<?php
declare(strict_types=1);

/**
 * Descarga media de WhatsApp y la transcribe/analiza con el proveedor de IA activo.
 * Retorna siempre texto plano para pasar al NluRouter.
 */
class MediaTranscriber
{
    // ── WhatsApp media download ───────────────────────────────────────────────

    private static function downloadMedia(string $mediaId): ?array
    {
        $token = env('WHATSAPP_ACCESS_TOKEN', '');
        if ($token === '') return null;

        // 1) Obtener URL del archivo
        $ch = curl_init("https://graph.facebook.com/v18.0/{$mediaId}");
        curl_setopt_array($ch, [
            CURLOPT_HTTPHEADER     => ["Authorization: Bearer {$token}", "User-Agent: bot-palmas360/1.0"],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 15,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        $url  = $data['url'] ?? '';
        $mime = $data['mime_type'] ?? 'application/octet-stream';
        if ($url === '') return null;

        // 2) Descargar binario
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_HTTPHEADER     => ["Authorization: Bearer {$token}", "User-Agent: bot-palmas360/1.0"],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT        => 45,
        ]);
        $bytes = curl_exec($ch);
        $code  = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$bytes || strlen($bytes) < 100) return null;

        return ['bytes' => $bytes, 'mime' => $mime];
    }

    // ── Audio → texto ─────────────────────────────────────────────────────────

    public static function transcribeAudio(string $mediaId, array $company): ?string
    {
        $cfg      = self::getConfig($company);
        $provider = $cfg['ai_provider'] ?? env('AI_PROVIDER', 'openai');

        $media = self::downloadMedia($mediaId);
        if ($media === null) return null;

        return match ($provider) {
            'openai' => self::whisper($media['bytes'], $media['mime'], $cfg),
            'gemini' => self::geminiAudio($media['bytes'], $media['mime'], $cfg),
            default  => null, // Claude no soporta audio
        };
    }

    private static function whisper(string $bytes, string $mime, array $cfg): ?string
    {
        $apiKey = $cfg['openai_api_key'] ?? env('OPENAI_API_KEY', '');
        if ($apiKey === '') return null;

        $ext     = str_contains($mime, 'ogg') ? 'ogg' : (str_contains($mime, 'mp4') ? 'mp4' : 'ogg');
        $tmpFile = tempnam(sys_get_temp_dir(), 'wa_audio_') . '.' . $ext;
        file_put_contents($tmpFile, $bytes);

        $ch = curl_init('https://api.openai.com/v1/audio/transcriptions');
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => [
                'file'     => new CURLFile($tmpFile, $mime, 'audio.' . $ext),
                'model'    => 'whisper-1',
                'language' => 'es',
            ],
            CURLOPT_HTTPHEADER     => ["Authorization: Bearer {$apiKey}"],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 60,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);
        @unlink($tmpFile);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        return isset($data['text']) ? trim($data['text']) : null;
    }

    private static function geminiAudio(string $bytes, string $mime, array $cfg): ?string
    {
        $apiKey = $cfg['gemini_api_key'] ?? env('GEMINI_API_KEY', '');
        $model  = $cfg['gemini_model']  ?? env('GEMINI_MODEL', 'gemini-2.5-flash');
        if ($apiKey === '') return null;

        // Gemini acepta audio inline como base64
        $payload = json_encode([
            'contents' => [[
                'parts' => [
                    ['inline_data' => ['mime_type' => $mime, 'data' => base64_encode($bytes)]],
                    ['text' => 'Transcribe este audio de WhatsApp en español. Devuelve SOLO el texto transcrito, sin explicaciones ni puntuación extra.'],
                ],
            ]],
        ]);

        $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
        $ch  = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json'],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 60,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        $text = $data['candidates'][0]['content']['parts'][0]['text'] ?? null;
        return $text !== null ? trim($text) : null;
    }

    // ── Imagen → intención/texto ──────────────────────────────────────────────

    public static function extractFromImage(string $mediaId, array $company): ?string
    {
        $cfg      = self::getConfig($company);
        $provider = $cfg['ai_provider'] ?? env('AI_PROVIDER', 'openai');

        $media = self::downloadMedia($mediaId);
        if ($media === null) return null;

