<?php
$authFile = __DIR__ . '/../auth.php';
if (file_exists($authFile)) {
    $current_project = basename(__DIR__);
    require_once $authFile;
}

if (session_status() === PHP_SESSION_NONE) {
    session_start();
}
require_once 'db.php';
if (file_exists(__DIR__ . '/vendor/autoload.php')) {
    require_once __DIR__ . '/vendor/autoload.php';
}

if (file_exists(__DIR__ . '/.env') && class_exists('Dotenv\Dotenv')) {
    $dotenv = Dotenv\Dotenv::createImmutable(__DIR__);
    $dotenv->safeLoad();
}

if (!isset($_SESSION['user_id'])) {
    http_response_code(401);
    echo json_encode(['error' => 'Benutzer nicht authentifiziert.']);
    exit;
}
$currentUserId = $_SESSION['user_id'];

// === HELPER FUNCTIONS ===
function callGeminiAPI(array $payload, string $apiKey): array {
    $googleApiUrl = 'https://generativelanguage.googleapis.com/v1beta/models/gemini-2.5-flash:generateContent';
    $fullApiUrl = $googleApiUrl . '?key=' . $apiKey;
    $ch = curl_init();
    curl_setopt_array($ch, [
        CURLOPT_URL            => $fullApiUrl,
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_POST           => true,
        CURLOPT_POSTFIELDS     => json_encode($payload),
        CURLOPT_HTTPHEADER     => ['Content-Type: application/json'],
        CURLOPT_TIMEOUT        => 90,
    ]);
    $response_body = curl_exec($ch);
    $http_code = curl_getinfo($ch, CURLINFO_HTTP_CODE);
    if (curl_errno($ch) || $http_code >= 400) {
        $error_message = curl_errno($ch) ? curl_error($ch) : 'KI-API-Fehler mit Status ' . $http_code . ' - ' . $response_body;
        curl_close($ch);
        throw new Exception('Fehler bei der Kommunikation mit der KI: ' . $error_message);
    }
    curl_close($ch);
    return json_decode($response_body, true);
}

function processUploadedPhoto(array $fileInfo, int $targetWidth = 800): ?string {
    if ($fileInfo['error'] !== UPLOAD_ERR_OK) return null;
    $allowedMimeTypes = ['image/jpeg', 'image/png', 'image/webp'];
    if (!in_array(mime_content_type($fileInfo['tmp_name']), $allowedMimeTypes) || $fileInfo['size'] > (10 * 1024 * 1024)) return null;
    $uploadDir = 'uploads/';
    if (!is_dir($uploadDir)) mkdir($uploadDir, 0755, true);
    $fileName = uniqid() . '-' . pathinfo($fileInfo['name'], PATHINFO_FILENAME) . '.webp';
    $targetFilePath = $uploadDir . $fileName;
    $sourceImage = null;
    switch (exif_imagetype($fileInfo['tmp_name'])) {
        case IMAGETYPE_JPEG: $sourceImage = imagecreatefromjpeg($fileInfo['tmp_name']); break;
        case IMAGETYPE_PNG: $sourceImage = imagecreatefrompng($fileInfo['tmp_name']); break;
        case IMAGETYPE_WEBP: $sourceImage = imagecreatefromwebp($fileInfo['tmp_name']); break;
    }
    if (!$sourceImage) return null;
    $resizedImage = (imagesx($sourceImage) > $targetWidth) ? imagescale($sourceImage, $targetWidth) : $sourceImage;
    imagewebp($resizedImage, $targetFilePath, 85);
    imagedestroy($sourceImage);
    if ($resizedImage !== $sourceImage) imagedestroy($resizedImage);
    return $targetFilePath;
}

function getPlantWithDueDates($pdo, $plantId, $userId) {
    $stmt = $pdo->prepare("SELECT p.id, p.name, p.latin_name, p.photo, p.last_watered, p.last_fertilized, p.watering_interval_days, p.fertilizing_interval_days, p.care_tips FROM plants p WHERE p.id = ? AND p.user_id = ?");
    $stmt->execute([$plantId, $userId]);
    $plant = $stmt->fetch(PDO::FETCH_ASSOC);
    if ($plant) {
        $plant['watering_interval'] = $plant['watering_interval_days'];
        $plant['fertilizing_interval'] = $plant['fertilizing_interval_days'];
        $isValidDate = fn($dateStr) => !empty($dateStr) && $dateStr !== '0000-00-00';
        if ((int)$plant['watering_interval'] > 0 && $isValidDate($plant['last_watered'])) {
            $plant['next_watering_due'] = (new DateTime($plant['last_watered']))->add(new DateInterval('P' . $plant['watering_interval'] . 'D'))->format('Y-m-d');
        } else { $plant['next_watering_due'] = null; }
        if ((int)$plant['fertilizing_interval'] > 0 && $isValidDate($plant['last_fertilized'])) {
            $plant['next_fertilizing_due'] = (new DateTime($plant['last_fertilized']))->add(new DateInterval('P' . $plant['fertilizing_interval'] . 'D'))->format('Y-m-d');
        } else { $plant['next_fertilizing_due'] = null; }
    }
    return $plant;
}

