# -*- Mode: perl; indent-tabs-mode: nil -*-
#
# The contents of this file are subject to the Mozilla Public
# License Version 1.1 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy of
# the License at http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS
# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
# implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code is the Bugzilla Bug Tracking System.
#
# The Initial Developer of the Original Code is Netscape Communications
# Corporation. Portions created by Netscape are
# Copyright (C) 1998 Netscape Communications Corporation. All
# Rights Reserved.
#
# Contributor(s): Myk Melez <myk@mozilla.org>
#                 Jouni Heikniemi <jouni@heikniemi.net>

################################################################################
# Module Initialization
################################################################################

# Make it harder for us to do dangerous things in Perl.
use strict;

# This module implements bug and attachment flags.
package Bugzilla::Flag;

use Bugzilla::FlagType;
use Bugzilla::User;
use Bugzilla::Config;
use Bugzilla::Util;
use Bugzilla::Error;
use Bugzilla::Attachment;
use Bugzilla::BugMail;

use constant TABLES_ALREADY_LOCKED => 1;

# Note that this line doesn't actually import these variables for some reason,
# so I have to use them as $::template and $::vars in the package code.
use vars qw($template $vars); 

# Note!  This module requires that its caller have said "require CGI.pl" 
# to import relevant functions from that script and its companion globals.pl.

################################################################################
# Global Variables
################################################################################

# basic sets of columns and tables for getting flags from the database

my @base_columns = 
  ("is_active", "id", "type_id", "bug_id", "attach_id", "requestee_id", 
   "setter_id", "status");

# Note: when adding tables to @base_tables, make sure to include the separator 
# (i.e. a comma or words like "LEFT OUTER JOIN") before the table name, 
# since tables take multiple separators based on the join type, and therefore 
# it is not possible to join them later using a single known separator.

my @base_tables = ("flags");

################################################################################
# Searching/Retrieving Flags
################################################################################

# !!! Implement a cache for this function!
sub get {
    # Retrieves and returns a flag from the database.

    my ($id) = @_;

    my $select_clause = "SELECT " . join(", ", @base_columns);
    my $from_clause = "FROM " . join(" ", @base_tables);
    
    # Execute the query, retrieve the result, and write it into a record.
    &::PushGlobalSQLState();
    &::SendSQL("$select_clause $from_clause WHERE flags.id = $id");
    my $flag = perlify_record(&::FetchSQLData());
    &::PopGlobalSQLState();

    return $flag;
}

sub match {
    # Queries the database for flags matching the given criteria 
    # (specified as a hash of field names and their matching values)
    # and returns an array of matching records.

    my ($criteria) = @_;

    my $select_clause = "SELECT " . join(", ", @base_columns);
    my $from_clause = "FROM " . join(" ", @base_tables);
    
    my @criteria = sqlify_criteria($criteria);
    
    my $where_clause = "WHERE " . join(" AND ", @criteria);
    
    # Execute the query, retrieve the results, and write them into records.
    &::PushGlobalSQLState();
    &::SendSQL("$select_clause $from_clause $where_clause");
    my @flags;
    while (&::MoreSQLData()) {
        my $flag = perlify_record(&::FetchSQLData());
        push(@flags, $flag);
    }
    &::PopGlobalSQLState();

    return \@flags;
}

sub count {
    # Queries the database for flags matching the given criteria 
    # (specified as a hash of field names and their matching values)
    # and returns an array of matching records.

    my ($criteria) = @_;

    my @criteria = sqlify_criteria($criteria);
    
    my $where_clause = "WHERE " . join(" AND ", @criteria);
    
    # Execute the query, retrieve the result, and write it into a record.
    &::PushGlobalSQLState();
    &::SendSQL("SELECT COUNT(id) FROM flags $where_clause");
    my $count = &::FetchOneColumn();
    &::PopGlobalSQLState();

    return $count;
}

################################################################################
# Creating and Modifying
################################################################################

sub validate {
    # Validates fields containing flag modifications.

    my $user = Bugzilla->user;
    my ($data, $bug_id) = @_;
  
