package App::Prove::State;

use strict;
use File::Find;
use File::Spec;
use Carp;
use TAP::Parser::YAMLish::Reader ();
use TAP::Parser::YAMLish::Writer ();
use TAP::Base;

use vars qw($VERSION @ISA);
@ISA = qw( TAP::Base );

use constant IS_WIN32 => ( $^O =~ /^(MS)?Win32$/ );
use constant NEED_GLOB => IS_WIN32;

=head1 NAME

App::Prove::State - State storage for the C<prove> command.

=head1 VERSION

Version 3.05

=cut

$VERSION = '3.05';

=head1 DESCRIPTION

The C<prove> command supports a C<--state> option that instructs it to
store persistent state across runs. This module implements that state
and the operations that may be performed on it.

=head1 SYNOPSIS

    # Re-run failed tests
    $ prove --state=fail,save -rbv

=cut

=head1 METHODS

=head2 Class Methods

=head3 C<new>

=cut

sub new {
    my $class = shift;
    my %args = %{ shift || {} };

    my $self = bless {
        _ => {
            tests      => {},
            generation => 1
        },
        select => [],
        seq    => 1,
        store  => delete $args{store},
    }, $class;

    my $store = $self->{store};
    $self->load($store)
      if defined $store && -f $store;

    return $self;
}

sub DESTROY {
    my $self = shift;
    if ( $self->{should_save} && defined( my $store = $self->{store} ) ) {
        $self->save($store);
    }
}

=head2 Instance Methods

=head3 C<apply_switch>

Apply a list of switch options to the state.

=over

=item C<last>

Run in the same order as last time

=item C<failed>

Run only the failed tests from last time

=item C<passed>

Run only the passed tests from last time

=item C<all>

Run all tests in normal order

=item C<hot>

Run the tests that most recently failed first

=item C<todo>

Run the tests ordered by number of todos.

=item C<slow>

Run the tests in slowest to fastest order.

=item C<fast>

Run test tests in fastest to slowest order.

=item C<new>

Run the tests in newest to oldest order.

=item C<old>

Run the tests in oldest to newest order.

=item C<save>

Save the state on exit.

=back

=cut

sub apply_switch {
    my $self = shift;
    my @opts = @_;

    my $last_gen = $self->{_}->{generation} - 1;
    my $now      = $self->get_time;

    my @switches = map { split /,/ } @opts;

    my %handler = (
        last => sub {
            $self->_select(
                where => sub { $_->{gen} >= $last_gen },
                order => sub { $_->{seq} }
            );
        },
        failed => sub {
            $self->_select(
                where => sub { $_->{last_result} != 0 },
                order => sub { -$_->{last_result} }
            );
        },
        passed => sub {
            $self->_select( where => sub { $_->{last_result} == 0 } );
        },
        all => sub {
            $self->_select();
        },
        todo => sub {
            $self->_select(
                where => sub { $_->{last_todo} != 0 },
                order => sub { -$_->{last_todo}; }
            );
        },
        hot => sub {
            $self->_select(
                where => sub { defined $_->{last_fail_time} },
                order => sub { $now - $_->{last_fail_time} }
            );
        },
        slow => sub {
            $self->_select( order => sub { -$_->{elapsed} } );
        },
        fast => sub {
            $self->_select( order => sub { $_->{elapsed} } );
        },
        new => sub {
            $self->_select(
                order => sub {
                        ( $_->{total_failures} || 0 )
                      + ( $_->{total_passes} || 0 );
                }
            );
        },
        old => sub {
            $self->_select(
                order => sub {
                    -(    ( $_->{total_failures} || 0 )
                        + ( $_->{total_passes} || 0 ) );
                }
            );
        },
        save => sub {
            $self->{should_save}++;
        },
        adrian => sub {
            unshift @switches, qw( hot all save );
        },
    );

    while ( defined( my $ele = shift @switches ) ) {
        my ( $opt, $arg )
          = ( $ele =~ /^([^:]+):(.*)/ )
          ? ( $1, $2 )
          : ( $ele, undef );
        my $code = $handler{$opt}
          || croak "Illegal state option: $opt";
        $code->($arg);
    }
}

sub _select {
    my ( $self, %spec ) = @_;
    push @{ $self->{select} }, \%spec;
}

