# vim: ts=4 sts=4 sw=4 et:
package HTTP::Tiny;
use strict;
use warnings;
# ABSTRACT: A small, simple, correct HTTP/1.1 client
our $VERSION = '0.022'; # VERSION

use Carp ();


my @attributes;
BEGIN {
    @attributes = qw(agent default_headers local_address max_redirect max_size proxy timeout SSL_options verify_SSL);
    no strict 'refs';
    for my $accessor ( @attributes ) {
        *{$accessor} = sub {
            @_ > 1 ? $_[0]->{$accessor} = $_[1] : $_[0]->{$accessor};
        };
    }
}

sub new {
    my($class, %args) = @_;
    (my $agent = $class) =~ s{::}{-}g;
    my $self = {
        agent        => $agent . "/" . ($class->VERSION || 0),
        max_redirect => 5,
        timeout      => 60,
        verify_SSL   => $args{verify_SSL} || $args{verify_ssl} || 0, # no verification by default
    };
    for my $key ( @attributes ) {
        $self->{$key} = $args{$key} if exists $args{$key}
    }

    # Never override proxy argument as this breaks backwards compat.
    if (!exists $self->{proxy} && (my $http_proxy = $ENV{http_proxy})) {
        if ($http_proxy =~ m{\Ahttp://[^/?#:@]+:\d+/?\z}) {
            $self->{proxy} = $http_proxy;
        }
        else {
            Carp::croak(qq{Environment 'http_proxy' must be in format http://<host>:<port>/\n});
        }
    }

    return bless $self, $class;
}


for my $sub_name ( qw/get head put post delete/ ) {
    my $req_method = uc $sub_name;
    no strict 'refs';
    eval <<"HERE"; ## no critic
    sub $sub_name {
        my (\$self, \$url, \$args) = \@_;
        \@_ == 2 || (\@_ == 3 && ref \$args eq 'HASH')
        or Carp::croak(q/Usage: \$http->$sub_name(URL, [HASHREF])/ . "\n");
        return \$self->request('$req_method', \$url, \$args || {});
    }
HERE
}


sub post_form {
    my ($self, $url, $data, $args) = @_;
    (@_ == 3 || @_ == 4 && ref $args eq 'HASH')
        or Carp::croak(q/Usage: $http->post_form(URL, DATAREF, [HASHREF])/ . "\n");

    my $headers = {};
    while ( my ($key, $value) = each %{$args->{headers} || {}} ) {
        $headers->{lc $key} = $value;
    }
    delete $args->{headers};

    return $self->request('POST', $url, {
            %$args,
            content => $self->www_form_urlencode($data),
            headers => {
                %$headers,
                'content-type' => 'application/x-www-form-urlencoded'
            },
        }
    );
}


sub mirror {
    my ($self, $url, $file, $args) = @_;
    @_ == 3 || (@_ == 4 && ref $args eq 'HASH')
      or Carp::croak(q/Usage: $http->mirror(URL, FILE, [HASHREF])/ . "\n");
    if ( -e $file and my $mtime = (stat($file))[9] ) {
        $args->{headers}{'if-modified-since'} ||= $self->_http_date($mtime);
    }
    my $tempfile = $file . int(rand(2**31));
    open my $fh, ">", $tempfile
        or Carp::croak(qq/Error: Could not open temporary file $tempfile for downloading: $!\n/);
    binmode $fh;
    $args->{data_callback} = sub { print {$fh} $_[0] };
    my $response = $self->request('GET', $url, $args);
    close $fh
        or Carp::croak(qq/Error: Could not close temporary file $tempfile: $!\n/);
    if ( $response->{success} ) {
        rename $tempfile, $file
            or Carp::croak(qq/Error replacing $file with $tempfile: $!\n/);
        my $lm = $response->{headers}{'last-modified'};
        if ( $lm and my $mtime = $self->_parse_http_date($lm) ) {
            utime $mtime, $mtime, $file;
        }
    }
    $response->{success} ||= $response->{status} eq '304';
    unlink $tempfile;
    return $response;
}


my %idempotent = map { $_ => 1 } qw/GET HEAD PUT DELETE OPTIONS TRACE/;

sub request {
    my ($self, $method, $url, $args) = @_;
    @_ == 3 || (@_ == 4 && ref $args eq 'HASH')
      or Carp::croak(q/Usage: $http->request(METHOD, URL, [HASHREF])/ . "\n");
    $args ||= {}; # we keep some state in this during _request

    # RFC 2616 Section 8.1.4 mandates a single retry on broken socket
    my $response;
    for ( 0 .. 1 ) {
        $response = eval { $self->_request($method, $url, $args) };
        last unless $@ && $idempotent{$method}
            && $@ =~ m{^(?:Socket closed|Unexpected end)};
    }

    if (my $e = "$@") {
        $response = {
            url     => $url,
            success => q{},
            status  => 599,
            reason  => 'Internal Exception',
            content => $e,
            headers => {
                'content-type'   => 'text/plain',
                'content-length' => length $e,
            }
        };
    }
    return $response;
}


sub www_form_urlencode {
    my ($self, $data) = @_;
    (@_ == 2 && ref $data)
        or Carp::croak(q/Usage: $http->www_form_urlencode(DATAREF)/ . "\n");
    (ref $data eq 'HASH' || ref $data eq 'ARRAY')
        or Carp::croak("form data must be a hash or array reference");

