use strict;
use warnings;

use lib 't/lib';
use T::RequireDateTime;

use Test::More;
use Test::Fatal;

use DateTime::TimeZone;
use Try::Tiny;

my @names = DateTime::TimeZone::all_names();
cmp_ok(
    scalar @names, '>', 100,
    'at least 100 zones'
);

my %links = DateTime::TimeZone->links();
cmp_ok(
    scalar keys %links, '>', 100,
    'at least 100 links'
);

my $is_maintainer = -d '.git' || $ENV{RELEASE_TESTING} ? 1 : 0;

foreach my $name (@names) {
    my $resolved_name = $links{$name} || $name;

    my $tz = DateTime::TimeZone->new( name => $name );
    isa_ok( $tz, 'DateTime::TimeZone' );

    is( $tz->name, $resolved_name, 'check ->name' );

    is( $tz->is_floating, 0, 'should not be floating' );
    is( $tz->is_utc,      0, 'should not be UTC' )
        unless $resolved_name eq 'UTC';

    # adding these tests makes the test suite take a _long_ time to
    # finish, and it uses up lots of memory too.
    if ($is_maintainer) {
        my $dt;
        is(
            exception { $dt = DateTime->now( time_zone => $name ) },
            undef,
            "Can call DateTime->now with $name"
        );

        is(
            exception { $dt->add( years => 50 ) },
            undef,
            "Can add 50 years with $name"
        );

        is(
            exception { $dt->subtract( years => 400 ) },
            undef,
            "Can subtract 400 years with $name"
        );

        try {
            $dt = DateTime->new(
                year      => 2000, month => 6, hour => 1,
                time_zone => $name
            );
        };
        is( $dt->hour, 1, 'make sure that local time is always respected' );

        try {
            $dt = DateTime->new(
                year      => 2000, month => 12, hour => 1,
                time_zone => $name
            );
        };
        is( $dt->hour, 1, 'make sure that local time is always respected' );
    }
}

foreach my $name ( '0', 'Z', 'UTC' ) {
    my $tz = DateTime::TimeZone->new( name => $name );
    isa_ok( $tz, 'DateTime::TimeZone' );

    is( $tz->name, 'UTC', 'name should be UTC' );

    is( $tz->is_floating, 0, 'should not be floating' );
    is( $tz->is_utc,      1, 'should be UTC' );
}

my $tz = DateTime::TimeZone->new( name => 'America/Chicago' );

# These tests are odd since we're feeding UTC times into the time zone
# object, which isn't what happens in real usage.  But doing this
# minimizes how much of DateTime.pm needs to work for these tests.
{
    my $dt = DateTime->new(
        year      => 2001,
        month     => 9,
        day       => 10,
        time_zone => 'UTC',
    );
    is( $tz->offset_for_datetime($dt), -18000, 'offset should be -18000' );
    is( $tz->short_name_for_datetime($dt), 'CDT', 'name should be CDT' );
}

{
    my $dt = DateTime->new(
        year      => 2001,
        month     => 10,
        day       => 29,
        time_zone => 'UTC',
    );
    is( $tz->offset_for_datetime($dt), -21600, 'offset should be -21600' );
    is( $tz->short_name_for_datetime($dt), 'CST', 'name should be CST' );
}

{

    # check that generation works properly
    my $dt = DateTime->new(
        year      => 2200,
        month     => 11,
        day       => 2,
        time_zone => 'UTC',
    );
    is(
        $tz->offset_for_datetime($dt), -18000,
        'generated offset should be -1800'
    );
    is(
        $tz->short_name_for_datetime($dt), 'CDT',
        'generated name should be CDT'
    );
}

{

    # check that generation works properly
    my $dt = DateTime->new(
        year      => 2200,
        month     => 11,
        day       => 3,
        time_zone => 'UTC',
    );
    is(
        $tz->offset_for_datetime($dt), -21600,
        'generated offset should be -21600'
    );
    is(
        $tz->short_name_for_datetime($dt), 'CST',
        'generated name should be CST'
    );
}

{
    my $dt = DateTime->new(
        year      => 1944,
        month     => 10,
        day       => 29,
        time_zone => 'UTC',
    );
    is( $tz->offset_for_datetime($dt), -18000, 'offset should be -18000' );
    is( $tz->short_name_for_datetime($dt), 'CWT', 'name should be CWT' );
}

{
    my $dt = DateTime->new(
        year      => 1936,
        month     => 3,
        day       => 2,
        time_zone => 'UTC',
    );

    is( $tz->offset_for_datetime($dt), -18000, 'offset should be -18000' );
    is( $tz->short_name_for_datetime($dt), 'EST', 'name should be EST' );
}

{
    my $dt = DateTime->new(
        year      => 1883,
        month     => 1,
        day       => 29,
        time_zone => 'UTC',
    );

    is( $tz->offset_for_datetime($dt), -21036, 'offset should be -21036' );
    is( $tz->short_name_for_datetime($dt), 'LMT', 'name should be LMT' );
}

{
    {

        package TestHack;

        sub new { bless {}, shift }

        # UTC RD secs == 63518486401
        sub utc_rd_values { ( 735167, 57601 ) }
    }

    # This is to check a bug in DT::TZ::_span_for_datetime, where it
    # was always looking at the LOCAL_END of the current max_span.
    #
    # Australia/Sydney's max_span (before generation) has a LOCAL_END
    # of 63518522400 and UTC_END of 63518486400.  The values above
    # create a utc_rd_seconds value that is after the UTC_END but
    # before the LOCAL_END.
    my $dt = DateTime->from_object( object => TestHack->new );

    is(
        exception {
            $dt->set_time_zone('UTC')->set_time_zone('Australia/Sydney')
        },
        undef,
        'should be able to set time zone without error'
    );

    ok( $dt->is_dst, 'is_dst should be true' );
}

{
    my $offset_tz = DateTime::TimeZone->new( name => '-0100' );
    ok(
        !$offset_tz->is_olson,
        'is_olson is false for offset only time zone'
    );
}

{

    # bug when creating new datetime for year just after time zone's
    # max year
    my $la_tz = DateTime::TimeZone->new( name => 'America/Los_Angeles' );

    my $dt = try {
        DateTime->new(
            year      => $la_tz->{max_year} + 1,
            month     => 5,
            day       => 20,
            time_zone => $la_tz
        );
    };
    ok( $dt, 'was able to create datetime object' );
}

done_testing();