#include "alfpriv.h"

#define ALF_TOPLEVEL_FLAG_MODALEND      ((DWORD)1)

typedef struct {
    HWND                hwnd;
    ALFToplevelVTable  *vtbl;
    void               *closure;
    ALFListHeader       toplevelList;
    ALFApplication     *app;
    DWORD               flags;
    LPARAM              modalResult;
    ALFLayout           layout;
    HWND                hwndFocus;
    HFONT               hMessageFont;
} ALFToplevelPriv;

struct tagALFApplication {
    ALFListHeader       toplevelList;
    ALFToplevelPriv    *activeToplevel;
    BOOL              (*pretranslatemessage)(void *,MSG *);
    void               *pretranslatemessage_closure;
};

struct ALFToplevel_CreateParams{
    ALFToplevelVTable *vtbl;
    void              *closure;
    ALFApplication    *app;
};

static TCHAR _alf_toplevelClass[28] = {0};

static void
ALF_InitializeToplevelPriv(HWND hwnd, ALFToplevelPriv *priv)
{
    priv->hwnd = hwnd;
    ALF_ListInit(&priv->toplevelList);
    ALF_Layout_Init(&priv->layout);
    priv->layout.bgcolor = ALF_COLOR_SYS(COLOR_BTNFACE);
}

static void
ALF_DestroyToplevelPriv(ALFToplevelPriv *priv)
{
    if (priv->vtbl && priv->vtbl->postdestroy)
        priv->vtbl->postdestroy(priv->closure);

    if (priv->app && priv->app->activeToplevel == priv)
        priv->app->activeToplevel = NULL;

    ALF_ListRemove(&priv->toplevelList);
    ALF_Layout_Clear(&priv->layout);

    if (priv->hMessageFont)
        DeleteObject(priv->hMessageFont);

    ALF_Free(priv);
}

static void
ALF_UpdateFontsPriv(HWND win, ALFToplevelPriv *priv)
{
    // XXX: SystemParametersInfoForDpi is Unicode-only and needs Vista+ NONCLIENTMETRICS,
    ALF_NONCLIENTMETRICSW_VISTA ncm;
    ZeroMemory(&ncm, sizeof(ncm));
    ncm.cbSize = sizeof(ncm);

    LOGFONT lfMessageFont;
    ZeroMemory(&lfMessageFont, sizeof(lfMessageFont));

    if (ALF_Compat_SystemParametersInfoForDpi(SPI_GETNONCLIENTMETRICS, ncm.cbSize, &ncm, 0, (UINT)priv->layout.dpi)) {
#ifdef UNICODE
        lfMessageFont = ncm.lfMessageFont;
#else
        ALF_Compat_LogFontWtoA(&ncm.lfMessageFont, &lfMessageFont);
#endif
    } else {
        // FIXME! fallback to default font, 8pt MS Shell Dlg
        ZeroMemory(&lfMessageFont, sizeof(lfMessageFont));

        lfMessageFont.lfHeight = -MulDiv(8, priv->layout.dpi, 72);
        lstrcpy(lfMessageFont.lfFaceName, TEXT("MS Shell Dlg"));
    }

    if (priv->hMessageFont) {
        DeleteObject(priv->hMessageFont);
    }

    priv->hMessageFont = CreateFontIndirect(&lfMessageFont);

    SendMessage(win, WM_SETFONT, (WPARAM)priv->hMessageFont, (LPARAM)1);
}


BOOL
ALF_Toplevel_PreTranslateMessage(HWND toplevel, MSG *message)
{
    ALFToplevelPriv *priv = (ALFToplevelPriv *)GetWindowLongPtr(toplevel, DLGWINDOWEXTRA);

    return (priv->vtbl && priv->vtbl->pretranslatemessage && priv->vtbl->pretranslatemessage(priv->closure, toplevel, message))
        || IsDialogMessage(toplevel, message);
}

void
ALF_Toplevel_EnsureBigEnough(HWND toplevel)
{
    MINMAXINFO i;
    ZeroMemory(&i, sizeof(i));
    SendMessage(toplevel, WM_GETMINMAXINFO, 0, (LPARAM)&i);

