/*
 * Copyright (c) 2017 ETH Zürich, Educational Development and Technology (LET)
 * 
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

using System;
using System.Runtime.InteropServices;
using System.Text;
using SafeExamBrowser.WindowsApi.Constants;
using SafeExamBrowser.WindowsApi.Types;

namespace SafeExamBrowser.WindowsApi
{
	internal delegate bool EnumWindowsDelegate(IntPtr hWnd, IntPtr lParam);
	internal delegate IntPtr HookProc(int code, IntPtr wParam, IntPtr lParam);
	internal delegate void EventProc(IntPtr hWinEventHook, uint eventType, IntPtr hwnd, int idObject, int idChild, uint dwEventThread, uint dwmsEventTime);

	/// <summary>
	/// Provides access to the native Windows API exposed by <c>user32.dll</c>.
	/// </summary>
	internal static class User32
	{
		[DllImport("user32.dll", SetLastError = true)]
		internal static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool EnumWindows(EnumWindowsDelegate enumProc, IntPtr lParam);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern IntPtr FindWindow(string lpClassName, string lpWindowName);

		[DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Unicode)]
		internal static extern int GetWindowText(IntPtr hWnd, StringBuilder strText, int maxCount);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern int GetWindowTextLength(IntPtr hWnd);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool IsWindowVisible(IntPtr hWnd);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool PostMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern IntPtr SendMessage(IntPtr hWnd, uint msg, IntPtr wParam, IntPtr lParam);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr hmodWinEventProc, EventProc lpfnWinEventProc, uint idProcess, uint idThread, uint dwFlags);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern IntPtr SetWindowsHookEx(HookType hookType, HookProc lpfn, IntPtr hMod, uint dwThreadId);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool SystemParametersInfo(SPI uiAction, uint uiParam, ref RECT pvParam, SPIF fWinIni);

		[DllImport("user32.dll", SetLastError = true)]
		internal static extern bool UnhookWinEvent(IntPtr hWinEventHook);

		[DllImport("user32.dll", SetLastError = true)]
		[return: MarshalAs(UnmanagedType.Bool)]
		internal static extern bool UnhookWindowsHookEx(IntPtr hhk);
	}
}