# 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.

package Bugzilla::Search::Quicksearch;

use 5.10.1;
use strict;
use warnings;

use Bugzilla::Error;
use Bugzilla::Constants;
use Bugzilla::Keyword;
use Bugzilla::Status;
use Bugzilla::Field;
use Bugzilla::Util;

use List::Util qw(min max);
use List::MoreUtils qw(firstidx);
use Text::ParseWords qw(parse_line);

use parent qw(Exporter);
@Bugzilla::Search::Quicksearch::EXPORT = qw(quicksearch);

# Custom mappings for some fields.
use constant MAPPINGS => {
    # Status, Resolution, Platform, OS, Priority, Severity
    "status"   => "bug_status",
    "platform" => "rep_platform",
    "os"       => "op_sys",
    "severity" => "bug_severity",

    # People: AssignedTo, Reporter, QA Contact, CC, etc.
    "assignee" => "assigned_to",
    "owner"    => "assigned_to",

    # Product, Version, Component, Target Milestone
    "milestone" => "target_milestone",

    # Summary, Description, URL, Status whiteboard, Keywords
    "summary"     => "short_desc",
    "description" => "longdesc",
    "comment"     => "longdesc",
    "url"         => "bug_file_loc",
    "whiteboard"  => "status_whiteboard",
    "sw"          => "status_whiteboard",
    "kw"          => "keywords",
    "group"       => "bug_group",

    # Flags
    "flag"        => "flagtypes.name",
    "requestee"   => "requestees.login_name",
    "setter"      => "setters.login_name",

    # Attachments
    "attachment"     => "attachments.description",
    "attachmentdesc" => "attachments.description",
    "attachdesc"     => "attachments.description",
    "attachmentdata" => "attach_data.thedata",
    "attachdata"     => "attach_data.thedata",
    "attachmentmimetype" => "attachments.mimetype",
    "attachmimetype" => "attachments.mimetype"
};

sub FIELD_MAP {
    my $cache = Bugzilla->request_cache;
    return $cache->{quicksearch_fields} if $cache->{quicksearch_fields};

    # Get all the fields whose names don't contain periods. (Fields that
    # contain periods are always handled in MAPPINGS.) 
    my @db_fields = grep { $_->name !~ /\./ } 
                         @{ Bugzilla->fields({ obsolete => 0 }) };
    my %full_map = (%{ MAPPINGS() }, map { $_->name => $_->name } @db_fields);

    # Eliminate the fields that start with bug_ or rep_, because those are
    # handled by the MAPPINGS instead, and we don't want too many names
    # for them. (Also, otherwise "rep" doesn't match "reporter".)
    #
    # Remove "status_whiteboard" because we have "whiteboard" for it in
    # the mappings, and otherwise "stat" can't match "status".
    #
    # Also, don't allow searching the _accessible stuff via quicksearch
    # (both because it's unnecessary and because otherwise 
    # "reporter_accessible" and "reporter" both match "rep".
    delete @full_map{qw(rep_platform bug_status bug_file_loc bug_group
                        bug_severity bug_status
                        status_whiteboard
                        cclist_accessible reporter_accessible)};

    Bugzilla::Hook::process('quicksearch_map', {'map' => \%full_map} );

    $cache->{quicksearch_fields} = \%full_map;

    return $cache->{quicksearch_fields};
}

# Certain fields, when specified like "field:value" get an operator other
# than "substring"
use constant FIELD_OPERATOR => {
    content         => 'matches',
    owner_idle_time => 'greaterthan',
};

# Mappings for operators symbols to support operators other than "substring"
use constant OPERATOR_SYMBOLS => {
    ':'  => 'substring',
    '='  => 'equals',
    '!=' => 'notequals',
    '>=' => 'greaterthaneq',
    '<=' => 'lessthaneq',
    '>'  => 'greaterthan',
    '<'  => 'lessthan',
};

