#!/usr/bin/perl

package MNU;

use warnings;
use strict;

use lib "./";
use NTVL;
use LPST;

use Try::Tiny;

my $SAVE_FN = "save.txt";

sub roll_back($){
    my @arr;
    my $game_str = shift;

    @arr = split(/\n/, $game_str);

    if(scalar @arr == 1){
	return "";
    }
    return join("\n", splice(@arr, 0, -1))."\n";
}

sub eval_game_str($$){
    my ($b, $game_str) = (shift, shift);
    try {
	NTVL->f1($b, $game_str);
	$b->disp_board();
    } catch {
	warn "invalid move: $_";
	$game_str = roll_back($game_str);
    };
    return $game_str;
}

sub disp_board($){
    my $b = shift;
    $b->disp_board();
}

sub load(){
    my $game_str;

    $game_str = "";
    open FILE, "<".$SAVE_FN or die "couldn't open save file";
    while(<FILE>){
	$game_str .= $_;
    }
    close FILE;
    
    return $game_str;
}

sub save($){
    my $game_str = shift;
    open FILE, ">".$SAVE_FN or die "couldn't open save file";
    printf FILE "%s", $game_str;
    close FILE;
    
    return $game_str;
}

sub parse_cmd($){
    my $in = shift;
    return -1 if $in =~ /^q(uit)?$/i;
    return 1 if($in =~ /^save$/i);
    return 2 if($in =~ /^load$/i);
    return 3 if($in =~ /^show$/i);
    return 0;
}

sub show($$){
    my ($b, $game_str) = (shift, shift);
    $b->shade_all_p1_mvmt();
    disp_board($b);
    return prompt($b, $game_str);
}
    

sub prompt($$){
    my ($b, $game_str) = (shift, shift);
    
    printf("> ");
    my $in;
    $in = <STDIN>;
    chomp $in;
    
    return "QUIT" if(parse_cmd($in) == -1);
    return save($game_str) if parse_cmd($in) == 1;
    return load() if parse_cmd($in) == 2;
    return show($b, $game_str) if parse_cmd($in) == 3;
    
    $game_str .= $in."\n";
    return $game_str;
}


sub loop($$){
    my ($class, $game_str) = (shift, shift);
    my $in;
    my $b;

    $b = LPST->new();
    $game_str = eval_game_str($b, $game_str);
    printf("%s\n", $game_str);

    $game_str = prompt($b, $game_str);
    return $game_str;
}

return 1;