use warnings "all";
use strict;
use Time::Local;
use DateTime;
use Date::Calc;
use Date::Manip;
use POSIX qw(strftime);
use config;

package time; 
use Data::Dumper;
use utf8;

require Exporter;
our @ISA = qw(Exporter);
our @EXPORT_OK = qw(
	format_datetime format_time 
	date_format time_format
	datetime_to_time time_to_datetime time_to_date
    datetime_to_date
	add_days_to_datetime add_hours_to_datetime add_minutes_to_datetime
    add_days_to_date
	datetime_to_array date_to_array array_to_date array_to_datetime array_to_time array_to_time_hm
	date_cond time_cond check_date check_time check_datetime check_year_month 
	datetime_to_rfc822 get_datetime datetime_to_utc datetime_to_utc_datetime
	get_duration get_duration_seconds 
	get_durations get_names get_all_names get_weekdays weekday_index
	$names 
);

our %EXPORT_TAGS = ( 'all'  => [ @EXPORT_OK ] );

our $names={
    'de' =>{
        months        =>['Januar','Februar','März','April','Mai','Juni','Juli','August','September','Oktober','November','Dezember'],
        months_abbr   =>['Jan','Feb','Mär','Apr','Mai','Jun','Jul','Aug','Sep','Okt','Nov','Dez'],
        weekdays      =>['Montag','Dienstag','Mittwoch','Donnerstag','Freitag','Samstag','Sonntag'],
        weekdays_abbr =>['Mo','Di','Mi','Do','Fr','Sa','So'],
    },
    'en' =>{
        months        =>['January','February','March','April','May','June','Jule','August','September','October','November','December'],
        months_abbr   =>['Jan','Feb','Mar','Apr','May','Jun','Jul','Aug','Sep','Oct','Nov','Dec'],
        weekdays      =>['Monday','Tuesday','Wednesday','Thursday','Friday','Saturday','Sunday'],
        weekdays_abbr =>['Mo','Tu','We','Th','Fr','Sa','Su'],
    },
};

our $durations=[
    0, 5,10,15,20,30,40,45,50,60,70,75,80,90,100,105,110,115,120,135,150,165,180,195,210,225,240,300,360,420,480,540,600,660,720,1440
];

sub get_names{
    my $language=shift||'en';
    return $time::names->{$language};
}

sub get_all_names{
    return $time::names;
}

sub get_durations{
    return $time::durations;
}

#TODO: build from datenames
our $weekday_index={
    '0' => 0,
    '1' => 1,
    '2' => 2,
    '3' => 3,
    '4' => 4,
    '5' => 5,
    '6' => 6,
    'Mo'=> 0,
    'Tu'=> 1,
    'Di'=> 1,
    'We'=> 2,
    'Mi'=> 2,
    'Th'=> 3,
    'Do'=> 3,
    'Fr'=> 4,
    'Sa'=> 5,
    'Su'=> 6,
    'So'=> 6
};

sub get_weekdays{
    return{
        0 => 0,
        1 => 1,
        2 => 2,
        3 => 3,
        4 => 4,
        5 => 5,
        6 => 6,
        'Mo'=>0,
        'Tu'=>1,
        'Di'=>1,
        'We'=>2,
        'Mi'=>2,
        'Th'=>3,
        'Do'=>3,
        'Fr'=>4,
        'Sa'=>5,
        'Su'=>6,
        'So'=>6
    };
}


#deprecated, for wordpress sync
sub format_datetime{
	my $datetime=shift;
	return $datetime if ($datetime eq '');
	return add_hours_to_datetime($datetime,0);
};

#deprecated
sub format_time{
	my $t=$_[0];

	my $year	=$t->[5]+1900;
	my $month	=$t->[4]+1;
	$month		='0'.$month	if(length($month)==1);

	my $day	=$t->[3];
	$day		='0'.$day 	if(length($day)==1);


	my $hour	=$t->[2];
	$hour		='0'.$hour 	if(length($hour)==1);

	my $minute	=$t->[1];
	$minute	='0'.$minute 	if(length($minute)==1);

	return [$day,$month,$year,$hour,$minute];
};


# convert datetime to unix time
sub datetime_to_time{
	my $datetime=$_[0];
#	print $datetime."\n";
	if ($datetime=~/(\d\d\d\d)\-(\d+)\-(\d+)[T\s](\d+)\:(\d+)(\:(\d+))?/){
		my $year=$1;
		my $month=$2-1;
		my $day=$3;
		my $hour=$4;
		my $minute=$5;
		my $second=$8||0;
		return Time::Local::timelocal($second,$minute,$hour,$day,$month,$year);
		