# We might want to put this into localconfig or somewhere
use constant PRODUCT_EXCEPTIONS => (
    'row',   # [Browser]
             #   ^^^
    'new',   # [MailNews]
             #      ^^^
);
use constant COMPONENT_EXCEPTIONS => (
    'hang'   # [Bugzilla: Component/Keyword Changes]
             #                               ^^^^
);

# Quicksearch-wide globals for boolean charts.
our ($chart, $and, $or, $fulltext, $bug_status_set);

sub quicksearch {
    my ($searchstring) = (@_);
    my $cgi = Bugzilla->cgi;

    $chart = 0;
    $and   = 0;
    $or    = 0;

    # Remove leading and trailing commas and whitespace.
    $searchstring =~ s/(^[\s,]+|[\s,]+$)//g;
    ThrowUserError('buglist_parameters_required') unless ($searchstring);

    if ($searchstring =~ m/^[0-9,\s]*$/) {
        _bug_numbers_only($searchstring);
    }
    else {
        _handle_alias($searchstring);

        # Retain backslashes and quotes, to know which strings are quoted,
        # and which ones are not.
        my @words = _parse_line('\s+', 1, $searchstring);
        # If parse_line() returns no data, this means strings are badly quoted.
        # Rather than trying to guess what the user wanted to do, we throw an error.
        scalar(@words)
          || ThrowUserError('quicksearch_unbalanced_quotes', {string => $searchstring});

        # A query cannot start with AND or OR, nor can it end with AND, OR or NOT.
        ThrowUserError('quicksearch_invalid_query')
          if ($words[0] =~ /^(?:AND|OR)$/ || $words[$#words] =~ /^(?:AND|OR|NOT)$/);

        my (@qswords, @or_group);
        while (scalar @words) {
            my $word = shift @words;
            # AND is the default word separator, similar to a whitespace,
            # but |a AND OR b| is not a valid combination.
            if ($word eq 'AND') {
                ThrowUserError('quicksearch_invalid_query', {operators => ['AND', 'OR']})
                  if $words[0] eq 'OR';
            }
            # |a OR AND b| is not a valid combination.
            # |a OR OR b| is equivalent to |a OR b| and so is harmless.
            elsif ($word eq 'OR') {
                ThrowUserError('quicksearch_invalid_query', {operators => ['OR', 'AND']})
                  if $words[0] eq 'AND';
            }
            # NOT negates the following word.
            # |NOT AND| and |NOT OR| are not valid combinations.
            # |NOT NOT| is fine but has no effect as they cancel themselves.
            elsif ($word eq 'NOT') {
                $word = shift @words;
                next if $word eq 'NOT';
                if ($word eq 'AND' || $word eq 'OR') {
                    ThrowUserError('quicksearch_invalid_query', {operators => ['NOT', $word]});
                }
                unshift(@words, "-$word");
            }
            else {
                # OR groups words together, as OR has higher precedence than AND.
                push(@or_group, $word);
                # If the next word is not OR, then we are not in a OR group,
                # or we are leaving it.
                if (!defined $words[0] || $words[0] ne 'OR') {
                    push(@qswords, join('|', @or_group));
                    @or_group = ();
                }
            }
        }

        _handle_status_and_resolution($qswords[0]);
        shift(@qswords) if $bug_status_set;

        my (@unknownFields, %ambiguous_fields);
        $fulltext = Bugzilla->user->setting('quicksearch_fulltext') eq 'on' ? 1 : 0;

        # Loop over all main-level QuickSearch words.
        foreach my $qsword (@qswords) {
            my @or_operand = _parse_line('\|', 1, $qsword);
            foreach my $term (@or_operand) {
                next unless defined $term;
                my $negate = substr($term, 0, 1) eq '-';
                if ($negate) {
                    $term = substr($term, 1);
                }

                next if _handle_special_first_chars($term, $negate);
                next if _handle_field_names($term, $negate, \@unknownFields,
                                            \%ambiguous_fields);

