#
#  Copyright 2014 MongoDB, Inc.
#
#  Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
#
#  Unless required by applicable law or agreed to in writing, software
#  distributed under the License is distributed on an "AS IS" BASIS,
#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
#  See the License for the specific language governing permissions and
#  limitations under the License.
#

use strict;
use warnings;
package MongoDB::_URI;

use version;
our $VERSION = 'v1.6.0';

use Moo;
use MongoDB::Error;
use Types::Standard qw(
    Any
    ArrayRef
    HashRef
    Str
);
use namespace::clean -except => 'meta';

my $uri_re =
    qr{
            mongodb://
            (?: ([^:]*) (?: : ([^@]*) )? @ )? # [username(:password)?@]
            ([^/?]*) # host1[:port1][,host2[:port2],...[,hostN[:portN]]]
            (?:
               / ([^?]*) # /[database]
                (?: [?] (.*) )? # [?options]
            )?
    }x;

my %options_with_list_type = map { lc($_) => 1 } qw(
  readPreferenceTags
);

has uri => (
    is => 'ro',
    isa => Str,
    required => 1,
);

has username => (
    is => 'ro',
    isa => Any,
    writer => '_set_username',
);

has password => (
    is => 'ro',
    isa => Any,
    writer => '_set_password',
);

has db_name => (
    is => 'ro',
    isa => Str,
    writer => '_set_db_name',
    default => '',
);

has options => (
    is => 'ro',
    isa => HashRef,
    writer => '_set_options',
    default => sub { {} },
);

has hostids => (
    is => 'ro',
    isa => ArrayRef,
    writer => '_set_hostids',
    default => sub { [] },
);

has valid_options => (
    is => 'ro',
    isa => HashRef,
    builder => '_build_valid_options',
);

sub _build_valid_options {
    return {
        map { lc($_) => 1 } qw(
            appName
            authMechanism
            authMechanismProperties
            connectTimeoutMS
            connect
            heartbeatFrequencyMS
            journal
            localThresholdMS
            maxStalenessSeconds
            maxTimeMS
            readPreference
            readPreferenceTags
            replicaSet
            serverSelectionTimeoutMS
            serverSelectionTryOnce
            socketCheckIntervalMS
            socketTimeoutMS
            ssl
            w
            wTimeoutMS
            readConcernLevel
        )
    };
}

sub _unescape_all {
    my $str = shift;
    return '' unless defined $str;
    $str =~ s/%([0-9a-f]{2})/chr(hex($1))/ieg;
    return $str;
}

sub _parse_doc {
    my ($name, $string) = @_;
    my $set = {};
    for my $tag ( split /,/, $string ) {
        if ( $tag =~ /\S/ ) {
            my @kv = map { my $s = $_; $s =~ s{^\s*}{}; $s =~ s{\s*$}{}; $s } split /:/, $tag, 2;
            MongoDB::UsageError->throw("in option '$name', '$tag' is not a key:value pair")
              unless @kv == 2;
            $set->{$kv[0]} = $kv[1];
        }
    }
    return $set;
}

sub BUILD {
    my ($self) = @_;

    my $uri = $self->uri;
    my %result;

    # we throw Error instead of UsageError for errors, to avoid stacktrace revealing credentials
    if ( $uri !~ m{^$uri_re$} ) {
        MongoDB::Error->throw("URI '$self' could not be parsed");
    }

    (
        $result{username}, $result{password}, $result{hostids},
        $result{db_name},  $result{options}
    ) = ( $1, $2, $3, $4, $5 );

    if ( defined $result{username} ) {
        MongoDB::Error->throw(
            "URI '$self' could not be parsed (username must be URL encoded, found unescaped '\@'"
        ) if $result{username} =~ /@/;
        $result{username} = _unescape_all( $result{username} );
    }

    if ( defined $result{password} ) {
        MongoDB::Error->throw(
            "URI '$self' could not be parsed (password must be URL encoded, found unescaped ':'")
          if $result{password} =~ /:/;
        $result{password} = _unescape_all( $result{password} );
    }

