package Coreutils;
# This is a testing framework.

# Copyright (C) 1998-2020 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <https://www.gnu.org/licenses/>.

use strict;
use vars qw($VERSION @ISA @EXPORT);

use FileHandle;
use File::Compare qw(compare);

@ISA = qw(Exporter);
($VERSION = '$Revision: 1.5 $ ') =~ tr/[0-9].//cd;
@EXPORT = qw (run_tests triple_test getlimits);

my $debug = $ENV{DEBUG};

my @Types = qw (IN IN_PIPE OUT ERR AUX CMP EXIT PRE POST OUT_SUBST
                ERR_SUBST ENV ENV_DEL);
my %Types = map {$_ => 1} @Types;
my %Zero_one_type = map {$_ => 1}
   qw (OUT ERR EXIT PRE POST OUT_SUBST ERR_SUBST ENV);
my $srcdir = "$ENV{srcdir}";
my $Global_count = 1;

# When running in a DJGPP environment, make $ENV{SHELL} point to bash.
# Otherwise, a bad shell might be used (e.g. command.com) and many
# tests would fail.
defined $ENV{DJDIR}
  and $ENV{SHELL} = "$ENV{DJDIR}/bin/bash.exe";

# A file spec: a scalar or a reference to a single-keyed hash
# ================
# 'contents'               contents only (file name is derived from test name)
# {filename => 'contents'} filename and contents
# {filename => undef}      filename only -- $(srcdir)/tests/filename must exist
#
# FIXME: If there is more than one input file, then you can't specify 'REDIR'.
# PIPE is still ok.
#
# I/O spec: a hash ref with the following properties
# ================
# - one key/value pair
# - the key must be one of these strings: IN, OUT, ERR, AUX, CMP, EXIT
# - the value must be a file spec
# {OUT => 'data'}    put data in a temp file and compare it to stdout from cmd
# {OUT => {'filename'=>undef}} compare contents of existing filename to
#           stdout from cmd
# {OUT => {'filename'=>[$CTOR, $DTOR]}} $CTOR and $DTOR are references to
#           functions, each which is passed the single argument 'filename'.
#           $CTOR must create 'filename'.
#           DTOR may be omitted in which case 'sub{unlink @_[0]}' is used.
#           FIXME: implement this
# {ERR => ...}
#           Same as for OUT, but compare with stderr, not stdout.
# {OUT_SUBST => 's/variable_output/expected_output/'}
#   Transform actual standard output before comparing it against expected.
#   This is useful e.g. for programs like du that produce output that
#   varies a lot from system.  E.g., an empty file may consume zero file
#   blocks, or more, depending on the OS and on the file system type.
# {ERR_SUBST => 's/variable_output/expected_output/'}
#   Transform actual stderr output before comparing it against expected.
#   This is useful when verifying that we get a meaningful diagnostic.
#   For example, in rm/fail-2eperm, we have to account for three different
#   diagnostics: Operation not permitted, Not owner, and Permission denied.
# {EXIT => N} expect exit status of cmd to be N
# {ENV => 'VAR=val ...'}
#   Prepend 'VAR=val ...' to the command that we execute via 'system'.
# {ENV_DEL => 'VAR'}
#   Remove VAR from the environment just before running the corresponding
#   command, and restore any value just afterwards.
#
# There may be many input file specs.  File names from the input specs
# are concatenated in order on the command line.
# There may be at most one of the OUT-, ERR-, and EXIT-keyed specs.
# If the OUT-(or ERR)-keyed hash ref is omitted, then expect no output
#   on stdout (or stderr).
# If the EXIT-keyed one is omitted, then expect the exit status to be zero.

