/* $Id$ */

/** @file osk_gui.cpp The On Screen Keyboard GUI */

#include "stdafx.h"
#include "openttd.h"

#include "textbuf_gui.h"
#include "window_gui.h"
#include "string_func.h"
#include "strings_func.h"
#include "debug.h"
#include "window_func.h"
#include "gfx_func.h"

#include "table/sprites.h"
#include "table/strings.h"

struct osk_d {
	querystr_d *qs; // text-input
	int text_btn;   // widget number of parent's text field
	int ok_btn;     // widget number of parent's ok button (=0 when ok shouldn't be passed on)
	int cancel_btn; // widget number of parent's cancel button (=0 when cancel shouldn't be passed on; text will be reverted to original)
	Textbuf *text;  // pointer to parent's textbuffer (to update caret position)
	char *orig;     // the original text, in case we cancel
};
assert_compile(WINDOW_CUSTOM_SIZE >= sizeof(osk_d));

enum OskWidgets {
	OSK_WIDGET_TEXT = 3,
	OSK_WIDGET_CANCEL = 5,
	OSK_WIDGET_OK,
	OSK_WIDGET_BACKSPACE,
	OSK_WIDGET_SPECIAL,
	OSK_WIDGET_CAPS,
	OSK_WIDGET_SHIFT,
	OSK_WIDGET_SPACE,
	OSK_WIDGET_LEFT,
	OSK_WIDGET_RIGHT,
	OSK_WIDGET_LETTERS
};

char _keyboard_opt[2][OSK_KEYBOARD_ENTRIES * 4 + 1];
static WChar _keyboard[2][OSK_KEYBOARD_ENTRIES];

enum {
	KEYS_NONE,
	KEYS_SHIFT,
	KEYS_CAPS
};
static byte _keystate = KEYS_NONE;

/*
 * Only show valid characters; do not show characters that would
 * only insert a space when we have a spacebar to do that or
 * characters that are not allowed to be entered.
 */
static void ChangeOskDiabledState(Window *w, const querystr_d *qs, bool shift)
{
	for (uint i = 0; i < OSK_KEYBOARD_ENTRIES; i++) {
		w->SetWidgetDisabledState(OSK_WIDGET_LETTERS + i,
				!IsValidChar(_keyboard[shift][i], qs->afilter) || _keyboard[shift][i] == ' ');
	}
	w->SetWidgetDisabledState(OSK_WIDGET_SPACE, !IsValidChar(' ', qs->afilter));
}

/* on screen keyboard */
static void OskWndProc(Window *w, WindowEvent *e)
{
	querystr_d *qs = WP(w, osk_d).qs;

	switch (e->event) {
		case WE_CREATE:
			SetBit(_no_scroll, SCROLL_EDIT);
			/* Not needed by default. */
			w->DisableWidget(OSK_WIDGET_SPECIAL);
			break;

		case WE_PAINT: {
			bool shift = HasBit(_keystate, KEYS_CAPS) ^ HasBit(_keystate, KEYS_SHIFT);

			w->LowerWidget(OSK_WIDGET_TEXT);
			w->SetWidgetLoweredState(OSK_WIDGET_SHIFT, HasBit(_keystate, KEYS_SHIFT));
			w->SetWidgetLoweredState(OSK_WIDGET_CAPS, HasBit(_keystate, KEYS_CAPS));

			ChangeOskDiabledState(w, qs, shift);

			SetDParam(0, qs->caption);
			DrawWindowWidgets(w);

			for (uint i = 0; i < OSK_KEYBOARD_ENTRIES; i++) {
				DrawCharCentered(_keyboard[shift][i],
					w->widget[OSK_WIDGET_LETTERS + i].left + 8,
					w->widget[OSK_WIDGET_LETTERS + i].top + 3,
					TC_BLACK);
			}

			DrawEditBox(w, qs, OSK_WIDGET_TEXT);
			break;
		}

		case WE_CLICK:
			/* clicked a letter */
			if (e->we.click.widget >= OSK_WIDGET_LETTERS) {
				bool shift = HasBit(_keystate, KEYS_CAPS) ^ HasBit(_keystate, KEYS_SHIFT);

				WChar c = _keyboard[shift][e->we.click.widget - OSK_WIDGET_LETTERS];

				if (!IsValidChar(c, qs->afilter)) break;

				if (InsertTextBufferChar(&qs->text, c)) w->InvalidateWidget(OSK_WIDGET_TEXT);

				if (HasBit(_keystate, KEYS_SHIFT)) {
					ToggleBit(_keystate, KEYS_SHIFT);
					w->widget[OSK_WIDGET_SHIFT].color = HasBit(_keystate, KEYS_SHIFT) ? 15 : 14;
					SetWindowDirty(w);
				}
				break;
			}

			switch (e->we.click.widget) {
				case OSK_WIDGET_BACKSPACE:
					if (DeleteTextBufferChar(&qs->text, WKC_BACKSPACE)) w->InvalidateWidget(OSK_WIDGET_TEXT);
					break;

