#!/usr/bin/env perl
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

use 5.10.1;
use strict;
use warnings;

use lib qw(. lib local/lib/perl5);

use Date::Parse;    # strptime

use Bugzilla;
use Bugzilla::Constants;    # LOGIN_*
use Bugzilla::Bug;          # list_relationship
use Bugzilla::Util;         # trim
use Bugzilla::Error;

#
# Date handling
#

sub date_adjust_down {

  my ($year, $month, $day) = @_;

  if ($day == 0) {
    $month -= 1;
    $day = 31;

    # Proper day adjustment is done later.

    if ($month == 0) {
      $year -= 1;
      $month = 12;
    }
  }

  if (($month == 2) && ($day > 28)) {
    if ($year % 4 == 0 && $year % 100 != 0) {
      $day = 29;
    }
    else {
      $day = 28;
    }
  }

  if (($month == 4 || $month == 6 || $month == 9 || $month == 11) && ($day == 31))
  {
    $day = 30;
  }
  return ($year, $month, $day);
}

sub date_adjust_up {
  my ($year, $month, $day) = @_;

  if ($day > 31) {
    $month += 1;
    $day = 1;

    if ($month == 13) {
      $month = 1;
      $year += 1;
    }
  }

  if ($month == 2 && $day > 28) {
    if ($year % 4 != 0 || $year % 100 == 0 || $day > 29) {
      $month = 3;
      $day   = 1;
    }
  }

  if (($month == 4 || $month == 6 || $month == 9 || $month == 11) && ($day == 31))
  {
    $month += 1;
    $day = 1;
  }

  return ($year, $month, $day);
}

sub split_by_month {

  # Takes start and end dates and splits them into a list of
  # monthly-spaced 2-lists of dates.
  my ($start_date, $end_date) = @_;

  # We assume at this point that the dates are provided and sane
  my (undef, undef, undef, $sd, $sm, $sy, undef) = strptime($start_date);
  my (undef, undef, undef, $ed, $em, $ey, undef) = strptime($end_date);

  # Find out how many months fit between the two dates so we know
  # how many times we loop.
  my $yd = $ey - $sy;
  my $md = 12 * $yd + $em - $sm;

# If the end day is smaller than the start day, last interval is not a whole month.
  if ($sd > $ed) {
    $md -= 1;
  }

  my (@months, $sub_start, $sub_end);

  # This +1 and +1900 are a result of strptime's bizarre semantics
  my $year  = $sy + 1900;
  my $month = $sm + 1;

  # Keep the original date, when the date will be changed in the adjust_date.
  my $sd_tmp    = $sd;
  my $month_tmp = $month;
  my $year_tmp  = $year;

  # This section handles only the whole months.
  for (my $i = 0; $i < $md; $i++) {

    # Start of interval is adjusted up: 31.2. -> 1.3.
    ($year_tmp, $month_tmp, $sd_tmp) = date_adjust_up($year, $month, $sd);
    $sub_start = sprintf("%04d-%02d-%02d", $year_tmp, $month_tmp, $sd_tmp);
    $month += 1;
    if ($month == 13) {
      $month = 1;
      $year += 1;
    }

    # End of interval is adjusted down: 31.2 -> 28.2.
    ($year_tmp, $month_tmp, $sd_tmp) = date_adjust_down($year, $month, $sd - 1);
    $sub_end = sprintf("%04d-%02d-%02d", $year_tmp, $month_tmp, $sd_tmp);
    push @months, [$sub_start, $sub_end];
  }

  # This section handles the last (unfinished) month.
  $sub_end = sprintf("%04d-%02d-%02d", $ey + 1900, $em + 1, $ed);
  ($year_tmp, $month_tmp, $sd_tmp) = date_adjust_up($year, $month, $sd);
  $sub_start = sprintf("%04d-%02d-%02d", $year_tmp, $month_tmp, $sd_tmp);
  push @months, [$sub_start, $sub_end];

  return @months;
}

sub sqlize_dates {
  my ($start_date, $end_date) = @_;
  my $date_bits = "";
  my @date_values;
  if ($start_date) {

    $date_bits = " AND longdescs.bug_when > ?";
    push @date_values, $start_date;
  }
  if ($end_date) {

