# uri.tcl
#
# A little support for Uniform Resource Identifiers.
#
# martin hamilton <martin@mrrl.lut.ac.uk>
# &
# John Robert LoVerso <loverso@osf.org>
# Toivo Pedaste <toivo@ucs.uwa.edu.au>
# Fred Douglis <douglis@research.att.com>

proc URI_Init {} {
    global env uri

    if [info exists uri(init)] {
	return
    }

    set uri(init) 1

    Preferences_Add "WWW" \
      "These options control how exmh deals with Uniform Resource
Identifiers, e.g. World-Wide Web URLs.  You can arrange for URLs
embedded in messages to be turned into hyperlinks, and there is an
option to decipher the experimental X-URL (or X-URI) header.  This may be used
by the sender of a message to include contact information, such as
the address of their World-Wide Web homepage.  You can add this
header to your messages by editing compcomps, replcomps and so on." {
	{uri(scanForXURIs) uriScanForXURIs	ON {Scan for X-URL: headers}
"This tells exmh whether to look for X-URL (or X_URI) headers in messages when
you read them."}
	{uri(scanForURIs) uriScanForURIs	OFF {Scan for URLs in messages}
"This tells exmh whether to look for URL in the bodies of messages.
If you turn it on, any URLs it finds will be turned into buttons
which you can click on to launch a viewer application.  NB - this can
slow down message displaying somewhat."}
	{uri(scanLimit) uriScanLimit	1000 {Max lines to scan for URL}
"This limits the number of lines scanned for embedded URLs,
which can run slowly on large messages.  Set to a number of lines,
or to the keyword \"end\" to scan the whole message."}
	{uri(scanSoftLimit) uriScanSoftLimit	1000 {Stop button max lines}
"If the number of lines to scan is more than this soft limit, then
a stop button is displayed so you can terminate URL scanning before
it completes.."}
	{uri(viewer)	uriViewer {CHOICE netscape Mosaic exmh webtk surfit tclcmd} {URL Viewer}
"The Mosaic and netscape options attempt to connect to a running
instance of these programs.  webtk and surfit are Tcl/Tk web browsers.
The exmh option uses the built-in HTML viewer.
The tclcmd option lets you define your
own Tcl command to display the URL.  Use the variable $xuri
for the URL to display."}
	{uri(viewHtml)	mimeShowHtml {CHOICE inline defer external} {How to display text/html}
"There are three ways to display text/html message parts:
inline - display text/html directly in the message window.
defer - use buttons to display in an external viewer.
external - display text/html immediatly, using an external viewer."}
	{uri(deferDisplaysInline) deferDisplaysInline OFF {Defer displays inline}
"If enabled, defer also shows text/html inline."}
	{uri(mosaicApp) uriMosaicApp	{Mosaic} {Mosaic program name}
"This is the name of the binary program that corresponds to the
Mosaic viewer option.  For example, some sites use \"xmosaic\"."}
	{uri(netscapeCmd) uriNetscapeCmd	{} {Netscape command}
"This is the netscape command used to contact netscape and/or start it up.
The -remote openURL($xuri) is removed in order to start up netscape.
Various examples might be:
netscape -display :0.1 -remote openURL($xuri,new-window)
/somewhere/weird/netscape -install -remote openURL($xuri,noraise)"}
	{uri(tclCmd) uriTclCmd	{NetRemote $xuri} {Tcl Command to view URL}
"This is the Tcl command used if you select the \"tclcmd\" browser option.
The variable \$xuri gets replaced with the URL.  If you want to run
an external program, use the \"exec\" Tcl command."}
	{uri(logOnEnter) uriLogOnEnter	ON	{Show selected URL}
"With 'Show selected URL' enabled exmh will display
the coresponding URL if you move with the mouse on an
activated (looks like a button) X-Face or URL in the
message text.
NOTE: When you change the option you have to rescan your
      current message or read another one to de/active
      the option."}
    }
    # Convert viewHtml from boolean to choice
    switch $uri(viewHtml) {
	1 -
	0 {
	    set uri(viewHtml) inline
	}
    }
    # Nuke old "other" viewer option.
    if {[string compare $uri(viewer) "other"] == 0} {
	set viewerApp [option get . uriViewerApp {}]
	if {[string length $viewerApp]} {
	    set uri(viewer) tclcmd
	    set uri(tclCmd) "exec $viewerApp"
	} else {
	    set uri(viewer) netscape
	}
    }

    if [catch {package require netscape_remote}] {
	Exmh_Debug "No netscape_remote package"
    } else {
	Exmh_Debug "Using netscape_remote package"
    }

