<?php
/**
 * API for Impossible Combinations Table Management
 */

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');
    }

    $db = Database::getInstance();
    $action = $_GET['action'] ?? $_POST['action'] ?? '';

    switch ($action) {
        case 'get_impossible_combinations':
            getImpossibleCombinations($db);
            break;
        case 'update_directive_status':
            updateDirectiveStatus($db);
            break;
        default:
            throw new Exception('Invalid action');
    }

} catch (Exception $e) {
    echo json_encode([
        'success' => false,
        'error' => $e->getMessage()
    ]);
}

function getImpossibleCombinations($db) {
    $page = (int)($_GET['page'] ?? 1);
    $limit = (int)($_GET['limit'] ?? 10);
    $offset = ($page - 1) * $limit;
    
    // Get total count
    $countQuery = $db->query("SELECT COUNT(*) as total FROM panel_directives WHERE llm_checked = 1 AND is_impossible = 1");
    $total = $countQuery->fetch_assoc()['total'];
    
    // Get paginated results with directive ID generation
    $query = $db->prepare("
        SELECT 
            id,
            attribute1_name,
            choice1,
            attribute2_name,
            choice2,
            llm_reasoning,
            status,
            updated_at,
            CONCAT('SYD', LPAD(id, 6, '0')) as directive_id
        FROM panel_directives 
        WHERE llm_checked = 1 AND is_impossible = 1 
        ORDER BY updated_at DESC 
        LIMIT ? OFFSET ?
    ");
    
    $query->bind_param('ii', $limit, $offset);
    $query->execute();
    $result = $query->get_result();
    
    $combinations = [];
    while ($row = $result->fetch_assoc()) {
        $combinations[] = [
            'id' => $row['id'],
            'directive_id' => $row['directive_id'],
            'combination' => "{$row['attribute1_name']} = {$row['choice1']} + {$row['attribute2_name']} = {$row['choice2']}",
            'reasoning' => $row['llm_reasoning'],
            'status' => $row['status'] ?? 'pending',
            'updated_at' => $row['updated_at']
        ];
    }
    
    echo json_encode([
        'success' => true,
        'combinations' => $combinations,
        'pagination' => [
            'page' => $page,
            'limit' => $limit,
            'total' => (int)$total,
            'total_pages' => ceil($total / $limit)
        ]
    ]);
}

function updateDirectiveStatus($db) {
    $input = json_decode(file_get_contents('php://input'), true);
    
    if (!isset($input['id']) || !isset($input['status'])) {
        throw new Exception('Missing required parameters');
    }

    $id = (int)$input['id'];
    $status = $input['status'];

    // Validate status
    if (!in_array($status, ['pending', 'approved', 'declined'])) {
        throw new Exception('Invalid status');
    }

    $stmt = $db->prepare("UPDATE panel_directives SET status = ?, updated_at = NOW() WHERE id = ?");
    $stmt->bind_param('si', $status, $id);
    
    if (!$stmt->execute()) {
        throw new Exception('Failed to update directive status');
    }

    if ($stmt->affected_rows === 0) {
        throw new Exception('Directive not found');
    }

    echo json_encode([
        'success' => true,
        'message' => 'Directive status updated successfully'
    ]);
}
?>