# http.tcl --
#
#       Client-side HTTP for GET, POST, and HEAD commands. These routines can
#       be used in untrusted code that uses the Safesock security policy.
#       These procedures use a callback interface to avoid using vwait, which
#       is not defined in the safe base.
#
# See the file "license.terms" for information on usage and redistribution of
# this file, and for a DISCLAIMER OF ALL WARRANTIES.
#
# RCS: @(#) $Id: http.tcl,v 1.67.2.9 2009/11/11 16:14:43 dgp Exp $

package require Tcl 8.4
# Keep this in sync with pkgIndex.tcl and with the install directories in
# Makefiles
package provide http 2.7.5

namespace eval http {
    # Allow resourcing to not clobber existing data

    variable http
    if {![info exists http]} {
        array set http {
            -accept */*
            -proxyhost {}
            -proxyport {}
            -proxyfilter http::ProxyRequired
            -urlencoding utf-8
        }
        set http(-useragent) "Tcl http client package [package provide http]"
    }

    proc init {} {
        # Set up the map for quoting chars. RFC3986 Section 2.3 say percent
        # encode all except: "... percent-encoded octets in the ranges of
        # ALPHA (%41-%5A and %61-%7A), DIGIT (%30-%39), hyphen (%2D), period
        # (%2E), underscore (%5F), or tilde (%7E) should not be created by URI
        # producers ..."
        for {set i 0} {$i <= 256} {incr i} {
            set c [format %c $i]
            if {![string match {[-._~a-zA-Z0-9]} $c]} {
                set map($c) %[format %.2x $i]
            }
        }
        # These are handled specially
        set map(\n) %0d%0a
        variable formMap [array get map]

        # Create a map for HTTP/1.1 open sockets
        variable socketmap
        if {[info exists socketmap]} {
            # Close but don't remove open sockets on re-init
            foreach {url sock} [array get socketmap] {
                catch {close $sock}
            }
        }
        array set socketmap {}
    }
    init

    variable urlTypes
    if {![info exists urlTypes]} {
        set urlTypes(http) [list 80 ::socket]
    }

    variable encodings [string tolower [encoding names]]
    # This can be changed, but iso8859-1 is the RFC standard.
    variable defaultCharset
    if {![info exists defaultCharset]} {
        set defaultCharset "iso8859-1"
    }

    # Force RFC 3986 strictness in geturl url verification?
    variable strict
    if {![info exists strict]} {
        set strict 1
    }

    # Let user control default keepalive for compatibility
    variable defaultKeepalive
    if {![info exists defaultKeepalive]} {
        set defaultKeepalive 0
    }

    namespace export geturl config reset wait formatQuery register unregister
    # Useful, but not exported: data size status code
}

# http::Log --
#
#       Debugging output -- define this to observe HTTP/1.1 socket usage.
#       Should echo any args received.
#
# Arguments:
#     msg       Message to output
#
proc http::Log {args} {}

# http::register --
#
#     See documentation for details.
#
# Arguments:
#     proto     URL protocol prefix, e.g. https
#     port      Default port for protocol
#     command   Command to use to create socket
# Results:
#     list of port and command that was registered.

proc http::register {proto port command} {
    variable urlTypes
    set urlTypes($proto) [list $port $command]
}

# http::unregister --
#
#     Unregisters URL protocol handler
#
# Arguments:
#     proto     URL protocol prefix, e.g. https
# Results:
#     list of port and command that was unregistered.

proc http::unregister {proto} {
    variable urlTypes
    if {![info exists urlTypes($proto)]} {
        return -code error "unsupported url type \"$proto\""
    }
    set old $urlTypes($proto)
    unset urlTypes($proto)
    return $old
}

# http::config --
#
#       See documentation for details.
#
# Arguments:
#       args            Options parsed by the procedure.
# Results:
#        TODO

proc http::config {args} {
    variable http
    set options [lsort [array names http -*]]
    set usage [join $options ", "]
    if {[llength $args] == 0} {
        set result {}
        foreach name $options {
            lappend result $name $http($name)
        }
        return $result
    }
    set options [string map {- ""} $options]
    set pat ^-(?:[join $options |])$
    if {[llength $args] == 1} {
        set flag [lindex $args 0]
        if {![regexp -- $pat $flag]} {
            return -code error "Unknown option $flag, must be: $usage"
        }
        return $http($flag)
    } else {
        foreach {flag value} $args {
            if {![regexp -- $pat $flag]} {
                return -code error "Unknown option $flag, must be: $usage"
            }
            set http($flag) $value
        }
    }
}

# http::Finish --
#
#       Clean up the socket and eval close time callbacks
#
# Arguments:
#       token       Connection token.
#       errormsg    (optional) If set, forces status to error.
#       skipCB      (optional) If set, don't call the -command callback. This
#                   is useful when geturl wants to throw an exception instead
#                   of calling the callback. That way, the same error isn't
#                   reported to two places.
#
# Side Effects:
#        Closes the socket

proc http::Finish {token {errormsg ""} {skipCB 0}} {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {$errormsg ne ""} {
        set state(error) [list $errormsg $errorInfo $errorCode]
        set state(status) "error"
    }
    if {
        ($state(status) eq "timeout") || ($state(status) eq "error") ||
        ([info exists state(connection)] && ($state(connection) eq "close"))
    } then {
        CloseSocket $state(sock) $token
    }
    if {[info exists state(after)]} {
        after cancel $state(after)
    }
    if {[info exists state(-command)] && !$skipCB} {
        if {[catch {eval $state(-command) {$token}} err]} {
            if {$errormsg eq ""} {
                set state(error) [list $err $errorInfo $errorCode]
                set state(status) error
            }
        }
        # Command callback may already have unset our state
        unset -nocomplain state(-command)
    }
}

