<?php

namespace App\Services;

use App\Models\Alumno;
use App\Models\Promocion;
use App\Models\WhatsappLog;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Storage;

class WhatsAppService
{
    private string $token;
    private string $phoneId;
    private string $apiUrl;

    public function __construct()
    {
        $token   = config('services.whatsapp.token');
        $phoneId = config('services.whatsapp.phone_id');

        if (!$token || !$phoneId) {
            throw new \RuntimeException(
                'WhatsApp no configurado. Agrega WHATSAPP_TOKEN y WHATSAPP_PHONE_ID en el archivo .env'
            );
        }

        $this->token   = $token;
        $this->phoneId = $phoneId;
        $this->apiUrl  = "https://graph.facebook.com/v19.0/{$this->phoneId}/messages";
    }

    public function enviarTemplate(string $telefono, string $templateName, array $parametros = [], ?string $imagenUrl = null): ?string
{
    $components = [];

    if ($imagenUrl) {
        $components[] = [
            'type'       => 'header',
            'parameters' => [
                [
                    'type'  => 'image',
                    'image' => ['link' => $imagenUrl],
                ]
            ],
        ];
    }

    if (!empty($parametros)) {
        $components[] = [
            'type'       => 'body',
            'parameters' => array_map(fn($p) => ['type' => 'text', 'text' => $p], $parametros),
        ];
    }

    $response = Http::withToken($this->token)->post($this->apiUrl, [
        'messaging_product' => 'whatsapp',
        'to'                => $this->normalizarTelefono($telefono),
        'type'              => 'template',
        'template'          => [
            'name'       => $templateName,
            'language'   => ['code' => 'es_MX'],
            'components' => $components,
        ],
    ]);

    if ($response->failed()) {
        Log::error('WhatsApp template error', ['telefono' => $telefono, 'response' => $response->json()]);
        return null;
    }

    return $response->json('messages.0.id');
}

    /*public function enviarPromocion(string $telefono, Promocion $promocion): string
    {
        $payload = [
            'messaging_product' => 'whatsapp',
            'to'                => $this->normalizarTelefono($telefono),
        ];

        if ($promocion->imagen) {
            $payload['type']  = 'image';
            $payload['image'] = [
                'link'    => asset('storage/' . $promocion->imagen),
                'caption' => "{$promocion->titulo}\n\n{$promocion->descripcion}",
            ];
        } else {
            $payload['type'] = 'text';
            $payload['text'] = ['body' => "{$promocion->titulo}\n\n{$promocion->descripcion}"];
        }

        $response = Http::withToken($this->token)->post($this->apiUrl, $payload);

        if ($response->failed()) {
            Log::error('WhatsApp promocion error', [
                'telefono' => $telefono,
                'status'   => $response->status(),
                'body'     => $response->body(),
            ]);

            throw new \RuntimeException($response->body());
        }

        return $response->json('messages.0.id');
    }*/

public function enviarPromocion(string $telefono, Promocion $promocion, string $nombre = ''): string
{
    $codigo = 'PROMO-' . strtoupper(substr(md5($promocion->id . $telefono), 0, 6));

    $mensajeId = $this->enviarTemplate(
        $telefono,
        'promocion_laravel',
        [
            $nombre,
            $promocion->fecha_inicio->locale('es')->isoFormat('D [de] MMMM'),
            $promocion->fecha_fin->locale('es')->isoFormat('D [de] MMMM'),
            $codigo,
        ],
        $promocion->imagenUrl()
    );

    if (!$mensajeId) {
        throw new \RuntimeException('No se pudo enviar la plantilla');
    }

    return $mensajeId;
}

    public function procesarOptOut(string $telefono): void
    {
        $normalizado = $this->normalizarTelefono($telefono);

        Alumno::whereHas('alumnos', function ($q) use ($normalizado) {
            $q->where('telefono', $normalizado)
              ->orWhere('telefono', ltrim($normalizado, '52'));
        })->each(function (Alumno $alumno) {
            $alumno->update([
                'opt_out'    => true,
                'opt_out_at' => now(),
            ]);
        });

        WhatsappLog::create([
            'telefono' => $normalizado,
            'tipo'     => 'opt_out',
            'mensaje'  => 'Usuario solicitó opt-out',
        ]);
    }

    public function descargarMedia(string $mediaId): ?string
    {
        $infoResponse = Http::withToken($this->token)
            ->get("https://graph.facebook.com/v19.0/{$mediaId}");

        if ($infoResponse->failed()) {
            Log::error('WhatsApp media info error', ['mediaId' => $mediaId]);
            return null;
        }

        $mediaUrl  = $infoResponse->json('url');
        $mimeType  = $infoResponse->json('mime_type', 'application/octet-stream');
        $extension = $this->extensionFromMime($mimeType);

        $fileResponse = Http::withToken($this->token)->get($mediaUrl);

        if ($fileResponse->failed()) {
            return null;
        }

        $filename = 'whatsapp_media/' . $mediaId . '.' . $extension;
        Storage::disk('public')->put($filename, $fileResponse->body());

        return $filename;
    }

    public function enviarTexto(string $telefono, string $texto): ?string
    {
        $response = Http::withToken($this->token)->post($this->apiUrl, [
            'messaging_product' => 'whatsapp',
            'to'                => $this->normalizarTelefono($telefono),
            'type'              => 'text',
            'text'              => ['body' => $texto],
        ]);

        if ($response->failed()) {
            return null;
        }

        return $response->json('messages.0.id');
    }

    private function normalizarTelefono(string $telefono): string
    {
        $limpio = preg_replace('/\D/', '', $telefono);

        // Si ya tiene el prefijo 52 (12 dígitos), quítalo para re-agregarlo limpio
        if (str_starts_with($limpio, '52') && strlen($limpio) === 12) {
            $limpio = substr($limpio, 2);
        }

        // Siempre anteponer el código de país México
        return '52' . $limpio;
    }

    private function extensionFromMime(string $mimeType): string
    {
        return match (true) {
            str_contains($mimeType, 'jpeg')       => 'jpg',
            str_contains($mimeType, 'png')        => 'png',
            str_contains($mimeType, 'gif')        => 'gif',
            str_contains($mimeType, 'webp')       => 'webp',
            str_contains($mimeType, 'mp4')        => 'mp4',
            str_contains($mimeType, 'ogg')        => 'ogg',
            str_contains($mimeType, 'mpeg')       => 'mp3',
            str_contains($mimeType, 'pdf')        => 'pdf',
            str_contains($mimeType, 'msword')     => 'doc',
            str_contains($mimeType, 'spreadsheet')=> 'xlsx',
            default                               => 'bin',
        };
    }
}