    my @params = ref $data eq 'HASH' ? %$data : @$data;
    @params % 2 == 0
        or Carp::croak("form data reference must have an even number of terms\n");

    my @terms;
    while( @params ) {
        my ($key, $value) = splice(@params, 0, 2);
        if ( ref $value eq 'ARRAY' ) {
            unshift @params, map { $key => $_ } @$value;
        }
        else {
            push @terms, join("=", map { $self->_uri_escape($_) } $key, $value);
        }
    }

    return join("&", sort @terms);
}

#--------------------------------------------------------------------------#
# private methods
#--------------------------------------------------------------------------#

my %DefaultPort = (
    http => 80,
    https => 443,
);

sub _request {
    my ($self, $method, $url, $args) = @_;

    my ($scheme, $host, $port, $path_query) = $self->_split_url($url);

    my $request = {
        method    => $method,
        scheme    => $scheme,
        host_port => ($port == $DefaultPort{$scheme} ? $host : "$host:$port"),
        uri       => $path_query,
        headers   => {},
    };

    my $handle  = HTTP::Tiny::Handle->new(
        timeout         => $self->{timeout},
        SSL_options     => $self->{SSL_options},
        verify_SSL      => $self->{verify_SSL},
        local_address   => $self->{local_address},
    );

    if ($self->{proxy}) {
        $request->{uri} = "$scheme://$request->{host_port}$path_query";
        die(qq/HTTPS via proxy is not supported\n/)
            if $request->{scheme} eq 'https';
        $handle->connect(($self->_split_url($self->{proxy}))[0..2]);
    }
    else {
        $handle->connect($scheme, $host, $port);
    }

    $self->_prepare_headers_and_cb($request, $args);
    $handle->write_request($request);

    my $response;
    do { $response = $handle->read_response_header }
        until (substr($response->{status},0,1) ne '1');

    if ( my @redir_args = $self->_maybe_redirect($request, $response, $args) ) {
        $handle->close;
        return $self->_request(@redir_args, $args);
    }

    if ($method eq 'HEAD' || $response->{status} =~ /^[23]04/) {
        # response has no message body
    }
    else {
        my $data_cb = $self->_prepare_data_cb($response, $args);
        $handle->read_body($data_cb, $response);
    }

    $handle->close;
    $response->{success} = substr($response->{status},0,1) eq '2';
    $response->{url} = $url;
    return $response;
}

sub _prepare_headers_and_cb {
    my ($self, $request, $args) = @_;

    for ($self->{default_headers}, $args->{headers}) {
        next unless defined;
        while (my ($k, $v) = each %$_) {
            $request->{headers}{lc $k} = $v;
        }
    }
    $request->{headers}{'host'}         = $request->{host_port};
    $request->{headers}{'connection'}   = "close";
    $request->{headers}{'user-agent'} ||= $self->{agent};

    if (defined $args->{content}) {
        $request->{headers}{'content-type'} ||= "application/octet-stream";
        if (ref $args->{content} eq 'CODE') {
            $request->{headers}{'transfer-encoding'} = 'chunked'
              unless $request->{headers}{'content-length'}
                  || $request->{headers}{'transfer-encoding'};
            $request->{cb} = $args->{content};
        }
        else {
            my $content = $args->{content};
            if ( $] ge '5.008' ) {
                utf8::downgrade($content, 1)
                    or die(qq/Wide character in request message body\n/);
            }
            $request->{headers}{'content-length'} = length $content
              unless $request->{headers}{'content-length'}
                  || $request->{headers}{'transfer-encoding'};
            $request->{cb} = sub { substr $content, 0, length $content, '' };
        }
        $request->{trailer_cb} = $args->{trailer_callback}
            if ref $args->{trailer_callback} eq 'CODE';
    }
    return;
}

sub _prepare_data_cb {
    my ($self, $response, $args) = @_;
    my $data_cb = $args->{data_callback};
    $response->{content} = '';

    if (!$data_cb || $response->{status} !~ /^2/) {
        if (defined $self->{max_size}) {
            $data_cb = sub {
                $_[1]->{content} .= $_[0];
                die(qq/Size of response body exceeds the maximum allowed of $self->{max_size}\n/)
                  if length $_[1]->{content} > $self->{max_size};
            };
        }
        else {
            $data_cb = sub { $_[1]->{content} .= $_[0] };
        }
    }
    return $data_cb;
}

sub _maybe_redirect {
    my ($self, $request, $response, $args) = @_;
    my $headers = $response->{headers};
    my ($status, $method) = ($response->{status}, $request->{method});
    if (($status eq '303' or ($status =~ /^30[127]/ && $method =~ /^GET|HEAD$/))
        and $headers->{location}
        and ++$args->{redirects} <= $self->{max_redirect}
    ) {
        my $location = ($headers->{location} =~ /^\//)
            ? "$request->{scheme}://$request->{host_port}$headers->{location}"
            : $headers->{location} ;
        return (($status eq '303' ? 'GET' : $method), $location);
    }
    return;
}

sub _split_url {
    my $url = pop;