    WINDOWPLACEMENT wp;
    ZeroMemory(&wp, sizeof(wp));
    wp.length = sizeof(wp);

    GetWindowPlacement(toplevel, &wp);

    if (wp.rcNormalPosition.right - wp.rcNormalPosition.left < i.ptMinTrackSize.x ||
                wp.rcNormalPosition.bottom - wp.rcNormalPosition.top < i.ptMinTrackSize.y) {
        if (wp.rcNormalPosition.right - wp.rcNormalPosition.left < i.ptMinTrackSize.x)
            wp.rcNormalPosition.right = wp.rcNormalPosition.left + i.ptMinTrackSize.x;
        if (wp.rcNormalPosition.bottom - wp.rcNormalPosition.top < i.ptMinTrackSize.y)
            wp.rcNormalPosition.bottom = wp.rcNormalPosition.top + i.ptMinTrackSize.y;

        SetWindowPlacement(toplevel, &wp);
    }
}

static INT_PTR CALLBACK
ALF_Toplevel_DlgProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    (void)hwnd;
    (void)msg;
    (void)wparam;
    (void)lparam;

    return FALSE;
}


static LRESULT CALLBACK
ALF_Toplevel_WindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    if (msg == WM_CREATE) {
        ALFToplevelPriv *priv = ALF_New(ALFToplevelPriv, 1);
        SetWindowLongPtr(hwnd, DLGWINDOWEXTRA, (LONG_PTR)priv);
        ALF_InitializeToplevelPriv(hwnd, priv);

        int dpi = (int)ALF_Compat_GetDpiForWindow(hwnd);
        SendMessage(hwnd, ALF_WM_DPICHANGE, 0, (LPARAM)dpi); // will also update fonts
    }

    ALFToplevelPriv *priv = (ALFToplevelPriv*)(void*)GetWindowLongPtr(hwnd, DLGWINDOWEXTRA);
    if (priv != NULL) {
        if (priv->vtbl && priv->vtbl->message) {
            return priv->vtbl->message(priv->closure, hwnd, msg, wparam, lparam);
        } else {
            return ALF_Toplevel_DefWindowProc(hwnd, msg, wparam, lparam);
        }
    } else {
        return DefDlgProc(hwnd, msg, wparam, lparam);
    }
}

static void
ALF_Toplevel_Paint(ALFToplevelPriv *priv, HWND hwnd, HDC dc, RECT *r)
{
    if (priv->vtbl && priv->vtbl->paint) {
        priv->vtbl->paint(priv->closure, hwnd, dc, r);
    } else {
        ALF_FillRect(dc, r, priv->layout.bgcolor);
    }
}

LRESULT
ALF_Toplevel_DefWindowProc(HWND hwnd, UINT msg, WPARAM wparam, LPARAM lparam)
{
    ALFToplevelPriv *priv = (ALFToplevelPriv*)GetWindowLongPtr(hwnd, DLGWINDOWEXTRA);

    if (msg == WM_INITDIALOG) {
        struct ALFToplevel_CreateParams *params = (struct ALFToplevel_CreateParams *)lparam;

        priv->vtbl = params->vtbl;
        priv->closure = params->closure;
        priv->app = params->app;

        if (priv->app) {
            ALF_ListInsert(&priv->app->toplevelList, &priv->toplevelList);
        }

        BOOL retval = TRUE;
        if (priv->vtbl && priv->vtbl->initialize) {
            retval = priv->vtbl->initialize(priv->closure, hwnd);
        }