    if ( !defined $result{hostids} || !length $result{hostids} ) {
        MongoDB::Error->throw("URI '$self' could not be parsed (missing host list)");
    }
    $result{hostids} = [ map { lc _unescape_all($_) } split ',', $result{hostids} ];
    for my $hostid ( @{ $result{hostids} } ) {
        MongoDB::Error->throw(
            "URI '$self' could not be parsed (Unix domain sockets are not supported)")
          if $hostid =~ /\// && $hostid =~ /\.sock/;
        MongoDB::Error->throw(
            "URI '$self' could not be parsed (IP literals are not supported)")
          if substr( $hostid, 0, 1 ) eq '[';
        my ( $host, $port ) = split ":", $hostid, 2;
        MongoDB::Error->throw("host list '@{ $result{hostids} }' contains empty host")
          unless length $host;
        if ( defined $port ) {
            MongoDB::Error->throw("URI '$self' could not be parsed (invalid port '$port')")
              unless $port =~ /^\d+$/;
            MongoDB::Error->throw(
                "URI '$self' could not be parsed (invalid port '$port' (must be in range [1,65535])")
              unless $port >= 1 && $port <= 65535;
        }
    }
    $result{hostids} = [ map { /:/ ? $_ : $_.":27017" } @{ $result{hostids} } ];

    if ( defined $result{db_name} ) {
        MongoDB::Error->throw(
            "URI '$self' could not be parsed (database name must be URL encoded, found unescaped '/'"
        ) if $result{db_name} =~ /\//;
        $result{db_name} = _unescape_all( $result{db_name} );
    }

    if ( defined $result{options} ) {
        my $valid = $self->valid_options;
        my %parsed;
        for my $opt ( split '&', $result{options} ) {
            my @kv = split '=', $opt, -1;
            MongoDB::UsageError->throw("expected key value pair") unless @kv == 2;
            my ( $k, $v ) = map { _unescape_all($_) } @kv;
            # connection string spec calls for case normalization
            ( my $lc_k = $k ) =~ tr[A-Z][a-z];
            if ( !$valid->{$lc_k} ) {
                warn "Unsupported option '$k' in URI $self\n";
                next;
            }
            if ( exists $parsed{$lc_k} && !exists $options_with_list_type{$lc_k} ) {
                warn "Multiple options were found for the same value '$lc_k'\n";
                next;
            }
            if ( $lc_k eq 'authmechanismproperties' ) {
                $parsed{$lc_k} = _parse_doc( $k, $v );
            }
            elsif ( $lc_k eq 'readpreferencetags' ) {
                $parsed{$lc_k} ||= [];
                push @{ $parsed{$lc_k} }, _parse_doc( $k, $v );
            }
            elsif ( $lc_k eq 'ssl' || $lc_k eq 'journal' || $lc_k eq 'serverselectiontryonce' ) {
                $parsed{$lc_k} = __str_to_bool( $k, $v );
            }
            else {
                $parsed{$lc_k} = $v;
            }
        }
        $result{options} = \%parsed;
    }

    for my $attr (qw/username password db_name options hostids/) {
        my $setter = "_set_$attr";
        $self->$setter( $result{$attr} ) if defined $result{$attr};
    }

    return;
}

sub __str_to_bool {
    my ($k, $str) = @_;
    MongoDB::UsageError->throw("cannot convert undef to bool for key '$k'")
      unless defined $str;
    my $ret = $str eq "true" ? 1 : $str eq "false" ? 0 : undef;
    return $ret if defined $ret;
    MongoDB::UsageError->throw("expected boolean string 'true' or 'false' for key '$k' but instead received '$str'");
}

# redact user credentials when stringifying
use overload
    '""' => sub {
        (my $s = $_[0]->uri) =~ s{^(\w+)://[^/]+\@}{$1://[**REDACTED**]\@};
        return $s
    },
    'fallback' => 1;


1;

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