<?php
require_once 'includes/config.php';
require_once 'includes/auth.php';
require_once 'includes/db.php';

header('Content-Type: application/json');

try {
    $auth = new Auth();
    if (!$auth->isLoggedIn()) {
        throw new Exception('Unauthorized');
    }

    $page = isset($_GET['page']) ? max(1, (int)$_GET['page']) : 1;
    $limit = isset($_GET['limit']) ? max(1, min(100, (int)$_GET['limit'])) : 10;
    $offset = ($page - 1) * $limit;

    $db = Database::getInstance();

    // Get total count of impossible combinations
    $countQuery = $db->query("
        SELECT COUNT(*) as total 
        FROM panel_directives 
        WHERE llm_checked = 1 AND is_impossible = 1
    ");
    
    $totalCount = $countQuery ? $countQuery->fetch_assoc()['total'] : 0;
    $totalPages = ceil($totalCount / $limit);

    // Get paginated impossible combinations
    $stmt = $db->prepare("
        SELECT 
            id,
            attribute1_id,
            attribute2_id,
            choice1,
            choice2,
            attribute1_name,
            attribute2_name,
            status,
            llm_reasoning,
            updated_at
        FROM panel_directives 
        WHERE llm_checked = 1 AND is_impossible = 1
        ORDER BY updated_at DESC
        LIMIT ? OFFSET ?
    ");
    
    $stmt->bind_param('ii', $limit, $offset);
    $stmt->execute();
    $result = $stmt->get_result();

    $combinations = [];
    while ($row = $result->fetch_assoc()) {
        $combinations[] = [
            'id' => (int)$row['id'],
            'attribute1_id' => (int)$row['attribute1_id'],
            'attribute2_id' => (int)$row['attribute2_id'],
            'choice1' => $row['choice1'],
            'choice2' => $row['choice2'],
            'attribute1_name' => $row['attribute1_name'],
            'attribute2_name' => $row['attribute2_name'],
            'status' => $row['status'],
            'reasoning' => $row['llm_reasoning'],
            'updated_at' => $row['updated_at']
        ];
    }

    echo json_encode([
        'success' => true,
        'combinations' => $combinations,
        'pagination' => [
            'page' => $page,
            'limit' => $limit,
            'total' => (int)$totalCount,
            'totalPages' => (int)$totalPages,
            'hasNext' => $page < $totalPages,
            'hasPrev' => $page > 1
        ],
        // Legacy fields for compatibility
        'page' => $page,
        'total' => (int)$totalCount,
        'totalPages' => (int)$totalPages
    ]);

} catch (Exception $e) {
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'message' => $e->getMessage(),
        'combinations' => [],
        'pagination' => [
            'page' => 1,
            'limit' => 10,
            'total' => 0,
            'totalPages' => 0,
            'hasNext' => false,
            'hasPrev' => false
        ]
    ]);
}