    # Get a list of flags to validate.  Uses the "map" function
    # to extract flag IDs from form field names by matching fields
    # whose name looks like "flag-nnn", where "nnn" is the ID,
    # and returning just the ID portion of matching field names.
    my @ids = map(/^flag-(\d+)$/ ? $1 : (), keys %$data);
  
    foreach my $id (@ids)
    {
        my $status = $data->{"flag-$id"};
        
        # Make sure the flag exists.
        my $flag = get($id);
        $flag || ThrowCodeError("flag_nonexistent", { id => $id });

        # Note that the deletedness of the flag (is_active or not) is not 
        # checked here; we do want to allow changes to deleted flags in
        # certain cases. Flag::modify() will revive the modified flags.
        # See bug 223878 for details.

        # Make sure the user chose a valid status.
        grep($status eq $_, qw(X + - ?))
          || ThrowCodeError("flag_status_invalid", 
                            { id => $id, status => $status });
                
        # Make sure the user didn't request the flag unless it's requestable.
        # If the flag was requested before it became unrequestable, leave it as is.
        if ($status eq '?' && $flag->{status} ne '?' && 
            !$flag->{type}->{is_requestable}) {
            ThrowCodeError("flag_status_invalid", 
                           { id => $id, status => $status });
        }
        
        # Make sure the requestee is authorized to access the bug.
        # (and attachment, if this installation is using the "insider group"
        # feature and the attachment is marked private).
        if ($status eq '?'
            && $flag->{type}->{is_requesteeble}
            && trim($data->{"requestee-$id"}))
        {
            my $requestee_email = trim($data->{"requestee-$id"});
            if ($requestee_email ne $flag->{'requestee'}->{'email'}) {
                # We know the requestee exists because we ran
                # Bugzilla::User::match_field before getting here.
                my $requestee = Bugzilla::User->new_from_login($requestee_email);

                # Throw an error if the user can't see the bug.
                if (!$requestee->can_see_bug($bug_id))
                {
                    ThrowUserError("flag_requestee_unauthorized",
                                   { flag_type => $flag->{'type'},
                                     requestee => $requestee,
                                     bug_id => $bug_id,
                                     attach_id =>
                                       $flag->{target}->{attachment}->{id} });
                }

                # Throw an error if the target is a private attachment and
                # the requestee isn't in the group of insiders who can see it.
                if ($flag->{target}->{attachment}->{exists}
                    && $data->{'isprivate'}
                    && Param("insidergroup")
                    && !$requestee->in_group(Param("insidergroup")))
                {
                    ThrowUserError("flag_requestee_unauthorized_attachment",
                                   { flag_type => $flag->{'type'},
                                     requestee => $requestee,
                                     bug_id    => $bug_id,
                                     attach_id =>
                                      $flag->{target}->{attachment}->{id} });
                }
            }
        }

        # Make sure the user is authorized to modify flags, see bug 180879
        # - The flag is unchanged
        next if ($status eq $flag->{status});

        # - User can clear flags set by itself
        next if (($status eq "X") && ($user->id eq $flag->{setter}->id));

        # - User in the $grant_gid group can set/clear flags,
        #   including "+" and "-"
        next if (!$flag->{type}->{grant_gid}
                 || $user->in_group(&::GroupIdToName($flag->{type}->{grant_gid})));

        # - Any other flag modification is denied
        ThrowUserError("flag_update_denied",
                        { name       => $flag->{type}->{name},
                          status     => $status,
                          old_status => $flag->{status} });
    }
}

sub process {
    # Processes changes to flags.

    # The target is the bug or attachment this flag is about, the timestamp
    # is the date/time the bug was last touched (so that changes to the flag
    # can be stamped with the same date/time), the data is the form data
    # with flag fields that the user submitted, the old bug is the bug record
    # before the user made changes to it, and the new bug is the bug record
    # after the user made changes to it.
    
    my ($target, $timestamp, $data, $oldbug, $newbug) = @_;

    # Use the date/time we were given if possible (allowing calling code
    # to synchronize the comment's timestamp with those of other records).
    $timestamp = ($timestamp ? &::SqlQuote($timestamp) : "NOW()");
    
