/*********************************************************************************
source of "nwriter", a basic text-editor for the Nspire; last modified 25.04.11
Copyright (C) 2011 Olivier Thill alias shrear

	This program 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
	any later version.

	This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
*********************************************************************************/

#include <os.h>
#include "key.h"
#include "store.h"
#include "screen.h"


int main(int argc, char* argv[])
{

	//silence compiler about argc
	argc = argc ;

	//local variables
	FILE* file ;
	int for_control ;

	//allocate screen buffers
	char* screen_buffer = (char*)malloc(SCREEN_HEIGHT*SCREEN_WIDTH) ;
	//initial clear screen
	char screen_color = 0xF ;
	memset(screen_buffer, screen_color, SCREEN_HEIGHT*SCREEN_WIDTH) ;
	display_buffer(screen_buffer) ;

	//create basic path
	char path[64] ;
	strcpy(path, argv[0]) ;
	char* path_tns ;

	//create default .txt path
	char file_path[64] ;
	strcpy(file_path, path) ;
	path_tns = strstr(file_path, ".tns") ;
	strcpy(path_tns, ".txt.tns") ;

	//create default .font path
	char font_path[64] ;
	strcpy(font_path, path) ;
	path_tns = strstr(font_path, ".tns") ;
	strcpy(path_tns, ".font.tns") ;

	//create font pointers
	char* file_temp ;
	char* file_meta ;
	char* font_description ;
	int* font_meta ;
	char* font ;

	//open font file
	file = fopen(font_path, "rb") ;

	//run only if file opend succesfull
	if ( file != NULL )
	{

		//load file_meta
		file_meta = (char*)malloc(20) ;
		fread(file_meta, 1, 20, file) ;
		rewind(file) ;

		//allocate and read to file_temp
		int file_size = file_meta[0]*0x1000000+file_meta[1]*0x10000+file_meta[2]*0x100+file_meta[3] ;
		file_temp = (char*)malloc(file_size) ;
		fread(file_temp, 1, file_size, file) ;
		//close font file
		fclose(file) ;

		//load font_description
		font_description = (char*)malloc(file_meta[4]-20) ;
		for ( for_control = 20 ; for_control < file_meta[4] ; for_control++ )
			font_description[for_control-20] = file_temp[for_control] ;

		//load font_meta
		font_meta = (int*)malloc(36) ;
		font_meta[0] = file_meta[5] ;
		font_meta[1] = file_meta[6] ;
		font_meta[2] = file_meta[7] ;
		font_meta[3] = file_meta[8]*0x100+file_meta[9] ;
		font_meta[4] = file_meta[10]*0x100+file_meta[11] ;
		font_meta[5] = file_meta[12]*0x100+file_meta[13] ;
		font_meta[6] = file_meta[14] ;
		font_meta[7] = file_meta[15]*0x1000000+file_meta[16]*0x10000+file_meta[17]*0x100+file_meta[18] ;
		font_meta[8] = file_meta[19] ;

		//load font
		font = (char*)malloc(font_meta[6]*font_meta[7]) ;
		for ( for_control = file_meta[4] ; for_control < font_meta[6]*font_meta[7]+file_meta[4] ; for_control++ )
			font[for_control-file_meta[4]] = file_temp[for_control] ;

		//free file_temp
		free(file_temp) ;

	}
	//exit program if no font could be loaded
	else
		return error(1) ;

	//screen variables
	int ycord_start = 1 ;
	int xcord_start = 1 ;
	int ycord_end = 1 ;
	int xcord_end = 1 ;

	//display variables
	int line_number = 0x600 ;
	int line_start = 0 ;
	int line_current = 0 ;
	int line_max = 0 ;
	int line_page = (SCREEN_HEIGHT-ycord_start-ycord_end)/font_meta[2]-1 ;

	//setup index
	short* index_line = (short*)malloc(line_number*2) ;
	memset(index_line, 0, line_number*2) ;
	int index = 0 ;
	int index_max = 0 ;

	//setup variable for vertical navigation
	int offset_x = 0 ;