    # URI regex adapted from the URI module
    my ($scheme, $authority, $path_query) = $url =~ m<\A([^:/?#]+)://([^/?#]*)([^#]*)>
      or die(qq/Cannot parse URL: '$url'\n/);

    $scheme     = lc $scheme;
    $path_query = "/$path_query" unless $path_query =~ m<\A/>;

    my $host = (length($authority)) ? lc $authority : 'localhost';
       $host =~ s/\A[^@]*@//;   # userinfo
    my $port = do {
       $host =~ s/:([0-9]*)\z// && length $1
         ? $1
         : ($scheme eq 'http' ? 80 : $scheme eq 'https' ? 443 : undef);
    };

    return ($scheme, $host, $port, $path_query);
}

# Date conversions adapted from HTTP::Date
my $DoW = "Sun|Mon|Tue|Wed|Thu|Fri|Sat";
my $MoY = "Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec";
sub _http_date {
    my ($sec, $min, $hour, $mday, $mon, $year, $wday) = gmtime($_[1]);
    return sprintf("%s, %02d %s %04d %02d:%02d:%02d GMT",
        substr($DoW,$wday*4,3),
        $mday, substr($MoY,$mon*4,3), $year+1900,
        $hour, $min, $sec
    );
}

sub _parse_http_date {
    my ($self, $str) = @_;
    require Time::Local;
    my @tl_parts;
    if ($str =~ /^[SMTWF][a-z]+, +(\d{1,2}) ($MoY) +(\d\d\d\d) +(\d\d):(\d\d):(\d\d) +GMT$/) {
        @tl_parts = ($6, $5, $4, $1, (index($MoY,$2)/4), $3);
    }
    elsif ($str =~ /^[SMTWF][a-z]+, +(\d\d)-($MoY)-(\d{2,4}) +(\d\d):(\d\d):(\d\d) +GMT$/ ) {
        @tl_parts = ($6, $5, $4, $1, (index($MoY,$2)/4), $3);
    }
    elsif ($str =~ /^[SMTWF][a-z]+ +($MoY) +(\d{1,2}) +(\d\d):(\d\d):(\d\d) +(?:[^0-9]+ +)?(\d\d\d\d)$/ ) {
        @tl_parts = ($5, $4, $3, $2, (index($MoY,$1)/4), $6);
    }
    return eval {
        my $t = @tl_parts ? Time::Local::timegm(@tl_parts) : -1;
        $t < 0 ? undef : $t;
    };
}

# URI escaping adapted from URI::Escape
# c.f. http://www.w3.org/TR/html4/interact/forms.html#h-17.13.4.1
# perl 5.6 ready UTF-8 encoding adapted from JSON::PP
my %escapes = map { chr($_) => sprintf("%%%02X", $_) } 0..255;
$escapes{' '}="+";
my $unsafe_char = qr/[^A-Za-z0-9\-\._~]/;

sub _uri_escape {
    my ($self, $str) = @_;
    if ( $] ge '5.008' ) {
        utf8::encode($str);
    }
    else {
        $str = pack("U*", unpack("C*", $str)) # UTF-8 encode a byte string
            if ( length $str == do { use bytes; length $str } );
        $str = pack("C*", unpack("C*", $str)); # clear UTF-8 flag
    }
    $str =~ s/($unsafe_char)/$escapes{$1}/ge;
    return $str;
}

package
    HTTP::Tiny::Handle; # hide from PAUSE/indexers
use strict;
use warnings;

use Errno      qw[EINTR EPIPE];
use IO::Socket qw[SOCK_STREAM];

sub BUFSIZE () { 32768 } ## no critic

my $Printable = sub {
    local $_ = shift;
    s/\r/\\r/g;
    s/\n/\\n/g;
    s/\t/\\t/g;
    s/([^\x20-\x7E])/sprintf('\\x%.2X', ord($1))/ge;
    $_;
};

my $Token = qr/[\x21\x23-\x27\x2A\x2B\x2D\x2E\x30-\x39\x41-\x5A\x5E-\x7A\x7C\x7E]/;

sub new {
    my ($class, %args) = @_;
    return bless {
        rbuf             => '',
        timeout          => 60,
        max_line_size    => 16384,
        max_header_lines => 64,
        verify_SSL       => 0,
        SSL_options      => {},
        %args
    }, $class;
}

sub connect {
    @_ == 4 || die(q/Usage: $handle->connect(scheme, host, port)/ . "\n");
    my ($self, $scheme, $host, $port) = @_;

    if ( $scheme eq 'https' ) {
        die(qq/IO::Socket::SSL 1.56 must be installed for https support\n/)
            unless eval {require IO::Socket::SSL; IO::Socket::SSL->VERSION(1.56)};
    }
    elsif ( $scheme ne 'http' ) {
      die(qq/Unsupported URL scheme '$scheme'\n/);
    }
    $self->{fh} = 'IO::Socket::INET'->new(
        PeerHost  => $host,
        PeerPort  => $port,
        $self->{local_address} ? 
            ( LocalAddr => $self->{local_address} ) : (),
        Proto     => 'tcp',
        Type      => SOCK_STREAM,
        Timeout   => $self->{timeout}
    ) or die(qq/Could not connect to '$host:$port': $@\n/);

    binmode($self->{fh})
      or die(qq/Could not binmode() socket: '$!'\n/);

    if ( $scheme eq 'https') {
        my $ssl_args = $self->_ssl_args($host);
        IO::Socket::SSL->start_SSL($self->{fh}, %$ssl_args);
        unless ( ref($self->{fh}) eq 'IO::Socket::SSL' ) {
            my $ssl_err = IO::Socket::SSL->errstr;
            die(qq/SSL connection failed for $host: $ssl_err\n/);
        }
    }