    # Take a snapshot of flags before any changes.
    my $flags = match({ 'bug_id'    => $target->{'bug'}->{'id'} , 
                        'attach_id' => $target->{'attachment'}->{'id'} ,
                        'is_active' => 1 });
    my @old_summaries;
    foreach my $flag (@$flags) {
        my $summary = $flag->{'type'}->{'name'} . $flag->{'status'};
        $summary .= "(" . $flag->{'requestee'}->login . ")" if $flag->{'requestee'};
        push(@old_summaries, $summary);
    }
    
    # Create new flags and update existing flags.
    my $new_flags = FormToNewFlags($target, $data);
    foreach my $flag (@$new_flags) { create($flag, $timestamp) }
    modify($data, $timestamp);
    
    # In case the bug's product/component has changed, clear flags that are
    # no longer valid.
    &::SendSQL("
        SELECT flags.id 
        FROM (flags INNER JOIN bugs ON flags.bug_id = bugs.bug_id)
          LEFT OUTER JOIN flaginclusions i
            ON (flags.type_id = i.type_id 
            AND (bugs.product_id = i.product_id OR i.product_id IS NULL)
            AND (bugs.component_id = i.component_id OR i.component_id IS NULL))
        WHERE bugs.bug_id = $target->{'bug'}->{'id'} 
        AND flags.is_active = 1
        AND i.type_id IS NULL
    ");
    clear(&::FetchOneColumn()) while &::MoreSQLData();
    &::SendSQL("
        SELECT flags.id 
        FROM flags, bugs, flagexclusions e
        WHERE bugs.bug_id = $target->{'bug'}->{'id'}
        AND flags.bug_id = bugs.bug_id
        AND flags.type_id = e.type_id
        AND flags.is_active = 1 
        AND (bugs.product_id = e.product_id OR e.product_id IS NULL)
        AND (bugs.component_id = e.component_id OR e.component_id IS NULL)
    ");
    clear(&::FetchOneColumn()) while &::MoreSQLData();
    
    # Take a snapshot of flags after changes.
    $flags = match({ 'bug_id'    => $target->{'bug'}->{'id'} , 
                     'attach_id' => $target->{'attachment'}->{'id'} ,
                     'is_active' => 1 });
    my @new_summaries;
    foreach my $flag (@$flags) {
        my $summary = $flag->{'type'}->{'name'} . $flag->{'status'};
        $summary .= "(" . $flag->{'requestee'}->login . ")" if $flag->{'requestee'};
        push(@new_summaries, $summary);
    }

    my $old_summaries = join(", ", @old_summaries);
    my $new_summaries = join(", ", @new_summaries);
    my ($removed, $added) = diff_strings($old_summaries, $new_summaries);
    if ($removed ne $added) {
        my $sql_removed = &::SqlQuote($removed);
        my $sql_added = &::SqlQuote($added);
        my $field_id = &::GetFieldID('flagtypes.name');
        my $attach_id = $target->{'attachment'}->{'id'} || 'NULL';
        &::SendSQL("INSERT INTO bugs_activity (bug_id, attach_id, who, " . 
                   "bug_when, fieldid, removed, added) VALUES " . 
                   "($target->{'bug'}->{'id'}, $attach_id, $::userid, " . 
                   "$timestamp, $field_id, $sql_removed, $sql_added)");
    }
}


sub create {
    # Creates a flag record in the database.

    my ($flag, $timestamp) = @_;

    # Determine the ID for the flag record by retrieving the last ID used
    # and incrementing it.
    &::SendSQL("SELECT MAX(id) FROM flags");
    $flag->{'id'} = (&::FetchOneColumn() || 0) + 1;
    
    # Insert a record for the flag into the flags table.
    my $attach_id = $flag->{'target'}->{'attachment'}->{'id'} || "NULL";
    my $requestee_id = $flag->{'requestee'} ? $flag->{'requestee'}->id : "NULL";
    &::SendSQL("INSERT INTO flags (id, type_id, 
                                      bug_id, attach_id, 
                                      requestee_id, setter_id, status, 
                                      creation_date, modification_date)
                VALUES ($flag->{'id'}, 
                        $flag->{'type'}->{'id'}, 
                        $flag->{'target'}->{'bug'}->{'id'}, 
                        $attach_id,
                        $requestee_id,
                        " . $flag->{'setter'}->id . ",
                        '$flag->{'status'}', 
                        $timestamp,
                        $timestamp)");
    
