#!/usr/bin/perl

use warnings;
use strict;
use Test::More qw/no_plan/;
use Test::Exception;
use Test::Differences;
use FindBin qw/$Bin/;

use SQL::Translator;
use SQL::Translator::Utils qw/ddl_parser_instance/;


### Set $ENV{SQLTTEST_RT_DEBUG} = 1 for more output

# What tests to run - parser/producer name, and optional args
my $plan = [
  {
    engine => 'XML',
    req => 'XML::LibXML 1.69',
    no_grammar => 1,
  },
  {
    engine => 'YAML',
    no_grammar => 1,
  },

  {
    engine => 'SQLite',
    producer_args => {},
    parser_args => {},
  },
  {
    engine => 'MySQL',
    producer_args => {},
    parser_args => {},
  },
  {
    engine => 'MySQL',
    name => 'MySQL 5.0',
    producer_args => { mysql_version => 5 },
    parser_args => { mysql_parser_version => 5 },
  },
  {
    engine => 'MySQL',
    name => 'MySQL 5.1',
    producer_args => { mysql_version => '5.1' },
    parser_args => { mysql_parser_version => '5.1' },
  },
  {
    engine => 'PostgreSQL',
    producer_args => {},
    parser_args => {},
  },
  {
    engine => 'SQLServer',
    producer_args => {},
    parser_args => {},
  },

  {
    engine => 'Oracle',
    producer_args => {},
    parser_args => {},
    todo => 'Needs volunteers',
  },
  {
    engine => 'Sybase',
    producer_args => {},
    parser_args => {},
    todo => 'Needs volunteers',
  },
  {
    engine => 'DB2',
    producer_args => {},
    parser_args => {},
    todo => 'Needs volunteers',
  },

# There is no Access producer
#  {
#    engine => 'Access',
#    producer_args => {},
#    parser_args => {},
#  },
];


# This data file has the right mix of table/view/procedure/trigger
# definitions, and lists enough quirks to trip up most combos
my $base_file = "$Bin/data/roundtrip_autogen.yaml";
open (my $base_fh, '<', $base_file) or die "$base_file: $!";

my $base_t = SQL::Translator->new;
$base_t->$_ (1) for qw/add_drop_table no_comments/;

my $base_schema = $base_t->translate (
  parser => 'YAML',
  data => do { local $/; <$base_fh>; },
) or die $base_t->error;


#assume there is at least one table
my $string_re = {
  XML => qr/<tables>\s*<table/,
  YAML => qr/\A---\n.+tables\:/s,
  SQL => qr/^\s*CREATE TABLE/m,
};

for my $args (@$plan) {
  SKIP: {
    $args->{name} ||= $args->{engine};

    my @req = ref $args->{req} ? @{$args->{req}} : $args->{req}||();
    my @missing;
    for (@req) {
      eval "use $_ ()";
      push @missing, $_ if ($@);
    }
    if (@missing) {
      skip sprintf ('Need %s for %s roundtrip test',
        join (', ', @missing),
        $args->{name},
      );
    }

    use_ok("SQL::Translator::Producer::$args->{engine}");
    use_ok("SQL::Translator::Parser::$args->{engine}");

    ok(ddl_parser_instance($args->{engine}), 'Got proper parser instance')
      unless $args->{no_grammar};

    TODO: {
      local $TODO = $args->{todo} if $args->{todo};

      no warnings 'once';
      # silence PR::D from spewing on STDERR
      local $::RD_ERRORS = 0 if $args->{todo};
      local $::RD_WARN = 0 if $args->{todo};
      local $::RD_HINT = 0 if $args->{todo};

      lives_ok (
        sub { check_roundtrip ($args, $base_schema) },
        "Round trip for $args->{name} did not throw an exception",
      );
    }
  }
}


sub check_roundtrip {
  my ($args, $base_schema) = @_;
  my $base_t = $base_schema->translator;

# create some output from the submitted schema
  my $base_out = $base_t->translate (
    data => $base_schema,
    producer => $args->{engine},
    producer_args => $args->{producer_args},
  );

  like (
    $base_out,
    $string_re->{$args->{engine}} || $string_re->{SQL},
    "Received some meaningful output from the first $args->{name} production",
  ) or do {
    diag ( _gen_diag ($base_t->error) );
    return;
  };

# parse the sql back
  my $parser_t = SQL::Translator->new;
  $parser_t->$_ (1) for qw/add_drop_table no_comments/;
  my $mid_schema = $parser_t->translate (
    data => $base_out,
    parser => $args->{engine},
    parser_args => $args->{parser_args},
  );

  isa_ok ($mid_schema, 'SQL::Translator::Schema', "First $args->{name} parser pass produced a schema:")
    or do {
      diag (_gen_diag ( $parser_t->error, $base_out ) );
      my $i;
      note join ("\n" . ( '=' x 76) . "\n",
        'Unparseable DDL:',
        (join ("\n", map { ++$i . ":\t$_" } split /\n/, $base_out) ),
        ''
      );
      return;
    };

# schemas should be comparable at least as far as table/field numbers go
  is_deeply (
    _get_table_info ($mid_schema->get_tables),
    _get_table_info ($base_schema->get_tables),
    "Schema tables generally match afer $args->{name} parser trip",
  ) or return;

# and produce sql once again

# Producing a schema with a Translator different from the one the schema was generated
# from does not work. This is arguably a bug, 61translator_agnostic.t works with that
#  my $producer_t = SQL::Translator->new;
#  $producer_t->$_ (1) for qw/add_drop_table no_comments/;

#  my $rt_sql = $producer_t->translate (
#    data => $mid_schema,
#    producer => $args->{engine},
#    producer_args => $args->{producer_args},
#  );

  my $rt_out = $parser_t->translate (
    data => $mid_schema,
    producer => $args->{engine},
    producer_args => $args->{producer_args},
  );

  like (
    $rt_out,
    $string_re->{$args->{engine}} || $string_re->{SQL},
    "Received some meaningful output from the second $args->{name} production",
  ) or do {
    diag ( _gen_diag ( $parser_t->error ) );
    return;
  };

# the two sql strings should be identical
  my $msg = "$args->{name} SQL roundtrip successful - SQL statements match";
  $ENV{SQLTTEST_RT_DEBUG}     #stringify below because IO::Scalar does not behave nice
    ? eq_or_diff ("$rt_out", "$base_out", $msg)
    : ok ("$rt_out" eq "$base_out", $msg)
  ;
}

sub _get_table_info {
  my @tables = @_;

  my @info;

  for my $t (@tables) {
    push @info, {
      name => $t->name,
      fields => [
        map { $_->name } ($t->get_fields),
      ],
    };
  }

  return \@info;
}

# takes an error string and an optional output block
# returns the string conctenated with a line-numbered block for
# easier reading
sub _gen_diag {
  my ($err, $out) = @_;

  return 'Unknown error' unless $err;


  if ($out and $ENV{SQLTTEST_RT_DEBUG}) {
    my @lines;
    for (split /\n/, $out) {
      push @lines, sprintf ('%03d: %s',
        scalar @lines + 1,
        $_,
      );
    }

    return "$err\n\n" . join ("\n", @lines);
  }

  return $err;
}