    $self->{host} = $host;
    $self->{port} = $port;

    return $self;
}

sub close {
    @_ == 1 || die(q/Usage: $handle->close()/ . "\n");
    my ($self) = @_;
    CORE::close($self->{fh})
      or die(qq/Could not close socket: '$!'\n/);
}

sub write {
    @_ == 2 || die(q/Usage: $handle->write(buf)/ . "\n");
    my ($self, $buf) = @_;

    if ( $] ge '5.008' ) {
        utf8::downgrade($buf, 1)
            or die(qq/Wide character in write()\n/);
    }

    my $len = length $buf;
    my $off = 0;

    local $SIG{PIPE} = 'IGNORE';

    while () {
        $self->can_write
          or die(qq/Timed out while waiting for socket to become ready for writing\n/);
        my $r = syswrite($self->{fh}, $buf, $len, $off);
        if (defined $r) {
            $len -= $r;
            $off += $r;
            last unless $len > 0;
        }
        elsif ($! == EPIPE) {
            die(qq/Socket closed by remote server: $!\n/);
        }
        elsif ($! != EINTR) {
            die(qq/Could not write to socket: '$!'\n/);
        }
    }
    return $off;
}

sub read {
    @_ == 2 || @_ == 3 || die(q/Usage: $handle->read(len [, allow_partial])/ . "\n");
    my ($self, $len, $allow_partial) = @_;

    my $buf  = '';
    my $got = length $self->{rbuf};

    if ($got) {
        my $take = ($got < $len) ? $got : $len;
        $buf  = substr($self->{rbuf}, 0, $take, '');
        $len -= $take;
    }

    while ($len > 0) {
        $self->can_read
          or die(q/Timed out while waiting for socket to become ready for reading/ . "\n");
        my $r = sysread($self->{fh}, $buf, $len, length $buf);
        if (defined $r) {
            last unless $r;
            $len -= $r;
        }
        elsif ($! != EINTR) {
            die(qq/Could not read from socket: '$!'\n/);
        }
    }
    if ($len && !$allow_partial) {
        die(qq/Unexpected end of stream\n/);
    }
    return $buf;
}

sub readline {
    @_ == 1 || die(q/Usage: $handle->readline()/ . "\n");
    my ($self) = @_;

    while () {
        if ($self->{rbuf} =~ s/\A ([^\x0D\x0A]* \x0D?\x0A)//x) {
            return $1;
        }
        if (length $self->{rbuf} >= $self->{max_line_size}) {
            die(qq/Line size exceeds the maximum allowed size of $self->{max_line_size}\n/);
        }
        $self->can_read
          or die(qq/Timed out while waiting for socket to become ready for reading\n/);
        my $r = sysread($self->{fh}, $self->{rbuf}, BUFSIZE, length $self->{rbuf});
        if (defined $r) {
            last unless $r;
        }
        elsif ($! != EINTR) {
            die(qq/Could not read from socket: '$!'\n/);
        }
    }
    die(qq/Unexpected end of stream while looking for line\n/);
}

sub read_header_lines {
    @_ == 1 || @_ == 2 || die(q/Usage: $handle->read_header_lines([headers])/ . "\n");
    my ($self, $headers) = @_;
    $headers ||= {};
    my $lines   = 0;
    my $val;

    while () {
         my $line = $self->readline;

         if (++$lines >= $self->{max_header_lines}) {
             die(qq/Header lines exceeds maximum number allowed of $self->{max_header_lines}\n/);
         }
         elsif ($line =~ /\A ([^\x00-\x1F\x7F:]+) : [\x09\x20]* ([^\x0D\x0A]*)/x) {
             my ($field_name) = lc $1;
             if (exists $headers->{$field_name}) {
                 for ($headers->{$field_name}) {
                     $_ = [$_] unless ref $_ eq "ARRAY";
                     push @$_, $2;
                     $val = \$_->[-1];
                 }
             }
             else {
                 $val = \($headers->{$field_name} = $2);
             }
         }
         elsif ($line =~ /\A [\x09\x20]+ ([^\x0D\x0A]*)/x) {
             $val
               or die(qq/Unexpected header continuation line\n/);
             next unless length $1;
             $$val .= ' ' if length $$val;
             $$val .= $1;
         }
         elsif ($line =~ /\A \x0D?\x0A \z/x) {
            last;
         }
         else {
            die(q/Malformed header line: / . $Printable->($line) . "\n");
         }
    }
    return $headers;
}

sub write_request {
    @_ == 2 || die(q/Usage: $handle->write_request(request)/ . "\n");
    my($self, $request) = @_;
    $self->write_request_header(@{$request}{qw/method uri headers/});
    $self->write_body($request) if $request->{cb};
    return;
}