    # Send an email notifying the relevant parties about the flag creation.
    if (($flag->{'requestee'} 
         && $flag->{'requestee'}->email_prefs->{'FlagRequestee'})
         || $flag->{'type'}->{'cc_list'})
    {
        notify($flag, "request/email.txt.tmpl");
    }
}

sub migrate {
    # Moves a flag from one attachment to another.  Useful for migrating
    # a flag from an obsolete attachment to the attachment that obsoleted it.

    my ($old_attach_id, $new_attach_id, $timestamp) = @_;

    # Use the date/time we were given if possible (allowing calling code
    # to synchronize the comment's timestamp with those of other records).
    $timestamp = ($timestamp ? &::SqlQuote($timestamp) : "NOW()");

    # Update the record in the flags table to point to the new attachment.
    &::SendSQL("UPDATE flags " . 
               "SET    attach_id = $new_attach_id , " . 
               "       modification_date = $timestamp " . 
               "WHERE  attach_id = $old_attach_id");
}

sub modify {
    # Modifies flags in the database when a user changes them.
    # Note that modified flags are always set active (is_active = 1) -
    # this will revive deleted flags that get changed through 
    # attachment.cgi midairs. See bug 223878 for details.

    my ($data, $timestamp) = @_;

    # Use the date/time we were given if possible (allowing calling code
    # to synchronize the comment's timestamp with those of other records).
    $timestamp = ($timestamp ? &::SqlQuote($timestamp) : "NOW()");
    
    # Extract a list of flags from the form data.
    my @ids = map(/^flag-(\d+)$/ ? $1 : (), keys %$data);
    
    # Loop over flags and update their record in the database if necessary.
    # Two kinds of changes can happen to a flag: it can be set to a different
    # state, and someone else can be asked to set it.  We take care of both
    # those changes.
    my @flags;
    foreach my $id (@ids) {
        my $flag = get($id);

        my $status = $data->{"flag-$id"};
        my $requestee_email = trim($data->{"requestee-$id"});

        
        # Ignore flags the user didn't change. There are two components here:
        # either the status changes (trivial) or the requestee changes.
        # Change of either field will cause full update of the flag.

        my $status_changed = ($status ne $flag->{'status'});
        
        # Requestee is considered changed, if all of the following apply:
        # 1. Flag status is '?' (requested)
        # 2. Flag can have a requestee
        # 3. The requestee specified on the form is different from the 
        #    requestee specified in the db.
        
        my $old_requestee = 
          $flag->{'requestee'} ? $flag->{'requestee'}->login : '';

        my $requestee_changed = 
          ($status eq "?" && 
           $flag->{'type'}->{'is_requesteeble'} &&
           $old_requestee ne $requestee_email);
           
        next unless ($status_changed || $requestee_changed);

        
        # Since the status is validated, we know it's safe, but it's still
        # tainted, so we have to detaint it before using it in a query.
        &::trick_taint($status);
        
        if ($status eq '+' || $status eq '-') {
            &::SendSQL("UPDATE flags 
                        SET    setter_id = $::userid , 
                               requestee_id = NULL , 
                               status = '$status' , 
                               modification_date = $timestamp ,
                               is_active = 1
                        WHERE  id = $flag->{'id'}");
            
            # Send an email notifying the relevant parties about the fulfillment.
            if ($flag->{'setter'}->email_prefs->{'FlagRequester'} 
                || $flag->{'type'}->{'cc_list'})
            {
                $flag->{'status'} = $status;
                notify($flag, "request/email.txt.tmpl");
            }
        }
        elsif ($status eq '?') {
            # Get the requestee, if any.
            my $requestee_id = "NULL";
            if ($requestee_email) {
                $requestee_id = login_to_id($requestee_email);
                $flag->{'requestee'} = new Bugzilla::User($requestee_id);
            }

            # Update the database with the changes.
            &::SendSQL("UPDATE flags 
                        SET    setter_id = $::userid , 
                               requestee_id = $requestee_id , 
                               status = '$status' , 
                               modification_date = $timestamp ,
                               is_active = 1
                        WHERE  id = $flag->{'id'}");
            