=head3 C<get_tests>

Given a list of args get the names of tests that should run

=cut

sub get_tests {
    my $self    = shift;
    my $recurse = shift;
    my @argv    = @_;
    my %seen;

    my @selected = $self->_query;

    unless ( @argv || @{ $self->{select} } ) {
        croak q{No tests named and 't' directory not found}
          unless -d 't';
        @argv = 't';
    }

    push @selected, $self->_get_raw_tests( $recurse, @argv ) if @argv;
    return grep { !$seen{$_}++ } @selected;
}

sub _query {
    my $self = shift;
    if ( my @sel = @{ $self->{select} } ) {
        warn "No saved state, selection will be empty\n"
          unless keys %{ $self->{_}->{tests} };
        return map { $self->_query_clause($_) } @sel;
    }
    return;
}

sub _query_clause {
    my ( $self, $clause ) = @_;
    my @got;
    my $tests = $self->{_}->{tests};
    my $where = $clause->{where} || sub {1};

    # Select
    for my $test ( sort keys %$tests ) {
        local $_ = $tests->{$test};
        push @got, $test if $where->();
    }

    # Sort
    if ( my $order = $clause->{order} ) {
        @got = map { $_->[0] }
          sort {
                 ( defined $b->[1] <=> defined $a->[1] )
              || ( ( $a->[1] || 0 ) <=> ( $b->[1] || 0 ) )
          } map {
            [   $_,
                do { local $_ = $tests->{$_}; $order->() }
            ]
          } @got;
    }

    return @got;
}

sub _get_raw_tests {
    my $self    = shift;
    my $recurse = shift;
    my @argv    = @_;
    my @tests;

    # Do globbing on Win32.
    @argv = map { glob "$_" } @argv if NEED_GLOB;

    for my $arg (@argv) {
        if ( '-' eq $arg ) {
            push @argv => <STDIN>;
            chomp(@argv);
            next;
        }

        push @tests,
          sort -d $arg
          ? $recurse
              ? $self->_expand_dir_recursive($arg)
              : glob( File::Spec->catfile( $arg, '*.t' ) )
          : $arg;
    }
    return @tests;
}

sub _expand_dir_recursive {
    my ( $self, $dir ) = @_;

    my @tests;
    find(
        {   follow => 1,      #21938
            wanted => sub {
                -f 
                  && /\.t$/
                  && push @tests => $File::Find::name;
              }
        },
        $dir
    );
    return @tests;
}

=head3 C<observe_test>

Store the results of a test.

=cut

sub observe_test {
    my ( $self, $test, $parser ) = @_;
    $self->_record_test(
        $test, scalar( $parser->failed ) + ( $parser->has_problems ? 1 : 0 ),
        scalar( $parser->todo ), $parser->start_time, $parser->end_time
    );
}

# Store:
#     last fail time
#     last pass time
#     last run time
#     most recent result
#     most recent todos
#     total failures
#     total passes
#     state generation

sub _record_test {
    my ( $self, $test, $fail, $todo, $start_time, $end_time ) = @_;
    my $rec = $self->{_}->{tests}->{ $test->[0] } ||= {};

    $rec->{seq} = $self->{seq}++;
    $rec->{gen} = $self->{_}->{generation};

    $rec->{last_run_time} = $end_time;
    $rec->{last_result}   = $fail;
    $rec->{last_todo}     = $todo;
    $rec->{elapsed}       = $end_time - $start_time;

    if ($fail) {
        $rec->{total_failures}++;
        $rec->{last_fail_time} = $end_time;
    }
    else {
        $rec->{total_passes}++;
        $rec->{last_pass_time} = $end_time;
    }
}

=head3 C<save>

Write the state to a file.

=cut

sub save {
    my ( $self, $name ) = @_;
    my $writer = TAP::Parser::YAMLish::Writer->new;
    local *FH;
    open FH, ">$name" or croak "Can't write $name ($!)";
    $writer->write( $self->{_} || {}, \*FH );
    close FH;
}

=head3 C<load>

Load the state from a file

=cut

sub load {
    my ( $self, $name ) = @_;
    my $reader = TAP::Parser::YAMLish::Reader->new;
    local *FH;
    open FH, "<$name" or croak "Can't read $name ($!)";
    $self->{_} = $reader->read(
        sub {
            my $line = <FH>;
            defined $line && chomp $line;
            return $line;
        }
    );

    # $writer->write( $self->{tests} || {}, \*FH );
    close FH;
    $self->_regen_seq;
    $self->{_}->{generation}++;
}

sub _regen_seq {
    my $self = shift;
    for my $rec ( values %{ $self->{_}->{tests} || {} } ) {
        $self->{seq} = $rec->{seq} + 1
          if defined $rec->{seq} && $rec->{seq} >= $self->{seq};
    }
}