/* This is a small demo of the high-performance GUIX graphics framework. */

#include <stdio.h>
#include "gx_api.h"

#include "guix_calculator_resources.h"
#include "guix_calculator_specifications.h"

GX_WINDOW_ROOT    *root;

#define TYPE_OPERAND       1
#define TYPE_OPERATION     2
#define TYPE_DOT           3
#define TYPE_FUNCTION      4

#define MAX_TEXT_LENGTH    3
#define MAX_EXPRESSION_LENGTH 99

extern GX_CHAR result[128];
void evaluate(GX_STRING *expression, GX_BOOL persent_flag);

GX_BOOL    clear_input_buffer = GX_FALSE;
GX_BOOL    is_decimal_point = GX_FALSE;

typedef struct
{
    GX_CHAR *text;
    INT      x_offset;
    INT      y_offset;
    USHORT   widget_id;
    USHORT   event_type;
    LONG     type;
} KEY_INFO_ENTRY;

KEY_INFO_ENTRY key_info[] = {
    { "0", 0, 0, ID_CALCULATOR_ZERO, GX_SIGNAL(ID_CALCULATOR_ZERO, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "1", 0, 0, ID_CALCULATOR_ONE, GX_SIGNAL(ID_CALCULATOR_ONE, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "2", 0, 0, ID_CALCULATOR_TWO, GX_SIGNAL(ID_CALCULATOR_TWO, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "3", 0, 0, ID_CALCULATOR_THREE, GX_SIGNAL(ID_CALCULATOR_THREE, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "4", 0, 0, ID_CALCULATOR_FOUR, GX_SIGNAL(ID_CALCULATOR_FOUR, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "5", 0, 0, ID_CALCULATOR_FIVE, GX_SIGNAL(ID_CALCULATOR_FIVE, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "6", 0, 0, ID_CALCULATOR_SIX, GX_SIGNAL(ID_CALCULATOR_SIX, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "7", 0, 0, ID_CALCULATOR_SEVEN, GX_SIGNAL(ID_CALCULATOR_SEVEN, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "8", 0, 0, ID_CALCULATOR_EIGHT, GX_SIGNAL(ID_CALCULATOR_EIGHT, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "9", 0, 0, ID_CALCULATOR_NINE, GX_SIGNAL(ID_CALCULATOR_NINE, GX_EVENT_CLICKED), TYPE_OPERAND },
    { "+", 0, -2, ID_CALCULATOR_PLUS, GX_SIGNAL(ID_CALCULATOR_PLUS, GX_EVENT_CLICKED), TYPE_OPERATION },
    { "-", 0, -2, ID_CALCULATOR_MINUS, GX_SIGNAL(ID_CALCULATOR_MINUS, GX_EVENT_CLICKED), TYPE_OPERATION },
    { "*", 0, 2, ID_CALCULATOR_MULTI, GX_SIGNAL(ID_CALCULATOR_MULTI, GX_EVENT_CLICKED), TYPE_OPERATION },
    { "/", 0, -2, ID_CALCULATOR_DIVIDE, GX_SIGNAL(ID_CALCULATOR_DIVIDE, GX_EVENT_CLICKED), TYPE_OPERATION },
    { ".", 0, 0, ID_CALCULATOR_DOT, GX_SIGNAL(ID_CALCULATOR_DOT, GX_EVENT_CLICKED), TYPE_DOT },
    { "C", 0, 0, ID_CALCULATOR_C, 0, TYPE_FUNCTION },
    { "MC", 0, 0, ID_CALCULATOR_MC, 0, TYPE_FUNCTION },
    { "MR", 0, 0, ID_CALCULATOR_MR, 0, TYPE_FUNCTION },
    { "Del", 0, 0, ID_CALCULATOR_DEL, 0, TYPE_FUNCTION },
    { "=", 0, 0, ID_CALCULATOR_RESULT, 0, TYPE_FUNCTION },
    { "%", 0, 0, ID_CALCULATOR_PERCENT, 0, TYPE_FUNCTION },
    { GX_NULL, 0, 0, 0, 0, 0 }
};

/* Define prototypes.   */
extern UINT win32_graphics_driver_setup_565rgb(GX_DISPLAY *display);
UINT string_length_get(GX_CONST GX_CHAR* input_string, UINT max_string_length);

int main(int argc, char ** argv)
{
  tx_kernel_enter();
  return(0);
}

/* Custom pixelmap button draw. */
VOID custom_pixelmap_button_draw(GX_PIXELMAP_BUTTON *key)
{
GX_RESOURCE_ID  font_id = GX_FONT_ID_MIDSIZE;
KEY_INFO_ENTRY *pKeyInfo = key_info;
INT             x_offset;
INT             y_offset;
GX_STRING       text;

    gx_pixelmap_button_draw(key);

    while (pKeyInfo->text)
    {
        if (pKeyInfo->widget_id == key->gx_widget_id)
        {
            x_offset = pKeyInfo->x_offset;
            y_offset = pKeyInfo->y_offset;

            if (key->gx_widget_style & GX_STYLE_BUTTON_PUSHED)
            {
                x_offset++;
                y_offset++;
            }

            text.gx_string_ptr = pKeyInfo->text;
            text.gx_string_length = string_length_get(pKeyInfo->text, MAX_TEXT_LENGTH);

            gx_widget_text_draw_ext(key, GX_COLOR_ID_WHITE,
                                    font_id, &text,
                                    x_offset, y_offset);
            break;
        }

        pKeyInfo++;
    }
}

VOID tx_application_define(void *first_unused_memory)
{
    /* Initialize GUIX.  */
    gx_system_initialize();

    gx_studio_display_configure(MAIN_SCREEN, win32_graphics_driver_setup_565rgb,
                                LANGUAGE_ENGLISH, MAIN_SCREEN_DEFAULT_THEME, &root);