// === CREDIT MANAGEMENT ===
try {
    $stmt = $pdo->prepare("SELECT ai_credits_last_reset FROM users WHERE id = ?");
    $stmt->execute([$currentUserId]);
    $lastReset = $stmt->fetchColumn();
    $now = new DateTime();
    if ($lastReset === null || (new DateTime($lastReset))->format('Y-m') < $now->format('Y-m')) {
        $stmt = $pdo->prepare("UPDATE users SET ai_credits = 100, ai_credits_last_reset = NOW() WHERE id = ?");
        $stmt->execute([$currentUserId]);
    }
} catch (Exception $e) { /* non-blocking */ }

// === API ROUTING ===
$method = $_SERVER['REQUEST_METHOD'];
$json_data = json_decode(file_get_contents('php://input'), true);
header('Content-Type: application/json');

try {
    // --- Handle JSON-based POST requests FIRST ---
    if ($method === 'POST' && !empty($json_data)) {
        $request_type = $json_data['request_type'] ?? '';
        switch ($request_type) {
            case 'ai_identification':
            case 'ai_enrichment':
                $pdo->beginTransaction();
                $stmt = $pdo->prepare("UPDATE users SET ai_credits = ai_credits - 1 WHERE id = ? AND ai_credits >= 1");
                $stmt->execute([$currentUserId]);
                $geminiKey = $_ENV['GEMINI_API_KEY'] ?? getenv('GEMINI_API_KEY') ?: '';
                if (empty($geminiKey) && file_exists(__DIR__ . '/../home/.env')) {
                    foreach (file(__DIR__ . '/../home/.env', FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES) as $line) {
                        $line = trim($line);
                        if ($line === '' || $line[0] === '#') continue;
                        if (strpos($line, '=') !== false) {
                            list($k, $v) = explode('=', $line, 2);
                            if (trim($k) === 'GEMINI_API_KEY') {
                                $geminiKey = trim(trim($v), '"\'');
                                break;
                            }
                        }
                    }
                }
                $response_data = callGeminiAPI($json_data['payload'], $geminiKey);
                $pdo->commit();
                echo json_encode($response_data);
                break;
            case 'update_user_settings':
                $settings = $json_data['settings'] ?? [];
                $allowedKeys = ['theme', 'allow_photo_sharing', 'auto_fill_watering', 'auto_fill_fertilizing', 'auto_fill_care_tips'];
                $sqlParts = []; $params = [];
                foreach ($settings as $key => $value) {
                    if (in_array($key, $allowedKeys)) {
                        $sqlParts[] = "$key = ?";
                        $params[] = is_bool($value) ? (int)$value : $value;
                    }
                }
                if (empty($sqlParts)) throw new Exception('Keine gültigen Einstellungsfelder.', 400);
                $params[] = $currentUserId;
                $stmt = $pdo->prepare("UPDATE users SET " . implode(', ', $sqlParts) . " WHERE id = ?");
                $stmt->execute($params);
                echo json_encode(['success' => true]);
                break;
            case 'care_action':
                $plantId = $json_data['id'];
                $column = ($json_data['action'] === 'water') ? 'last_watered' : 'last_fertilized';
                $entryType = ($json_data['action'] === 'water') ? 'watered' : 'fertilized';
                $pdo->beginTransaction();
                $stmt = $pdo->prepare("UPDATE plants SET $column = CURDATE() WHERE id = ? AND user_id = ?");
                $stmt->execute([$plantId, $currentUserId]);
                $stmt = $pdo->prepare("INSERT INTO plant_diary (plant_id, user_id, entry_type) VALUES (?, ?, ?)");
                $stmt->execute([$plantId, $currentUserId, $entryType]);
                $pdo->commit();
                echo json_encode(['success' => true, 'plant' => getPlantWithDueDates($pdo, $plantId, $currentUserId)]);
                break;
             case 'set_profile_picture':
                $stmt = $pdo->prepare("UPDATE users SET profile_image = ? WHERE id = ?");
                $stmt->execute([$json_data['photo_path'], $currentUserId]);
                echo json_encode(['success' => true, 'new_image' => $json_data['photo_path']]);
                break;
            default:
                throw new Exception('Unbekannter JSON-Request-Typ.', 400);
        }
        exit;
    }

