sanitizeParam($text),
                    ];
                }, array_values($bodyParams)),
            ]];
        }

        $version = config('whatsapp.api_version', 'v25.0');
        $phoneId = config('whatsapp.phone_number_id');
        $url = 'https://graph.facebook.com/' . $version . '/' . $phoneId . '/messages';

        $response = Http::withToken(config('whatsapp.token'))
            ->acceptJson()
            ->asJson()
            ->post($url, $payload);

        if (!$response->successful()) {
            Log::error('WhatsApp Cloud send failed', [
                'to' => $to,
                'template' => $templateName,
                'status' => $response->status(),
                'body' => $response->json() ?: $response->body(),
            ]);
        }

        return $response;
    }

    protected function sanitizeParam($text)
    {
        $text = trim(preg_replace('/\s+/', ' ', (string) $text));
        if ($text === '') {
            return '-';
        }

        return mb_substr($text, 0, 200);
    }
}