#include "../nasal.h"
#include <iostream>
#ifdef _WIN32
#include <conio.h>
#else
#include <fcntl.h>
#include <termios.h>
#endif

class noecho_input{
private:
#ifndef _WIN32
    struct termios init_termios;
    struct termios new_termios;
    int peek_char=-1;
#endif
public:
    noecho_input(){
#ifndef _WIN32
        tcflush(0,TCIOFLUSH);
        tcgetattr(0,&init_termios);
        new_termios=init_termios;
        new_termios.c_lflag&=~(ICANON|ECHO|ECHONL|ECHOE);
        // vmin=0 is nonblock input, but in wsl there is a bug that will block input
        // so we use fcntl to write the nonblock input
        new_termios.c_cc[VMIN]=1;
        new_termios.c_cc[VTIME]=0;
        tcsetattr(0,TCSANOW,&new_termios);
#endif
    }
    ~noecho_input(){
#ifndef _WIN32
        tcflush(0,TCIOFLUSH);
        tcsetattr(0,TCSANOW,&init_termios);
#endif
    }
    int noecho_kbhit(){
#ifndef _WIN32
        unsigned char ch=0;
        int nread=0;
        if(peek_char!=-1)
            return 1;
        int flag=fcntl(0,F_GETFL);
        fcntl(0,F_SETFL,flag|O_NONBLOCK);
        nread=read(0,&ch,1);
        fcntl(0,F_SETFL,flag);
        if(nread==1){
            peek_char=ch;
            return 1;
        }
        return 0;
#else
        return kbhit();
#endif
    }
    int noecho_getch(){
#ifndef _WIN32
        int ch=0;
        if(peek_char!=-1){
            ch=peek_char;
            peek_char=-1;
            return ch;
        }
        read(0,&ch,1);
        return ch;
#else
        return getch();
#endif
    }
};

noecho_input this_window;
extern "C" nasal_ref nas_getch(std::vector<nasal_ref>& args,nasal_gc& gc){
    return {vm_num,(double)this_window.noecho_getch()};
}
extern "C" nasal_ref nas_kbhit(std::vector<nasal_ref>& args,nasal_gc& gc){
    return {vm_num,(double)this_window.noecho_kbhit()};
}
extern "C" nasal_ref nas_noblock(std::vector<nasal_ref>& args,nasal_gc& gc){
    if(this_window.noecho_kbhit())
        return {vm_num,(double)this_window.noecho_getch()};
    return nil;
}