                # Having ruled out the special cases, we may now split
                # by comma, which is another legal boolean OR indicator.
                # Remove quotes from quoted words, if any.
                @words = _parse_line(',', 0, $term);
                foreach my $word (@words) {
                    if (!_special_field_syntax($word, $negate)) {
                        _default_quicksearch_word($word, $negate);
                    }
                    _handle_urls($word, $negate);
                }
            }
            $chart++;
            $and = 0;
            $or = 0;
        }

        # If there is no mention of a bug status, we restrict the query
        # to open bugs by default.
        unless ($bug_status_set) {
            $cgi->param('bug_status', BUG_STATE_OPEN);
        }

        # Inform user about any unknown fields
        if (scalar(@unknownFields) || scalar(keys %ambiguous_fields)) {
            ThrowUserError("quicksearch_unknown_field",
                           { unknown   => \@unknownFields,
                             ambiguous => \%ambiguous_fields });
        }

        # Make sure we have some query terms left
        scalar($cgi->param())>0 || ThrowUserError("buglist_parameters_required");
    }

    # List of quicksearch-specific CGI parameters to get rid of.
    my @params_to_strip = ('quicksearch', 'load', 'run');
    my $modified_query_string = $cgi->canonicalise_query(@params_to_strip);

    if ($cgi->param('load')) {
        my $urlbase = correct_urlbase();
        # Param 'load' asks us to display the query in the advanced search form.
        print $cgi->redirect(-uri => "${urlbase}query.cgi?format=advanced&amp;"
                             . $modified_query_string);
    }

    # Otherwise, pass the modified query string to the caller.
    # We modified $cgi->params, so the caller can choose to look at that, too,
    # and disregard the return value.
    $cgi->delete(@params_to_strip);
    return $modified_query_string;
}

##########################
# Parts of quicksearch() #
##########################

sub _parse_line {
    my ($delim, $keep, $line) = @_;
    return () unless defined $line;

    # parse_line always treats ' as a quote character, making it impossible
    # to sanely search for contractions. As this behavour isn't
    # configurable, we replace ' with a placeholder to hide it from the
    # parser.

    # only treat ' at the start or end of words as quotes
    # it's easier to do this in reverse with regexes
    $line =~ s/(^|\s|:)'/$1\001/g;
    $line =~ s/'($|\s)/\001$1/g;
    $line =~ s/\\?'/\000/g;
    $line =~ tr/\001/'/;

    my @words = parse_line($delim, $keep, $line);
    foreach my $word (@words) {
        $word =~ tr/\000/'/ if defined $word;
    }
    return @words;
}

sub _bug_numbers_only {
    my $searchstring = shift;
    my $cgi = Bugzilla->cgi;
    # Allow separation by comma or whitespace.
    $searchstring =~ s/[,\s]+/,/g;

    if ($searchstring !~ /,/ && !i_am_webservice()) {
        # Single bug number; shortcut to show_bug.cgi.
        print $cgi->redirect(
            -uri => correct_urlbase() . "show_bug.cgi?id=$searchstring");
        exit;
    }
    else {
        # List of bug numbers.
        $cgi->param('bug_id', $searchstring);
        $cgi->param('order', 'bugs.bug_id');
        $cgi->param('bug_id_type', 'anyexact');
    }
}

sub _handle_alias {
    my $searchstring = shift;
    if ($searchstring =~ /^([^,\s]+)$/) {
        my $alias = $1;
        # We use this direct SQL because we want quicksearch to be VERY fast.
        my $bug_id = Bugzilla->dbh->selectrow_array(
            q{SELECT bug_id FROM bugs_aliases WHERE alias = ?}, undef, $alias);
        # If the user cannot see the bug or if we are using a webservice,
        # do not resolve its alias.
        if ($bug_id && Bugzilla->user->can_see_bug($bug_id) && !i_am_webservice()) {
            $alias = url_quote($alias);
            print Bugzilla->cgi->redirect(
                -uri => correct_urlbase() . "show_bug.cgi?id=$alias");
            exit;
        }
    }
}