    /* Create calculator screen */
    gx_studio_named_widget_create("frame", (GX_WIDGET *)root, GX_NULL);

    /* Show the root window to make it and patients screen visible.  */
    gx_widget_show(root);

    /* start GUIX thread */
    gx_system_start();
}

UINT calculator_event_handler(GX_WINDOW *window, GX_EVENT *event_ptr)
{
GX_SINGLE_LINE_TEXT_INPUT *text_input;
KEY_INFO_ENTRY            *pKeyInfo = key_info;
GX_CHAR                    pre_char = '\0';
INT                        string_size;
GX_STRING                  string;

    text_input = &frame.frame_display_result;

    if ((event_ptr->gx_event_type & GX_SIGNAL_EVENT_MASK) == GX_EVENT_CLICKED)
    {
        while (pKeyInfo->text)
        {
            if (pKeyInfo->event_type == event_ptr->gx_event_type)
            {
                if (clear_input_buffer)
                {
                    if ((pKeyInfo->text[0] >= '0') && (pKeyInfo->text[0] <= '9'))
                    {
                        /* Clear input buffer.  */
                        gx_single_line_text_input_buffer_clear(text_input);
                    }
                    else if (!strcmp(text_input->gx_single_line_text_input_buffer, "Error Format"))
                    {
                        return 0;
                    }

                    clear_input_buffer = GX_FALSE;
                }

                string_size = text_input->gx_single_line_text_input_string_size;

                if (string_size)
                {
                    /* Get previous character.  */
                    pre_char = text_input->gx_single_line_text_input_buffer[string_size - 1];
                }

                if (pKeyInfo->type == TYPE_OPERAND)
                {
                    if ((pre_char == '0') && (string_size == 1))
                    {
                        gx_single_line_text_input_backspace(text_input);
                    }
                    else if ((pre_char == '/') && (pKeyInfo->text[0] == '0'))
                    {
                        return 0;
                    }

                    gx_single_line_text_input_character_insert(text_input, (GX_UBYTE *)&pKeyInfo->text[0], 1);
                }
                else if (string_size)
                {
                    if ((pre_char >= '0') && (pre_char <= '9'))
                    {
                        if (pKeyInfo->type == TYPE_OPERATION)
                        {
                            gx_single_line_text_input_character_insert(text_input, (GX_UBYTE *)&pKeyInfo->text[0], 1);
                            is_decimal_point = GX_FALSE;
                        }
                        else if ((pKeyInfo->type == TYPE_DOT) && !is_decimal_point)
                        {
                            gx_single_line_text_input_character_insert(text_input, (GX_UBYTE *)&pKeyInfo->text[0], 1);
                            is_decimal_point = GX_TRUE;
                        }
                    }
                }

                return 0;
            }
            pKeyInfo++;
        }
    }

    switch (event_ptr->gx_event_type)
    {
    case GX_SIGNAL(ID_CALCULATOR_DEL, GX_EVENT_CLICKED):
        gx_single_line_text_input_backspace(text_input);
        break;

    case GX_SIGNAL(ID_CALCULATOR_C, GX_EVENT_CLICKED):
        /* Clear input buffer. */
        gx_single_line_text_input_buffer_clear(text_input);
        break;

    case GX_SIGNAL(ID_CALCULATOR_RESULT, GX_EVENT_CLICKED):
        if (string_length_get(text_input->gx_single_line_text_input_buffer, MAX_EXPRESSION_LENGTH) > 0)
        {
            /* Evaluate expression. */
            string.gx_string_ptr = text_input->gx_single_line_text_input_buffer;
            string.gx_string_length = string_length_get(string.gx_string_ptr, text_input->gx_single_line_text_input_buffer_size - 1);
            evaluate(&string, GX_FALSE);

            /* Clear input buffer. */
            gx_single_line_text_input_buffer_clear(text_input);

            /* Show result. */
            gx_single_line_text_input_character_insert(text_input, (GX_UBYTE *)result, string_length_get(result, MAX_EXPRESSION_LENGTH));

            clear_input_buffer = GX_TRUE;
        }
        break;

    case GX_SIGNAL(ID_CALCULATOR_PERCENT, GX_EVENT_CLICKED):
        if (string_length_get(text_input->gx_single_line_text_input_buffer, MAX_EXPRESSION_LENGTH) > 0)
        {
            string.gx_string_ptr = text_input->gx_single_line_text_input_buffer;
            string.gx_string_length = string_length_get(string.gx_string_ptr, text_input->gx_single_line_text_input_buffer_size - 1);
            evaluate(&string, GX_TRUE);
        
            /* Clear input buffer. */
            gx_single_line_text_input_buffer_clear(text_input);

            /* Show result. */
            gx_single_line_text_input_character_insert(text_input, (GX_UBYTE *)result, string_length_get(result, MAX_EXPRESSION_LENGTH));

            clear_input_buffer = GX_TRUE;
        }
        break;

    default:
        return gx_window_event_process(window, event_ptr);
    }

    return 0;
}

UINT string_length_get(GX_CONST GX_CHAR *input_string, UINT max_string_length)
{
UINT length = 0;

    if (input_string)
    {
        /* Traverse the string.  */
        for (length = 0; input_string[length]; length++)
        {
            /* Check if the string length is bigger than the max string length.  */
            if (length >= max_string_length)
            {
                break;
            }
        }
    }

    return length;
}

VOID safe_string_copy(GX_CHAR *put, const GX_CHAR *get, INT max_len)
{
    while(max_len > 1 && *get)
    {
        *put++ = *get++;
        max_len--;
    }
    *put = 0;
}