	//allocate memory for store and set to zero
	int store_size = 0x4000 ;
	char* store = (char*)malloc(store_size) ;
	memset(store, 0, store_size) ;


	//start of interaction
	while ( !isKeyPressed(KEY_NSPIRE_ESC) )
	{
		//if no input save battery
		idle() ;
		if ( any_key_pressed() )
		{
			if ( !isKeyPressed(KEY_NSPIRE_CTRL) )
			{

				//navigate througth text
				if ( key_pressed(KEY_NSPIRE_CLICK) )
					index = index_max ;
				else if ( key_pressed(KEY_NSPIRE_UP) && line_current )
				{
					offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
					index = get_index(store, font, font_meta, offset_x, index_line[line_current-1], index_line[line_current]-1) ;
				}
				else if ( key_pressed(KEY_NSPIRE_UPRIGHT) )
				{
					if ( line_current )
					{
						offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
						index = get_index(store, font, font_meta, offset_x, index_line[line_current-1], index_line[line_current]-1) ;
					}
					if ( index != index_max )
						index++ ;
				}
				else if ( key_pressed(KEY_NSPIRE_RIGHT) && index != index_max )
					index++ ;
				else if ( key_pressed(KEY_NSPIRE_RIGHTDOWN) )
				{
					if ( line_current != line_max )
					{
						offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
						if ( line_current+2 < line_max )
							index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_line[line_current+2]-1) ;
						else
							index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_max) ;
					}
					if ( index != index_max )
						index++ ;
				}
				else if ( key_pressed(KEY_NSPIRE_DOWN) && line_current != line_max )
				{
					offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
					if ( line_current+2 < line_max )
						index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_line[line_current+2]-1) ;
					else
						index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_max) ;
				}
				else if ( key_pressed(KEY_NSPIRE_DOWNLEFT) )
				{
					if ( line_current != line_max )
					{
						offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
						if ( line_current+2 < line_max )
							index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_line[line_current+2]-1) ;
						else
							index = get_index(store, font, font_meta, offset_x, index_line[line_current+1], index_max) ;
					}
					if ( index != 0 )
						index-- ;
				}
				else if ( key_pressed(KEY_NSPIRE_LEFT) && index != 0 )
					index-- ;
				else if ( key_pressed(KEY_NSPIRE_LEFTUP) )
				{
					if ( line_current != 0 )
					{
						offset_x = get_offset(store, font, font_meta, index_line[line_current], index) ;
						index = get_index(store, font, font_meta, offset_x, index_line[line_current-1], index_line[line_current]-1) ;
					}
					if ( index != 0 )
						index-- ;
				}

				//flip screen color
				else if ( key_pressed(KEY_NSPIRE_CAT) )
					screen_color = 0xF-screen_color ;

				//delete last char
				else if ( key_pressed(KEY_NSPIRE_DEL) )
				{
					if ( index != 0 )
					{
						index-- ;
						if ( store[index] != 0 )
							store_char(0, store, index) ;
					}
				}

				//save to file
				else if ( key_pressed(KEY_NSPIRE_VAR) )
					save_file(store, index_max, file_path) ;
				//load from file
				else if ( key_pressed(KEY_NSPIRE_MENU) )
					index = load_file(store, store_size, file_path) ;
			}
			//key combos
			else if ( isKeyPressed(KEY_NSPIRE_CTRL) )
			{

				//navigate througth text
				if ( key_pressed(KEY_NSPIRE_CLICK) )
				{
					line_current = 0 ;
					index = 0 ;
				}
				else if ( key_pressed(KEY_NSPIRE_LEFT) && index != index_line[line_current] )
					index = index_line[line_current] ;
				else if ( key_pressed(KEY_NSPIRE_RIGHT) )
				{
					if ( index_line[line_current+1] != 0 )
					{
						index = index_line[line_current+1] ;
						if ( store[index-1] == 0x0A )
							index-- ;
					}
					else
						index = index_max ;
				}
				else if ( key_pressed(KEY_NSPIRE_UP) && line_start )
					line_start-- ;
				else if ( key_pressed(KEY_NSPIRE_DOWN) && index_line[line_start+1] )
					line_start++ ;