    // --- Handle GET, DELETE, and multipart/form-data POST requests ---
    switch ($method) {
        case 'GET':
            $action = $_GET['action'] ?? 'get_plants';
            switch ($action) {
                case 'get_plants':
                    $stmt = $pdo->prepare("SELECT id FROM plants WHERE user_id = ? ORDER BY id DESC");
                    $stmt->execute([$currentUserId]);
                    $plant_ids = $stmt->fetchAll(PDO::FETCH_COLUMN);
                    echo json_encode(array_map(fn($id) => getPlantWithDueDates($pdo, $id, $currentUserId), $plant_ids));
                    break;
                case 'get_diary':
                    $stmt = $pdo->prepare("SELECT * FROM plant_diary WHERE plant_id = ? AND user_id = ? ORDER BY entry_date DESC");
                    $stmt->execute([$_GET['plant_id'], $currentUserId]);
                    echo json_encode($stmt->fetchAll());
                    break;
                case 'get_user_settings':
                    $stmt = $pdo->prepare("SELECT username, email, profile_image, theme, allow_photo_sharing, ai_credits, auto_fill_watering, auto_fill_fertilizing, auto_fill_care_tips FROM users WHERE id = ?");
                    $stmt->execute([$currentUserId]);
                    $userSettings = $stmt->fetch();
                    $stmt_count = $pdo->prepare("SELECT COUNT(id) as plant_count FROM plants WHERE user_id = ?");
                    $stmt_count->execute([$currentUserId]);
                    $userSettings['plant_count'] = $stmt_count->fetchColumn();
                    echo json_encode($userSettings);
                    break;
                case 'get_lexicon_entries':
                    $stmt = $pdo->prepare("SELECT pl.name, pl.latin_name, lp.photo_path as photo_url FROM plant_lexicon pl LEFT JOIN (SELECT plant_latin_name, photo_path, ROW_NUMBER() OVER(PARTITION BY plant_latin_name ORDER BY ai_photo_quality_score DESC, id DESC) as rn FROM lexicon_photos WHERE status = 'approved') lp ON pl.latin_name = lp.plant_latin_name AND lp.rn = 1 WHERE pl.entry_count > 0 ORDER BY pl.name ASC");
                    $stmt->execute();
                    echo json_encode($stmt->fetchAll());
                    break;
                case 'get_lexicon_entry_details':
                    $latinName = $_GET['latin_name'] ?? '';
                    if (empty($latinName)) throw new Exception('Kein botanischer Name angegeben.', 400);
                    $stmt = $pdo->prepare("SELECT * FROM plant_lexicon WHERE latin_name = ?");
                    $stmt->execute([$latinName]);
                    $plantDetails = $stmt->fetch();
                    if (!$plantDetails) throw new Exception('Pflanze nicht im Lexikon gefunden.', 404);
                    $stmtPhotos = $pdo->prepare("SELECT photo_path FROM lexicon_photos WHERE plant_latin_name = ? AND status = 'approved' ORDER BY ai_photo_quality_score DESC, id DESC LIMIT 10");
                    $stmtPhotos->execute([$latinName]);
                    $plantDetails['photo_gallery'] = $stmtPhotos->fetchAll(PDO::FETCH_COLUMN);
                    echo json_encode($plantDetails);
                    break;
                default:
                    throw new Exception('Ungültige GET-Aktion.', 400);
            }
            break;

        case 'POST':
            $action = $_POST['action'] ?? 'save_plant';
            switch ($action) {
                case 'add_diary_entry':
                    $photoPath = isset($_FILES['photo']) ? processUploadedPhoto($_FILES['photo'], 600) : null;
                    $stmt = $pdo->prepare("INSERT INTO plant_diary (plant_id, user_id, notes, photo, entry_type) VALUES (?, ?, ?, ?, ?)");
                    $stmt->execute([$_POST['plant_id'], $currentUserId, $_POST['notes'] ?? null, $photoPath, isset($_POST['is_milestone']) ? 'milestone' : 'manual']);
                    $newEntryId = $pdo->lastInsertId();
                    $stmt = $pdo->prepare("SELECT * FROM plant_diary WHERE id = ?");
                    $stmt->execute([$newEntryId]);
                    echo json_encode(['success' => true, 'entry' => $stmt->fetch()]);
                    break;
                case 'save_plant':
                    $name = trim($_POST['name'] ?? '');
                    if (empty($name)) throw new Exception('Der Name der Pflanze darf nicht leer sein.', 400);
                    