# http::CloseSocket -
#
#       Close a socket and remove it from the persistent sockets table.  If
#       possible an http token is included here but when we are called from a
#       fileevent on remote closure we need to find the correct entry - hence
#       the second section.

proc ::http::CloseSocket {s {token {}}} {
    variable socketmap
    catch {fileevent $s readable {}}
    set conn_id {}
    if {$token ne ""} {
        variable $token
        upvar 0 $token state
        if {[info exists state(socketinfo)]} {
            set conn_id $state(socketinfo)
        }
    } else {
        set map [array get socketmap]
        set ndx [lsearch -exact $map $s]
        if {$ndx != -1} {
            incr ndx -1
            set conn_id [lindex $map $ndx]
        }
    }
    if {$conn_id eq {} || ![info exists socketmap($conn_id)]} {
        Log "Closing socket $s (no connection info)"
        if {[catch {close $s} err]} {
            Log "Error: $err"
        }
    } else {
        if {[info exists socketmap($conn_id)]} {
            Log "Closing connection $conn_id (sock $socketmap($conn_id))"
            if {[catch {close $socketmap($conn_id)} err]} {
                Log "Error: $err"
            }
            unset socketmap($conn_id)
        } else {
            Log "Cannot close connection $conn_id - no socket in socket map"
        }
    }
}

# http::reset --
#
#       See documentation for details.
#
# Arguments:
#       token   Connection token.
#       why     Status info.
#
# Side Effects:
#       See Finish

proc http::reset {token {why reset}} {
    variable $token
    upvar 0 $token state
    set state(status) $why
    catch {fileevent $state(sock) readable {}}
    catch {fileevent $state(sock) writable {}}
    Finish $token
    if {[info exists state(error)]} {
        set errorlist $state(error)
        unset state
        eval ::error $errorlist
    }
}

# http::geturl --
#
#       Establishes a connection to a remote url via http.
#
# Arguments:
#       url             The http URL to goget.
#       args            Option value pairs. Valid options include:
#                               -blocksize, -validate, -headers, -timeout
# Results:
#       Returns a token for this connection. This token is the name of an
#       array that the caller should unset to garbage collect the state.

proc http::geturl {url args} {
    variable http
    variable urlTypes
    variable defaultCharset
    variable defaultKeepalive
    variable strict

    # Initialize the state variable, an array. We'll return the name of this
    # array as the token for the transaction.

    if {![info exists http(uid)]} {
        set http(uid) 0
    }
    set token [namespace current]::[incr http(uid)]
    variable $token
    upvar 0 $token state
    reset $token

    # Process command options.

    array set state {
        -binary         false
        -blocksize      8192
        -queryblocksize 8192
        -validate       0
        -headers        {}
        -timeout        0
        -type           application/x-www-form-urlencoded
        -queryprogress  {}
        -protocol       1.1
        binary          0
        state           connecting
        meta            {}
        coding          {}
        currentsize     0
        totalsize       0
        querylength     0
        queryoffset     0
        type            text/html
        body            {}
        status          ""
        http            ""
        connection      close
    }
    set state(-keepalive) $defaultKeepalive
    set state(-strict) $strict
    # These flags have their types verified [Bug 811170]
    array set type {
        -binary         boolean
        -blocksize      integer
        -queryblocksize integer
        -strict         boolean
        -timeout        integer
        -validate       boolean
    }
    set state(charset)  $defaultCharset
    set options {
        -binary -blocksize -channel -command -handler -headers -keepalive
        -method -myaddr -progress -protocol -query -queryblocksize
        -querychannel -queryprogress -strict -timeout -type -validate
    }
    set usage [join [lsort $options] ", "]
    set options [string map {- ""} $options]
    set pat ^-(?:[join $options |])$
    foreach {flag value} $args {
        if {[regexp -- $pat $flag]} {
            # Validate numbers
            if {
                [info exists type($flag)] &&
                ![string is $type($flag) -strict $value]
            } then {
                unset $token
                return -code error \
                    "Bad value for $flag ($value), must be $type($flag)"
            }
            set state($flag) $value
        } else {
            unset $token
            return -code error "Unknown option $flag, can be: $usage"
        }
    }

    # Make sure -query and -querychannel aren't both specified

    set isQueryChannel [info exists state(-querychannel)]
    set isQuery [info exists state(-query)]
    if {$isQuery && $isQueryChannel} {
        unset $token
        return -code error "Can't combine -query and -querychannel options!"
    }

    # Validate URL, determine the server host and port, and check proxy case
    # Recognize user:pass@host URLs also, although we do not do anything with
    # that info yet.