        ALF_Toplevel_EnsureBigEnough(hwnd);

        return retval;
    }

    if (msg == ALF_WM_GETMODALRESULT) {
        return (LRESULT)priv->modalResult;
    }
    if (msg == ALF_WM_SETMODALRESULT) {
        priv->modalResult = lparam;
        priv->flags |= ALF_TOPLEVEL_FLAG_MODALEND;
        return 0;
    }

    if (msg == ALF_WM_GETDPI) {
        return (LRESULT)priv->layout.dpi;
    }

    if (msg == ALF_WM_UPDATEFONTS) {
        ALF_UpdateFontsPriv(hwnd, priv);
        return 0;
    }

    if (msg == WM_ACTIVATE) {
        if (wparam) {
            if (priv->app) {
                priv->app->activeToplevel = priv;
            }
        } else {
            if (priv->app && priv->app->activeToplevel == priv) {
                priv->app->activeToplevel = NULL;
            }
        }
    }

    if (msg == WM_ERASEBKGND) {
        return TRUE; // handled in WM_PAINT
    }

    if (msg == WM_PRINTCLIENT) {
        RECT r = { 0, 0, 0, 0 };
        GetClientRect(hwnd, &r);

        ALF_Toplevel_Paint(priv, hwnd, (HDC)wparam, &r);
        return TRUE;
    }

    if (msg == WM_PAINT) {
        PAINTSTRUCT ps;
        HDC dc = BeginPaint(hwnd, &ps);

        ALF_Toplevel_Paint(priv, hwnd, dc, &ps.rcPaint);

        EndPaint(hwnd, &ps);

        return 0;
    }

    if (msg == WM_COMMAND) {
        HWND source = (HWND)lparam;
        WORD code   = HIWORD(wparam);
        WORD id     = LOWORD(wparam);
        LRESULT ret = 0;
        if (source != 0)
            ret = SendMessage(source, 0x2000 + WM_COMMAND, wparam, lparam);

        if (ret == 0 && priv->vtbl && priv->vtbl->command)
            ret = priv->vtbl->command(priv->closure, hwnd, code, id, source);

        return ret;
    }

    if (msg == WM_NOTIFY) {
        NMHDR *nmhdr = (NMHDR *)lparam;
        LRESULT ret = 0;

        if (nmhdr->hwndFrom)
            ret = SendMessage(nmhdr->hwndFrom, 0x2000 + WM_NOTIFY, wparam, lparam);

        if (ret == 0 && priv->vtbl && priv->vtbl->notify)
            ret = priv->vtbl->notify(priv->closure, hwnd, wparam, nmhdr);

        return ret;
    }

    if (msg == WM_DRAWITEM) {
        LPDRAWITEMSTRUCT dis = (DRAWITEMSTRUCT *)lparam;
        LRESULT ret = 0;
        if (wparam && dis->hwndItem) {
            ret = SendMessage(dis->hwndItem, 0x2000 + WM_DRAWITEM, wparam, lparam);
        }

        if (ret)
            return ret;
    }

    if (msg == WM_CTLCOLORSTATIC) {
        LRESULT ret = SendMessage((HWND)lparam, 0x2000 + WM_CTLCOLORSTATIC, wparam, lparam);

        if (ret) {
            return ret;
        } else {
            SetBkColor((HDC)wparam, GetSysColor(COLOR_BTNFACE));
            SetTextColor((HDC)wparam, GetSysColor(COLOR_BTNTEXT));
            return (LRESULT)GetSysColorBrush(COLOR_BTNFACE);
        }
    }

    if (msg == WM_CTLCOLORBTN) {
        LRESULT ret = SendMessage((HWND)lparam, 0x2000 + WM_CTLCOLORBTN, wparam, lparam);

        if (ret) {
            return ret;
        } else {
            SetBkColor((HDC)wparam, GetSysColor(COLOR_BTNFACE));
            SetTextColor((HDC)wparam, GetSysColor(COLOR_BTNTEXT));
            return (LRESULT)GetSysColorBrush(COLOR_BTNFACE);
        }
    }

    if (msg == WM_SIZE) {
        ALF_Layout_Apply(&priv->layout, hwnd);
    }

    if (msg == WM_SHOWWINDOW) {
        if (wparam)
            ALF_Layout_Validate(&priv->layout, hwnd);
    }

    if (msg == WM_GETMINMAXINFO) {
        RECT tmp;
        ZeroMemory(&tmp, sizeof(tmp));

