export default async function handler(req, res) {
    res.setHeader('Cache-Control', 'no-store, no-cache, must-revalidate, proxy-revalidate');
    res.setHeader('Pragma', 'no-cache');
    res.setHeader('Expires', '0');

    if (req.method !== 'GET') {
        return res.status(405).json({ error: 'Método no permitido' });
    }

    try {
        let jobId = req.query?.job_id;
        if (!jobId && req.url) {
            try {
                const parsedUrl = new URL(req.url, 'https://localhost');
                jobId = parsedUrl.searchParams.get('job_id');
            } catch (e) {}
        }

        if (!jobId) {
            return res.status(400).json({ error: 'El parámetro job_id es requerido.' });
        }

        const hfToken = process.env.HF_TOKEN;

        if (jobId.startsWith('hf:')) {
            const parts = jobId.split(':');
            const spaceHost = parts[1] || 'logicaltrue-trellis-2';
            const sessionHash = parts[2];
            const eventId = parts[3];
            const decimationTarget = parseInt(parts[4]) || 300000;
            const textureSize = parseInt(parts[5]) || 1024;
            const spaceUrl = `https://${spaceHost}.hf.space`;

            // Cabecera obligatoria Accept: text/event-stream para endpoints SSE de Gradio v4
            const sseHeaders = {
                'Accept': 'text/event-stream',
                'Cache-Control': 'no-cache',
                ...(hfToken ? { 'Authorization': `Bearer ${hfToken}` } : {})
            };

            const jsonHeaders = {
                'Content-Type': 'application/json',
                ...(hfToken ? { 'Authorization': `Bearer ${hfToken}` } : {})
            };

            // ─── 1. Verificar estado del Paso 1 (/image_to_3d) ────────────────────
            const step1Urls = [
                `${spaceUrl}/gradio_api/call/image_to_3d/${eventId}`,
                `${spaceUrl}/call/image_to_3d/${eventId}`,
                `${spaceUrl}/gradio_api/queue/data?session_hash=${sessionHash}`,
                `${spaceUrl}/queue/data?session_hash=${sessionHash}`
            ];

            let isStep1Complete = false;

            for (const statusUrl of step1Urls) {
                try {
                    const qRes = await fetch(statusUrl, {
                        headers: sseHeaders,
                        signal: AbortSignal.timeout(9000)
                    }).catch(() => null);

                    if (qRes && qRes.ok) {
                        const txt = await qRes.text().catch(() => '');
                        console.log(`[Paso 1 Stream SSE ${eventId}]`, txt.slice(0, 300));

                        // Validar si el evento complete o process_completed fue emitido con éxito
                        if (txt.includes('event: complete') || txt.includes('process_completed') || txt.includes('event: generating')) {
                            if (txt.includes('"success":false')) {
                                continue;
                            }
                            isStep1Complete = true;
                            break;
                        }

                        if (txt.includes('process_starts') || txt.includes('estimation') || txt.includes('event: heartbeat')) {
                            return res.status(200).json({
                                status: 'processing',
                                progress: 65,
                                message: 'Inferencia 3D en progreso en la GPU A100 (Sparse & SLaT)...'
                            });
                        }
                    }
                } catch (e) {}
            }

            // Si la GPU aún está calculando el volumen 3D
            if (!isStep1Complete) {
                return res.status(200).json({
                    status: 'processing',
                    progress: 60,
                    message: 'Calculando volumen 3D en la GPU A100...'
                });
            }

            // ─── 2. Paso 1 completado! Ejecutar Extracción GLB (/extract_glb) ─────
            console.log(`[Paso 1 completado] Iniciando Paso 2 (/extract_glb) decimation=${decimationTarget}...`);

            let extractEventId = null;
            try {
                const extractRes = await fetch(`${spaceUrl}/gradio_api/call/extract_glb`, {
                    method: 'POST',
                    headers: jsonHeaders,
                    body: JSON.stringify({
                        data: [decimationTarget, textureSize],
                        session_hash: sessionHash
                    }),
                    signal: AbortSignal.timeout(10000)
                }).catch(() => null);

                if (extractRes && extractRes.ok) {
                    const extractJson = await extractRes.json().catch(() => ({}));
                    extractEventId = extractJson.event_id;
                    console.log(`[Paso 2 /extract_glb Iniciado] event_id: ${extractEventId}`);
                }
            } catch (e) {}

            // Consultar resultado de /extract_glb
            const extractCheckUrls = [
                extractEventId ? `${spaceUrl}/gradio_api/call/extract_glb/${extractEventId}` : null,
                extractEventId ? `${spaceUrl}/call/extract_glb/${extractEventId}` : null,
                `${spaceUrl}/gradio_api/queue/data?session_hash=${sessionHash}`,
                `${spaceUrl}/queue/data?session_hash=${sessionHash}`
            ].filter(Boolean);

            for (const extUrl of extractCheckUrls) {
                try {
                    const extRes = await fetch(extUrl, {
                        headers: sseHeaders,
                        signal: AbortSignal.timeout(9000)
                    }).catch(() => null);

                    if (extRes && extRes.ok) {
                        const extTxt = await extRes.text().catch(() => '');
                        const glbMatch = extTxt.match(/"([^"]+\.glb)"/i);

                        if (glbMatch && glbMatch[1]) {
                            let rawGlb = glbMatch[1];
                            let fullGlbUrl = rawGlb;

                            if (!rawGlb.startsWith('http')) {
                                if (rawGlb.startsWith('/tmp/') || rawGlb.startsWith('tmp/')) {
                                    fullGlbUrl = `${spaceUrl}/file=${rawGlb.startsWith('/') ? '' : '/'}${rawGlb}`;
                                } else if (rawGlb.startsWith('/file=') || rawGlb.startsWith('file=')) {
                                    fullGlbUrl = `${spaceUrl}${rawGlb.startsWith('/') ? '' : '/'}${rawGlb}`;
                                } else {
                                    fullGlbUrl = `${spaceUrl}/file=${rawGlb}`;
                                }
                            }

                            console.log(`[GLB EXTRACCION EXITOSA 100%] ${fullGlbUrl}`);
                            return res.status(200).json({
                                status: 'completed',
                                progress: 100,
                                result: {
                                    gltfUrl: fullGlbUrl,
                                    glbUrl: fullGlbUrl,
                                    fbxUrl: fullGlbUrl,
                                    detectedCategory: 'objeto'
                                }
                            });
                        }
                    }
                } catch (e) {}
            }

            return res.status(200).json({
                status: 'processing',
                progress: 85,
                message: 'Extrayendo texturas PBR y generando archivo GLB...'
            });
        }

        return res.status(200).json({
            status: 'processing',
            progress: 50,
            message: 'Procesando modelo 3D en la nube...'
        });

    } catch (err) {
        console.error('[Vercel Job-Status Error]', err);
        return res.status(500).json({ error: err.message || 'Error verificando el estado de la tarea.' });
    }
}