            # Send an email notifying the relevant parties about the request.
            if ($flag->{'requestee'} 
                && ($flag->{'requestee'}->email_prefs->{'FlagRequestee'} 
                    || $flag->{'type'}->{'cc_list'}))
            {
                notify($flag, "request/email.txt.tmpl");
            }
        }
        # The user unset the flag; set is_active = 0
        elsif ($status eq 'X') {
            clear($flag->{'id'});
        }
        
        push(@flags, $flag);
    }
    
    return \@flags;
}

sub clear {
    my ($id) = @_;
    
    my $flag = get($id);
    
    &::PushGlobalSQLState();
    &::SendSQL("UPDATE flags SET is_active = 0 WHERE id = $id");
    &::PopGlobalSQLState();

    $flag->{'exists'} = 0;    
    # Set the flag's status to "cleared" so the email template
    # knows why email is being sent about the request.
    $flag->{'status'} = "X";
    
    notify($flag, "request/email.txt.tmpl") if $flag->{'requestee'};
}


################################################################################
# Utility Functions
################################################################################

sub FormToNewFlags {
    my ($target, $data) = @_;
    
    # Get information about the setter to add to each flag.
    # Uses a conditional to suppress Perl's "used only once" warnings.
    my $setter = new Bugzilla::User($::userid);

    # Extract a list of flag type IDs from field names.
    my @type_ids = map(/^flag_type-(\d+)$/ ? $1 : (), keys %$data);
    @type_ids = grep($data->{"flag_type-$_"} ne 'X', @type_ids);
    
    # Process the form data and create an array of flag objects.
    my @flags;
    foreach my $type_id (@type_ids) {
        my $status = $data->{"flag_type-$type_id"};
        &::trick_taint($status);
    
        # Create the flag record and populate it with data from the form.
        my $flag = { 
            type   => Bugzilla::FlagType::get($type_id) , 
            target => $target , 
            setter => $setter , 
            status => $status 
        };

        if ($status eq "?") {
            my $requestee = $data->{"requestee_type-$type_id"};
            if ($requestee) {
                my $requestee_id = login_to_id($requestee);
                $flag->{'requestee'} = new Bugzilla::User($requestee_id);
            }
        }
        
        # Add the flag to the array of flags.
        push(@flags, $flag);
    }

    # Return the list of flags.
    return \@flags;
}

# Ideally, we'd use Bug.pm, but it's way too heavyweight, and it can't be
# made lighter without totally rewriting it, so we'll use this function
# until that one gets rewritten.
sub GetBug {
    # Returns a hash of information about a target bug.
    my ($id) = @_;

    # Save the currently running query (if any) so we do not overwrite it.
    &::PushGlobalSQLState();

    &::SendSQL("SELECT    1, short_desc, product_id, component_id,
                          COUNT(bug_group_map.group_id)
                FROM      bugs LEFT JOIN bug_group_map
                            ON (bugs.bug_id = bug_group_map.bug_id)
                WHERE     bugs.bug_id = $id
                GROUP BY  bugs.bug_id");

    my $bug = { 'id' => $id };
    
    ($bug->{'exists'}, $bug->{'summary'}, $bug->{'product_id'}, 
     $bug->{'component_id'}, $bug->{'restricted'}) = &::FetchSQLData();

    # Restore the previously running query (if any).
    &::PopGlobalSQLState();

    return $bug;
}

sub GetTarget {
    my ($bug_id, $attach_id) = @_;
    
    # Create an object representing the target bug/attachment.
    my $target = { 'exists' => 0 };

    if ($attach_id) {
        $target->{'attachment'} = new Bugzilla::Attachment($attach_id);
        if ($bug_id) {
            # Make sure the bug and attachment IDs correspond to each other
            # (i.e. this is the bug to which this attachment is attached).
            $bug_id == $target->{'attachment'}->{'bug_id'}
              || return { 'exists' => 0 };
        }
        $target->{'bug'} = GetBug($target->{'attachment'}->{'bug_id'});
        $target->{'exists'} = $target->{'attachment'}->{'exists'};
        $target->{'type'} = "attachment";
    }
    elsif ($bug_id) {
        $target->{'bug'} = GetBug($bug_id);
        $target->{'exists'} = $target->{'bug'}->{'exists'};
        $target->{'type'} = "bug";
    }

    return $target;
}

sub notify {
    # Sends an email notification about a flag being created or fulfilled.
    