	}else{
		print STDERR "datetime_to_time: no valid date time found! ($datetime	)\n";
		return -1;
	}
};

#get rfc822 datetime string from datetime string
sub datetime_to_rfc822{
	my $datetime=$_[0];
	my $time=datetime_to_time($datetime);
	return POSIX::strftime("%a, %d %b %Y %H:%M:%S %z", localtime($time));
}

#get seconds from epoch
sub datetime_to_utc{
	my $datetime=shift;
	my $time_zone=shift;
	$datetime=get_datetime($datetime, $time_zone);
	return $datetime->epoch();
}

# get full utc datetime including timezone offset
sub datetime_to_utc_datetime{
	my $datetime=shift;
	my $time_zone=shift;
	$datetime=get_datetime($datetime, $time_zone);
	return $datetime->format_cldr("yyyy-MM-ddTHH:mm:ssZZZZZ");
}

    

#add hours to datetime string
sub add_hours_to_datetime{
	my $datetime=shift;
	my $hours=shift;
	return time_to_datetime(datetime_to_time($datetime)+(3600*$hours));
};

#add minutes to datetime string
sub add_minutes_to_datetime{
	my $datetime=shift;
	my $minutes=shift;
	return time_to_datetime(datetime_to_time($datetime)+(60*$minutes));
};

#add days to datetime string
sub add_days_to_datetime{
	my $datetime=shift;
	my $days=shift;
	my $time=datetime_to_array($datetime);
	#print STDERR Dumper($time);
	($time->[0], $time->[1], $time->[2]) =Date::Calc::Add_Delta_Days($time->[0]+0, $time->[1]+0, $time->[2]+0, $days);
	return array_to_datetime($time);
}

sub add_days_to_date{
	my $datetime=shift;
	my $days=shift;
    my $date=date_to_array($datetime);
	($date->[0], $date->[1], $date->[2]) =Date::Calc::Add_Delta_Days($date->[0]+0, $date->[1]+0, $date->[2]+0, $days);
	return array_to_date($date);
}

# convert unix time to datetime format
sub time_to_datetime{
	my $time=shift;
	$time=time() unless((defined $time) && ($time ne''));
	my @t=localtime($time);
	return sprintf('%04d-%02d-%02d %02d:%02d:%02d', $t[5]+1900, $t[4]+1, $t[3], $t[2], $t[1], $t[0]);
};

# convert unix time to date format
sub time_to_date{
	my $time=shift;
	$time=time() unless((defined $time) && ($time ne''));
	my @t=localtime($time);
	return sprintf('%04d-%02d-%02d', $t[5]+1900, $t[4]+1, $t[3]);
};

# convert datetime to a array of date/time values
sub datetime_to_array{
	my $datetime=$_[0]||'';
	if ($datetime=~/(\d\d\d\d)\-(\d+)\-(\d+)([T\s]+(\d+)\:(\d+)(\:(\d+))?)?/){
		my $year=$1;
		my $month=$2;
		my $day=$3;
		my $hour=$5||'00';
		my $minute=$6||'00';
		my $second=$8||'00';
		return [$year,$month,$day,$hour,$minute,$second];
	}
	return undef;
};

# convert datetime to date
sub datetime_to_date{
	my $datetime=$_[0]||'';
	if ($datetime=~/(\d\d\d\d)\-(\d+)\-(\d+)/){
		my $year=$1;
		my $month=$2;
		my $day=$3;
		return sprintf("%04d-%02d-%02d",$year,$month,$day);
	}
	return undef;
};

#convert datetime array or single value to datetime string
sub array_to_datetime{
	my $date =shift;
	if(ref($date)eq'ARRAY'){
		return sprintf("%04d-%02d-%02d %02d:%02d:%02d", $date->[0], $date->[1], $date->[2], $date->[3], $date->[4], $date->[5]);
	}
	my $month   =shift;
	my $day     =shift;
	my $hour    =shift||'0';
	my $minute  =shift||'0';
	my $second  =shift||'0';
	return sprintf("%04d-%02d-%02d %02d:%02d:%02d", $date, $month, $day, $hour, $minute, $second);
}

#convert date array or single values to date string
sub array_to_date{
	my $date =shift;
	if(ref($date)eq'ARRAY'){
		return sprintf("%04d-%02d-%02d", $date->[0], $date->[1], $date->[2]);
	}
	my $month=shift;
	my $day  =shift;
	return sprintf("%04d-%02d-%02d", $date, $month, $day);
}

sub array_to_time{
	my $date =shift;
	if(ref($date)eq'ARRAY'){
		return sprintf("%02d:%02d:%02d", $date->[3], $date->[4], $date->[5]);
	}
	my $minute = shift||0;
	my $second = shift||0;
	return sprintf("%02d:%02d:%02d", $date, $minute, $second);
}

sub array_to_time_hm{
	my $date =shift;
	if(ref($date)eq'ARRAY'){
		return sprintf("%02d:%02d", $date->[3], $date->[4]);
	}
	my $minute = shift||0;
	return sprintf("%02d:%02d", $date, $minute);
}