    # we need to add one day to end_date to catch stuff done today
    # do not forget to adjust date if it was the last day of month
    my (undef, undef, undef, $ed, $em, $ey, undef) = strptime($end_date);
    ($ey, $em, $ed) = date_adjust_up($ey + 1900, $em + 1, $ed + 1);
    $end_date = sprintf("%04d-%02d-%02d", $ey, $em, $ed);

    $date_bits .= " AND longdescs.bug_when < ?";
    push @date_values, $end_date;
  }
  return ($date_bits, \@date_values);
}

# Return all blockers of the current bug, recursively.
sub get_blocker_ids {
  my ($bug_id, $unique) = @_;
  $unique ||= {$bug_id => 1};
  my $deps
    = Bugzilla::Bug::list_relationship('dependencies', 'blocked', 'dependson', $bug_id);
  my @unseen = grep { !$unique->{$_}++ } @$deps;
  foreach $bug_id (@unseen) {
    get_blocker_ids($bug_id, $unique);
  }
  return keys %$unique;
}

# Return a hashref whose key is chosen by the user (bug ID or commenter)
# and value is a hash of the form {bug ID, commenter, time spent}.
# So you can either view it as the time spent by commenters on each bug
# or the time spent in bugs by each commenter.
sub get_list {
  my ($bugids, $start_date, $end_date, $keyname) = @_;
  my $dbh = Bugzilla->dbh;

  my ($date_bits, $date_values) = sqlize_dates($start_date, $end_date);
  my $buglist = join(", ", @$bugids);

  # Returns the total time worked on each bug *per developer*.
  my $data = $dbh->selectall_arrayref(
    qq{SELECT SUM(work_time) AS total_time, login_name, longdescs.bug_id
                 FROM longdescs
           INNER JOIN profiles
                   ON longdescs.who = profiles.userid
           INNER JOIN bugs
                   ON bugs.bug_id = longdescs.bug_id
                WHERE longdescs.bug_id IN ($buglist) $date_bits }
      . $dbh->sql_group_by('longdescs.bug_id, login_name', 'longdescs.bug_when')
      . qq{ HAVING SUM(work_time) > 0}, {Slice => {}}, @$date_values
  );

  my %list;

  # What this loop does is to push data having the same key in an array.
  push(@{$list{$_->{$keyname}}}, $_) foreach @$data;
  return \%list;
}

# Return bugs which had no activity (a.k.a work_time = 0) during the given time range.
sub get_inactive_bugs {
  my ($bugids, $start_date, $end_date) = @_;
  my $dbh = Bugzilla->dbh;
  my ($date_bits, $date_values) = sqlize_dates($start_date, $end_date);
  my $buglist = join(", ", @$bugids);

  my $bugs = $dbh->selectcol_arrayref(
    "SELECT bug_id
           FROM bugs
          WHERE bugs.bug_id IN ($buglist)
            AND NOT EXISTS (
                SELECT 1
                  FROM longdescs
                 WHERE bugs.bug_id = longdescs.bug_id
                   AND work_time > 0 $date_bits)", undef, @$date_values
  );

  return $bugs;
}

# Return 1st day of the month of the earliest activity date for a given list of bugs.
sub get_earliest_activity_date {
  my ($bugids) = @_;
  my $dbh = Bugzilla->dbh;

  my ($date) = $dbh->selectrow_array(
        'SELECT '
      . $dbh->sql_date_format('MIN(bug_when)', '%Y-%m-01')
      . ' FROM longdescs
          WHERE ' . $dbh->sql_in('bug_id', $bugids) . ' AND work_time > 0'
  );

  return $date;
}

#
# Template code starts here
#

Bugzilla->login(LOGIN_REQUIRED);

my $cgi      = Bugzilla->cgi;
my $user     = Bugzilla->user;
my $template = Bugzilla->template;
my $vars     = {};

Bugzilla->switch_to_shadow_db();