        SIZE s;
        ZeroMemory(&s, sizeof(s));
        ALF_Layout_GetMinSize(&priv->layout, hwnd, &s);

        tmp.right = s.cx;
        tmp.bottom = s.cy;

        if (ALF_Compat_AdjustWindowRectExForDpi(
                               &tmp,
                               (DWORD)GetWindowLong(hwnd, GWL_STYLE),
                               GetMenu(hwnd) != NULL,
                               (DWORD)GetWindowLong(hwnd, GWL_EXSTYLE),
                               (UINT)priv->layout.dpi)) {
            MINMAXINFO *i = (MINMAXINFO *)lparam;
            i->ptMinTrackSize.x = tmp.right - tmp.left;
            i->ptMinTrackSize.y = tmp.bottom - tmp.top;
            return 0;
        }
    }

    if (msg == WM_DESTROY && priv->vtbl && priv->vtbl->destroy) {
        priv->vtbl->destroy(priv->closure, hwnd);
    }

    if (msg == WM_CLOSE) {
        if (priv->vtbl && priv->vtbl->close)
            priv->vtbl->close(priv->closure, hwnd);

        return 0;
    }

    if (msg == WM_NCDESTROY) {
        SetWindowLongPtr(hwnd, DLGWINDOWEXTRA, 0);
        ALF_DestroyToplevelPriv(priv);
    }

    if (msg == WM_DPICHANGED) {
        int dpi = LOWORD(wparam);
        SendMessage(hwnd, ALF_WM_DPICHANGE, 0, (LPARAM)dpi); // will also update fonts and invalidate layout

        RECT *r = (RECT*)lparam;
        SetWindowPos(hwnd, NULL, r->left, r->top, r->right-r->left, r->bottom-r->top, SWP_NOACTIVATE|SWP_NOZORDER);
    }

    if (msg == WM_THEMECHANGED || msg == WM_SETTINGCHANGE) {
        ALF_UpdateFontsPriv(hwnd, priv);
        ALF_Layout_Invalidate(&priv->layout, hwnd);
        ALF_InvalidateBackground(hwnd);
        InvalidateRect(hwnd, NULL, TRUE);
    }

    if (msg == WM_WINDOWPOSCHANGED) {
        if (priv->vtbl && priv->vtbl->windowposchanged) {
            priv->vtbl->windowposchanged(priv->closure, hwnd, (WINDOWPOS *)lparam);
        }
    }

    if (msg == ALF_WM_GETAPPLICATION) {
        return (LRESULT)priv->app;
    }

    LRESULT ret = 0;
    if (ALF_Layout_HandleMessage(&priv->layout, hwnd, msg, wparam, lparam, &ret)) {
        // if the layout was changed, our current size might be too small
        if (msg == ALF_WM_VALIDATELAYOUT) {
            ALF_Toplevel_EnsureBigEnough(hwnd);
        }

        if (msg == ALF_WM_DPICHANGE) {
            ALF_UpdateFontsPriv(hwnd, priv);
        }

        return ret;
    }

    return DefDlgProc(hwnd, msg, wparam, lparam);
}

void
ALF_RegisterToplevelClass(void)
{
    WNDCLASS cls;
    ZeroMemory(&cls, sizeof(cls));

    wsprintf(_alf_toplevelClass, TEXT("ALFWindow.%p"), (ULONG_PTR)&_alf_toplevelClass[0]);

    cls.style = 0;
    cls.hInstance = ALF_HINSTANCE;
    cls.hCursor = LoadCursor(NULL, (LPTSTR)IDC_ARROW);
    cls.hbrBackground = NULL;
    cls.lpszClassName = _alf_toplevelClass;
    cls.cbWndExtra = DLGWINDOWEXTRA + sizeof(void*);
    cls.cbClsExtra = 0;
    cls.lpfnWndProc = ALF_Toplevel_WindowProc;