    # URLs have basically four parts.
    # First, before the colon, is the protocol scheme (e.g. http)
    # Second, for HTTP-like protocols, is the authority
    #   The authority is preceded by // and lasts up to (but not including)
    #   the following / and it identifies up to four parts, of which only one,
    #   the host, is required (if an authority is present at all). All other
    #   parts of the authority (user name, password, port number) are optional.
    # Third is the resource name, which is split into two parts at a ?
    #   The first part (from the single "/" up to "?") is the path, and the
    #   second part (from that "?" up to "#") is the query. *HOWEVER*, we do
    #   not need to separate them; we send the whole lot to the server.
    # Fourth is the fragment identifier, which is everything after the first
    #   "#" in the URL. The fragment identifier MUST NOT be sent to the server
    #   and indeed, we don't bother to validate it (it could be an error to
    #   pass it in here, but it's cheap to strip).
    #
    # An example of a URL that has all the parts:
    #
    #     http://jschmoe:xyzzy@www.bogus.net:8000/foo/bar.tml?q=foo#changes
    #
    # The "http" is the protocol, the user is "jschmoe", the password is
    # "xyzzy", the host is "www.bogus.net", the port is "8000", the path is
    # "/foo/bar.tml", the query is "q=foo", and the fragment is "changes".
    #
    # Note that the RE actually combines the user and password parts, as
    # recommended in RFC 3986. Indeed, that RFC states that putting passwords
    # in URLs is a Really Bad Idea, something with which I would agree utterly.
    # Also note that we do not currently support IPv6 addresses.
    #
    # From a validation perspective, we need to ensure that the parts of the
    # URL that are going to the server are correctly encoded.  This is only
    # done if $state(-strict) is true (inherited from $::http::strict).

    set URLmatcher {(?x)                # this is _expanded_ syntax
        ^
        (?: (\w+) : ) ?                 # <protocol scheme>
        (?: //
            (?:
                (
                    [^@/\#?]+           # <userinfo part of authority>
                ) @
            )?
            ( [^/:\#?]+ )               # <host part of authority>
            (?: : (\d+) )?              # <port part of authority>
        )?
        ( / [^\#]*)?                    # <path> (including query)
        (?: \# (.*) )?                  # <fragment>
        $
    }

    # Phase one: parse
    if {![regexp -- $URLmatcher $url -> proto user host port srvurl]} {
        unset $token
        return -code error "Unsupported URL: $url"
    }
    # Phase two: validate
    if {$host eq ""} {
        # Caller has to provide a host name; we do not have a "default host"
        # that would enable us to handle relative URLs.
        unset $token
        return -code error "Missing host part: $url"
        # Note that we don't check the hostname for validity here; if it's
        # invalid, we'll simply fail to resolve it later on.
    }
    if {$port ne "" && $port > 65535} {
        unset $token
        return -code error "Invalid port number: $port"
    }
    # The user identification and resource identification parts of the URL can
    # have encoded characters in them; take care!
    if {$user ne ""} {
        # Check for validity according to RFC 3986, Appendix A
        set validityRE {(?xi)
            ^
            (?: [-\w.~!$&'()*+,;=:] | %[0-9a-f][0-9a-f] )+
            $
        }
        if {$state(-strict) && ![regexp -- $validityRE $user]} {
            unset $token
            # Provide a better error message in this error case
            if {[regexp {(?i)%(?![0-9a-f][0-9a-f]).?.?} $user bad]} {
                return -code error \
                        "Illegal encoding character usage \"$bad\" in URL user"
            }
            return -code error "Illegal characters in URL user"
        }
    }
    if {$srvurl ne ""} {
        # Check for validity according to RFC 3986, Appendix A
        set validityRE {(?xi)
            ^
            # Path part (already must start with / character)
            (?:       [-\w.~!$&'()*+,;=:@/]  | %[0-9a-f][0-9a-f] )*
            # Query part (optional, permits ? characters)
            (?: \? (?: [-\w.~!$&'()*+,;=:@/?] | %[0-9a-f][0-9a-f] )* )?
            $
        }
        if {$state(-strict) && ![regexp -- $validityRE $srvurl]} {
            unset $token
            # Provide a better error message in this error case
            if {[regexp {(?i)%(?![0-9a-f][0-9a-f])..} $srvurl bad]} {
                return -code error \
                    "Illegal encoding character usage \"$bad\" in URL path"
            }
            return -code error "Illegal characters in URL path"
        }
    } else {
        set srvurl /
    }
    if {$proto eq ""} {
        set proto http
    }
    if {![info exists urlTypes($proto)]} {
        unset $token
        return -code error "Unsupported URL type \"$proto\""
    }
    set defport [lindex $urlTypes($proto) 0]
    set defcmd [lindex $urlTypes($proto) 1]

    if {$port eq ""} {
        set port $defport
    }
    if {![catch {$http(-proxyfilter) $host} proxy]} {
        set phost [lindex $proxy 0]
        set pport [lindex $proxy 1]
    }

    # OK, now reassemble into a full URL
    set url ${proto}://
    if {$user ne ""} {
        append url $user
        append url @
    }
    append url $host
    if {$port != $defport} {
        append url : $port
    }
    append url $srvurl
    # Don't append the fragment!
    set state(url) $url