sub _handle_status_and_resolution {
    my $word = shift;
    my $legal_statuses = get_legal_field_values('bug_status');
    my (%states, %resolutions);
    $bug_status_set = 1;

    if ($word eq 'OPEN') {
        $states{$_} = 1 foreach BUG_STATE_OPEN;
    }
    # If we want all bugs, then there is nothing to do.
    elsif ($word ne 'ALL'
           && !matchPrefixes(\%states, \%resolutions, $word, $legal_statuses))
    {
        $bug_status_set = 0;
    }

    # If we have wanted resolutions, allow closed states
    if (keys(%resolutions)) {
        foreach my $status (@$legal_statuses) {
            $states{$status} = 1 unless is_open_state($status);
        }
    }

    Bugzilla->cgi->param('bug_status', keys(%states));
    Bugzilla->cgi->param('resolution', keys(%resolutions));
}


sub _handle_special_first_chars {
    my ($qsword, $negate) = @_;
    return 0 if !defined $qsword || length($qsword) <= 1;

    my $firstChar = substr($qsword, 0, 1);
    my $baseWord = substr($qsword, 1);
    my @subWords = split(/,/, $baseWord);

    if ($firstChar eq '#') {
        addChart('short_desc', 'substring', $baseWord, $negate);
        addChart('content', 'matches', _matches_phrase($baseWord), $negate) if $fulltext;
        return 1;
    }
    if ($firstChar eq ':') {
        foreach (@subWords) {
            addChart('product', 'substring', $_, $negate);
            addChart('component', 'substring', $_, $negate);
        }
        return 1;
    }
    if ($firstChar eq '@') {
        addChart('assigned_to', 'substring', $_, $negate) foreach (@subWords);
        return 1;
    }
    if ($firstChar eq '[') {
        addChart('short_desc', 'substring', $baseWord, $negate);
        addChart('status_whiteboard', 'substring', $baseWord, $negate);
        return 1;
    }
    if ($firstChar eq '!') {
        addChart('keywords', 'anywords', $baseWord, $negate);
        return 1;
    }
    return 0;
}

sub _handle_field_names {
    my ($or_operand, $negate, $unknownFields, $ambiguous_fields) = @_;

    # Generic field1,field2,field3:value1,value2 notation.
    # We have to correctly ignore commas and colons in quotes.
    # Longer operators must be tested first as we don't want single character
    # operators such as <, > and = to be tested before <=, >= and !=.
    my @operators = sort { length($b) <=> length($a) } keys %{ OPERATOR_SYMBOLS() };

    foreach my $symbol (@operators) {
        my @field_values = _parse_line($symbol, 1, $or_operand);
        next unless scalar @field_values == 2;
        my @fields = _parse_line(',', 1, $field_values[0]);
        my @values = _parse_line(',', 1, $field_values[1]);
        foreach my $field (@fields) {
            my $translated = _translate_field_name($field);
            # Skip and record any unknown fields
            if (!defined $translated) {
                push(@$unknownFields, $field);
            }
            # If we got back an array, that means the substring is
            # ambiguous and could match more than field name
            elsif (ref $translated) {
                $ambiguous_fields->{$field} = $translated;
            }
            else {
                if ($translated eq 'bug_status' || $translated eq 'resolution') {
                    $bug_status_set = 1;
                }
                foreach my $value (@values) {
                    my $operator = FIELD_OPERATOR->{$translated}
                        || OPERATOR_SYMBOLS->{$symbol}
                        || 'substring';
                    # If the string was quoted to protect some special
                    # characters such as commas and colons, we need
                    # to remove quotes.
                    if ($value =~ /^(["'])(.+)\1$/) {
                        $value = $2;
                        $value =~ s/\\(["'])/$1/g;
                    }
                    # If a requestee is set, we need to handle it separately.
                    if ($translated eq 'flagtypes.name' && $value =~ /^([^\?]+\?)([^\?]+)$/) {
                        _handle_flags($1, $2, $negate);
                        next;
                    }
                    addChart($translated, $operator, $value, $negate);
                }
            }
        }
        return 1;
    }

