<?php
header('Content-Type: application/json');
require_once __DIR__ . '/../ai/LocalAIApi.php';

$debugFile = __DIR__ . '/analyze_debug.log';
function debugLog($msg) {
    global $debugFile;
    file_put_contents($debugFile, "[" . date('Y-m-d H:i:s') . "] " . $msg . "\n", FILE_APPEND);
}

$rawInput = file_get_contents('php://input');
$data = json_decode($rawInput, true);
$image = $data['image'] ?? null;
$barcode = $data['barcode'] ?? null;

debugLog("Request received. Barcode: " . ($barcode ?? 'none') . ", Image size: " . ($image ? strlen($image) : 0));

if (!$image && !$barcode) {
    debugLog("Error: No image or barcode provided");
    echo json_encode(['success' => false, 'error' => 'No image or barcode provided']);
    exit;
}

$productData = null;
$errorDetails = null;

// Try Barcode Lookup via Open Food Facts if barcode is present
if ($barcode) {
    debugLog("Attempting Open Food Facts lookup for $barcode");
    $url = "https://world.openfoodfacts.org/api/v0/product/" . urlencode($barcode) . ".json";
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
    curl_setopt($ch, CURLOPT_USERAGENT, 'HomePantryTracker/1.0');
    $response = curl_exec($ch);
    $httpCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    curl_close($ch);

    if ($httpCode === 200 && $response) {
        $offData = json_decode($response, true);
        if (isset($offData['status']) && $offData['status'] == 1) {
            $p = $offData['product'];
            $productData = [
                'name' => $p['product_name'] ?? ($p['product_name_en'] ?? 'Unknown Product'),
                'category' => 'Pantry', // Default
                'quantity' => $p['quantity'] ?? '',
                'expiration_date' => null
            ];
            debugLog("Barcode found: " . $productData['name']);
            
            // Try to map category
            if (!empty($p['categories_tags'])) {
                $tags = implode(' ', $p['categories_tags']);
                if (stripos($tags, 'dairy') !== false || stripos($tags, 'milk') !== false) $productData['category'] = 'Dairy';
                elseif (stripos($tags, 'meat') !== false) $productData['category'] = 'Meat';
                elseif (stripos($tags, 'bakery') !== false || stripos($tags, 'bread') !== false) $productData['category'] = 'Bakery';
                elseif (stripos($tags, 'fruit') !== false || stripos($tags, 'vegetable') !== false) $productData['category'] = 'Produce';
                elseif (stripos($tags, 'frozen') !== false) $productData['category'] = 'Frozen';
            }
        } else {
            debugLog("Barcode not found in Open Food Facts");
        }
    } else {
        debugLog("Open Food Facts API error: $httpCode");
    }
}

// If barcode lookup failed or we have an image, use AI
if (!$productData) {
    debugLog("Using AI for identification...");
    $prompt = "You are a professional pantry organizer. Identify the product from the image provided. 
    Return ONLY a valid JSON object. 
    Keys:
    - name: Specific brand and product name.
    - category: Dairy, Meat, Bakery, Produce, Pantry, Frozen.
    - quantity: e.g., '1.5 L', '500g'.
    - expiration_date: Look for 'Best Before', 'Use By', or 'EXP' date in YYYY-MM-DD format, or null.
    If the package is not in English, translate name/category to English.";

    if ($image) {
        // Use "Simple" approach: data URL directly in the content string
        $content = $prompt . "\nAnalyze this image: " . $image;
        $messages = [
            ['role' => 'user', 'content' => $content]
        ];
    } else {
        $messages = [
            ['role' => 'user', 'content' => $prompt . " Product barcode: $barcode"]
        ];
    }

    $resp = LocalAIApi::createResponse([
        'input' => $messages,
        'temperature' => 0.1
    ]);

    if (!empty($resp['success'])) {
        debugLog("AI response successful");
        $result = LocalAIApi::decodeJsonFromResponse($resp);
        if ($result) {
            $productData = $result;
        } else {
            $text = LocalAIApi::extractText($resp);
            debugLog("AI returned text instead of JSON. Extracting...");
            if (preg_match('/\{.*\}/s', $text, $matches)) {
                $productData = json_decode($matches[0], true);
            } else {
                $errorDetails = "AI returned text instead of JSON: " . substr($text, 0, 100);
                debugLog("Error: $errorDetails");
            }
        }
    } else {
        $errorDetails = $resp['error'] ?? $resp['message'] ?? 'AI request failed';
        $httpStatus = $resp['status'] ?? 'unknown';
        debugLog("AI Request failed. Status: $httpStatus, Error: $errorDetails");
        
        if (isset($resp['response'])) {
            debugLog("Full proxy response: " . json_encode($resp['response']));
        }
    }
}

if ($productData) {
    if (isset($productData['expiration_date']) && ($productData['expiration_date'] === 'null' || $productData['expiration_date'] === '')) {
        $productData['expiration_date'] = null;
    }
    debugLog("Returning success for " . ($productData['name'] ?? 'unknown'));
    echo json_encode(['success' => true, 'data' => $productData]);
} else {
    debugLog("Returning failure: " . ($errorDetails ?? 'Could not identify product'));
    echo json_encode(['success' => false, 'error' => $errorDetails ?: 'Could not identify product']);
}