my %HeaderCase = (
    'content-md5'      => 'Content-MD5',
    'etag'             => 'ETag',
    'te'               => 'TE',
    'www-authenticate' => 'WWW-Authenticate',
    'x-xss-protection' => 'X-XSS-Protection',
);

sub write_header_lines {
    (@_ == 2 && ref $_[1] eq 'HASH') || die(q/Usage: $handle->write_header_lines(headers)/ . "\n");
    my($self, $headers) = @_;

    my $buf = '';
    while (my ($k, $v) = each %$headers) {
        my $field_name = lc $k;
        if (exists $HeaderCase{$field_name}) {
            $field_name = $HeaderCase{$field_name};
        }
        else {
            $field_name =~ /\A $Token+ \z/xo
              or die(q/Invalid HTTP header field name: / . $Printable->($field_name) . "\n");
            $field_name =~ s/\b(\w)/\u$1/g;
            $HeaderCase{lc $field_name} = $field_name;
        }
        for (ref $v eq 'ARRAY' ? @$v : $v) {
            /[^\x0D\x0A]/
              or die(qq/Invalid HTTP header field value ($field_name): / . $Printable->($_). "\n");
            $buf .= "$field_name: $_\x0D\x0A";
        }
    }
    $buf .= "\x0D\x0A";
    return $self->write($buf);
}

sub read_body {
    @_ == 3 || die(q/Usage: $handle->read_body(callback, response)/ . "\n");
    my ($self, $cb, $response) = @_;
    my $te = $response->{headers}{'transfer-encoding'} || '';
    if ( grep { /chunked/i } ( ref $te eq 'ARRAY' ? @$te : $te ) ) {
        $self->read_chunked_body($cb, $response);
    }
    else {
        $self->read_content_body($cb, $response);
    }
    return;
}

sub write_body {
    @_ == 2 || die(q/Usage: $handle->write_body(request)/ . "\n");
    my ($self, $request) = @_;
    if ($request->{headers}{'content-length'}) {
        return $self->write_content_body($request);
    }
    else {
        return $self->write_chunked_body($request);
    }
}

sub read_content_body {
    @_ == 3 || @_ == 4 || die(q/Usage: $handle->read_content_body(callback, response, [read_length])/ . "\n");
    my ($self, $cb, $response, $content_length) = @_;
    $content_length ||= $response->{headers}{'content-length'};

    if ( $content_length ) {
        my $len = $content_length;
        while ($len > 0) {
            my $read = ($len > BUFSIZE) ? BUFSIZE : $len;
            $cb->($self->read($read, 0), $response);
            $len -= $read;
        }
    }
    else {
        my $chunk;
        $cb->($chunk, $response) while length( $chunk = $self->read(BUFSIZE, 1) );
    }

    return;
}

sub write_content_body {
    @_ == 2 || die(q/Usage: $handle->write_content_body(request)/ . "\n");
    my ($self, $request) = @_;

    my ($len, $content_length) = (0, $request->{headers}{'content-length'});
    while () {
        my $data = $request->{cb}->();

        defined $data && length $data
          or last;

        if ( $] ge '5.008' ) {
            utf8::downgrade($data, 1)
                or die(qq/Wide character in write_content()\n/);
        }

        $len += $self->write($data);
    }

    $len == $content_length
      or die(qq/Content-Length missmatch (got: $len expected: $content_length)\n/);

    return $len;
}

sub read_chunked_body {
    @_ == 3 || die(q/Usage: $handle->read_chunked_body(callback, $response)/ . "\n");
    my ($self, $cb, $response) = @_;

    while () {
        my $head = $self->readline;

        $head =~ /\A ([A-Fa-f0-9]+)/x
          or die(q/Malformed chunk head: / . $Printable->($head) . "\n");

        my $len = hex($1)
          or last;

        $self->read_content_body($cb, $response, $len);

        $self->read(2) eq "\x0D\x0A"
          or die(qq/Malformed chunk: missing CRLF after chunk data\n/);
    }
    $self->read_header_lines($response->{headers});
    return;
}

sub write_chunked_body {
    @_ == 2 || die(q/Usage: $handle->write_chunked_body(request)/ . "\n");
    my ($self, $request) = @_;

    my $len = 0;
    while () {
        my $data = $request->{cb}->();

        defined $data && length $data
          or last;

        if ( $] ge '5.008' ) {
            utf8::downgrade($data, 1)
                or die(qq/Wide character in write_chunked_body()\n/);
        }

        $len += length $data;

        my $chunk  = sprintf '%X', length $data;
           $chunk .= "\x0D\x0A";
           $chunk .= $data;
           $chunk .= "\x0D\x0A";

        $self->write($chunk);
    }
    $self->write("0\x0D\x0A");
    $self->write_header_lines($request->{trailer_cb}->())
        if ref $request->{trailer_cb} eq 'CODE';
    return $len;
}

sub read_response_header {
    @_ == 1 || die(q/Usage: $handle->read_response_header()/ . "\n");
    my ($self) = @_;

    my $line = $self->readline;