# FIXME: Make sure that no junkfile is also listed as a
# non-junkfile (i.e., with undef for contents)

sub _shell_quote ($)
{
  my ($string) = @_;
  $string =~ s/\'/\'\\\'\'/g;
  return "'$string'";
}

sub _create_file ($$$$)
{
  my ($program_name, $test_name, $file_name, $data) = @_;
  my $file;
  if (defined $file_name)
    {
      $file = $file_name;
    }
  else
    {
      $file = "$test_name.$Global_count";
      ++$Global_count;
    }

  warn "creating file '$file' with contents '$data'\n" if $debug;

  # The test spec gave a string.
  # Write it to a temp file and return tempfile name.
  my $fh = new FileHandle "> $file";
  die "$program_name: $file: $!\n" if ! $fh;
  print $fh $data;
  $fh->close || die "$program_name: $file: $!\n";

  return $file;
}

sub _compare_files ($$$$$)
{
  my ($program_name, $test_name, $in_or_out, $actual, $expected) = @_;

  my $differ = compare ($actual, $expected);
  if ($differ)
    {
      my $info = (defined $in_or_out ? "std$in_or_out " : '');
      warn "$program_name: test $test_name: ${info}mismatch, comparing "
        . "$expected (expected) and $actual (actual)\n";
      # Ignore any failure, discard stderr.
      system "diff -c $expected $actual 2>/dev/null";
    }

  return $differ;
}

sub _process_file_spec ($$$$$)
{
  my ($program_name, $test_name, $file_spec, $type, $junk_files) = @_;

  my ($file_name, $contents);
  if (!ref $file_spec)
    {
      ($file_name, $contents) = (undef, $file_spec);
    }
  elsif (ref $file_spec eq 'HASH')
    {
      my $n = keys %$file_spec;
      die "$program_name: $test_name: $type spec has $n elements --"
        . " expected 1\n"
          if $n != 1;
      ($file_name, $contents) = each %$file_spec;

      # This happens for the AUX hash in an io_spec like this:
      # {CMP=> ['zy123utsrqponmlkji', {'@AUX@'=> undef}]},
      defined $contents
        or return $file_name;
    }
  else
    {
      die "$program_name: $test_name: invalid RHS in $type-spec\n"
    }

  my $is_junk_file = (! defined $file_name
                      || (($type eq 'IN' || $type eq 'AUX' || $type eq 'CMP')
                          && defined $contents));
  my $file = _create_file ($program_name, $test_name,
                           $file_name, $contents);

  if ($is_junk_file)
    {
      push @$junk_files, $file
    }
  else
    {
      # FIXME: put $srcdir in here somewhere
      warn "$program_name: $test_name: specified file '$file' does"
        . " not exist\n"
          if ! -f "$srcdir/tests/$file";
    }

  return $file;
}

sub _at_replace ($$)
{
  my ($map, $s) = @_;
  foreach my $eo (qw (AUX OUT ERR))
    {
      my $f = $map->{$eo};
      $f
        and $s =~ /\@$eo\@/
          and $s =~ s/\@$eo\@/$f/g;
    }
  return $s;
}

sub getlimits()
{
  my $NV;
  open $NV, "getlimits |" or die "Error running getlimits\n";
  my %limits = map {split /=|\n/} <$NV>;
  return \%limits;
}

# FIXME: cleanup on interrupt
# FIXME: extract 'do_1_test' function

# FIXME: having to include $program_name here is an expedient kludge.
# Library code doesn't 'die'.
sub run_tests ($$$$$)
{
  my ($program_name, $prog, $t_spec, $save_temps, $verbose) = @_;

  # To indicate that $prog is a shell built-in, you'd make it a string 'ref'.
  # E.g., call run_tests ($prog, \$prog, \@Tests, $save_temps, $verbose);
  # If it's a ref, invoke it via "env":
  my $built_prog = ref $prog ? $$prog : $prog;
  my @prog = ref $prog ? (qw(env --), $$prog) : $prog;

