upload_ai.php

<?php
// upload_ai.php
header("Content-Type: application/json");

// -------------------------------
// CONFIG — EDIT THESE
// -------------------------------
$HUGGINGFACE_TOKEN = "35zqzztS09h1JSavStHwWUgQ3Ug_5bcvys1Yc3Cwj2FaJdjQG";  // Put new token here (PRIVATE)
$MODEL = "facebook/detr-resnet-50";                      // Or your custom model
$UPLOAD_DIR = __DIR__ . '/uploads/';

// Create folder if missing
if (!file_exists($UPLOAD_DIR)) {
    mkdir($UPLOAD_DIR, 0755, true);
}

// Helper function
function json_error($msg) {
    echo json_encode(["success" => false, "message" => $msg]);
    exit;
}

// -------------------------------
// 1. Check file upload
// -------------------------------
if (!isset($_FILES['file'])) {
    json_error("No file uploaded");
}

$file = $_FILES['file'];

if ($file['error'] !== UPLOAD_ERR_OK) {
    json_error("Upload error code: " . $file['error']);
}

// Sanitize filename and save
$basename = preg_replace('/[^A-Za-z0-9_\-\.]/', '_', basename($file['name']));
$target = $UPLOAD_DIR . time() . "_" . $basename;

if (!move_uploaded_file($file['tmp_name'], $target)) {
    json_error("Failed to save uploaded file");
}

// Read bytes for HF API
$imageBytes = file_get_contents($target);

// -------------------------------
// 2. CALL HUGGINGFACE INFERENCE API
// -------------------------------
$hfUrl = "https://api-inference.huggingface.co/models/" . $MODEL;

$ch = curl_init($hfUrl);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_POST, true);
curl_setopt($ch, CURLOPT_HTTPHEADER, [
    "Authorization: Bearer " . $HUGGINGFACE_TOKEN,
    "Content-Type: application/octet-stream"
]);
curl_setopt($ch, CURLOPT_POSTFIELDS, $imageBytes);

$response = curl_exec($ch);
$httpcode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
curl_close($ch);

// -------------------------------
// 3. Handle HF "model loading" case
// -------------------------------
if ($httpcode == 503) {
    json_error("Model loading on HuggingFace. Try again in 5–10 seconds.");
}

// Debug if HF returns error
if ($httpcode !== 200) {
    echo json_encode([
        "success" => false,
        "http_code" => $httpcode,
        "hf_response" => $response
    ]);
    exit;
}

// Decode HF output
$pred = json_decode($response, true);

if (!is_array($pred)) {
    json_error("Invalid HF response: " . $response);
}

// -------------------------------
// 4. Process predictions
// -------------------------------
$bottleDetected = false;
$threshold = 0.50;
$predictions = [];

foreach ($pred as $item) {
    $label = strtolower($item["label"] ?? "");
    $score = floatval($item["score"] ?? 0);
    $box   = $item["box"] ?? null;

    // Collect prediction for logging/debug
    $predictions[] = [
        "label" => $label,
        "score" => $score,
        "box"   => $box
    ];

    // Bottle detected?
    if ($label === "bottle" && $score >= $threshold) {
        $bottleDetected = true;
    }
}

$result = $bottleDetected ? "bottle" : "not_bottle";

// -------------------------------
// 5. Return clean JSON back to ESP32
// -------------------------------
echo json_encode([
    "success" => true,
    "result" => $result,            // "bottle" or "not_bottle"
    "predictions" => $predictions   // optional debug info
]);
?>