#include "alfpriv.h"

/* LABEL */

static
int ALF__LabelTopPadding(HWND hwnd, ALFAPP app)
{
    // some pixels on top to align with the edit control
    // see also: alfedit.cpp
    return app->compatFn->GetSystemMetricsForDpi(
                SM_CYEDGE, ALF_CentipointsToPixels(GetParent(hwnd), 7200))
            + ((LOBYTE(LOWORD(GetVersion())) < 4) ? 2 : 1) /* internal padding in edit control */
            + 1 /* external padding around edit control */;
}

static LRESULT CALLBACK
ALF__LabelSubclassProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, UINT_PTR uIdSubclass, DWORD_PTR dwRefData)
{
    (void)uIdSubclass;
    (void)dwRefData;

    ALFAPP app = (ALFAPP)dwRefData;

    if (uMsg == ALF_WM_QUERYSIZE) {
        HDC hdcLabel = GetDC(hwnd);
        HFONT font = (HFONT)SendMessage(hwnd, WM_GETFONT, 0, 0);
        HFONT oldFont = 0;
        if (font)
            oldFont = SelectFont(hdcLabel, font);

        // calc drawtext style
        DWORD style = GetWindowLong(hwnd, GWL_STYLE);
        UINT format = DT_LEFT | DT_EXPANDTABS | DT_CALCRECT;
        if (style & SS_NOPREFIX)
            format |= DT_NOPREFIX;
        if (style & SS_EDITCONTROL)
            format |= DT_EDITCONTROL;
        if (style & SS_ENDELLIPSIS || style & SS_PATHELLIPSIS || style & SS_WORDELLIPSIS)
            format |= DT_SINGLELINE;

        RECT r = { 0, 0, 100, 100 };

        int textlen = GetWindowTextLength(hwnd);
        TCHAR *textbuf = (TCHAR*)HeapAlloc(GetProcessHeap(), HEAP_ZERO_MEMORY|HEAP_GENERATE_EXCEPTIONS, (textlen + 1)*sizeof(TCHAR));
        GetWindowText(hwnd, textbuf, textlen+1);

        DrawText(hdcLabel, textbuf, -1, &r, format);

        HeapFree(GetProcessHeap(), 0, textbuf);

        SIZE *pSize = (SIZE*)(void*)lParam;
        if (pSize->cx == 0)
            pSize->cx = r.right - r.left;
        if (pSize->cy == 0)
            pSize->cy = r.bottom - r.top + ALF__LabelTopPadding(hwnd, app);

        if (font)
            SelectFont(hdcLabel, oldFont);

        ReleaseDC(hwnd, hdcLabel);
    } else if (uMsg == ALF_WM_APPLYSIZE) {
        RECT *p = (RECT *)lParam;

        int topPadding = ALF__LabelTopPadding(hwnd, app);

        return (LRESULT)DeferWindowPos((HDWP)wParam,
                                       hwnd, NULL,
                                       p->left, p->top + topPadding,
                                       p->right - p->left, p->bottom - p->top - topPadding,
                                       SWP_NOZORDER|SWP_NOACTIVATE);
    } else if (uMsg == WM_DESTROY) {
        app->compatFn->RemoveWindowSubclass(hwnd, ALF__LabelSubclassProc, 0);
    }

    return app->compatFn->DefSubclassProc(hwnd, uMsg, wParam, lParam);
}

HWND
ALF_AddLabel(HWND win, WORD id, UINT x, UINT y, const TCHAR *text)
{
    HWND hwndLabel = CreateWindow(TEXT("STATIC"),
                                  text,
                                  WS_CHILD | WS_VISIBLE | SS_LEFTNOWORDWRAP,
                                  0, 0, 100, 100,
                                  win,
                                  (HMENU)(int)id,
                                  (HINSTANCE)GetWindowLongPtr(win, GWLP_HINSTANCE),
                                  NULL);

    ALFAPP app = ALF_ApplicationFromWindow(win);
    app->compatFn->SetWindowSubclass(hwndLabel, ALF__LabelSubclassProc, 0, (DWORD_PTR)app);

    ALFWidgetLayoutParams p;
    ZeroMemory(&p, sizeof(p));
    p.hwnd = hwndLabel;
    p.x = x;
    p.y = y;
    p.width = 0;
    p.height = 0;
    p.flags = ALF_QUERYSIZE | ALF_APPLYSIZE | ALF_MESSAGEFONT;

    ALF_AddWidgetEx(win, &p);

    return hwndLabel;
}