                    $plantId = $_POST['id'] ?? null;
                    $latinName = trim($_POST['latin_name'] ?? '') ?: null;
                    $photoPath = isset($_FILES['photo']) ? processUploadedPhoto($_FILES['photo']) : null;
                    $finalPhotoPath = $photoPath ?? $_POST['current_photo'] ?? null;
                    
                    // ROBUSTE PRÜFUNG DER INTERVALLE
                    $wateringInterval = (isset($_POST['watering_interval']) && is_numeric($_POST['watering_interval'])) ? (int)$_POST['watering_interval'] : null;
                    $fertilizingInterval = (isset($_POST['fertilizing_interval']) && is_numeric($_POST['fertilizing_interval'])) ? (int)$_POST['fertilizing_interval'] : null;

                    $careTips = trim($_POST['care_tips'] ?? '') ?: null;

                    $pdo->beginTransaction();
                    
                    $oldLatinName = null;
                    if ($plantId) { // Edit
                        $stmtOld = $pdo->prepare("SELECT latin_name FROM plants WHERE id = ? AND user_id = ?");
                        $stmtOld->execute([$plantId, $currentUserId]);
                        $oldLatinName = $stmtOld->fetchColumn();

                        $stmt = $pdo->prepare("UPDATE plants SET name = ?, latin_name = ?, photo = ?, watering_interval_days = ?, fertilizing_interval_days = ?, care_tips = ? WHERE id = ? AND user_id = ?");
                        $stmt->execute([$name, $latinName, $finalPhotoPath, $wateringInterval, $fertilizingInterval, $careTips, $plantId, $currentUserId]);
                    } else { // Add
                        $stmt = $pdo->prepare("INSERT INTO plants (user_id, name, latin_name, photo, last_watered, last_fertilized, watering_interval_days, fertilizing_interval_days, care_tips) VALUES (?, ?, ?, ?, CURDATE(), CURDATE(), ?, ?, ?)");
                        $stmt->execute([$currentUserId, $name, $latinName, $finalPhotoPath, $wateringInterval, $fertilizingInterval, $careTips]);
                        $plantId = $pdo->lastInsertId();
                        $stmt = $pdo->prepare("INSERT INTO plant_diary (plant_id, user_id, entry_type, notes) VALUES (?, ?, 'milestone', 'Pflanze hinzugefügt')");
                        $stmt->execute([$plantId, $currentUserId]);
                    }

                    // Handle lexicon entry count changes
                    if ($oldLatinName && $oldLatinName !== $latinName) {
                        $stmtDec = $pdo->prepare("UPDATE plant_lexicon SET entry_count = entry_count - 1 WHERE latin_name = ? AND entry_count > 0");
                        $stmtDec->execute([$oldLatinName]);
                    }
                    if ($latinName && (!$oldLatinName || $oldLatinName !== $latinName)) {
                         $stmt = $pdo->prepare("INSERT INTO plant_lexicon (latin_name, name) VALUES (?, ?) ON DUPLICATE KEY UPDATE entry_count = entry_count + 1, name = VALUES(name)");
                        $stmt->execute([$latinName, $name]);
                    }

                    // Process AI data for lexicon if available
                    $enrichmentData = json_decode($_POST['ai_enrichment_json'] ?? '{}', true);

                    if(!empty($enrichmentData)) {
                        $stmt = $pdo->prepare("UPDATE plant_lexicon SET plant_family = :plant_family, plant_genus = :plant_genus, description_full = :description_full, care_tips = :care_tips, watering_interval_days = :watering_interval_days, fertilizing_interval_days = :fertilizing_interval_days, light_requirement = :light_requirement, water_requirement = :water_requirement, humidity_requirement = :humidity_requirement, care_difficulty = :care_difficulty, growth_habit = :growth_habit, mature_size = :mature_size, toxicity = :toxicity, edibility = :edibility, temperature_preference = :temperature_preference, flowering_period = :flowering_period, substrate_recommendation = :substrate_recommendation, native_to = :native_to, tags = :tags, updated_at = NOW() WHERE latin_name = :latin_name AND description_full IS NULL");
                        $stmt->execute([
                            'plant_family' => $enrichmentData['plant_family'] ?? null,
                            'plant_genus' => $enrichmentData['plant_genus'] ?? null,
                            'description_full' => $enrichmentData['description_full'] ?? null,
                            'care_tips' => $enrichmentData['care_tips'] ?? null,
                            'watering_interval_days' => $enrichmentData['watering_interval_days'] ?? null,
                            'fertilizing_interval_days' => $enrichmentData['fertilizing_interval_days'] ?? null,
                            'light_requirement' => $enrichmentData['light_requirement'] ?? null,
                            'water_requirement' => $enrichmentData['water_requirement'] ?? null,
                            'humidity_requirement' => $enrichmentData['humidity_requirement'] ?? null,
                            'care_difficulty' => $enrichmentData['care_difficulty'] ?? null,
                            'growth_habit' => $enrichmentData['growth_habit'] ?? null,
                            'mature_size' => $enrichmentData['mature_size'] ?? null,
                            'toxicity' => $enrichmentData['toxicity'] ?? null,
                            'edibility' => $enrichmentData['edibility'] ?? null,
                            'temperature_preference' => $enrichmentData['temperature_preference'] ?? null,
                            'flowering_period' => $enrichmentData['flowering_period'] ?? null,
                            'substrate_recommendation' => $enrichmentData['substrate_recommendation'] ?? null,
                            'native_to' => $enrichmentData['native_to'] ?? null,
                            'tags' => $enrichmentData['tags'] ?? null,
                            'latin_name' => $latinName
                        ]);
                    }
                    