    my ($flag, $template_file) = @_;
    
    # If the target bug is restricted to one or more groups, then we need
    # to make sure we don't send email about it to unauthorized users
    # on the request type's CC: list, so we have to trawl the list for users
    # not in those groups or email addresses that don't have an account.
    if ($flag->{'target'}->{'bug'}->{'restricted'}
        || $flag->{'target'}->{'attachment'}->{'isprivate'})
    {
        my @new_cc_list;
        foreach my $cc (split(/[, ]+/, $flag->{'type'}->{'cc_list'})) {
            my $ccuser = Bugzilla::User->new_from_login($cc,
                                                        TABLES_ALREADY_LOCKED)
              || next;

            next if $flag->{'target'}->{'bug'}->{'restricted'}
              && !$ccuser->can_see_bug($flag->{'target'}->{'bug'}->{'id'});
            next if $flag->{'target'}->{'attachment'}->{'isprivate'}
              && Param("insidergroup")
              && !$ccuser->in_group(Param("insidergroup"));
            push(@new_cc_list, $cc);
        }
        $flag->{'type'}->{'cc_list'} = join(", ", @new_cc_list);
    }

    $flag->{'requestee'}->{'email'} .= Param('emailsuffix');
    $flag->{'setter'}->{'email'} .= Param('emailsuffix');
    $::vars->{'flag'} = $flag;
    
    my $message;
    my $rv = 
      $::template->process($template_file, $::vars, \$message);
    if (!$rv) {
        Bugzilla->cgi->header();
        ThrowTemplateError($::template->error());
    }

    Bugzilla::BugMail::MessageToMTA($message);
}

################################################################################
# Private Functions
################################################################################

sub sqlify_criteria {
    # Converts a hash of criteria into a list of SQL criteria.
    
    # a reference to a hash containing the criteria (field => value)
    my ($criteria) = @_;

    # the generated list of SQL criteria; "1=1" is a clever way of making sure
    # there's something in the list so calling code doesn't have to check list
    # size before building a WHERE clause out of it
    my @criteria = ("1=1");
    
    # If the caller specified only bug or attachment flags,
    # limit the query to those kinds of flags.
    if (defined($criteria->{'target_type'})) {
        if    ($criteria->{'target_type'} eq 'bug')        { push(@criteria, "attach_id IS NULL") }
        elsif ($criteria->{'target_type'} eq 'attachment') { push(@criteria, "attach_id IS NOT NULL") }
    }
    
    # Go through each criterion from the calling code and add it to the query.
    foreach my $field (keys %$criteria) {
        my $value = $criteria->{$field};
        next unless defined($value);
        if    ($field eq 'type_id')      { push(@criteria, "type_id      = $value") }
        elsif ($field eq 'bug_id')       { push(@criteria, "bug_id       = $value") }
        elsif ($field eq 'attach_id')    { push(@criteria, "attach_id    = $value") }
        elsif ($field eq 'requestee_id') { push(@criteria, "requestee_id = $value") }
        elsif ($field eq 'setter_id')    { push(@criteria, "setter_id    = $value") }
        elsif ($field eq 'status')       { push(@criteria, "status       = '$value'") }
        elsif ($field eq 'is_active')    { push(@criteria, "is_active    = $value") }
    }
    
    return @criteria;
}

sub perlify_record {
    # Converts a row from the database into a Perl record.
    my ($exists, $id, $type_id, $bug_id, $attach_id, 
        $requestee_id, $setter_id, $status) = @_;
    
    return undef unless defined($exists);
    
    my $flag =
      {
        exists    => $exists , 
        id        => $id ,
        type      => Bugzilla::FlagType::get($type_id) ,
        target    => GetTarget($bug_id, $attach_id) , 
        requestee => $requestee_id ? new Bugzilla::User($requestee_id) : undef,
        setter    => new Bugzilla::User($setter_id) ,
        status    => $status , 
      };
    
    return $flag;
}

1;