        $b64    = base64_encode($media['bytes']);
        $mime   = $media['mime'];
        $prompt = 'Analiza esta imagen de WhatsApp. Si contiene texto, extráelo. '
                . 'Describe en una oración qué quiere hacer el usuario o qué información contiene. '
                . 'Responde en español, máximo 2 oraciones.';

        return match ($provider) {
            'openai' => self::openaiVision($b64, $mime, $prompt, $cfg),
            'gemini' => self::geminiVision($b64, $mime, $prompt, $cfg),
            'claude' => self::claudeVision($b64, $mime, $prompt, $cfg),
            default  => null,
        };
    }

    private static function openaiVision(string $b64, string $mime, string $prompt, array $cfg): ?string
    {
        $apiKey = $cfg['openai_api_key'] ?? env('OPENAI_API_KEY', '');
        $model  = $cfg['ai_model']      ?? env('OPENAI_MODEL', 'gpt-4o');
        // Vision requires gpt-4o or gpt-4.1 — downgrade if mini is selected
        if (str_contains($model, 'mini') || str_contains($model, '3.5')) $model = 'gpt-4o';
        if ($apiKey === '') return null;

        $payload = json_encode([
            'model'      => $model,
            'max_tokens' => 200,
            'messages'   => [[
                'role'    => 'user',
                'content' => [
                    ['type' => 'image_url', 'image_url' => ['url' => "data:{$mime};base64,{$b64}"]],
                    ['type' => 'text',      'text'      => $prompt],
                ],
            ]],
        ]);

        $ch = curl_init('https://api.openai.com/v1/chat/completions');
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json', "Authorization: Bearer {$apiKey}"],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 30,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        $text = $data['choices'][0]['message']['content'] ?? null;
        return $text !== null ? trim($text) : null;
    }

    private static function geminiVision(string $b64, string $mime, string $prompt, array $cfg): ?string
    {
        $apiKey = $cfg['gemini_api_key'] ?? env('GEMINI_API_KEY', '');
        $model  = $cfg['gemini_model']  ?? env('GEMINI_MODEL', 'gemini-2.5-flash');
        if ($apiKey === '') return null;

        $payload = json_encode([
            'contents' => [[
                'parts' => [
                    ['inline_data' => ['mime_type' => $mime, 'data' => $b64]],
                    ['text' => $prompt],
                ],
            ]],
        ]);

        $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
        $ch  = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json'],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 30,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        $text = $data['candidates'][0]['content']['parts'][0]['text'] ?? null;
        return $text !== null ? trim($text) : null;
    }

    private static function claudeVision(string $b64, string $mime, string $prompt, array $cfg): ?string
    {
        $apiKey = $cfg['claude_api_key'] ?? env('CLAUDE_API_KEY', '');
        $model  = $cfg['claude_model']  ?? env('CLAUDE_MODEL', 'claude-haiku-4-5');
        if ($apiKey === '') return null;

        $payload = json_encode([
            'model'      => $model,
            'max_tokens' => 200,
            'messages'   => [[
                'role'    => 'user',
                'content' => [
                    ['type' => 'image',  'source' => ['type' => 'base64', 'media_type' => $mime, 'data' => $b64]],
                    ['type' => 'text',   'text'   => $prompt],
                ],
            ]],
        ]);

        $ch = curl_init('https://api.anthropic.com/v1/messages');
        curl_setopt_array($ch, [
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => $payload,
            CURLOPT_HTTPHEADER     => ['Content-Type: application/json', "x-api-key: {$apiKey}", 'anthropic-version: 2023-06-01'],
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_TIMEOUT        => 30,
        ]);
        $resp = curl_exec($ch);
        $code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        if ($code !== 200 || !$resp) return null;

        $data = json_decode($resp, true);
        $text = $data['content'][0]['text'] ?? null;
        return $text !== null ? trim($text) : null;
    }

    // ── Helpers ───────────────────────────────────────────────────────────────

    private static function getConfig(array $company): array
    {
        $json = $company['config_json'] ?? '';
        if ($json === '') return [];
        $cfg = json_decode($json, true);
        return is_array($cfg) ? $cfg : [];
    }
}