				//reset
				else if ( key_pressed(KEY_NSPIRE_DEL) )
				{
					index = 0 ;
					memset(store, 0, store_size) ;
				}

				//configure txt || font file
				else if ( key_pressed(KEY_NSPIRE_SHIFT) || key_pressed(KEY_NSPIRE_CAPS) )
					while (set_configuration(file_path, font_path, font, font_meta, font_description, screen_buffer, screen_color) )
					{
						//open font file
						file = fopen(font_path, "rb") ;

						//run only if file opend succesfull
						if ( file != NULL )
						{

							//load file_meta
							file_meta = (char*)malloc(20) ;
							fread(file_meta, 1, 20, file) ;
							rewind(file) ;

							//allocate and read to file_temp
							int file_size = file_meta[0]*0x1000000+file_meta[1]*0x10000+file_meta[2]*0x100+file_meta[3] ;
							file_temp = (char*)malloc(file_size) ;
							fread(file_temp, 1, file_size, file) ;
							//close font file
							fclose(file) ;

							//load font_description
							font_description = (char*)malloc(file_meta[4]-20) ;
							for ( for_control = 20 ; for_control < file_meta[4] ; for_control++ )
								font_description[for_control-20] = file_temp[for_control] ;

							//load font_meta
							font_meta = (int*)malloc(36) ;
							font_meta[0] = file_meta[5] ;
							font_meta[1] = file_meta[6] ;
							font_meta[2] = file_meta[7] ;
							font_meta[3] = file_meta[8]*0x100+file_meta[9] ;
							font_meta[4] = file_meta[10]*0x100+file_meta[11] ;
							font_meta[5] = file_meta[12]*0x100+file_meta[13] ;
							font_meta[6] = file_meta[14] ;
							font_meta[7] = file_meta[15]*0x1000000+file_meta[16]*0x10000+file_meta[17]*0x100+file_meta[18] ;
							font_meta[8] = file_meta[19] ;

							//load font
							font = (char*)malloc(font_meta[6]*font_meta[7]) ;
							for ( for_control = file_meta[4] ; for_control < font_meta[6]*font_meta[7]+file_meta[4] ; for_control++ )
								font[for_control-file_meta[4]] = file_temp[for_control] ;

							//free file_temp
							free(file_temp) ;

						}
						else
							error(1) ;
					}
			}

			//write characters to store
			index = write_key(store, index) ;
			//update index_max and index_line
			index_max = update_index(store, font, font_meta, xcord_start, xcord_end, index_line, line_number) ;
			//check if index_max is smaller than store
			if ( index_max > store_size )
				error(4) ;
			//check for invalid index
			if ( index > store_size-1 )
			{
				index = 0 ;
				index_max = 0 ;
			}
			if ( index < 0 || index > index_max)
			{
				error(2) ;
				index = index_max ;
			}
			//get the line of index_max
			line_max = 0 ;
			while ( index_line[line_max+1] )
				line_max++ ;
			//check current line
			while ( index < index_line[line_current] )
				line_current-- ;
			while ( index >= index_line[line_current+1] && line_current != line_max )
				line_current++ ;
			while ( line_current < line_start )
				line_start-- ;
			while ( line_current > line_start+line_page-1 )
				line_start++ ;
			//update buffer
			update_buffer(store, font, font_meta, screen_buffer, screen_color, ycord_start, xcord_start, ycord_end, xcord_end, index_line[line_start], index) ;
			//update screen
			display_buffer(screen_buffer) ;

		}

	}

	//deallocate screen_buffers
	free(screen_buffer) ;

	//unload font
	free(font) ;
	free(font_meta) ;
	free(file_meta) ;
	free(font_description) ;

	//deallocate store and store_save
	free(store) ;

	//deallocate line index
	free(index_line) ;

	//the sily return statement of main()
	return 0 ;


}