  # Warn about empty t_spec.
  # FIXME

  # Remove all temp files upon interrupt.
  # FIXME

  # Verify that test names are distinct.
  my $bad_test_name = 0;
  my %seen;
  my %seen_8dot3;
  my $t;
  foreach $t (@$t_spec)
    {
      my $test_name = $t->[0];
      if ($seen{$test_name})
        {
          warn "$program_name: $test_name: duplicate test name\n";
          $bad_test_name = 1;
        }
      $seen{$test_name} = 1;

      if (0)
        {
          my $t8 = lc substr $test_name, 0, 8;
          if ($seen_8dot3{$t8})
            {
              warn "$program_name: 8.3 test name conflict: "
                . "$test_name, $seen_8dot3{$t8}\n";
              $bad_test_name = 1;
            }
          $seen_8dot3{$t8} = $test_name;
        }

      # The test name may be no longer than 30 bytes.
      # Yes, this is an arbitrary limit.  If it causes trouble,
      # consider removing it.
      my $max = 30;
      if ($max < length $test_name)
        {
          warn "$program_name: $test_name: test name is too long (> $max)\n";
          $bad_test_name = 1;
        }
    }
  return 1 if $bad_test_name;

  $ENV{built_programs} =~ /\b$built_prog\b/ ||
    CuSkip::skip "required program(s) not built [$built_prog]\n";

  # FIXME check exit status
  system (@prog, '--version') if $verbose;

  my @junk_files;
  my $fail = 0;
  foreach my $tt (@$t_spec)
    {
      my @post_compare;
      my @dummy = @$tt;
      my $t = \@dummy;
      my $test_name = shift @$t;
      my $expect = {};
      my ($pre, $post);

      # FIXME: maybe don't reset this.
      $Global_count = 1;
      my @args;
      my $io_spec;
      my %seen_type;
      my @env_delete;
      my $env_prefix = '';
      my $input_pipe_cmd;
      foreach $io_spec (@$t)
        {
          if (!ref $io_spec)
            {
              push @args, $io_spec;
              next;
            }

          if (ref $io_spec ne 'HASH')
            {
              eval 'use Data::Dumper';
              die "$program_name: $test_name: invalid entry in test spec; "
                . "expected HASH-ref,\nbut got this:\n"
                  . Data::Dumper->Dump ([\$io_spec], ['$io_spec']) . "\n";
            }

          my $n = keys %$io_spec;
          die "$program_name: $test_name: spec has $n elements --"
            . " expected 1\n"
              if $n != 1;
          my ($type, $val) = each %$io_spec;
          die "$program_name: $test_name: invalid key '$type' in test spec\n"
            if ! $Types{$type};

          # Make sure there's no more than one of OUT, ERR, EXIT, etc.
          die "$program_name: $test_name: more than one $type spec\n"
            if $Zero_one_type{$type} and $seen_type{$type}++;

          if ($type eq 'PRE' or $type eq 'POST')
            {
              $expect->{$type} = $val;
              next;
            }

          if ($type eq 'CMP')
            {
              my $t = ref $val;
              $t && $t eq 'ARRAY'
                or die "$program_name: $test_name: invalid CMP spec\n";
              @$val == 2
                or die "$program_name: $test_name: invalid CMP list;  must have"
                  . " exactly 2 elements\n";
              my @cmp_files;
              foreach my $e (@$val)
                {
                  my $r = ref $e;
                  $r && $r ne 'HASH'
                    and die "$program_name: $test_name: invalid element ($r)"
                      . " in CMP list;  only scalars and hash references "
                        . "are allowed\n";
                  if ($r && $r eq 'HASH')
                    {
                      my $n = keys %$e;
                      $n == 1
                        or die "$program_name: $test_name: CMP spec has $n "
                          . "elements -- expected 1\n";

                      # Replace any '@AUX@' in the key of %$e.
                      my ($ff, $val) = each %$e;
                      my $new_ff = _at_replace $expect, $ff;
                      if ($new_ff ne $ff)
                        {
                          $e->{$new_ff} = $val;
                          delete $e->{$ff};
                        }
                    }
                  my $cmp_file = _process_file_spec ($program_name, $test_name,
                                                     $e, $type, \@junk_files);
                  push @cmp_files, $cmp_file;
                }
              push @post_compare, [@cmp_files];

