package ShellSequence;

use strict;
use warnings;

use Capture::Tiny 'tee_stdout';
use Array::Iterator;
use Term::UI;
use Term::ReadLine;
use ScriptStatus;

sub new {
    my $class = shift;

    my $self = {
                'commands' => []
               };
    bless $self, $class;

    return $self;
}

# the advantage of using the add_ functions and queuing up commands is
# that the user will be informed what the next command will be, which
# helps them decide whether to give up and skip the command (e.g.: `mr
# autoci` is failing, and `mr push` will be next)

sub add_should_zero {
    my $self = shift;
    my @args = @_;

    my $cmd = ['ZERO', @args];

    push @{$self->{'commands'}}, $cmd;
}

sub add_should_succeed {
    my $self = shift;
    my @args = @_;

    my $cmd = ['SUCCEED', @args];

    push @{$self->{'commands'}}, $cmd;
}

sub should_zero {
    my $self = shift;
    my @args = @_;

    $self->add_should_zero(@args);
    $self->run();
}

sub should_succeed {
    my $self = shift;
    my @args = @_;

    $self->add_should_succeed(@args);
    $self->run();
}

sub choice {
    my $i = shift @_;
    my @args = @_;
    my $term = Term::ReadLine->new('brand');


    my $shell = $term->ask_yn(
                              prompt => 'Spawn a shell to investigate?',
                              default => 'n',
                             );
    if ($shell) {
        status "I will try running `@args' again when this shell exits";
        system $ENV{'SHELL'};
        return 1;
    } else {
        if ($i->peek()) {
            my @maybe_next = @{$i->peek()};
            shift @maybe_next;
            my @next = @maybe_next;
            status "info: if you skip, the next command will be `@next'";
        }
        my $give_up = $term->ask_yn(
                                    prompt => 'Give up and skip this command?',
                                    default => 'n',
                                   );
        return !$give_up;
    }
}

sub run {
    my $self = shift;

    my $i = Array::Iterator->new($self->{'commands'});

    while ( my $cmd = $i->get_next() ) {
        my $require = shift @$cmd;
        my @args = @$cmd;

        # previously we always used tee_stdout, and then looked at
        # both $output and its exit code.  However, tee_stdout works
        # badly for ncurses, such as debconf prompts which appeared
        # during apt runs.  So don't use tee_stdout except when we
        # have to
        while (42) {
            status "running `@args'";
            if ($require eq 'SUCCEED') {
                system @args;
                my $exit = $? >> 8;
                if ($exit != 0) {
                    status "`@args' failed but it was required to succeed";
                    choice($i, @args) || last;
                } else {
                    last;
                }
            } else {
                (my $output, undef) = tee_stdout {
                    system @args;
                };
                if (length($output)) {
                    status "`@args' was required to produce no output";
                    choice($i, @args) || last;
                } else {
                    last;
                }
            }
        }
    }

    $self->{'commands'} = [];
}

1;