/**
 * POST /v1/extract — Extrahering av data från bilder
 * OCR-liknande extraktion via AI + bildanalys
 */
import { Router } from 'express';
import sharp from 'sharp';
import { fetchImage, hashInput, saveResult, genReqId, requireAuth } from './utils.mjs';

const router = Router();

const OLLAMA_BASE = process.env.OLLAMA_URL || 'http://172.31.40.60:11434';
const GROQ_KEY = process.env.GROQ_API_KEY || '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';

async function extractData(buffer, extractType) {
  const base64 = buffer.toString('base64');
  
  // Image analysis for structure
  const { data, info } = await sharp(buffer).resize(128, 128).raw().toBuffer({ resolveWithObject: true });
  const w = info.width, h = info.height;
  
  // Detect text-like regions (high contrast horizontal bands)
  const textRegions = [];
  for (let y = 2; y < h - 2; y++) {
    let rowContrast = 0;
    for (let x = 1; x < w - 1; x++) {
      const i = (y * w + x) * 3;
      const gray = (data[i] + data[i+1] + data[i+2]) / 3;
      const prevGray = (data[i-3] + data[i-2] + data[i-1]) / 3;
      rowContrast += Math.abs(gray - prevGray);
    }
    if (rowContrast / w > 15) {
      textRegions.push({ y, contrast: Math.round(rowContrast / w) });
    }
  }
  
  // Try AI extraction
  let extracted = null;
  try {
    const promptMap = {
      text: 'Extract all visible text from this image. Return as plain text.',
      faces: 'Count the number of faces in this image. Return only the number.',
      objects: 'List all objects visible in this image as a comma-separated list.',
      colors: 'List the dominant colors in this image as hex codes.',
      metadata: 'Describe the image type, approximate dimensions, and visible content.',
    };
    
    const r = await fetch(`${OLLAMA_BASE}/api/generate`, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify({
        model: 'amos-r2:latest',
        prompt: promptMap[extractType] || promptMap.text,
        images: [base64],
        stream: false,
        options: { num_predict: 300 }
      }),
      signal: AbortSignal.timeout(15000)
    });
    if (r.ok) {
      const d = await r.json();
      extracted = d.response?.trim();
    }
  } catch (e) { console.log('[extract] ollama failed:', e.message); }

  // Fallback extraction
  if (!extracted) {
    const fallbacks = {
      text: `Detected ${textRegions.length} text-like horizontal bands in the image. Text extraction requires OCR engine.`,
      faces: 'Face count requires face detection model. Use /v1/detect endpoint.',
      objects: 'Object list requires object detection model. Use /v1/detect endpoint.',
      colors: extractDominantColors(data, w, h),
      metadata: `Image analyzed: ${w*4}x${h*4}px estimated, ${textRegions.length > 10 ? 'text-heavy' : 'image-heavy'} content.`,
    };
    extracted = fallbacks[extractType] || fallbacks.text;
  }

  return {
    extracted,
    text_regions_detected: textRegions.length,
    has_text: textRegions.length > 5,
  };
}

function extractDominantColors(data, w, h) {
  const colorMap = {};
  for (let i = 0; i < w * h; i++) {
    const r = Math.round(data[i*3] / 32) * 32;
    const g = Math.round(data[i*3+1] / 32) * 32;
    const b = Math.round(data[i*3+2] / 32) * 32;
    const key = `#${r.toString(16).padStart(2,'0')}${g.toString(16).padStart(2,'0')}${b.toString(16).padStart(2,'0')}`;
    colorMap[key] = (colorMap[key] || 0) + 1;
  }
  return Object.entries(colorMap)
    .sort((a, b) => b[1] - a[1])
    .slice(0, 5)
    .map(([color, count]) => ({ color, coverage_pct: Math.round(count / (w * h) * 100) }));
}

router.post('/', requireAuth, async (req, res) => {
  const requestId = genReqId();
  const start = Date.now();
  try {
    const { image_url, image_base64, extract_type = 'text' } = req.body || {};
    const img = await fetchImage({ image_url, image_base64 });
    const inputHash = hashInput(img.buffer);

    const { extracted, text_regions_detected, has_text } = await extractData(img.buffer, extract_type);
    const confidence = has_text ? 0.8 : 0.5;

    const result = {
      ok: true,
      endpoint: 'extract',
      request_id: requestId,
      extract_type,
      extracted_data: extracted,
      text_regions_detected,
      has_text_content: has_text,
      confidence,
      inference_time_ms: Date.now() - start,
    };

    await saveResult('extract', requestId, inputHash, result, confidence, { extract_type, source: img.source });
    res.json(result);
  } catch (e) {
    console.error('[extract]', e);
    res.status(500).json({ ok: false, error: e.message, request_id: requestId });
  }
});

export default router;