# get number of days between two days
sub days_between{
	my $today=$_[0];
	my $date=$_[1];
	my $delta_days=eval{Date::Calc::Delta_Days(
		$today->[0],$today->[1],$today->[2],
		$date->[0], $date->[1], $date->[2]
	)};
	return $delta_days;
}

sub dayOfYear{
	my $datetime=$_[0];
	if ($datetime=~/(\d\d\d\d)\-(\d+)\-(\d+)/){
		my $year  = $1;
		my $month = $2;
		my $day   = $3;
        return Date::Calc::Day_of_Year($year,$month,$day);
	}
	return undef;
}

# get duration in minutes
sub get_duration{
	my $start   = shift;
	my $end     = shift;
	my $timezone= shift;
	$start=time::get_datetime($start, $timezone);
	$end  =time::get_datetime($end,   $timezone);
	my $duration=$end->epoch()-$start->epoch();
	return $duration/60;
}

# get duration in seconds
sub get_duration_seconds{
	my $start   = shift;
	my $end     = shift;
	my $timezone= shift||'UTC';
	$start=time::get_datetime($start, $timezone);
	$end  =time::get_datetime($end,   $timezone);
	my $duration=$end->epoch()-$start->epoch();
	return $duration;
}

# convert date string to a array of date values
sub date_to_array{
	my $datetime=$_[0];
	if ($datetime=~/(\d\d\d\d)\-(\d+)\-(\d+)/){
		my $year  = $1;
		my $month = $2;
		my $day   = $3;
		return [$year,$month,$day];
	}
	return undef;
};

# parse date string and return date string 
# pass 'today', return '' on parse error
sub date_cond{
	my $date=shift;

	return '' if ($date eq'');
	if ($date=~/(\d\d\d\d)\-(\d\d?)\-(\d\d?)/){
		my $year  = $1;
		my $month = $2;
		my $day	  = $3;
		return sprintf("%04d-%02d-%02d", $year, $month, $day);
	}
	return 'today' if ($date eq 'today');
	return '';
};

#parse time and return time string hh:mm:ss
#return hh:00 if time is 'now'
sub time_cond{
	my $time = shift;

	return '' if ($time eq'');
	if ($time=~/(\d\d?)\:(\d\d?)(\:(\d\d))?/){
		my $hour=$1;
		my $minute=$2;
		my $second=$4||'00';
		return sprintf("%02d:%02d:%02d", $hour, $minute, $second);
	}
	if ($time eq 'now'){
		my $date=datetime_to_array(time_to_datetime(time()));
		my $hour=$date->[3]-2;
		$hour=0 if ($hour<0);
        $time=sprintf("%02d:00",$hour);
		return $time;
	}
	return '';
};

#parse date and time string and return yyyy-mm-ddThh:mm:ss
sub datetime_cond{
	my $datetime = shift;

	return '' if ($datetime eq'');
	(my $date,my $time)=split /[ T]/,$datetime;
	$date=time::date_cond($date);
	return '' if ($date eq'');
	$time=time::time_cond($time);
	return '' if ($time eq'');

	return $date.'T'.$time;
}

sub check_date{
	my $date=shift;

	return "" if((!defined $date) || ($date eq ''));
	if($date=~/(\d\d\d\d)\-(\d\d?)\-(\d\d?)/){
		return $1.'-'.$2.'-'.$3;
	}elsif($date=~/(\d\d?)\.(\d\d?)\.(\d\d\d\d)/){
		return $3.'-'.$2.'-'.$1;
	}
	return $date if ($date eq'today' || $date eq'tomorrow' || $date eq'yesterday');
	return -1;
	#error("no valid date format given!");
};

sub check_time{
	my $time=shift;
	return "" if((!defined $time) || ($time eq ''));
	return $time if(($time eq 'now') || ($time eq 'future'));
	if($time=~/(\d\d?)\:(\d\d?)/){
		return $1.':'.$2 	
	}
	return -1;
};

sub check_datetime{
	my $date=shift;

	return "" if((!defined $date) || ($date eq ''));
	if($date=~/(\d\d\d\d)\-(\d\d?)\-(\d\d?)[T ](\d\d?)\:(\d\d?)/){
		return sprintf("%04d-%02d-%02dT%02d:%02d",$1,$2,$3,$4,$5);
	}
	return -1;
};

sub check_year_month{
	my $date=shift;
	return -1 unless(defined $date);
	return $date if($date eq '');
	if($date=~/(\d\d\d\d)\-(\d\d?)/){
		return $1.'-'.$2.'-'.$3;
	}
	return -1;
};