    $line =~ /\A (HTTP\/(0*\d+\.0*\d+)) [\x09\x20]+ ([0-9]{3}) [\x09\x20]+ ([^\x0D\x0A]*) \x0D?\x0A/x
      or die(q/Malformed Status-Line: / . $Printable->($line). "\n");

    my ($protocol, $version, $status, $reason) = ($1, $2, $3, $4);

    die (qq/Unsupported HTTP protocol: $protocol\n/)
        unless $version =~ /0*1\.0*[01]/;

    return {
        status   => $status,
        reason   => $reason,
        headers  => $self->read_header_lines,
        protocol => $protocol,
    };
}

sub write_request_header {
    @_ == 4 || die(q/Usage: $handle->write_request_header(method, request_uri, headers)/ . "\n");
    my ($self, $method, $request_uri, $headers) = @_;

    return $self->write("$method $request_uri HTTP/1.1\x0D\x0A")
         + $self->write_header_lines($headers);
}

sub _do_timeout {
    my ($self, $type, $timeout) = @_;
    $timeout = $self->{timeout}
        unless defined $timeout && $timeout >= 0;

    my $fd = fileno $self->{fh};
    defined $fd && $fd >= 0
      or die(qq/select(2): 'Bad file descriptor'\n/);

    my $initial = time;
    my $pending = $timeout;
    my $nfound;

    vec(my $fdset = '', $fd, 1) = 1;

    while () {
        $nfound = ($type eq 'read')
            ? select($fdset, undef, undef, $pending)
            : select(undef, $fdset, undef, $pending) ;
        if ($nfound == -1) {
            $! == EINTR
              or die(qq/select(2): '$!'\n/);
            redo if !$timeout || ($pending = $timeout - (time - $initial)) > 0;
            $nfound = 0;
        }
        last;
    }
    $! = 0;
    return $nfound;
}

sub can_read {
    @_ == 1 || @_ == 2 || die(q/Usage: $handle->can_read([timeout])/ . "\n");
    my $self = shift;
    return $self->_do_timeout('read', @_)
}

sub can_write {
    @_ == 1 || @_ == 2 || die(q/Usage: $handle->can_write([timeout])/ . "\n");
    my $self = shift;
    return $self->_do_timeout('write', @_)
}

# Try to find a CA bundle to validate the SSL cert,
# prefer Mozilla::CA or fallback to a system file
sub _find_CA_file {
    return Mozilla::CA::SSL_ca_file()
        if eval { require Mozilla::CA };

    foreach my $ca_bundle (qw{
        /etc/ssl/certs/ca-certificates.crt
        /etc/pki/tls/certs/ca-bundle.crt
        /etc/ssl/ca-bundle.pem
        }
    ) {
        return $ca_bundle if -e $ca_bundle;
    }

    die qq/Couldn't find a CA bundle with which to verify the SSL certificate.\n/
      . qq/Try installing Mozilla::CA from CPAN\n/;
}

sub _ssl_args {
    my ($self, $host) = @_;

    my %ssl_args = (
        SSL_hostname        => $host,  # SNI
    );

    if ($self->{verify_SSL}) {
        $ssl_args{SSL_verifycn_scheme}  = 'http'; # enable CN validation
        $ssl_args{SSL_verifycn_name}    = $host;  # set validation hostname
        $ssl_args{SSL_verify_mode}      = 0x01;   # enable cert validation
        $ssl_args{SSL_ca_file}          = $self->_find_CA_file;
    }
    else {
        $ssl_args{SSL_verifycn_scheme}  = 'none'; # disable CN validation
        $ssl_args{SSL_verify_mode}      = 0x00;   # disable cert validation
    }

    # user options override settings from verify_SSL
    for my $k ( keys %{$self->{SSL_options}} ) {
        $ssl_args{$k} = $self->{SSL_options}{$k} if $k =~ m/^SSL_/;
    }

    return \%ssl_args;
}

1;



__END__
=pod

=head1 NAME

HTTP::Tiny - A small, simple, correct HTTP/1.1 client

=head1 VERSION

version 0.022

=head1 SYNOPSIS

    use HTTP::Tiny;

    my $response = HTTP::Tiny->new->get('http://example.com/');

    die "Failed!\n" unless $response->{success};

    print "$response->{status} $response->{reason}\n";

    while (my ($k, $v) = each %{$response->{headers}}) {
        for (ref $v eq 'ARRAY' ? @$v : $v) {
            print "$k: $_\n";
        }
    }

    print $response->{content} if length $response->{content};

=head1 DESCRIPTION

This is a very simple HTTP/1.1 client, designed for doing simple GET
requests without the overhead of a large framework like L<LWP::UserAgent>.

It is more correct and more complete than L<HTTP::Lite>.  It supports
proxies (currently only non-authenticating ones) and redirection.  It
also correctly resumes after EINTR.

=head1 METHODS

=head2 new

    $http = HTTP::Tiny->new( %attributes );

This constructor returns a new HTTP::Tiny object.  Valid attributes include:

=over 4

=item *

C<agent>

A user-agent string (defaults to 'HTTP::Tiny/$VERSION')

=item *

C<default_headers>

A hashref of default headers to apply to requests

=item *

C<local_address>

The local IP address to bind to

=item *

C<max_redirect>

Maximum number of redirects allowed (defaults to 5)

=item *

C<max_size>

Maximum response size (only when not using a data callback).  If defined,
responses larger than this will return an exception.