              $expect->{$type} = $val;
              next;
            }

          if ($type eq 'EXIT')
            {
              die "$program_name: $test_name: invalid EXIT code\n"
                if $val !~ /^\d+$/;
              # FIXME: make sure $data is numeric
              $expect->{EXIT} = $val;
              next;
            }

          if ($type =~ /^(OUT|ERR)_SUBST$/)
            {
              $expect->{RESULT_SUBST} ||= {};
              $expect->{RESULT_SUBST}->{$1} = $val;
              next;
            }

          if ($type eq 'ENV')
            {
              $env_prefix = "$val ";
              next;
            }

          if ($type eq 'ENV_DEL')
            {
              push @env_delete, $val;
              next;
            }

          my $file = _process_file_spec ($program_name, $test_name, $val,
                                         $type, \@junk_files);

          if ($type eq 'IN' || $type eq 'IN_PIPE')
            {
              my $quoted_file = _shell_quote $file;
              if ($type eq 'IN_PIPE')
                {
                  defined $input_pipe_cmd
                    and die "$program_name: $test_name: only one input"
                      . " may be specified with IN_PIPE\n";
                  $input_pipe_cmd = "cat $quoted_file |";
                }
              else
                {
                  push @args, $quoted_file;
                }
            }
          elsif ($type eq 'AUX' || $type eq 'OUT' || $type eq 'ERR')
            {
              $expect->{$type} = $file;
            }
          else
            {
              die "$program_name: $test_name: invalid type: $type\n"
            }
        }

      # Expect an exit status of zero if it's not specified.
      $expect->{EXIT} ||= 0;

      # Allow ERR to be omitted -- in that case, expect no error output.
      foreach my $eo (qw (OUT ERR))
        {
          if (!exists $expect->{$eo})
            {
              $expect->{$eo} = _create_file ($program_name, $test_name,
                                             undef, '');
              push @junk_files, $expect->{$eo};
            }
        }

      # FIXME: Does it ever make sense to specify a filename *and* contents
      # in OUT or ERR spec?

      # FIXME: this is really suboptimal...
      my @new_args;
      foreach my $a (@args)
        {
          $a = _at_replace $expect, $a;
          push @new_args, $a;
        }
      @args = @new_args;

      warn "$test_name...\n" if $verbose;
      &{$expect->{PRE}} if $expect->{PRE};
      my %actual;
      $actual{OUT} = "$test_name.O";
      $actual{ERR} = "$test_name.E";
      push @junk_files, $actual{OUT}, $actual{ERR};
      my @cmd = (@prog, @args, "> $actual{OUT}", "2> $actual{ERR}");
      $env_prefix
        and unshift @cmd, $env_prefix;
      defined $input_pipe_cmd
        and unshift @cmd, $input_pipe_cmd;
      my $cmd_str = join (' ', @cmd);

      # Delete from the environment any symbols specified by syntax
      # like this: {ENV_DEL => 'TZ'}.
      my %pushed_env;
      foreach my $env_sym (@env_delete)
        {
          my $val = delete $ENV{$env_sym};
          defined $val
            and $pushed_env{$env_sym} = $val;
        }

      warn "Running command: '$cmd_str'\n" if $debug;
      my $rc = 0xffff & system $cmd_str;