    ATOM classatom = RegisterClass(&cls);
    if (!classatom) {
        MessageBox(NULL, TEXT("FATAL: Couldn't register toplevel window class"), TEXT("DEBUG"), MB_ICONHAND|MB_OK);
    }
}

void
ALF_UnregisterToplevelClass(void)
{
    UnregisterClass(_alf_toplevelClass, ALF_HINSTANCE);
}

HWND
ALF_CreateToplevelWindow(DWORD exstyle, DWORD style, HWND hwndOwner, ALFApplication *app, ALFToplevelVTable *vtbl, void *closure)
{
#pragma pack(push, 1)
    struct {
        DLGTEMPLATE t;
        WCHAR s[32];
    } t;
#pragma pack(pop)
    ZeroMemory(&t, sizeof(t));
    t.t.style = style;
    t.t.dwExtendedStyle = exstyle;
    t.t.x = 0;
    t.t.y = 0;
    t.t.cx = 10;
    t.t.cy = 10;
    t.t.cdit = 0;

    // NOTE: this only works because we know the window class name is all ascii
    for (int i = 0; _alf_toplevelClass[i]; ++i) {
        t.s[i+1] = _alf_toplevelClass[i];
    }

    if (hwndOwner == GetDesktopWindow())
        hwndOwner = NULL;

    if (hwndOwner && GetWindowLong(hwndOwner, GWL_STYLE) & WS_CHILD)
        hwndOwner = GetParent(hwndOwner);

    struct ALFToplevel_CreateParams params;
    params.vtbl = vtbl;
    params.closure = closure;
    params.app = app;
    return CreateDialogIndirectParam(ALF_HINSTANCE, &t.t, hwndOwner, ALF_Toplevel_DlgProc, (LPARAM)&params);
}

void
ALF_Toplevel_SetDefaultButton(HWND win, WORD id)
{
    SendMessage(win, DM_SETDEFID, (WPARAM)id, 0);
}

LPARAM
ALF_Toplevel_ShowModal(HWND toplevel)
{
    ALFToplevelPriv *priv = (ALFToplevelPriv *)GetWindowLongPtr(toplevel, DLGWINDOWEXTRA);

    priv->flags &= ~ALF_TOPLEVEL_FLAG_MODALEND;
    priv->modalResult = 0;

    HWND owner = GetWindow(toplevel, GW_OWNER);
    BOOL ownerEnabled = FALSE;

    ShowWindow(toplevel, SW_SHOW);

    if (owner)
        ownerEnabled = !EnableWindow(owner, FALSE);

    while (!(priv->flags & ALF_TOPLEVEL_FLAG_MODALEND)) {
        MSG msg;
        if (GetMessage(&msg, NULL, 0, 0)) {
            if (!(priv->app && ALF_Application_PreTranslateMessage(priv->app, &msg, toplevel))
                && !ALF_Toplevel_PreTranslateMessage(toplevel, &msg)) {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        } else {
            PostQuitMessage((int)msg.wParam);
            break;
        }
    }

    if (owner)
        EnableWindow(owner, ownerEnabled);

    ShowWindow(toplevel, SW_HIDE);

    return priv->modalResult;
}


void
ALF_Toplevel_SetModalResult(HWND win, LPARAM result)
{
    SendMessage(win, ALF_WM_SETMODALRESULT, 0, result);
}

LPARAM
ALF_Toplevel_GetModalResult(HWND win)
{
    return (LPARAM)SendMessage(win, ALF_WM_GETMODALRESULT, 0, 0);
}

void
ALF_Toplevel_Resize(HWND win, int cptWidth, int cptHeight)
{
    int dpi = ALF_GetDpi(win);

    int pxwidth = ALF_CentipointsToPixels(cptWidth, dpi);
    int pxheight = ALF_CentipointsToPixels(cptHeight, dpi);