=item *

C<proxy>

URL of a proxy server to use (default is C<$ENV{http_proxy}> if set)

=item *

C<timeout>

Request timeout in seconds (default is 60)

=item *

C<verify_SSL>

A boolean that indicates whether to validate the SSL certificate of an C<https>
connection (default is false)

=item *

C<SSL_options>

A hashref of C<SSL_*> options to pass through to L<IO::Socket::SSL>

=back

Exceptions from C<max_size>, C<timeout> or other errors will result in a
pseudo-HTTP status code of 599 and a reason of "Internal Exception". The
content field in the response will contain the text of the exception.

See L</SSL SUPPORT> for more on the C<verify_SSL> and C<SSL_options> attributes.

=head2 get|head|put|post|delete

    $response = $http->get($url);
    $response = $http->get($url, \%options);
    $response = $http->head($url);

These methods are shorthand for calling C<request()> for the given method.  The
URL must have unsafe characters escaped and international domain names encoded.
See C<request()> for valid options and a description of the response.

The C<success> field of the response will be true if the status code is 2XX.

=head2 post_form

    $response = $http->post_form($url, $form_data);
    $response = $http->post_form($url, $form_data, \%options);

This method executes a C<POST> request and sends the key/value pairs from a
form data hash or array reference to the given URL with a C<content-type> of
C<application/x-www-form-urlencoded>.  See documentation for the
C<www_form_urlencode> method for details on the encoding.

The URL must have unsafe characters escaped and international domain names
encoded.  See C<request()> for valid options and a description of the response.
Any C<content-type> header or content in the options hashref will be ignored.

The C<success> field of the response will be true if the status code is 2XX.

=head2 mirror

    $response = $http->mirror($url, $file, \%options)
    if ( $response->{success} ) {
        print "$file is up to date\n";
    }

Executes a C<GET> request for the URL and saves the response body to the file
name provided.  The URL must have unsafe characters escaped and international
domain names encoded.  If the file already exists, the request will includes an
C<If-Modified-Since> header with the modification timestamp of the file.  You
may specify a different C<If-Modified-Since> header yourself in the C<<
$options->{headers} >> hash.

The C<success> field of the response will be true if the status code is 2XX
or if the status code is 304 (unmodified).

If the file was modified and the server response includes a properly
formatted C<Last-Modified> header, the file modification time will
be updated accordingly.

=head2 request

    $response = $http->request($method, $url);
    $response = $http->request($method, $url, \%options);

Executes an HTTP request of the given method type ('GET', 'HEAD', 'POST',
'PUT', etc.) on the given URL.  The URL must have unsafe characters escaped and
international domain names encoded.  A hashref of options may be appended to
modify the request.

Valid options are:

=over 4

=item *

C<headers>

A hashref containing headers to include with the request.  If the value for
a header is an array reference, the header will be output multiple times with
each value in the array.  These headers over-write any default headers.

=item *

C<content>

A scalar to include as the body of the request OR a code reference
that will be called iteratively to produce the body of the request

=item *

C<trailer_callback>

A code reference that will be called if it exists to provide a hashref
of trailing headers (only used with chunked transfer-encoding)

=item *

C<data_callback>

A code reference that will be called for each chunks of the response
body received.

=back

If the C<content> option is a code reference, it will be called iteratively
to provide the content body of the request.  It should return the empty
string or undef when the iterator is exhausted.

If the C<data_callback> option is provided, it will be called iteratively until
the entire response body is received.  The first argument will be a string
containing a chunk of the response body, the second argument will be the
in-progress response hash reference, as described below.  (This allows
customizing the action of the callback based on the C<status> or C<headers>
received prior to the content body.)

The C<request> method returns a hashref containing the response.  The hashref
will have the following keys:

=over 4

=item *

C<success>

Boolean indicating whether the operation returned a 2XX status code

=item *

C<url>

URL that provided the response. This is the URL of the request unless
there were redirections, in which case it is the last URL queried
in a redirection chain

=item *

C<status>

The HTTP status code of the response

=item *

C<reason>

The response phrase returned by the server

=item *

C<content>

The body of the response.  If the response does not have any content
or if a data callback is provided to consume the response body,
this will be the empty string

=item *

C<headers>

A hashref of header fields.  All header field names will be normalized
to be lower case. If a header is repeated, the value will be an arrayref;
it will otherwise be a scalar string containing the value

=back

On an exception during the execution of the request, the C<status> field will
contain 599, and the C<content> field will contain the text of the exception.

=head2 www_form_urlencode

    $params = $http->www_form_urlencode( $data );
    $response = $http->get("http://example.com/query?$params");

This method converts the key/value pairs from a data hash or array reference
into a C<x-www-form-urlencoded> string.  The keys and values from the data
reference will be UTF-8 encoded and escaped per RFC 3986.  If a value is an
array reference, the key will be repeated with each of the values of the array
reference.  The key/value pairs in the resulting string will be sorted by key
and value.

=for Pod::Coverage agent
default_headers
local_address
max_redirect
max_size
proxy
timeout
verify_SSL
SSL_options

=head1 SSL SUPPORT

Direct C<https> connections are supported only if L<IO::Socket::SSL> 1.56 or
greater is installed. An exception will be thrown if a new enough
IO::Socket::SSL is not installed or if the SSL encryption fails. There is no
support for C<https> connections via proxy (i.e. RFC 2817).