				case OSK_WIDGET_SPECIAL:
					/*
					 * Anything device specific can go here.
					 * The button itself is hidden by default, and when you need it you
					 * can not hide it in the create event.
					 */
					break;

				case OSK_WIDGET_CAPS:
					ToggleBit(_keystate, KEYS_CAPS);
					SetWindowDirty(w);
					break;

				case OSK_WIDGET_SHIFT:
					ToggleBit(_keystate, KEYS_SHIFT);
					SetWindowDirty(w);
					break;

				case OSK_WIDGET_SPACE:
					if (InsertTextBufferChar(&qs->text, ' ')) w->InvalidateWidget(OSK_WIDGET_TEXT);
					break;

				case OSK_WIDGET_LEFT:
					if (MoveTextBufferPos(&qs->text, WKC_LEFT)) w->InvalidateWidget(OSK_WIDGET_TEXT);
					break;

				case OSK_WIDGET_RIGHT:
					if (MoveTextBufferPos(&qs->text, WKC_RIGHT)) w->InvalidateWidget(OSK_WIDGET_TEXT);
					break;

				case OSK_WIDGET_OK:
					if (qs->orig == NULL || strcmp(qs->text.buf, qs->orig) != 0) {
						/* pass information by simulating a button press on parent window */
						if (WP(w, osk_d).ok_btn != 0) {
							Window *parent = w->parent;
							WindowEvent e;
							e.event = WE_CLICK;
							e.we.click.widget = WP(w, osk_d).ok_btn;
							parent->wndproc(parent, &e);
						}
					}
					DeleteWindow(w);
					break;

				case OSK_WIDGET_CANCEL:
					if (WP(w, osk_d).cancel_btn != 0) { // pass a cancel event to the parent window
						Window *parent = w->parent;
						WindowEvent e;
						e.event = WE_CLICK;
						e.we.click.widget = WP(w, osk_d).cancel_btn;
						parent->wndproc(parent, &e);
					} else { // or reset to original string
						strcpy(qs->text.buf, WP(w, osk_d).orig);
						UpdateTextBufferSize(&qs->text);
						MoveTextBufferPos(&qs->text, WKC_END);
					}
					DeleteWindow(w);
					break;
			}
			/* make sure that the parent window's textbox also gets updated */
			if (w->parent != NULL) w->parent->InvalidateWidget(WP(w, osk_d).text_btn);
			break;

		case WE_MOUSELOOP:
			HandleEditBox(w, qs, OSK_WIDGET_TEXT);
			/* make the caret of the parent window also blink */
			w->parent->InvalidateWidget(WP(w, osk_d).text_btn);
			break;
	}
}

static const Widget _osk_widgets[] = {
{      WWT_EMPTY, RESIZE_NONE,     0,     0,     0,     0,     0, 0x0,               STR_NULL},
{    WWT_CAPTION, RESIZE_NONE,    14,     0,   255,     0,    13, STR_012D,          STR_NULL},
{      WWT_PANEL, RESIZE_NONE,    14,     0,   255,    14,    29, 0x0,               STR_NULL},
{    WWT_EDITBOX, RESIZE_NONE,    14,     2,   253,    16,    27, 0x0,               STR_NULL},

{      WWT_PANEL, RESIZE_NONE,    14,     0,   255,    30,   139, 0x0,               STR_NULL},

{    WWT_TEXTBTN, RESIZE_NONE,    14,     3,   108,    35,    46, STR_012E_CANCEL,   STR_NULL},
{    WWT_TEXTBTN, RESIZE_NONE,    14,   111,   216,    35,    46, STR_012F_OK,       STR_NULL},
{ WWT_PUSHIMGBTN, RESIZE_NONE,    14,   219,   252,    35,    46, SPR_OSK_BACKSPACE, STR_NULL},

{ WWT_PUSHIMGBTN, RESIZE_NONE,    14,     3,    27,    67,    82, SPR_OSK_SPECIAL,   STR_NULL},
{     WWT_IMGBTN, RESIZE_NONE,    14,     3,    36,    85,   100, SPR_OSK_CAPS,      STR_NULL},
{     WWT_IMGBTN, RESIZE_NONE,    14,     3,    27,   103,   118, SPR_OSK_SHIFT,     STR_NULL},

{ WWT_PUSHTXTBTN, RESIZE_NONE,    14,    75,   189,   121,   136, STR_EMPTY,         STR_NULL},

{ WWT_PUSHIMGBTN, RESIZE_NONE,    14,   219,   234,   121,   136, SPR_OSK_LEFT,      STR_NULL},
{ WWT_PUSHIMGBTN, RESIZE_NONE,    14,   237,   252,   121,   136, SPR_OSK_RIGHT,     STR_NULL},

{    WWT_PUSHBTN, RESIZE_NONE,    14,     3,    18,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    21,    36,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    39,    54,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    57,    72,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    75,    90,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    93,   108,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   111,   126,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   129,   144,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   147,   162,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   165,   180,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   183,   198,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   201,   216,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   219,   234,    49,    64, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   237,   252,    49,    64, 0x0,    STR_NULL},