    # Do not look inside quoted strings.
    return 0 if ($or_operand =~ /^(["']).*\1$/);

    # Flag and requestee shortcut.
    if ($or_operand =~ /^([^\?]+\?)([^\?]*)$/) {
        _handle_flags($1, $2, $negate);
        return 1;
    }

    return 0;
}

sub _handle_flags {
    my ($flag, $requestee, $negate) = @_;

    addChart('flagtypes.name', 'substring', $flag, $negate);
    if ($requestee) {
        # FIXME - Every time a requestee is involved and you use OR somewhere
        # in your quick search, the logic will be wrong because boolean charts
        # are unable to run queries of the form (a AND b) OR c. In our case:
        # (flag name is foo AND requestee is bar) OR (any other criteria).
        # But this has never been possible, so this is not a regression. If one
        # needs to run such queries, they must use the Custom Search section of
        # the Advanced Search page.
        $chart++;
        $and = $or = 0;
        addChart('requestees.login_name', 'substring', $requestee, $negate);
    }
}

sub _translate_field_name {
    my $field = shift;
    $field = lc($field);
    my $field_map = FIELD_MAP;

    # If the field exactly matches a mapping, just return right now.
    return $field_map->{$field} if exists $field_map->{$field};

    # Check if we match, as a starting substring, exactly one field.
    my @field_names = keys %$field_map;
    my @matches = grep { $_ =~ /^\Q$field\E/ } @field_names;
    # Eliminate duplicates that are actually the same field
    # (otherwise "assi" matches both "assignee" and "assigned_to", and
    # the lines below fail when they shouldn't.)
    my %match_unique = map { $field_map->{$_} => $_ } @matches;
    @matches = values %match_unique;

    if (scalar(@matches) == 1) {
        return $field_map->{$matches[0]};
    }
    elsif (scalar(@matches) > 1) {
        return \@matches;
    }

    # Check if we match exactly one custom field, ignoring the cf_ on the
    # custom fields (to allow people to type things like "build" for 
    # "cf_build").
    my %cfless;
    foreach my $name (@field_names) {
        my $no_cf = $name;
        if ($no_cf =~ s/^cf_//) {
            if ($field eq $no_cf) {
                return $field_map->{$name};
            }
            $cfless{$no_cf} = $name;
        }
    }

    # See if we match exactly one substring of any of the cf_-less fields.
    my @cfless_matches = grep { $_ =~ /^\Q$field\E/ } (keys %cfless);

    if (scalar(@cfless_matches) == 1) {
        my $match = $cfless_matches[0];
        my $actual_field = $cfless{$match};
        return $field_map->{$actual_field};
    }
    elsif (scalar(@matches) > 1) {
        return \@matches;
    }

    return undef;
}

sub _special_field_syntax {
    my ($word, $negate) = @_;
    
    # P1-5 Syntax
    if ($word =~ m/^P(\d+)(?:-(\d+))?$/i) {
        my ($p_start, $p_end) = ($1, $2);
        my $legal_priorities = get_legal_field_values('priority');

        # If Pn exists explicitly, use it.
        my $start = firstidx { $_ eq "P$p_start" } @$legal_priorities;
        my $end;
        $end = firstidx { $_ eq "P$p_end" } @$legal_priorities if defined $p_end;

