# rddb.pm
#
#  rhrdlibs
#
#  Copyright (C) 2015-2016 Christian Pointner <equinox@helsinki.at>
#
#  This file is part of rhrdlibs.
#
#  rhrdlibs is free software: you can redistribute it and/or modify
#  it under the terms of the GNU Affero General Public License as published by
#  the Free Software Foundation, either version 3 of the License, or
#  any later version.
#
#  rhrdlibs is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU Affero General Public License for more details.
#
#  You should have received a copy of the GNU Affero General Public License
#  along with rhrdlibs. If not, see <http://www.gnu.org/licenses/>.
#

package RHRD::utils;

use strict;
use POSIX;
use DateTime;
use DateTime::TimeZone;
use LWP::Simple;
use URI::Fetch;
use JSON::MaybeXS;
use URI::QueryParam;

sub get_rd_week
{
  my ($time) = @_;
  #
  # This computes the current Rivendell Week based on the number
  # of weeks since epoch.
  #
  # Explanation:
  #  epoch was at 01.01.1970 which was a Thursday.
  #  Monday in that week is (s-from-epoch + 3*24*60*60) seconds ago.
  #  This needs to be adjusted by the timezone offset for Europe/Vienna
  #  which is of course not constant (damn you daylight savings time)
  #  Divide this by (7*24*60*60) and you get the number of
  #  weeks since the Monday in the week of epoch adjusted for timezone offsets.
  #  This week had week number 3 so add an offset of 2 and
  #  get the modulo of 4. This rounded down gives you the current week
  #  with 0 meaning Week 1. So add 1 to that number and you will get
  #  the current RD week.
  #
  if(!defined($time)) {
    $time = DateTime->now();
  }
  my $tz = DateTime::TimeZone->new(name => 'Europe/Vienna');
  my $tz_offset = $tz->offset_for_datetime($time);
  my $sEpoch = $time->epoch() + $tz_offset;
  my $week = floor(((($sEpoch + 259200)/604800) + 2) % 4) + 1;

  return $week;
}

use constant {
  DB_PARAM_TYPE_HINT => "only S, M and J are allowed with S -> Show, M -> Musicpool, J -> Jingles",
  DB_PARAM_RHYTHM_HINT => "only 0 or 1 are allowed, length must be exactly 4 and it must not be '0000'",
  DB_PARAM_DOW_HINT => "must be between 1 and 7 (1=Monday, ..., 7=Sunday)",
  DB_PARAM_STARTTIME_HINT => "must be in format HHMM (without seperator) in 24 hour format",
  DB_PARAM_LEN_HINT => "must be a positive number below 1440",

  CMDLINE_WEEK_HINT => "must be one of W1, W2, W3, W4",
  CMDLINE_DOW_HINT => "must be one of MO, TU, WE, TH, FR, SA, SU",
};

sub dropbox_param_type_ok
{
  my ($type) = @_;

  unless(defined($type) && ($type == 'S' || $type == 'M' || $type == 'J')) {
    return (0, "unkown type '" . (defined($type) ? $type : 'undef') . "'", DB_PARAM_TYPE_HINT);
  }
  return (1, 'OK', DB_PARAM_TYPE_HINT);
}

sub dropbox_param_rhythm_ok
{
  my ($rhythm) = @_;

  if(!defined($rhythm) || $rhythm !~ m/^[01]{4}$/ || $rhythm eq '0000') {
    return (0, "rhythm '" . (defined($rhythm) ? $rhythm : 'undef') . "' contains illegal characters or is too long/short", DB_PARAM_RHYTHM_HINT);
  }
  return (1, 'OK', DB_PARAM_RHYTHM_HINT);
}

sub dropbox_param_dow_ok
{
  my ($dow) = @_;

  if(!defined($dow) || $dow < 1 || $dow > 7) {
    return (0, "dow '" . (defined($dow) ? $dow : 'undef') . "' is out of bounds", DB_PARAM_DOW_HINT);
  }
  return (1, 'OK', DB_PARAM_DOW_HINT);
}

sub dropbox_param_starttime_ok
{
  my ($starttime) = @_;

  if(!defined($starttime) || $starttime !~ m/^[0-2][0-9][0-5][0-9]$/ || $starttime > 2359) {
    return (0, "starttime '" . (defined($starttime) ? $starttime : 'undef') . "' is not a valid clock time", DB_PARAM_STARTTIME_HINT);
  }
  return (1, 'OK', DB_PARAM_STARTTIME_HINT);
}

sub dropbox_param_len_ok
{
  my ($len) = @_;

  if(!defined($len) || $len <= 0 || $len > 1440) {
    return (0, "len '" . (defined($len) ? $len : 'undef') . "' is out of bounds", DB_PARAM_LEN_HINT);
  }
  return (1, 'OK', DB_PARAM_LEN_HINT);
}

sub cmdline_rdweek
{
  my ($dow) = @_;

  if(uc($dow) eq "W1") {
    return (1, 'OK', CMDLINE_WEEK_HINT);
  } elsif(uc($dow) eq "W2") {
    return (2, 'OK', CMDLINE_WEEK_HINT);
  } elsif(uc($dow) eq "W3") {
    return (3, 'OK', CMDLINE_WEEK_HINT);
  } elsif(uc($dow) eq "W4") {
    return (4, 'OK', CMDLINE_WEEK_HINT);
  }
  return (undef, 'invalid week', CMDLINE_WEEK_HINT);
}

sub cmdline_dow
{
  my ($dow) = @_;

  if(uc($dow) eq "MO") {
    return (1, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "TU") {
    return (2, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "WE") {
    return (3, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "TH") {
    return (4, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "FR") {
    return (5, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "SA") {
    return (6, 'OK', CMDLINE_DOW_HINT);
  } elsif(uc($dow) eq "SU") {
    return (7, 'OK', CMDLINE_DOW_HINT);
  }
  return (undef, 'invalid day-of-week', CMDLINE_DOW_HINT);
}

sub fetch_parse_json
{
  my ($url, $ua_str, $headers, $queries) = @_;

  my $uri = URI->new($url);
  if (defined $queries) {
    while(my ($name, $value) = each %{$queries}) {
      $uri->query_param($name => $value);
    }
  }

  $ua_str = "Radio Helsinki Rivendell Utilities" unless $ua_str;
  my $ua  = LWP::UserAgent->new;
  $ua->agent($ua_str);
  $ua->env_proxy;
  if (defined $headers) {
    while(my ($field, $value) = each %{$headers}) {
      $ua->default_header($field, $value);
    }
  }

  my $res = URI::Fetch->fetch($uri, UserAgent => $ua)
    or return (0, URI::Fetch->errstr);
  if($res->status == URI::Fetch::URI_GONE()) {
    return (0, "This resource has been permanently removed");
  }

  my $json = $res->content;
  my $data;
  eval {
    my $j = JSON::MaybeXS->new(utf8 => 0);
    $data = $j->decode($json);
    1;
  } or do {
    return (0, "error parsing import result");
  };

  return (1, $data);
}


return 1;