<?php
require_once '../include/init.php';
require_once '../include/auth.php';

// --- Security Check: Only Admin can access this API ---
if (!isAdmin()) {
    http_response_code(403); // Forbidden
    echo json_encode(['error' => 'Permission denied.']);
    exit;
}

header('Content-Type: application/json');

try {
    $details = [];
    
    // 1. Check current state
    $stmt = $pdo->query("SELECT id, name, user_id FROM tabs ORDER BY id");
    $all_tabs = $stmt->fetchAll();
    
    $details[] = "Found " . count($all_tabs) . " total tabs in database";
    
    // 2. Find tabs with empty string user_id (should be public)
    $stmt = $pdo->query("SELECT id, name FROM tabs WHERE user_id = ''");
    $empty_user_tabs = $stmt->fetchAll();
    
    if (empty($empty_user_tabs)) {
        $details[] = "No tabs found with empty string user_id - all tabs are properly configured";
        $message = "No public tabs need fixing. All tabs are properly configured.";
    } else {
        $details[] = "Found " . count($empty_user_tabs) . " tab(s) with empty string user_id that should be public:";
        foreach ($empty_user_tabs as $tab) {
            $details[] = "  - Tab ID {$tab['id']}: '{$tab['name']}'";
        }
        
        // 3. Fix the tabs
        $stmt = $pdo->prepare("UPDATE tabs SET user_id = NULL WHERE user_id = ''");
        $stmt->execute();
        $affected_rows = $stmt->rowCount();
        
        $details[] = "Updated {$affected_rows} tab(s) to be truly public (set user_id to NULL)";
        
        // 4. Verify the fix
        $stmt = $pdo->query("SELECT id, name FROM tabs WHERE user_id IS NULL");
        $public_tabs = $stmt->fetchAll();
        
        $details[] = "Verification: Found " . count($public_tabs) . " public tab(s) after fix:";
        foreach ($public_tabs as $tab) {
            $details[] = "  - Tab ID {$tab['id']}: '{$tab['name']}' (PUBLIC)";
        }
        
        $message = "Successfully fixed {$affected_rows} public tab(s). Users and viewers can now see public tabs properly.";
    }
    
    // 5. Test visibility for a user (if users exist)
    $stmt = $pdo->query("SELECT id, username, role FROM users WHERE role IN ('user', 'viewer') LIMIT 1");
    $test_user = $stmt->fetch();
    
    if ($test_user) {
        $test_user_id = $test_user['id'];
        $details[] = "Testing visibility for user: {$test_user['username']} (ID: {$test_user_id}, Role: {$test_user['role']})";
        
        // Test the query
        $tabs_stmt_sql = "SELECT DISTINCT t.* FROM tabs t 
            LEFT JOIN tab_viewer_access tva ON t.id = tva.tab_id
            LEFT JOIN user_tab_visibility utv ON t.id = utv.tab_id AND utv.user_id = :current_user_id
            WHERE utv.user_id IS NULL
            AND (t.user_id IS NULL OR t.user_id = :current_user_id OR tva.user_id = :current_user_id)
            ORDER BY t.id";
        
        $tabs_stmt = $pdo->prepare($tabs_stmt_sql);
        $tabs_stmt->execute([':current_user_id' => $test_user_id]);
        $visible_tabs = $tabs_stmt->fetchAll();
        
        $details[] = "Visible tabs for this user: " . count($visible_tabs);
        foreach ($visible_tabs as $tab) {
            $user_info = $tab['user_id'] === null ? 'PUBLIC' : "User ID: {$tab['user_id']}";
            $details[] = "  - Tab ID {$tab['id']}: '{$tab['name']}' ({$user_info})";
        }
    } else {
        $details[] = "No users found to test visibility with";
    }
    
    echo json_encode([
        'success' => true,
        'message' => $message,
        'details' => $details
    ]);
    
} catch (PDOException $e) {
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'message' => 'Database error: ' . $e->getMessage()
    ]);
} catch (Exception $e) {
    http_response_code(500);
    echo json_encode([
        'success' => false,
        'message' => 'Error: ' . $e->getMessage()
    ]);
}
?>