#include <stdio.h>
#include <ncurses.h>
#include <stdlib.h>
#include <string.h>

int rows, cols;

typedef struct commandLine {
	int* string;
	int length;
	int position;
} commandLine;

void clearInput() {
	for (int i = 0; i < cols; i ++)
		mvprintw(rows - 1, i, " ");
}

void printPrompt(commandLine cmdLine, int len) {
	mvprintw(rows - 1, 0, ">");
	for (int i = 0; i < len; i ++) 
		mvprintw(rows - 1, i + 1, "%c", cmdLine.string[i]);
		
	attron(A_BLINK);
	mvprintw(rows - 1, cmdLine.position + 1, "");
	attroff(A_BLINK);
}

void clearScreen() {
	for (int i = 0; i < rows; i ++)
		for (int j = 0; j < cols; j ++) 
			mvprintw(i, j, " ");
}

void printContent(commandLine *content) {
	for (int i = 0; i < rows - 2; i ++)
		for (int j = 0; j < cols; j ++)
			mvprintw(rows - 2 - i, j, "%c", content[i].string[j]);
}

void insertInStartString(commandLine *cmdLine, int* toInsert ) {
	for (int i = rows - 2; i > 0 ; i --)
		for (int j = 0; j < cols; j ++)
			cmdLine[i].string[j] = cmdLine[i - 1].string[j];
			
	for (int i = 0; i < cols; i ++) 
		cmdLine[0].string[i] = toInsert[i];
}

void copyCommandLine(commandLine* destination, commandLine source) {
	for (int i = 0; i < source.length; i ++)
		destination->string[i] = source.string[i];

	destination->position = source.position;
	destination->length = source.length;
}

void insertInStartCommandLine(commandLine *cmdLine, commandLine toInsert, int arrayLength) {
	for (int i = arrayLength - 1; i > 0 ; i --) {
		copyCommandLine(&(cmdLine[i]), cmdLine[i - 1]);
	}
	copyCommandLine(&(cmdLine[0]), toInsert);
}

void insert(int *cmd_string, int toInsert , int position, int len) {
	for (int i = len + 1; i > position; i --)
		cmd_string[i] = cmd_string[i - 1];
		
	cmd_string[position] = toInsert;
}

void pop(commandLine* cmdLine) {
	if (cmdLine->position < 1)
		return;
		
	for (int i = cmdLine->position; i < cmdLine->length; i ++) 
		cmdLine->string[i] = cmdLine->string[i + 1];

	cmdLine->string[(cmdLine->length) - 1] = 0;

	cmdLine->length --;	
	cmdLine->position --;
}

void resetBuffer (commandLine *buffer) {
	memset(buffer->string, 0, sizeof(int) * cols);
	buffer->length = 0;
	buffer->position = 0;
}



int main (int argc, char* argv[]) {
	initscr();
	keypad(stdscr, TRUE);
	noecho();
	start_color();
	keypad(stdscr, true);

	getmaxyx(stdscr, rows, cols);
	
	int ch = ' ';
	int historySize = 150;
	int historyPosition = 0;

	commandLine *content;
	commandLine *history;
	commandLine buffer;
	
	content = malloc(rows * sizeof (commandLine));
	history = malloc(historySize * sizeof (commandLine));

	for (int i = 0; i < rows; i ++)
		content[i].string = malloc(cols * sizeof(int));
		
	for (int i = 0; i < historySize; i ++) 
		history[i].string = malloc(cols * sizeof(int));

	buffer.string = malloc(cols * sizeof(int));
	
	for (int i = 0; i < rows; i ++)
		for (int j = 0; j < cols; j ++)
			content[i].string[j] = 0;
		
	for (int i = 0; i < historySize; i ++)
		for (int j = 0; j < cols; j ++)
			history[i].string[j] = 0;

	printPrompt(buffer, buffer.length);
	
	while (1){
		ch = getch();	
		switch (ch) {
			case 10: {
				insertInStartString(content, buffer.string);
				insertInStartCommandLine(history, buffer, historySize);
	
				historyPosition = 0;
				resetBuffer(&buffer);
			break;
			}
			case KEY_LEFT:
				if (historyPosition > 0)
					buffer.position -= buffer.position > 0? 1 : 0;
				else
					buffer.position -= buffer.position > 0? 1 : 0;
			break;
			case KEY_RIGHT:
				if (historyPosition > 0)
					buffer.position += buffer.position < buffer.length? 1 : 0;
				else
					buffer.position += buffer.position > 0? 1 : 0;
			break;
			case KEY_UP:
				historyPosition += historyPosition < historySize? 1 : 0;
				resetBuffer(&buffer);
				if (historyPosition > 0)
					copyCommandLine(&buffer, history[historyPosition - 1]);
			break;
			case KEY_DOWN:
				historyPosition -= historyPosition > 0? 1 : 0;
				resetBuffer(&buffer);
				if (historyPosition > 0)
					copyCommandLine(&buffer, history[historyPosition - 1]);
			break;
			case KEY_BACKSPACE:
				pop(&buffer);
			break;
			case KEY_F(1):
				endwin();
				for (int i = 0; i < 10; i ++) {
					printf("%i (%i symbols): ", i, history[i].length);
					for (int j = 0; j < history[i].length; j ++)
						printf("%c", history[i].string[j]);
						
					printf("\n");
				}
			break;
			default:
				insert(buffer.string, ch, buffer.position, buffer.length);
				buffer.position ++;
				buffer.length ++;
			break;
		}

		clearScreen();
		clearInput();
		printContent(content);
		printPrompt(buffer, buffer.length);

		mvprintw(0, 0, "%i", historyPosition);
		
		refresh();
	}
	
	endwin();	
	return 0;
}