{    WWT_PUSHBTN, RESIZE_NONE,    14,    30,    45,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    48,    63,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    66,    81,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    84,    99,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   102,   117,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   120,   135,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   138,   153,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   156,   171,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   174,   189,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   192,   207,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   210,   225,    67,    82, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   228,   243,    67,    82, 0x0,    STR_NULL},

{    WWT_PUSHBTN, RESIZE_NONE,    14,    39,    54,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    57,    72,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    75,    90,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    93,   108,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   111,   126,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   129,   144,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   147,   162,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   165,   180,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   183,   198,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   201,   216,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   219,   234,    85,   100, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   237,   252,    85,   100, 0x0,    STR_NULL},

{    WWT_PUSHBTN, RESIZE_NONE,    14,    30,    45,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    48,    63,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    66,    81,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,    84,    99,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   102,   117,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   120,   135,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   138,   153,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   156,   171,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   174,   189,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   192,   207,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   210,   225,   103,   118, 0x0,    STR_NULL},
{    WWT_PUSHBTN, RESIZE_NONE,    14,   228,   243,   103,   118, 0x0,    STR_NULL},

{   WIDGETS_END},
};

WindowDesc _osk_desc = {
	WDP_CENTER, WDP_CENTER, 256, 140, 256, 140,
	WC_OSK, WC_NONE,
	WDF_STD_TOOLTIPS | WDF_STD_BTN | WDF_DEF_WIDGET | WDF_UNCLICK_BUTTONS,
	_osk_widgets,
	OskWndProc
};

/**
 * Retrieve keyboard layout from language string or (if set) config file.
 * Also check for invalid characters.
 */
void GetKeyboardLayout()
{
	char keyboard[2][OSK_KEYBOARD_ENTRIES * 4 + 1];
	char errormark[2][OSK_KEYBOARD_ENTRIES + 1]; // used for marking invalid chars
	bool has_error = false; // true when an invalid char is detected

	if (StrEmpty(_keyboard_opt[0])) {
		GetString(keyboard[0], STR_OSK_KEYBOARD_LAYOUT, lastof(keyboard[0]));
	} else {
		strncpy(keyboard[0], _keyboard_opt[0], lengthof(keyboard[0]));
	}

	if (StrEmpty(_keyboard_opt[1])) {
		GetString(keyboard[1], STR_OSK_KEYBOARD_LAYOUT_CAPS, lastof(keyboard[1]));
	} else {
		strncpy(keyboard[1], _keyboard_opt[1], lengthof(keyboard[1]));
	}

	for (uint j = 0; j < 2; j++) {
		const char *kbd = keyboard[j];
		bool ended = false;
		for (uint i = 0; i < OSK_KEYBOARD_ENTRIES; i++) {
			_keyboard[j][i] = Utf8Consume(&kbd);

			/* Be lenient when the last characters are missing (is quite normal) */
			if (_keyboard[j][i] == '\0' || ended) {
				ended = true;
				_keyboard[j][i] = ' ';
				continue;
			}

			if (IsPrintable(_keyboard[j][i])) {
				errormark[j][i] = ' ';
			} else {
				has_error = true;
				errormark[j][i] = '^';
				_keyboard[j][i] = ' ';
			}
		}
	}

	if (has_error) {
		ShowInfoF("The keyboard layout you selected contains invalid chars. Please check those chars marked with ^.");
		ShowInfoF("Normal keyboard:  %s", keyboard[0]);
		ShowInfoF("                  %s", errormark[0]);
		ShowInfoF("Caps Lock:        %s", keyboard[1]);
		ShowInfoF("                  %s", errormark[1]);
	}
}

/**
 * Show the osk associated with a given textbox
 * @param parent pointer to the Window where this keyboard originated from
 * @param q      querystr_d pointer to the query string of the parent, which is
 *               shared for both windows
 * @param button widget number of parent's textbox
 * @param cancel widget number of parent's cancel button (0 if cancel events
 *               should not be passed)
 * @param ok     widget number of parent's ok button  (0 if ok events should not
 *               be passed)
 */
void ShowOnScreenKeyboard(Window *parent, querystr_d *q, int button, int cancel, int ok)
{
	DeleteWindowById(WC_OSK, 0);

	Window *w = AllocateWindowDesc(&_osk_desc);

	w->parent = parent;
	assert(parent != NULL);

	if (parent->widget[button].data != 0) q->caption = parent->widget[button].data;

	WP(w, osk_d).qs         = q;
	WP(w, osk_d).text_btn   = button;
	WP(w, osk_d).cancel_btn = cancel;
	WP(w, osk_d).ok_btn     = ok;
	WP(w, osk_d).text       = &q->text;

	GetKeyboardLayout();

	/* make a copy in case we need to reset later */
	strcpy(_orig_str_buf, WP(w, osk_d).qs->text.buf);
	WP(w, osk_d).orig = _orig_str_buf;
}