#TODO: remove config dependency
sub date_time_format{
	my $datetime=shift;
    my $language=shift || $config::config->{date}->{language} || 'en';
	if (defined $datetime && $datetime=~/(\d\d\d\d)\-(\d\d?)\-(\d\d?)[\sT](\d\d?\:\d\d?)/){
		my $time=$4;
		my $day=$3;
		my $month=$2;
		my $year=$1;
		
		$month=$time::names->{$language}->{months_abbr}->[$month-1]||'';
		return "$day. $month $year $time";
	}
	return $datetime;
}

#format datetime to date string
#TODO: remove config dependency
sub date_format{
	my $datetime=shift;
    my $language=shift || $config::config->{date}->{language} || 'en';

	if (defined $datetime && $datetime=~/(\d\d\d\d)\-(\d\d?)\-(\d\d?)/){
		my $day=$3;
		my $month=$2;
		my $year=$1;
		$month=$time::names->{$language}->{months_abbr}->[$month-1]||'';
		return "$day. $month $year";
	}
	return $datetime;
};

#format datetime to time string
sub time_format{
	my $datetime=shift;
	if (defined $datetime && $datetime=~/(\d\d?\:\d\d?)/){
		return $1;
	}
	return $datetime;
};

#get offset from given time_zone
sub utc_offset{
	my $time_zone=shift;

	$a=DateTime->now();
	$a->set_time_zone($time_zone);
	return $a->strftime("%z");
}

#get weekday from (yyyy,mm,dd)
sub weekday{
	my ($year,$month,$day)=@_;
	my $time = Time::Local::timelocal(0,0,0,$day,$month-1,$year);
  	return (localtime($time))[6];
}

#get current date, related to starting day_starting_hour
#TODO: remove config dependency
sub get_event_date{
    my $config=shift;
    $config=$config::config unless defined $config;

	my $datetime=time::time_to_datetime(time());
	my $hour=(time::datetime_to_array($datetime))->[3];
	#today: between 0:00 and starting_hour show last day
	if ($hour < $config->{date}->{day_starting_hour}){
		my $date=time::datetime_to_array(time::add_hours_to_datetime($datetime,-24));
		return $date->[0].'-'.$date->[1].'-'.$date->[2];
	}else{
	#today: between starting_hour and end of day show current day
		my $date=time::datetime_to_array(time::time_to_datetime(time()));
		return $date->[0]."-".$date->[1]."-".$date->[2];
	}
}

#get datetime object from datetime string
sub get_datetime{
	my $datetime=shift;
	my $timezone=shift;

    return unless defined $datetime;
	return if $datetime eq '';
	my @l = @{time::datetime_to_array($datetime)};
	return undef if scalar(@l)==0;

    # catch invalid datees
	$datetime=undef;
    eval{
	    $datetime=DateTime->new(
		    year	=>$l[0],
		    month	=>$l[1],
		    day	    =>$l[2],
		    hour	=>$l[3],
		    minute	=>$l[4],
		    second	=>$l[5],
		    time_zone=> $timezone
	    );
	};
	return undef unless defined $datetime;
    $datetime->set_locale('de_DE');
	return $datetime;
}

#get list of nth weekday in month from start to end
sub get_nth_weekday_in_month{
    my $start=shift;   # datetime string
    my $end=shift;     # datetime string
    my $nth=shift;     # every nth week of month
    my $weekday=shift; # weekday [0..6,'Mo'-'Su','Mo'-'Fr'] 

    my $weekdays=time::get_weekdays();
    $weekday=$weekdays->{$weekday+1};
    
    my $dates=[];
    if ($start=~/(\d\d\d\d)-(\d\d)-(\d\d)[ T](\d\d)\:(\d\d)/){
        my $hour=int($4);
        my $min=int($5);
        my $sec=0;
        my  @date = Date::Manip::ParseRecur("0:1*$nth:$weekday:$hour:$min:$sec", "", $start, $end);
        for my $date (@date){
            if ($date=~/(\d\d\d\d)(\d\d)(\d\d)(\d\d)\:(\d\d)\:(\d\d)/){
                push @$dates,"$1-$2-$3 $4:$5:$6";
            }
        }
    }
    return $dates;
}

#do not delete last line!
1;