# we need to comment this out or PAUSE might index it

# pack age DateTime::Format::ICal;

use strict;

use DateTime;

# Builder relevant stuff starts here.

use DateTime::Format::Builder parsers => {

    parse_datetime => [

        [ preprocess => \&_parse_tz ],

        {

            length => 15,

            params => [qw( year month day hour minute second )],

            regex  => qr/^(\d\d\d\d)(\d\d)(\d\d)T(\d\d)(\d\d)(\d\d)$/,

        },

        {

            length => 13,

            params => [qw( year month day hour minute )],

            regex  => qr/^(\d\d\d\d)(\d\d)(\d\d)T(\d\d)(\d\d)$/,

        },

        {

            length => 11,

            params => [qw( year month day hour )],

            regex  => qr/^(\d\d\d\d)(\d\d)(\d\d)T(\d\d)$/,

        },

        {

            length => 8,

            params => [qw( year month day )],

            regex  => qr/^(\d\d\d\d)(\d\d)(\d\d)$/,

        },

    ],

};

sub _parse_tz {

    my %args = @_;

    my ( $date, $p ) = @args{qw( input parsed )};

    if ( $date =~ s/^TZID=([^:]+):// ) {

        $p->{time_zone} = $1;

    }

    # Z at end means UTC

    elsif ( $date =~ s/Z$// ) {

        $p->{time_zone} = 'UTC';

    }

    else {

        $p->{time_zone} = 'floating';

    }

    return $date;

}

# Builder relevant stuff ends here.

sub parse_duration {

    my ( $self, $dur ) = @_;

    my @units = qw( weeks days hours minutes seconds );

    $dur =~ m{ ([\+\-])?         # Sign

               P                 # 'P' for period? This is our magic character)

               (?:

                   (?:(\d+)W)?   # Weeks

                   (?:(\d+)D)?   # Days

               )?

               (?: T             # Time prefix

                   (?:(\d+)H)?   # Hours

                   (?:(\d+)M)?   # Minutes

                   (?:(\d+)S)?   # Seconds

               )?

             }x;

    my $sign = $1;

    my %units;

    $units{weeks}   = $2 if defined $2;

    $units{days}    = $3 if defined $3;

    $units{hours}   = $4 if defined $4;

    $units{minutes} = $5 if defined $5;

    $units{seconds} = $6 if defined $6;

    die "Invalid ICal duration string ($dur)\n"

        unless %units;

    if ( $sign eq '-' ) {

        $_ *= -1 foreach values %units;

    }

    return DateTime::Duration->new(%units);

}

sub format_datetime {

    my ( $self, $dt ) = @_;

    my $tz = $dt->time_zone;

    unless ( $tz->is_floating || $tz->is_utc || $tz->name ) {

        $dt = $dt->clone->set_time_zone('UTC');

        $tz = $dt->time_zone;

    }

    my $base = (

        $dt->hour || $dt->min || $dt->sec

        ? sprintf(

            '%04d%02d%02dT%02d%02d%02d',

            $dt->year, $dt->month,  $dt->day,

            $dt->hour, $dt->minute, $dt->second

            )

        : sprintf( '%04d%02d%02d', $dt->year, $dt->month, $dt->day )

    );

    return $base if $tz->is_floating;

    return $base . 'Z' if $tz->is_utc;

    return 'TZID=' . $tz->name . ':' . $base;

}

sub format_duration {

    my ( $self, $duration ) = @_;

    die "Cannot represent years or months in an iCal duration\n"

        if $duration->delta_months;

    # simple string for 0-length durations

    return '+PT0S'

        unless $duration->delta_days || $duration->delta_seconds;

    my $ical = $duration->is_positive ? '+' : '-';

    $ical .= 'P';

    if ( $duration->delta_days ) {

        $ical .= $duration->weeks . 'W' if $duration->weeks;

        $ical .= $duration->days . 'D'  if $duration->days;

    }

    if ( $duration->delta_seconds ) {

        $ical .= 'T';

        $ical .= $duration->hours . 'H'   if $duration->hours;

        $ical .= $duration->minutes . 'M' if $duration->minutes;

        $ical .= $duration->seconds . 'S' if $duration->seconds;

    }

    return $ical;

}

1;