                    // Process photo for lexicon if allowed and available
                    $fullAiResponse = json_decode($_POST['ai_full_response_json'] ?? '{}', true);
                    $stmtAllow = $pdo->prepare("SELECT allow_photo_sharing FROM users WHERE id = ?");
                    $stmtAllow->execute([$currentUserId]);
                    if ($stmtAllow->fetchColumn() && $finalPhotoPath && $photoPath && !empty($fullAiResponse['photo_analysis'])) {
                        $photoData = $fullAiResponse['photo_analysis'];
                        $isHighQuality = $photoData['is_high_quality'] ?? false;
                        
                        $stmt = $pdo->prepare("INSERT INTO lexicon_photos (user_id, plant_latin_name, photo_path, status, rejection_reason, ai_confidence, photo_type, focal_point_x, focal_point_y, dominant_color_hex, ai_photo_quality_score) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)");
                        $stmt->execute([
                            $currentUserId,
                            $latinName,
                            $finalPhotoPath,
                            ($isHighQuality ? 'approved' : 'rejected'),
                            $photoData['rejection_reason'] ?? null,
                            $fullAiResponse['identification']['confidence_score'] ?? null,
                            $photoData['photo_type'] ?? null,
                            $photoData['focal_point']['x'] ?? null,
                            $photoData['focal_point']['y'] ?? null,
                            $photoData['dominant_color_hex'] ?? null,
                            $photoData['photo_quality_score'] ?? null
                        ]);
                    }

                    $pdo->commit();
                    echo json_encode(['success' => true, 'plant' => getPlantWithDueDates($pdo, $plantId, $currentUserId)]);
                    break;
                default:
                     throw new Exception('Ungültige Formular-Aktion.', 400);
            }
            break;

        case 'DELETE':
            $plantId = $_GET['id'] ?? null;
            if ($plantId) {
                $pdo->beginTransaction();

                $stmtLatin = $pdo->prepare("SELECT latin_name FROM plants WHERE id = ? AND user_id = ?");
                $stmtLatin->execute([$plantId, $currentUserId]);
                $latinNameToDecrement = $stmtLatin->fetchColumn();

                $stmt = $pdo->prepare("DELETE FROM plants WHERE id = ? AND user_id = ?");
                $stmt->execute([$plantId, $currentUserId]);
                
                if ($latinNameToDecrement) {
                    $stmtDec = $pdo->prepare("UPDATE plant_lexicon SET entry_count = entry_count - 1 WHERE latin_name = ? AND entry_count > 0");
                    $stmtDec->execute([$latinNameToDecrement]);
                }

                $pdo->commit();
                echo json_encode(['success' => true]);
            } else if (isset($_GET['diary_entry_id'])) {
                $entryId = $_GET['diary_entry_id'];
                $stmt = $pdo->prepare("DELETE FROM plant_diary WHERE id = ? AND user_id = ?");
                $stmt->execute([$entryId, $currentUserId]);
                echo json_encode(['success' => $stmt->rowCount() > 0]);
            }
            else {
                throw new Exception('Keine ID zum Löschen angegeben.', 400);
            }
            break;

        default:
            throw new Exception('Methode nicht erlaubt.', 405);
    }
} catch (Exception $e) {
    if ($pdo->inTransaction()) $pdo->rollBack();
    $code = $e->getCode();
    if (!is_int($code) || $code < 400 || $code >= 600) {
        $code = 500;
    }
    http_response_code($code);
    echo json_encode(['error' => $e->getMessage()]);
}
?>