#!perl -w

use strict;

my $version = 0.02;

use Getopt::Long;
$|++;

use Test::More tests => 32;

## The option name as specified to the GetOptions() function is called the option specification.
## Later we'll see that this specification can contain more than just the option name.
## The reference to the variable is called the option destination.

{
    my $case = "Case 1 - from module synopsis";
    local @ARGV = ();
    my $data   = "file.dat";
    my $length = 24;
    my $verbose;
    my $result = GetOptions(
        "length=i" => \$length,    # numeric
        "file=s"   => \$data,      # string
        "verbose"  => \$verbose    # flag
    );

    ok( $result, 'Case 1 from module synopsis' );
    is_deeply( [ $data, $length, $verbose ], [ 'file.dat', 24, undef ], 'Case 1 from module synopsis' );
}

## For options that take values it must be specified whether the option value is required or not, and what kind of value the option expects.

## Three kinds of values are supported: integer numbers, floating point numbers, and strings.

## If the option value is required, Getopt::Long will take the command line argument that follows the option and assign this to the option variable.
## If, however, the option value is specified as optional, this will only be done if that value does not look like a valid command line option itself.

{
    my $case = "Case 2 - option has default value, none given";
    local @ARGV = ();
    my $tag = 'deftag';
    my $result = GetOptions( 'tag=s' => \$tag );
    ok( $result, $case );
    is_deeply( [$tag], ['deftag'], $case );
}

{
    my $case = "Case 3 - option has default value, option with value given";
    local @ARGV = ('--tag=MYTAG');
    my $tag = 'deftag';
    my $result = GetOptions( 'tag=s' => \$tag );
    ok( $result, $case );
    is_deeply( [$tag], ['MYTAG'], $case );
}

{
    my $case = "Case 4 - option has default value, option with value and unknown option given";
    local @ARGV = ('--bingo --tag=OTHERTAG');
    my $tag = 'deftag';
    my $result = GetOptions( 'tag=s' => \$tag );
    ok( !$result, $case );
    is_deeply( [$tag], ['deftag'], $case );
}

## In the option specification, the option name is followed by an equals sign = and the letter s.
## The equals sign indicates that this option requires a value.
## The letter s indicates that this value is an arbitrary string.
## Other possible value types are i for integer values, and f for floating point values.

{
    my $case = "Case 5a - options have no default values, option values required if option given, no options given";
    local @ARGV = ();
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ undef, undef ], $case );
}

{
    my $case = "Case 5b - options have no default values, option values required if option given, options with values given";
    local @ARGV = ( '--tag=thisyear', '--ival=2007' );
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'thisyear', 2007 ], $case );
}

{
    my $case = "Case 5c - options have no default values, option values required if option given, options without values given";
    local @ARGV = ( '--tag', '--ival' );
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ '--ival', undef ], $case );
}

{
    my $case = "Case 5x - options have default values, option values required if option given, no options given";
    local @ARGV = ();
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'deftag', -1 ], $case );
}

{
    my $case = "Case 5y - options have default values, option values required if option given, options with values given";
    local @ARGV = ( '--tag=thisyear', '--ival=2007' );
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'thisyear', 2007 ], $case );
}

{
    my $case = "Case 5z - options have default values, option values required if option given, options without values given";
    local @ARGV = ( '--tag', '--ival' );
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag=s'  => \$tag,
        'ival=i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ '--ival', -1 ], $case );
}

## Using a colon : instead of the equals sign indicates that the option value is optional.
## In this case, if no suitable value is supplied, string valued options get an empty string '' assigned, while numeric options are set to 0.

{
    my $case = "Case 6a - options have no default values, option values not required if options given, no options given";
    local @ARGV = ();
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ undef, undef ], $case );
}

{
    my $case = "Case 6b - options have no default values, option value not required if option given, options with values given";
    local @ARGV = ( '--tag=thisyear', '--ival=2007' );
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'thisyear', 2007 ], $case );
}

{
    my $case = "Case 6c - options have no default values, option value not required if option given, options without values given";
    local @ARGV = ( '--tag', '--ival' );
    my $tag;
    my $ival;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ '', 0 ], $case );
}

{
    my $case = "Case 6x - options have default values, option values not required if options given, no options given";
    local @ARGV = ();
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'deftag', -1 ], $case );
}

{
    my $case = "Case 6y - options have default values, option value not required if option given, options with values given";
    local @ARGV = ( '--tag=thisyear', '--ival=2007' );
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ 'thisyear', 2007 ], $case );
}

{
    my $case = "Case 6z - options have default values, option value not required if option given, options without values given";
    local @ARGV = ( '--tag', '--ival' );
    my $tag = 'deftag';
    my $ival = -1;
    my $result = GetOptions(
        'tag:s'  => \$tag,
        'ival:i' => \$ival
    );
    ok( $result, $case );
    is_deeply( [ $tag, $ival ], [ '', 0 ], $case );
}

__END__