    ALF_Toplevel_ResizePx(win, pxwidth, pxheight);
}

void
ALF_Toplevel_ResizePx(HWND win, int pxwidth, int pxheight)
{
    MINMAXINFO tmp = {
        { 0, 0 },
        { pxwidth, pxheight },
        { 0, 0 },
        { pxwidth, pxheight },
        { pxwidth, pxheight }
    };
    SendMessage(win, WM_GETMINMAXINFO, 0, (LPARAM)&tmp);

    if (tmp.ptMinTrackSize.x > pxwidth)
        pxwidth = tmp.ptMinTrackSize.x;
    if (tmp.ptMinTrackSize.y > pxheight)
        pxheight = tmp.ptMinTrackSize.y;

    SetWindowPos(win, NULL, 0, 0, pxwidth, pxheight, SWP_NOACTIVATE|SWP_NOMOVE|SWP_NOZORDER);
}

ALFApplication *
ALF_Toplevel_Application(HWND toplevel)
{
    return (ALFApplication *)SendMessage(toplevel, ALF_WM_GETAPPLICATION, 0, 0);
}

ALFApplication *
ALF_CreateApplication(void)
{
    ALFApplication *app = ALF_New(ALFApplication, 1);
    ALF_ListInit(&app->toplevelList);

    return app;
}

void
ALF_Application_ProcessMessages(ALFApplication *app)
{
    MSG msg;
    while (PeekMessage(&msg, NULL, 0, 0, PM_REMOVE)) {
        if (msg.message == WM_QUIT) {
            PostQuitMessage((int)msg.wParam);
            return;
        } else {
            if (!ALF_Application_PreTranslateMessage(app, &msg, NULL)) {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        }
    }
}

void
ALF_Application_Run(ALFApplication *app)
{
    while (!ALF_ListIsEmpty(&app->toplevelList)) {
        MSG msg;
        if (GetMessage(&msg, NULL, 0, 0)) {
            if (!ALF_Application_PreTranslateMessage(app, &msg, NULL)) {
                TranslateMessage(&msg);
                DispatchMessage(&msg);
            }
        } else {
            PostQuitMessage((int)msg.wParam);
            return;
        }
    }
}

BOOL
ALF_Application_EnumToplevels(ALFApplication *app, WNDENUMPROC proc, LPARAM param)
{
    ALF_FOR_LIST(ALFToplevelPriv, toplevelList, &app->toplevelList, t) {
        if (!proc(t->hwnd, param))
            return FALSE;
    }

    return TRUE;
}

HWND
ALF_Application_ActiveToplevel(ALFApplication *app)
{
    return app->activeToplevel->hwnd;
}

void
ALF_Application_SetPreTranslateMessageHandler(ALFApplication *app, BOOL(*handler)(void *,MSG *), void *closure)
{
    app->pretranslatemessage = handler;
    app->pretranslatemessage_closure = closure;
}

BOOL
ALF_Application_PreTranslateMessage(ALFApplication *app, MSG *msg, HWND modalToplevel)
{
    return (app->pretranslatemessage && app->pretranslatemessage(app->pretranslatemessage_closure, msg))
        || (app->activeToplevel && app->activeToplevel->hwnd != modalToplevel && ALF_Toplevel_PreTranslateMessage(app->activeToplevel->hwnd, msg));
}

// TODO: implement modal stuff
/*void
ALF_Application_DisableWindowsForModal(ALFApplication *app, HWND skip);

void
ALF_Application_ReenableWindowsForModal(ALFApplication *app, HWND skip);*/

void
ALF_DestroyApplication(ALFApplication *app)
{
    // don't use ALF_FOR_LIST here, since ALF_FOR_LIST can only handle destroying
    // the current element. But the window might to anything in WM_DESTROY,
    // including destroying various other windows.
    while (!ALF_ListIsEmpty(&app->toplevelList)) {
        HWND w = ALF_LIST_CONTAINER(ALFToplevelPriv, toplevelList, app->toplevelList.next)->hwnd;
        DestroyWindow(w);
    }

    ALF_Free(app);
}