$user->is_timetracker || ThrowUserError(
  "auth_failure",
  {
    group  => "time-tracking",
    action => "access",
    object => "timetracking_summaries"
  }
);

my @ids = split(",", $cgi->param('id') || '');
@ids = map { Bugzilla::Bug->check($_)->id } @ids;
scalar(@ids) || ThrowUserError('no_bugs_chosen', {action => 'view'});

my $group_by   = $cgi->param('group_by') || "number";
my $monthly    = $cgi->param('monthly');
my $detailed   = $cgi->param('detailed');
my $do_report  = $cgi->param('do_report');
my $inactive   = $cgi->param('inactive');
my $do_depends = $cgi->param('do_depends');
my $ctype      = scalar($cgi->param("ctype"));

my ($start_date, $end_date);
if ($do_report) {
  my @bugs = @ids;

  # Dependency mode requires a single bug and grabs dependents.
  if ($do_depends) {
    if (scalar(@bugs) != 1) {
      ThrowCodeError("bad_arg", {argument => "id", function => "summarize_time"});
    }
    @bugs = get_blocker_ids($bugs[0]);
    @bugs = grep { $user->can_see_bug($_) } @bugs;
  }

  $start_date = trim $cgi->param('start_date');
  $end_date   = trim $cgi->param('end_date');

  foreach my $date ($start_date, $end_date) {
    next unless $date;
    validate_date($date)
      || ThrowUserError('illegal_date', {date => $date, format => 'YYYY-MM-DD'});
  }

  # Swap dates in case the user put an end_date before the start_date
  if ($start_date && $end_date && str2time($start_date) > str2time($end_date)) {
    $vars->{'warn_swap_dates'} = 1;
    ($start_date, $end_date) = ($end_date, $start_date);
  }

  # Store dates in a session cookie so re-visiting the page
  # for other bugs keeps them around.
  $cgi->send_cookie(
    -name  => 'time-summary-dates',
    -value => join ";",
    ($start_date, $end_date)
  );

  my (@parts, $part_data, @part_list);

  # Break dates apart into months if necessary; if not, we use the
  # same @parts list to allow us to use a common codepath.
  if ($monthly) {

    # Calculate the earliest activity date if the user doesn't
    # specify a start date.
    if (!$start_date) {
      $start_date = get_earliest_activity_date(\@bugs);
    }

    # Provide a default end date. Note that this differs in semantics
    # from the open-ended queries we use when start/end_date aren't
    # provided -- and clock skews will make this evident!
    @parts = split_by_month($start_date,
      $end_date || format_time(scalar localtime(time()), '%Y-%m-%d'));
  }
  else {
    @parts = ([$start_date, $end_date]);
  }

  # For each of the separate divisions, grab the relevant data.
  my $keyname = ($group_by eq 'owner') ? 'login_name' : 'bug_id';
  foreach my $part (@parts) {
    my ($sub_start, $sub_end) = @$part;
    $part_data = get_list(\@bugs, $sub_start, $sub_end, $keyname);
    push(@part_list, $part_data);
  }

  # Do we want to see inactive bugs?
  if ($inactive) {
    $vars->{'null'} = get_inactive_bugs(\@bugs, $start_date, $end_date);
  }
  else {
    $vars->{'null'} = {};
  }

  # Convert bug IDs to bug objects.
  @bugs = map { new Bugzilla::Bug($_) } @bugs;

  $vars->{'part_list'} = \@part_list;
  $vars->{'parts'}     = \@parts;

  # We pass the list of bugs as a hashref.
  $vars->{'bugs'} = {map { $_->id => $_ } @bugs};
}
elsif ($cgi->cookie("time-summary-dates")) {
  ($start_date, $end_date) = split ";", $cgi->cookie('time-summary-dates');
}

$vars->{'ids'}        = \@ids;
$vars->{'start_date'} = $start_date;
$vars->{'end_date'}   = $end_date;
$vars->{'group_by'}   = $group_by;
$vars->{'monthly'}    = $monthly;
$vars->{'detailed'}   = $detailed;
$vars->{'inactive'}   = $inactive;
$vars->{'do_report'}  = $do_report;
$vars->{'do_depends'} = $do_depends;

my $format = $template->get_format("bug/summarize-time", undef, $ctype);

# Get the proper content-type
print $cgi->header(-type => $format->{'ctype'});
$template->process("$format->{'template'}", $vars)
  || ThrowTemplateError($template->error());