    # If a timeout is specified we set up the after event and arrange for an
    # asynchronous socket connection.

    set sockopts [list -async]
    if {$state(-timeout) > 0} {
        set state(after) [after $state(-timeout) \
                [list http::reset $token timeout]]
    }

    # If we are using the proxy, we must pass in the full URL that includes
    # the server name.

    if {[info exists phost] && ($phost ne "")} {
        set srvurl $url
        set targetAddr [list $phost $pport]
    } else {
        set targetAddr [list $host $port]
    }
    # Proxy connections aren't shared among different hosts.
    set state(socketinfo) $host:$port

    # See if we are supposed to use a previously opened channel.
    if {$state(-keepalive)} {
        variable socketmap
        if {[info exists socketmap($state(socketinfo))]} {
            if {[catch {fconfigure $socketmap($state(socketinfo))}]} {
                Log "WARNING: socket for $state(socketinfo) was closed"
                unset socketmap($state(socketinfo))
            } else {
                set sock $socketmap($state(socketinfo))
                Log "reusing socket $sock for $state(socketinfo)"
                catch {fileevent $sock writable {}}
                catch {fileevent $sock readable {}}
            }
        }
        # don't automatically close this connection socket
        set state(connection) {}
    }
    if {![info exists sock]} {
        # Pass -myaddr directly to the socket command
        if {[info exists state(-myaddr)]} {
            lappend sockopts -myaddr $state(-myaddr)
        }
        if {[catch {eval $defcmd $sockopts $targetAddr} sock]} {
            # something went wrong while trying to establish the connection.
            # Clean up after events and such, but DON'T call the command
            # callback (if available) because we're going to throw an
            # exception from here instead.

            set state(sock) $sock
            Finish $token "" 1
            cleanup $token
            return -code error $sock
        }
    }
    set state(sock) $sock
    Log "Using $sock for $state(socketinfo)" \
        [expr {$state(-keepalive)?"keepalive":""}]
    if {$state(-keepalive)} {
        set socketmap($state(socketinfo)) $sock
    }

    if {![info exists phost]} {
        set phost ""
    }
    fileevent $sock writable [list http::Connect $token $proto $phost $srvurl]

    # Wait for the connection to complete.
    if {![info exists state(-command)]} {
        # geturl does EVERYTHING asynchronously, so if the user
        # calls it synchronously, we just do a wait here.
        http::wait $token

        if {![info exists state]} {
            # If we timed out then Finish has been called and the users
            # command callback may have cleaned up the token. If so we end up
            # here with nothing left to do.
            return $token
        } elseif {$state(status) eq "error"} {
            # Something went wrong while trying to establish the connection.
            # Clean up after events and such, but DON'T call the command
            # callback (if available) because we're going to throw an
            # exception from here instead.
            set err [lindex $state(error) 0]
            cleanup $token
            return -code error $err
        }
    }


    return $token
}


proc http::Connected { token proto phost srvurl} {
    variable http
    variable urlTypes

    variable $token
    upvar 0 $token state

    # Set back the variables needed here
    set sock $state(sock)
    set isQueryChannel [info exists state(-querychannel)]
    set isQuery [info exists state(-query)]
    set host [lindex [split $state(socketinfo) :] 0]
    set port [lindex [split $state(socketinfo) :] 1]

    set defport [lindex $urlTypes($proto) 0]

    # Send data in cr-lf format, but accept any line terminators
    fconfigure $sock -translation {auto crlf} -buffersize $state(-blocksize)

    # The following is disallowed in safe interpreters, but the socket is
    # already in non-blocking mode in that case.

    catch {fconfigure $sock -blocking off}
    set how GET
    if {$isQuery} {
        set state(querylength) [string length $state(-query)]
        if {$state(querylength) > 0} {
            set how POST
            set contDone 0
        } else {
            # There's no query data.
            unset state(-query)
            set isQuery 0
        }
    } elseif {$state(-validate)} {
        set how HEAD
    } elseif {$isQueryChannel} {
        set how POST
        # The query channel must be blocking for the async Write to
        # work properly.
        fconfigure $state(-querychannel) -blocking 1 -translation binary
        set contDone 0
    }
    if {[info exists state(-method)] && $state(-method) ne ""} {
        set how $state(-method)
    }

    if {[catch {
        puts $sock "$how $srvurl HTTP/$state(-protocol)"
        puts $sock "Accept: $http(-accept)"
        array set hdrs $state(-headers)
        if {[info exists hdrs(Host)]} {
            # Allow Host spoofing. [Bug 928154]
            puts $sock "Host: $hdrs(Host)"
        } elseif {$port == $defport} {
            # Don't add port in this case, to handle broken servers. [Bug
            # #504508]
            puts $sock "Host: $host"
        } else {
            puts $sock "Host: $host:$port"
        }
        unset hdrs
        puts $sock "User-Agent: $http(-useragent)"
        if {$state(-protocol) == 1.0 && $state(-keepalive)} {
            puts $sock "Connection: keep-alive"
        }
        if {$state(-protocol) > 1.0 && !$state(-keepalive)} {
            puts $sock "Connection: close" ;# RFC2616 sec 8.1.2.1
        }
        if {[info exists phost] && ($phost ne "") && $state(-keepalive)} {
            puts $sock "Proxy-Connection: Keep-Alive"
        }
        set accept_encoding_seen 0
        foreach {key value} $state(-headers) {
            if {[string equal -nocase $key "host"]} {
                continue
            }
            if {[string equal -nocase $key "accept-encoding"]} {
                set accept_encoding_seen 1
            }
            set value [string map [list \n "" \r ""] $value]
            set key [string trim $key]
            if {[string equal -nocase $key "content-length"]} {
                set contDone 1
                set state(querylength) $value
            }
            if {[string length $key]} {
                puts $sock "$key: $value"
            }
        }
        # Soft zlib dependency check - no package require
        if {
            !$accept_encoding_seen &&
            ([package vsatisfies [package provide Tcl] 8.6]
                || [llength [package provide zlib]]) &&
            !([info exists state(-channel)] || [info exists state(-handler)])
        } then {
            puts $sock "Accept-Encoding: gzip, identity, *;q=0.1"
        }
        if {$isQueryChannel && $state(querylength) == 0} {
            # Try to determine size of data in channel. If we cannot seek, the
            # surrounding catch will trap us

            set start [tell $state(-querychannel)]
            seek $state(-querychannel) 0 end
            set state(querylength) \
                    [expr {[tell $state(-querychannel)] - $start}]
            seek $state(-querychannel) $start
        }

        # Flush the request header and set up the fileevent that will either
        # push the POST data or read the response.
        #
        # fileevent note:
        #
        # It is possible to have both the read and write fileevents active at
        # this point. The only scenario it seems to affect is a server that
        # closes the connection without reading the POST data. (e.g., early
        # versions TclHttpd in various error cases). Depending on the
        # platform, the client may or may not be able to get the response from
        # the server because of the error it will get trying to write the post
        # data.  Having both fileevents active changes the timing and the
        # behavior, but no two platforms (among Solaris, Linux, and NT) behave
        # the same, and none behave all that well in any case. Servers should
        # always read their POST data if they expect the client to read their
        # response.

        if {$isQuery || $isQueryChannel} {
            puts $sock "Content-Type: $state(-type)"
            if {!$contDone} {
                puts $sock "Content-Length: $state(querylength)"
            }
            puts $sock ""
            fconfigure $sock -translation {auto binary}
            fileevent $sock writable [list http::Write $token]
        } else {
            puts $sock ""
            flush $sock
            fileevent $sock readable [list http::Event $sock $token]
        }

    } err]} then {
        # The socket probably was never connected, or the connection dropped
        # later.

        # if state(status) is error, it means someone's already called Finish
        # to do the above-described clean up.
        if {$state(status) ne "error"} {
            Finish $token $err
        }
    }

}

# Data access functions:
# Data - the URL data
# Status - the transaction status: ok, reset, eof, timeout
# Code - the HTTP transaction code, e.g., 200
# Size - the size of the URL data

proc http::data {token} {
    variable $token
    upvar 0 $token state
    return $state(body)
}
proc http::status {token} {
    if {![info exists $token]} {
        return "error"
    }
    variable $token
    upvar 0 $token state
    return $state(status)
}
proc http::code {token} {
    variable $token
    upvar 0 $token state
    return $state(http)
}
proc http::ncode {token} {
    variable $token
    upvar 0 $token state
    if {[regexp {[0-9]{3}} $state(http) numeric_code]} {
        return $numeric_code
    } else {
        return $state(http)
    }
}
proc http::size {token} {
    variable $token
    upvar 0 $token state
    return $state(currentsize)
}
proc http::meta {token} {
    variable $token
    upvar 0 $token state
    return $state(meta)
}
proc http::error {token} {
    variable $token
    upvar 0 $token state
    if {[info exists state(error)]} {
        return $state(error)
    }
    return ""
}

# http::cleanup
#
#       Garbage collect the state associated with a transaction
#
# Arguments
#       token   The token returned from http::geturl
#
# Side Effects
#       unsets the state array

proc http::cleanup {token} {
    variable $token
    upvar 0 $token state
    if {[info exists state]} {
        unset state
    }
}

# http::Connect
#
#       This callback is made when an asyncronous connection completes.
#
# Arguments
#       token   The token returned from http::geturl
#
# Side Effects
#       Sets the status of the connection, which unblocks
#       the waiting geturl call

proc http::Connect {token proto phost srvurl} {
    variable $token
    upvar 0 $token state
    global errorInfo errorCode
    if {
        [eof $state(sock)] ||
        [string length [fconfigure $state(sock) -error]]
    } then {
        Finish $token "connect failed [fconfigure $state(sock) -error]"
    } else {
        fileevent $state(sock) writable {}
        ::http::Connected $token $proto $phost $srvurl
    }
    return
}

# http::Write
#
#       Write POST query data to the socket
#
# Arguments
#       token   The token for the connection
#
# Side Effects
#       Write the socket and handle callbacks.

proc http::Write {token} {
    variable $token
    upvar 0 $token state
    set sock $state(sock)

    # Output a block.  Tcl will buffer this if the socket blocks
    set done 0
    if {[catch {
        # Catch I/O errors on dead sockets

        if {[info exists state(-query)]} {
            # Chop up large query strings so queryprogress callback can give
            # smooth feedback.

            puts -nonewline $sock \
                [string range $state(-query) $state(queryoffset) \
                     [expr {$state(queryoffset) + $state(-queryblocksize) - 1}]]
            incr state(queryoffset) $state(-queryblocksize)
            if {$state(queryoffset) >= $state(querylength)} {
                set state(queryoffset) $state(querylength)
                puts $sock ""
                set done 1
            }
        } else {
            # Copy blocks from the query channel

            set outStr [read $state(-querychannel) $state(-queryblocksize)]
            puts -nonewline $sock $outStr
            incr state(queryoffset) [string length $outStr]
            if {[eof $state(-querychannel)]} {
                set done 1
            }
        }
    } err]} then {
        # Do not call Finish here, but instead let the read half of the socket
        # process whatever server reply there is to get.

        set state(posterror) $err
        set done 1
    }
    if {$done} {
        catch {flush $sock}
        fileevent $sock writable {}
        fileevent $sock readable [list http::Event $sock $token]
    }

    # Callback to the client after we've completely handled everything.

    if {[string length $state(-queryprogress)]} {
        eval $state(-queryprogress) \
            [list $token $state(querylength) $state(queryoffset)]
    }
}

# http::Event
#
#       Handle input on the socket
#
# Arguments
#       sock    The socket receiving input.
#       token   The token returned from http::geturl
#
# Side Effects
#       Read the socket and handle callbacks.

proc http::Event {sock token} {
    variable $token
    upvar 0 $token state

    if {![info exists state]} {
        Log "Event $sock with invalid token '$token' - remote close?"
        if {![eof $sock]} {
            if {[set d [read $sock]] ne ""} {
                Log "WARNING: additional data left on closed socket"
            }
        }
        CloseSocket $sock
        return
    }
    if {$state(state) eq "connecting"} {
        if {[catch {gets $sock state(http)} n]} {
            return [Finish $token $n]
        } elseif {$n >= 0} {
            set state(state) "header"
        }
    } elseif {$state(state) eq "header"} {
        if {[catch {gets $sock line} n]} {
            return [Finish $token $n]
        } elseif {$n == 0} {
            # We have now read all headers
            # We ignore HTTP/1.1 100 Continue returns. RFC2616 sec 8.2.3
            if {$state(http) == "" || [lindex $state(http) 1] == 100} {
                return
            }

            set state(state) body

            # If doing a HEAD, then we won't get any body
            if {$state(-validate)} {
                Eof $token
                return
            }

            # For non-chunked transfer we may have no body - in this case we
            # may get no further file event if the connection doesn't close
            # and no more data is sent. We can tell and must finish up now -
            # not later.
            if {
                !(([info exists state(connection)]
                        && ($state(connection) eq "close"))
                    || [info exists state(transfer)])
                && ($state(totalsize) == 0)
            } then {
                Log "body size is 0 and no events likely - complete."
                Eof $token
                return
            }

            # We have to use binary translation to count bytes properly.
            fconfigure $sock -translation binary

            if {
                $state(-binary) || ![string match -nocase text* $state(type)]
            } then {
                # Turn off conversions for non-text data
                set state(binary) 1
            }
            if {
                $state(binary) || [string match *gzip* $state(coding)] ||
                [string match *compress* $state(coding)]
            } then {
                if {[info exists state(-channel)]} {
                    fconfigure $state(-channel) -translation binary
                }
            }
            if {
                [info exists state(-channel)] &&
                ![info exists state(-handler)]
            } then {
                # Initiate a sequence of background fcopies
                fileevent $sock readable {}
                CopyStart $sock $token
                return
            }
        } elseif {$n > 0} {
            # Process header lines
            if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {
                switch -- [string tolower $key] {
                    content-type {
                        set state(type) [string trim [string tolower $value]]
                        # grab the optional charset information
                        if {[regexp -nocase \
                                 {charset\s*=\s*\"((?:[^""]|\\\")*)\"} \
                                 $state(type) -> cs]} {
                            set state(charset) [string map {{\"} \"} $cs]
                        } else {
                            regexp -nocase {charset\s*=\s*(\S+?);?} \
                                $state(type) -> state(charset)
                        }
                    }
                    content-length {
                        set state(totalsize) [string trim $value]
                    }
                    content-encoding {
                        set state(coding) [string trim $value]
                    }
                    transfer-encoding {
                        set state(transfer) \
                            [string trim [string tolower $value]]
                    }
                    proxy-connection -
                    connection {
                        set state(connection) \
                            [string trim [string tolower $value]]
                    }
                }
                lappend state(meta) $key [string trim $value]
            }
        }
    } else {
        # Now reading body
        if {[catch {
            if {[info exists state(-handler)]} {
                set n [eval $state(-handler) [list $sock $token]]
            } elseif {[info exists state(transfer_final)]} {
                set line [getTextLine $sock]
                set n [string length $line]
                if {$n > 0} {
                    Log "found $n bytes following final chunk"
                    append state(transfer_final) $line
                } else {
                    Log "final chunk part"
                    Eof $token
                }
            } elseif {
                [info exists state(transfer)]
                && $state(transfer) eq "chunked"
            } then {
                set size 0
                set chunk [getTextLine $sock]
                set n [string length $chunk]
                if {[string trim $chunk] ne ""} {
                    scan $chunk %x size
                    if {$size != 0} {
                        set bl [fconfigure $sock -blocking]
                        fconfigure $sock -blocking 1
                        set chunk [read $sock $size]
                        fconfigure $sock -blocking $bl
                        set n [string length $chunk]
                        if {$n >= 0} {
                            append state(body) $chunk
                        }
                        if {$size != [string length $chunk]} {
                            Log "WARNING: mis-sized chunk:\
                                was [string length $chunk], should be $size"
                        }
                        getTextLine $sock
                    } else {
                        set state(transfer_final) {}
                    }
                }
            } else {
                #Log "read non-chunk $state(currentsize) of $state(totalsize)"
                set block [read $sock $state(-blocksize)]
                set n [string length $block]
                if {$n >= 0} {
                    append state(body) $block
                }
            }
            if {[info exists state]} {
                if {$n >= 0} {
                    incr state(currentsize) $n
                }
                # If Content-Length - check for end of data.
                if {
                    ($state(totalsize) > 0)
                    && ($state(currentsize) >= $state(totalsize))
                } then {
                    Eof $token
                }
            }
        } err]} then {
            return [Finish $token $err]
        } else {
            if {[info exists state(-progress)]} {
                eval $state(-progress) \
                    [list $token $state(totalsize) $state(currentsize)]
            }
        }
    }

    # catch as an Eof above may have closed the socket already
    if {![catch {eof $sock} eof] && $eof} {
        if {[info exists $token]} {
            set state(connection) close
            Eof $token
        } else {
            # open connection closed on a token that has been cleaned up.
            CloseSocket $sock
        }
        return
    }
}

# http::getTextLine --
#
#       Get one line with the stream in blocking crlf mode
#
# Arguments
#       sock    The socket receiving input.
#
# Results:
#       The line of text, without trailing newline

proc http::getTextLine {sock} {
    set tr [fconfigure $sock -translation]
    set bl [fconfigure $sock -blocking]
    fconfigure $sock -translation crlf -blocking 1
    set r [gets $sock]
    fconfigure $sock -translation $tr -blocking $bl
    return $r
}

# http::CopyStart
#
#       Error handling wrapper around fcopy
#
# Arguments
#       sock    The socket to copy from
#       token   The token returned from http::geturl
#
# Side Effects
#       This closes the connection upon error

proc http::CopyStart {sock token} {
    variable $token
    upvar 0 $token state
    if {[catch {
        fcopy $sock $state(-channel) -size $state(-blocksize) -command \
            [list http::CopyDone $token]
    } err]} then {
        Finish $token $err
    }
}

# http::CopyDone
#
#       fcopy completion callback
#
# Arguments
#       token   The token returned from http::geturl
#       count   The amount transfered
#
# Side Effects
#       Invokes callbacks

proc http::CopyDone {token count {error {}}} {
    variable $token
    upvar 0 $token state
    set sock $state(sock)
    incr state(currentsize) $count
    if {[info exists state(-progress)]} {
        eval $state(-progress) \
            [list $token $state(totalsize) $state(currentsize)]
    }
    # At this point the token may have been reset
    if {[string length $error]} {
        Finish $token $error
    } elseif {[catch {eof $sock} iseof] || $iseof} {
        Eof $token
    } else {
        CopyStart $sock $token
    }
}

# http::Eof
#
#       Handle eof on the socket
#
# Arguments
#       token   The token returned from http::geturl
#
# Side Effects
#       Clean up the socket

proc http::Eof {token {force 0}} {
    variable $token
    upvar 0 $token state
    if {$state(state) eq "header"} {
        # Premature eof
        set state(status) eof
    } else {
        set state(status) ok
    }

    if {($state(coding) eq "gzip") && [string length $state(body)] > 0} {
        if {[catch {
            if {[package vsatisfies [package present Tcl] 8.6]} {
                # The zlib integration into 8.6 includes proper gzip support
                set state(body) [zlib gunzip $state(body)]
            } else {
                set state(body) [Gunzip $state(body)]
            }
        } err]} then {
            return [Finish $token $err]
        }
    }

    if {!$state(binary)} {
        # If we are getting text, set the incoming channel's encoding
        # correctly.  iso8859-1 is the RFC default, but this could be any IANA
        # charset.  However, we only know how to convert what we have
        # encodings for.

        set enc [CharsetToEncoding $state(charset)]
        if {$enc ne "binary"} {
            set state(body) [encoding convertfrom $enc $state(body)]
        }

        # Translate text line endings.
        set state(body) [string map {\r\n \n \r \n} $state(body)]
    }

    Finish $token
}

# http::wait --
#
#       See documentation for details.
#
# Arguments:
#       token   Connection token.
#
# Results:
#        The status after the wait.

proc http::wait {token} {
    variable $token
    upvar 0 $token state

    if {![info exists state(status)] || $state(status) eq ""} {
        # We must wait on the original variable name, not the upvar alias
        vwait ${token}(status)
    }

    return [status $token]
}

# http::formatQuery --
#
#       See documentation for details.  Call http::formatQuery with an even
#       number of arguments, where the first is a name, the second is a value,
#       the third is another name, and so on.
#
# Arguments:
#       args    A list of name-value pairs.
#
# Results:
#       TODO

proc http::formatQuery {args} {
    set result ""
    set sep ""
    foreach i $args {
        append result $sep [mapReply $i]
        if {$sep eq "="} {
            set sep &
        } else {
            set sep =
        }
    }
    return $result
}

# http::mapReply --
#
#       Do x-www-urlencoded character mapping
#
# Arguments:
#       string  The string the needs to be encoded
#
# Results:
#       The encoded string

proc http::mapReply {string} {
    variable http
    variable formMap

    # The spec says: "non-alphanumeric characters are replaced by '%HH'". Use
    # a pre-computed map and [string map] to do the conversion (much faster
    # than [regsub]/[subst]). [Bug 1020491]

    if {$http(-urlencoding) ne ""} {
        set string [encoding convertto $http(-urlencoding) $string]
        return [string map $formMap $string]
    }
    set converted [string map $formMap $string]
    if {[string match "*\[\u0100-\uffff\]*" $converted]} {
        regexp {[\u0100-\uffff]} $converted badChar
        # Return this error message for maximum compatability... :^/
        return -code error \
            "can't read \"formMap($badChar)\": no such element in array"
    }
    return $converted
}

# http::ProxyRequired --
#       Default proxy filter.
#
# Arguments:
#       host    The destination host
#
# Results:
#       The current proxy settings

proc http::ProxyRequired {host} {
    variable http
    if {[info exists http(-proxyhost)] && [string length $http(-proxyhost)]} {
        if {
            ![info exists http(-proxyport)] ||
            ![string length $http(-proxyport)]
        } then {
            set http(-proxyport) 8080
        }
        return [list $http(-proxyhost) $http(-proxyport)]
    }
}

# http::CharsetToEncoding --
#
#       Tries to map a given IANA charset to a tcl encoding.  If no encoding
#       can be found, returns binary.
#

proc http::CharsetToEncoding {charset} {
    variable encodings

    set charset [string tolower $charset]
    if {[regexp {iso-?8859-([0-9]+)} $charset -> num]} {
        set encoding "iso8859-$num"
    } elseif {[regexp {iso-?2022-(jp|kr)} $charset -> ext]} {
        set encoding "iso2022-$ext"
    } elseif {[regexp {shift[-_]?js} $charset]} {
        set encoding "shiftjis"
    } elseif {[regexp {(?:windows|cp)-?([0-9]+)} $charset -> num]} {
        set encoding "cp$num"
    } elseif {$charset eq "us-ascii"} {
        set encoding "ascii"
    } elseif {[regexp {(?:iso-?)?lat(?:in)?-?([0-9]+)} $charset -> num]} {
        switch -- $num {
            5 {set encoding "iso8859-9"}
            1 - 2 - 3 {
                set encoding "iso8859-$num"
            }
        }
    } else {
        # other charset, like euc-xx, utf-8,...  may directly map to encoding
        set encoding $charset
    }
    set idx [lsearch -exact $encodings $encoding]
    if {$idx >= 0} {
        return $encoding
    } else {
        return "binary"
    }
}

# http::Gunzip --
#
#       Decompress data transmitted using the gzip transfer coding.
#

# FIX ME: redo using zlib sinflate
proc http::Gunzip {data} {
    binary scan $data Scb5icc magic method flags time xfl os
    set pos 10
    if {$magic != 0x1f8b} {
        return -code error "invalid data: supplied data is not in gzip format"
    }
    if {$method != 8} {
        return -code error "invalid compression method"
    }

    # lassign [split $flags ""] f_text f_crc f_extra f_name f_comment
    foreach {f_text f_crc f_extra f_name f_comment} [split $flags ""] break
    set extra ""
    if {$f_extra} {
        binary scan $data @${pos}S xlen
        incr pos 2
        set extra [string range $data $pos $xlen]
        set pos [incr xlen]
    }

    set name ""
    if {$f_name} {
        set ndx [string first \0 $data $pos]
        set name [string range $data $pos $ndx]
        set pos [incr ndx]
    }

    set comment ""
    if {$f_comment} {
        set ndx [string first \0 $data $pos]
        set comment [string range $data $pos $ndx]
        set pos [incr ndx]
    }

    set fcrc ""
    if {$f_crc} {
        set fcrc [string range $data $pos [incr pos]]
        incr pos
    }

    binary scan [string range $data end-7 end] ii crc size
    set inflated [zlib inflate [string range $data $pos end-8]]
    set chk [zlib crc32 $inflated]
    if {($crc & 0xffffffff) != ($chk & 0xffffffff)} {
        return -code error "invalid data: checksum mismatch $crc != $chk"
    }
    return $inflated
}

# Local variables:
# indent-tabs-mode: t
# End:
