/*
 * Process Hacker -
 *   Property Sheet Control
 *
 * Copyright (C) 2010 wj32
 * Copyright (C) 2010 dmex
 *
 * This file is part of Process Hacker.
 *
 * Process Hacker is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Process Hacker is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with Process Hacker.  If not, see <http://www.gnu.org/licenses/>.
 */

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows.Forms;
using System.Runtime.InteropServices;

using ProcessHacker.Native;

namespace ProcessHacker.Api
{
    public class PropertySheetPage : UserControl
    {
        private static readonly List<PropertySheetPage> _keepAliveList = new List<PropertySheetPage>();

        public unsafe static IntPtr CreateDialogTemplate(int width, int height, string title, short fontSize, string fontName)
        {
            DlgTemplate* template;
            int templateStructSize;
            int offset;

            templateStructSize = DlgTemplate.SizeOf;
            template = (DlgTemplate*)MemoryAlloc.PrivateHeap.Allocate(templateStructSize + 2 + 2 + (title.Length + 1) * 2 + 2 + (fontName.Length + 1) * 2);
            template->style = 0x40; // DS_SETFONT
            template->dwExtendedStyle = 0;
            template->cdit = 0;
            template->x = 0;
            template->y = 0;
            template->cx = (short)width;
            template->cy = (short)height;

            offset = templateStructSize;

            // No menu
            *(short*)((byte*)template + offset) = 0;
            offset += 2;

            // No class
            *(short*)((byte*)template + offset) = 0;
            offset += 2;

            // Title
            fixed (char* titlePtr = title)
                NativeApi.RtlMoveMemory((byte*)template + offset, titlePtr, (IntPtr)((title.Length + 1) * 2));
            offset += (title.Length + 1) * 2;

            // Font size
            *(short*)((byte*)template + offset) = fontSize;
            offset += 2;

            // Font name
            fixed (char* fontNamePtr = fontName)
                NativeApi.RtlMoveMemory((byte*)template + offset, fontNamePtr, (IntPtr)((fontName.Length + 1) * 2));
            //offset += (fontName.Length + 1) * 2;

            return (IntPtr)template;
        }

        public event EventHandler PageGotFocus;
        public event EventHandler PageLostFocus;

        private readonly IContainer components;
        private IntPtr _dialogWindowParentHandle;

        public PropertySheetPage()
        {
            components = new Container();
            this.AutoScaleMode = AutoScaleMode.Font;
        }

        /// <summary>
        /// Clean up any resources being used.
        /// </summary>
        /// <param name="disposing">true if managed resources should be disposed; otherwise, false.</param>
        protected override void Dispose(bool disposing)
        {
            if (disposing && (components != null))
            {
                components.Dispose();
            }

            base.Dispose(disposing);
        }

        public virtual IntPtr CreatePageHandle()
        {
            throw new NotImplementedException();
        }

        protected virtual bool DialogProc(IntPtr hwndDlg, WindowMessage uMsg, IntPtr wParam, IntPtr lParam)
        {
            switch (uMsg)
            {
                case WindowMessage.InitDialog:
                    {
                        _dialogWindowParentHandle = NativeApi.GetParent(hwndDlg);
                        NativeApi.SetParent(this.Handle, hwndDlg);
                    }
                    break;
                case WindowMessage.Notify:
                    return OnDialogNotify(hwndDlg, wParam, lParam);
            }

            return false;
        }

        private unsafe bool OnDialogNotify(IntPtr hwndDlg, IntPtr wParam, IntPtr lParam)
        {
            NmHdr* hdr = (NmHdr*)lParam;

            if (hdr->hwndFrom != _dialogWindowParentHandle)
                return false;

            switch (hdr->code)
            {
                case (uint)PropSheetNotification.SetActive:
                    if (this.PageGotFocus != null)
                        this.PageGotFocus(this, new EventArgs());
                    break;
                case (uint)PropSheetNotification.KillActive:
                    if (this.PageLostFocus != null)
                        this.PageLostFocus(this, new EventArgs());
                    break;
            }

            return false;
        }

        protected int PropPageProc(IntPtr hwnd, PropSheetPageCallbackMessage uMsg, IntPtr ppsp)
        {
            switch (uMsg)
            {
                case PropSheetPageCallbackMessage.AddRef:
                    _keepAliveList.Add(this);
                    break;
                case PropSheetPageCallbackMessage.Release:
                    _keepAliveList.Remove(this);
                    this.Dispose();
                    break;
            }

            return 1;
        }
    }
}