      # Restore any environment setting we changed via a deletion.
      foreach my $env_sym (keys %pushed_env)
        {
          $ENV{$env_sym} = $pushed_env{$env_sym};
        }

      if ($rc == 0xff00)
        {
          warn "$program_name: test $test_name failed: command failed:\n"
            . "  '$cmd_str': $!\n";
          $fail = 1;
          goto cleanup;
        }
      $rc >>= 8 if $rc > 0x80;
      if ($expect->{EXIT} != $rc)
        {
          warn "$program_name: test $test_name failed: exit status mismatch:"
            . "  expected $expect->{EXIT}, got $rc\n";
          $fail = 1;
          goto cleanup;
        }

      my %actual_data;
      # Record actual stdout and stderr contents, if POST may need them.
      if ($expect->{POST})
        {
          foreach my $eo (qw (OUT ERR))
            {
              my $out_file = $actual{$eo};
              open IN, $out_file
                or (warn
                    "$program_name: cannot open $out_file for reading: $!\n"),
                  $fail = 1, next;
              $actual_data{$eo} = <IN>;
              close IN
                or (warn "$program_name: failed to read $out_file: $!\n"),
                  $fail = 1;
            }
        }

      foreach my $eo (qw (OUT ERR))
        {
          my $subst_expr = $expect->{RESULT_SUBST}->{$eo};
          if (defined $subst_expr)
            {
              my $out = $actual{$eo};
              my $orig = "$out.orig";

              # Move $out aside (to $orig), then recreate $out
              # by transforming each line of $orig via $subst_expr.
              rename $out, $orig
                or (warn "$program_name: cannot rename $out to $orig: $!\n"),
                  $fail = 1, next;
              open IN, $orig
                or (warn "$program_name: cannot open $orig for reading: $!\n"),
                  $fail = 1, (unlink $orig), next;
              unlink $orig
                or (warn "$program_name: cannot unlink $orig: $!\n"),
                  $fail = 1;
              open OUT, ">$out"
                or (warn "$program_name: cannot open $out for writing: $!\n"),
                  $fail = 1, next;
              while (defined (my $line = <IN>))
                {
                  eval "\$_ = \$line; $subst_expr; \$line = \$_";
                  print OUT $line;
                }
              close IN;
              close OUT
                or (warn "$program_name: failed to write $out: $!\n"),
                  $fail = 1, next;
            }

          my $eo_lower = lc $eo;
          _compare_files ($program_name, $test_name, $eo_lower,
                          $actual{$eo}, $expect->{$eo})
            and $fail = 1;
        }

      foreach my $pair (@post_compare)
        {
          my ($expected, $actual) = @$pair;
          _compare_files $program_name, $test_name, undef, $actual, $expected
            and $fail = 1;
        }

    cleanup:
      $expect->{POST}
        and &{$expect->{POST}} ($actual_data{OUT}, $actual_data{ERR});

    }

  # FIXME: maybe unlink files inside the big foreach loop?
  unlink @junk_files if ! $save_temps;

  return $fail;
}

# For each test in @$TESTS, generate two additional tests,
# one using stdin, the other using a pipe.  I.e., given this one
# ['idem-0', {IN=>''}, {OUT=>''}],
# generate these:
# ['idem-0.r', '<', {IN=>''}, {OUT=>''}],
# ['idem-0.p', {IN_PIPE=>''}, {OUT=>''}],
# Generate new tests only if there is exactly one input spec.
# The returned list of tests contains each input test, followed
# by zero or two derived tests.
sub triple_test($)
{
  my ($tests) = @_;
  my @new;
  foreach my $t (@$tests)
    {
      push @new, $t;

      my @in;
      my @args;
      my @list_of_hash;
      foreach my $e (@$t)
        {
          !ref $e
            and push (@args, $e), next;

          ref $e && ref $e eq 'HASH'
            or (warn "$0: $t->[0]: unexpected entry type\n"), next;
          defined $e->{IN}
            and (push @in, $e->{IN}), next;
          push @list_of_hash, $e;
        }
      # Add variants IFF there is exactly one input file.
      @in == 1
        or next;
      shift @args; # discard test name
      push @new, ["$t->[0].r", @args, '<', {IN => $in[0]}, @list_of_hash];
      push @new, ["$t->[0].p", @args, {IN_PIPE => $in[0]}, @list_of_hash];
    }
  return @new;
}

## package return
1;