        # If Pn doesn't exist explicitly, then we mean the nth priority.
        if ($start == -1) {
            $start = max(0, $p_start - 1);
        }
        my $prios = $legal_priorities->[$start];

        if (defined $end) {
            # If Pn doesn't exist explicitly, then we mean the nth priority.
            if ($end == -1) {
                $end = min(scalar(@$legal_priorities), $p_end) - 1;
                $end = max(0, $end); # Just in case the user typed P0.
            }
            ($start, $end) = ($end, $start) if $end < $start;
            $prios = join(',', @$legal_priorities[$start..$end])
        }

        addChart('priority', 'anyexact', $prios, $negate);
        return 1;
    }
    return 0;    
}

sub _default_quicksearch_word {
    my ($word, $negate) = @_;
    
    if (!grep { lc($word) eq $_ } PRODUCT_EXCEPTIONS and length($word) > 2) {
        addChart('product', 'substring', $word, $negate);
    }
    
    if (!grep { lc($word) eq $_ } COMPONENT_EXCEPTIONS and length($word) > 2) {
        addChart('component', 'substring', $word, $negate);
    }
    
    my @legal_keywords = map($_->name, Bugzilla::Keyword->get_all);
    if (grep { lc($word) eq lc($_) } @legal_keywords) {
        addChart('keywords', 'substring', $word, $negate);
    }
    
    addChart('alias', 'substring', $word, $negate);
    addChart('short_desc', 'substring', $word, $negate);
    addChart('status_whiteboard', 'substring', $word, $negate);
    addChart('content', 'matches', _matches_phrase($word), $negate) if $fulltext;
}

sub _handle_urls {
    my ($word, $negate) = @_;
    # URL field (for IP addrs, host.names,
    # scheme://urls)
    if ($word =~ m/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/
        || $word =~ /^[A-Za-z]+(\.[A-Za-z]+)+/
        || $word =~ /:[\\\/][\\\/]/
        || $word =~ /localhost/
        || $word =~ /mailto[:]?/)
        # || $word =~ /[A-Za-z]+[:][0-9]+/ #host:port
    {
        addChart('bug_file_loc', 'substring', $word, $negate);
    }
}

###########################################################################
# Helpers
###########################################################################

# Quote and escape a phrase appropriately for a "content matches" search.
sub _matches_phrase {
    my ($phrase) = @_;
    $phrase =~ s/"/\\"/g;
    return "\"$phrase\"";
}

# Expand found prefixes to states or resolutions
sub matchPrefixes {
    my ($hr_states, $hr_resolutions, $word, $ar_check_states) = @_;
    return unless $word =~ /^[A-Z_]+(,[A-Z_]+)*$/;

    my @ar_prefixes = split(/,/, $word);
    my $ar_check_resolutions = get_legal_field_values('resolution');
    my $foundMatch = 0;

    foreach my $prefix (@ar_prefixes) {
        foreach (@$ar_check_states) {
            if (/^$prefix/) {
                $$hr_states{$_} = 1;
                $foundMatch = 1;
            }
        }
        foreach (@$ar_check_resolutions) {
            if (/^$prefix/) {
                $$hr_resolutions{$_} = 1;
                $foundMatch = 1;
            }
        }
    }
    return $foundMatch;
}

# Negate comparison type
sub negateComparisonType {
    my $comparisonType = shift;

    if ($comparisonType eq 'anywords') {
        return 'nowords';
    }
    return "not$comparisonType";
}

# Add a boolean chart
sub addChart {
    my ($field, $comparisonType, $value, $negate) = @_;

    $negate && ($comparisonType = negateComparisonType($comparisonType));
    makeChart("$chart-$and-$or", $field, $comparisonType, $value);
    if ($negate) {
        $and++;
        $or = 0;
    }
    else {
        $or++;
    }
}

# Create the CGI parameters for a boolean chart
sub makeChart {
    my ($expr, $field, $type, $value) = @_;

    my $cgi = Bugzilla->cgi;
    $cgi->param("field$expr", $field);
    $cgi->param("type$expr",  $type);
    $cgi->param("value$expr", $value);
}

1;

=head1 B<Methods in need of POD>

=over

=item FIELD_MAP

=item quicksearch

=item negateComparisonType

=item makeChart

=item addChart

=item matchPrefixes

=back