SSL provides two distinct capabilities:

=over 4

=item *

Encrypted communication channel

=item *

Verification of server identity

=back

B<By default, HTTP::Tiny does not verify server identity>.

Server identity verification is controversial and potentially tricky because it
depends on a (usually paid) third-party Certificate Authority (CA) trust model
to validate a certificate as legitimate.  This discriminates against servers
with self-signed certificates or certificates signed by free, community-driven
CA's such as L<CAcert.org|http://cacert.org>.

By default, HTTP::Tiny does not make any assumptions about your trust model,
threat level or risk tolerance.  It just aims to give you an encrypted channel
when you need one.

Setting the C<verify_SSL> attribute to a true value will make HTTP::Tiny verify
that an SSL connection has a valid SSL certificate corresponding to the host
name of the connection and that the SSL certificate has been verified by a CA.
Assuming you trust the CA, this will protect against a L<man-in-the-middle
attack|http://en.wikipedia.org/wiki/Man-in-the-middle_attack>.  If you are
concerned about security, you should enable this option.

Certificate verification requires a file containing trusted CA certificates.
If the L<Mozilla::CA> module is installed, HTTP::Tiny will use the CA file
included with it as a source of trusted CA's.  (This means you trust Mozilla,
the author of Mozilla::CA, the CPAN mirror where you got Mozilla::CA, the
toolchain used to install it, and your operating system security, right?)

If that module is not available, then HTTP::Tiny will search several
system-specific default locations for a CA certificate file:

=over 4

=item *

/etc/ssl/certs/ca-certificates.crt

=item *

/etc/pki/tls/certs/ca-bundle.crt

=item *

/etc/ssl/ca-bundle.pem

=back

An exception will be raised if C<verify_SSL> is true and no CA certificate file
is available.

If you desire complete control over SSL connections, the C<SSL_options> attribute
lets you provide a hash reference that will be passed through to
C<IO::Socket::SSL::start_SSL()>, overriding any options set by HTTP::Tiny. For
example, to provide your own trusted CA file:

    SSL_options => {
        SSL_ca_file => $file_path,
    }

The C<SSL_options> attribute could also be used for such things as providing a
client certificate for authentication to a server or controlling the choice of
cipher used for the SSL connection. See L<IO::Socket::SSL> documentation for
details.

=head1 LIMITATIONS

HTTP::Tiny is I<conditionally compliant> with the
L<HTTP/1.1 specification|http://www.w3.org/Protocols/rfc2616/rfc2616.html>.
It attempts to meet all "MUST" requirements of the specification, but does not
implement all "SHOULD" requirements.

Some particular limitations of note include:

=over

=item *

HTTP::Tiny focuses on correct transport.  Users are responsible for ensuring
that user-defined headers and content are compliant with the HTTP/1.1
specification.

=item *

Users must ensure that URLs are properly escaped for unsafe characters and that
international domain names are properly encoded to ASCII. See L<URI::Escape>,
L<URI::_punycode> and L<Net::IDN::Encode>.

=item *

Redirection is very strict against the specification.  Redirection is only
automatic for response codes 301, 302 and 307 if the request method is 'GET' or
'HEAD'.  Response code 303 is always converted into a 'GET' redirection, as
mandated by the specification.  There is no automatic support for status 305
("Use proxy") redirections.

=item *

Persistent connections are not supported.  The C<Connection> header will
always be set to C<close>.

=item *

Cookies are not directly supported.  Users that set a C<Cookie> header
should also set C<max_redirect> to zero to ensure cookies are not
inappropriately re-transmitted.

=item *

Only the C<http_proxy> environment variable is supported in the format
C<http://HOST:PORT/>.  If a C<proxy> argument is passed to C<new> (including
undef), then the C<http_proxy> environment variable is ignored.

=item *

There is no provision for delaying a request body using an C<Expect> header.
Unexpected C<1XX> responses are silently ignored as per the specification.

=item *

Only 'chunked' C<Transfer-Encoding> is supported.

=item *

There is no support for a Request-URI of '*' for the 'OPTIONS' request.

=item *

There is no support for IPv6 of any kind.

=back

=head1 SEE ALSO

=over 4

=item *

L<LWP::UserAgent>

=item *

L<IO::Socket::SSL>

=item *

L<Mozilla::CA>

=back

=for :stopwords cpan testmatrix url annocpan anno bugtracker rt cpants kwalitee diff irc mailto metadata placeholders metacpan

=head1 SUPPORT

=head2 Bugs / Feature Requests

Please report any bugs or feature requests through the issue tracker
at L<http://rt.cpan.org/Public/Dist/Display.html?Name=HTTP-Tiny>.
You will be notified automatically of any progress on your issue.

=head2 Source Code

This is open source software.  The code repository is available for
public review and contribution under the terms of the license.

L<https://github.com/dagolden/p5-http-tiny>

  git clone https://github.com/dagolden/p5-http-tiny.git

=head1 AUTHORS

=over 4

=item *

Christian Hansen <chansen@cpan.org>

=item *

David Golden <dagolden@cpan.org>

=item *

Mike Doherty <doherty@cpan.org>

=back

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2012 by Christian Hansen.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut

