# 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.

#

# RCS: @(#) $Id: http.tcl,v 1.4 2000/02/01 11:48:30 hobbs Exp $

#

# See the http.n man page for documentation

package provide http 1.0

array set http {

    -accept */*

    -proxyhost {}

    -proxyport {}

    -useragent {Tcl http client package 1.0}

    -proxyfilter httpProxyRequired

}

proc http_config {args} {

    global 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

    }

    regsub -all -- - $options {} options

    set pat ^-([join $options |])$

    if {[llength $args] == 1} {

	set flag [lindex $args 0]

	if {[regexp -- $pat $flag]} {

	    return $http($flag)

	} else {

	    return -code error "Unknown option $flag, must be: $usage"

	}

    } else {

	foreach {flag value} $args {

	    if {[regexp -- $pat $flag]} {

		set http($flag) $value

	    } else {

		return -code error "Unknown option $flag, must be: $usage"

	    }

	}

    }

}

 proc httpFinish { token {errormsg ""} } {

    upvar #0 $token state

    global errorInfo errorCode

    if {[string length $errormsg] != 0} {

	set state(error) [list $errormsg $errorInfo $errorCode]

	set state(status) error

    }

    catch {close $state(sock)}

    catch {after cancel $state(after)}

    if {[info exists state(-command)]} {

	if {[catch {eval $state(-command) {$token}} err]} {

	    if {[string length $errormsg] == 0} {

		set state(error) [list $err $errorInfo $errorCode]

		set state(status) error

	    }

	}

	unset state(-command)

    }

}

proc http_reset { token {why reset} } {

    upvar #0 $token state

    set state(status) $why

    catch {fileevent $state(sock) readable {}}

    httpFinish $token

    if {[info exists state(error)]} {

	set errorlist $state(error)

	unset state(error)

	eval error $errorlist

    }

}

proc http_get { url args } {

    global http

    if {![info exists http(uid)]} {

	set http(uid) 0

    }

    set token http#[incr http(uid)]

    upvar #0 $token state

    http_reset $token

    array set state {

	-blocksize 	8192

	-validate 	0

	-headers 	{}

	-timeout 	0

	state		header

	meta		{}

	currentsize	0

	totalsize	0

        type            text/html

        body            {}

	status		""

    }

    set options {-blocksize -channel -command -handler -headers \

		-progress -query -validate -timeout}

    set usage [join $options ", "]

    regsub -all -- - $options {} options

    set pat ^-([join $options |])$

    foreach {flag value} $args {

	if {[regexp $pat $flag]} {

	    # Validate numbers

	    if {[info exists state($flag)] && \

		    [regexp {^[0-9]+$} $state($flag)] && \

		    ![regexp {^[0-9]+$} $value]} {

		return -code error "Bad value for $flag ($value), must be integer"

	    }

	    set state($flag) $value

	} else {

	    return -code error "Unknown option $flag, can be: $usage"

	}

    }

    if {! [regexp -nocase {^(http://)?([^/:]+)(:([0-9]+))?(/.*)?$} $url \

	    x proto host y port srvurl]} {

	error "Unsupported URL: $url"

    }

    if {[string length $port] == 0} {

	set port 80

    }

    if {[string length $srvurl] == 0} {

	set srvurl /

    }

    if {[string length $proto] == 0} {

	set url http://$url

    }

    set state(url) $url

    if {![catch {$http(-proxyfilter) $host} proxy]} {

	set phost [lindex $proxy 0]

	set pport [lindex $proxy 1]

    }

    if {$state(-timeout) > 0} {

	set state(after) [after $state(-timeout) [list http_reset $token timeout]]

    }

    if {[info exists phost] && [string length $phost]} {

	set srvurl $url

	set s [socket $phost $pport]

    } else {

	set s [socket $host $port]

    }

    set state(sock) $s

    # Send data in cr-lf format, but accept any line terminators

    fconfigure $s -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 $s -blocking off}

    set len 0

    set how GET

    if {[info exists state(-query)]} {

	set len [string length $state(-query)]

	if {$len > 0} {

	    set how POST

	}

    } elseif {$state(-validate)} {

	set how HEAD

    }

    puts $s "$how $srvurl HTTP/1.0"

    puts $s "Accept: $http(-accept)"

    puts $s "Host: $host"

    puts $s "User-Agent: $http(-useragent)"

    foreach {key value} $state(-headers) {

	regsub -all \[\n\r\]  $value {} value

	set key [string trim $key]

	if {[string length $key]} {

	    puts $s "$key: $value"

	}

    }

    if {$len > 0} {

	puts $s "Content-Length: $len"

	puts $s "Content-Type: application/x-www-form-urlencoded"

	puts $s ""

	fconfigure $s -translation {auto binary}

	puts -nonewline $s $state(-query)

    } else {

	puts $s ""

    }

    flush $s

    fileevent $s readable [list httpEvent $token]

    if {! [info exists state(-command)]} {

	http_wait $token

    }

    return $token

}

proc http_data {token} {

    upvar #0 $token state

    return $state(body)

}

proc http_status {token} {

    upvar #0 $token state

    return $state(status)

}

proc http_code {token} {

    upvar #0 $token state

    return $state(http)

}

proc http_size {token} {

    upvar #0 $token state

    return $state(currentsize)

}

 proc httpEvent {token} {

    upvar #0 $token state

    set s $state(sock)

     if {[eof $s]} {

	httpEof $token

	return

    }

    if {$state(state) == "header"} {

	set n [gets $s line]

	if {$n == 0} {

	    set state(state) body

	    if {![regexp -nocase ^text $state(type)]} {

		# Turn off conversions for non-text data

		fconfigure $s -translation binary

		if {[info exists state(-channel)]} {

		    fconfigure $state(-channel) -translation binary

		}

	    }

	    if {[info exists state(-channel)] &&

		    ![info exists state(-handler)]} {

		# Initiate a sequence of background fcopies

		fileevent $s readable {}

		httpCopyStart $s $token

	    }

	} elseif {$n > 0} {

	    if {[regexp -nocase {^content-type:(.+)$} $line x type]} {

		set state(type) [string trim $type]

	    }

	    if {[regexp -nocase {^content-length:(.+)$} $line x length]} {

		set state(totalsize) [string trim $length]

	    }

	    if {[regexp -nocase {^([^:]+):(.+)$} $line x key value]} {

		lappend state(meta) $key $value

	    } elseif {[regexp ^HTTP $line]} {

		set state(http) $line

	    }

	}

    } else {

	if {[catch {

	    if {[info exists state(-handler)]} {

		set n [eval $state(-handler) {$s $token}]

	    } else {

		set block [read $s $state(-blocksize)]

		set n [string length $block]

		if {$n >= 0} {

		    append state(body) $block

		}

	    }

	    if {$n >= 0} {

		incr state(currentsize) $n

	    }

	} err]} {

	    httpFinish $token $err

	} else {

	    if {[info exists state(-progress)]} {

		eval $state(-progress) {$token $state(totalsize) $state(currentsize)}

	    }

	}

    }

}

 proc httpCopyStart {s token} {

    upvar #0 $token state

    if {[catch {

	fcopy $s $state(-channel) -size $state(-blocksize) -command \

	    [list httpCopyDone $token]

    } err]} {

	httpFinish $token $err

    }

}

 proc httpCopyDone {token count {error {}}} {

    upvar #0 $token state

    set s $state(sock)

    incr state(currentsize) $count

    if {[info exists state(-progress)]} {

	eval $state(-progress) {$token $state(totalsize) $state(currentsize)}

    }

    if {([string length $error] != 0)} {

	httpFinish $token $error

    } elseif {[eof $s]} {

	httpEof $token

    } else {

	httpCopyStart $s $token

    }

}

 proc httpEof {token} {

    upvar #0 $token state

    if {$state(state) == "header"} {

	# Premature eof

	set state(status) eof

    } else {

	set state(status) ok

    }

    set state(state) eof

    httpFinish $token

}

proc http_wait {token} {

    upvar #0 $token state

    if {![info exists state(status)] || [string length $state(status)] == 0} {

	vwait $token\(status)

    }

    if {[info exists state(error)]} {

	set errorlist $state(error)

	unset state(error)

	eval error $errorlist

    }

    return $state(status)

}

# 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.

proc http_formatQuery {args} {

    set result ""

    set sep ""

    foreach i $args {

	append result  $sep [httpMapReply $i]

	if {$sep != "="} {

	    set sep =

	} else {

	    set sep &

	}

    }

    return $result

}

# do x-www-urlencoded character mapping

# The spec says: "non-alphanumeric characters are replaced by '%HH'"

# 1 leave alphanumerics characters alone

# 2 Convert every other character to an array lookup

# 3 Escape constructs that are "special" to the tcl parser

# 4 "subst" the result, doing all the array substitutions

 proc httpMapReply {string} {

    global httpFormMap

    set alphanumeric	a-zA-Z0-9

    if {![info exists httpFormMap]} {

	for {set i 1} {$i <= 256} {incr i} {

	    set c [format %c $i]

	    if {![string match \[$alphanumeric\] $c]} {

		set httpFormMap($c) %[format %.2x $i]

	    }

	}

	# These are handled specially

	array set httpFormMap {

	    " " +   \n %0d%0a

	}

    }

    regsub -all \[^$alphanumeric\] $string {$httpFormMap(&)} string

    regsub -all \n $string {\\n} string

    regsub -all \t $string {\\t} string

    regsub -all {[][{})\\]\)} $string {\\&} string

    return [subst $string]

}

# Default proxy filter. 

 proc httpProxyRequired {host} {

    global http

    if {[info exists http(-proxyhost)] && [string length $http(-proxyhost)]} {

	if {![info exists http(-proxyport)] || ![string length $http(-proxyport)]} {

	    set http(-proxyport) 8080

	}

	return [list $http(-proxyhost) $http(-proxyport)]

    } else {

	return {}

    }

}