    # Fix up netscape command from the old flags argument
    set flags [option get . uriNetscapeFlags {}]
    set cmd $uri(netscapeCmd)
    if {[string length $cmd] && [string match *$flags* $cmd]} {
	# flags already in the command
    } else {
	if {![regexp {^([^ 	]+)[ 	]?(.*)$} $cmd x program args]} {
	    set program netscape
	    set args {-remote openURL($xuri)}
	}
	set uri(netscapeCmd) "$program $flags $args"
    }
}
proc Uri_ShowPart { tkw part } {
    global uri mimeHdr
    switch -- $uri(viewHtml) {
	defer {
	    set start [$tkw index insert]
	    $tkw insert insert "View HTML contents with "
	    if {$uri(viewer) == "other"} {
		$tkw insert insert $uri(viewerApp)
	    } else {
		$tkw insert insert $uri(viewer)
	    }
	    set end [$tkw index insert]
	    $tkw insert insert "\n"

	    TextButtonRange $tkw $start $end [list Uri_ShowPartDirect $tkw $part]

	    MimeMenuAdd $part checkbutton \
		    -label "Display HTML inline" \
		    -command [list busy MimeRedisplayPart $tkw $part] \
		    -variable mimeHdr($part,display)

	    if {$mimeHdr($part,display)} {
		uplevel {
		    if [info exists mimeHdr($part,hdr,content-base)] {
			set var(S_url) $mimeHdr($part,hdr,content-base)
		    } else {
			set var(S_url) file:$mimeHdr($part,file)
		    }
		    if [catch {open $mimeHdr($part,file)} in] {
			$tkw insert insert "Cannot open temp file: $in\n"
		    } else {
			set html [read $in]
			close $in
			if [regexp -nocase <frameset $html] {
			    $tkw insert insert "Frames will not display inline\n"
			} else {
			    $tkw config -wrap word
			    Html_DisplayInline $tkw $var(S_url) $html
			}
		    }
		}
	    } else {
		$tkw insert insert ". . .\t"
		MimeInsertNote $tkw [MimeLabel $part part] \
			"Invoke menu with right button."
	    }
	}
	external {
	    Uri_ShowPartDirect $tkw $part
	}
	inline -
	default {
	    Html_MimeShow $tkw $part
	}
    }
}
proc Uri_ShowPartDirect { tkw part } {
    global mimeHdr mime
    set fileName $mimeHdr($part,file)
    File_Delete [Env_Tmp]/exmh.[pid].html
    if [catch {exec ln $fileName [Env_Tmp]/exmh.[pid].html}] {
	exec cp $fileName [Env_Tmp]/exmh.[pid].html
    }
    set fileName [Env_Tmp]/exmh.[pid].html
    Exmh_Status "HTML Load $fileName"
    $tkw insert insert "Viewing HTML ...\n"
    URI_StartViewer file://localhost$fileName
}

proc URI_StartViewer {xuri} {
    global uri auto_index

    regsub -nocase "URL:" $xuri {} xuri
    string trimright $xuri "."

    if [regexp {^mailto:(.*)$} $xuri x address] {
	Msg_Mailto $xuri
	return
    }
    regsub -all {[][$\\,~ ]} $xuri {[scan \\& %c x ; format "%%%02x" $x]} xuri
    set xuri [subst $xuri]
    Exmh_Status "$uri(viewer) $xuri"
    if [catch {
	switch -- $uri(viewer) {
	    Mosaic	{ Mosaic_Load $xuri}
	    netscape {
		set rmtcmd $uri(netscapeCmd)
		set sendargs {openURL($xuri)}
		regexp {openURL\(.*\)} $rmtcmd sendargs
		set sendargs [subst $sendargs]
		regsub -- {-remote openURL\(.*\)} $rmtcmd {} startcmd

		Exmh_Debug rmtcmd $rmtcmd \n sendargs $sendargs \n startcmd $startcmd

		if {([info commands info-netscape] == "info-netscape") ||
		    [info exists auto_index(info-netscape)]} {
		    # Use send-netscape extension
		    if [llength [info-netscape list]] {
			send-netscape $sendargs
		    } else {
		        eval exec $startcmd { $xuri & }
		        Exmh_Status "Starting netscape"
		    }
		} elseif {[ catch {eval exec $rmtcmd >& /dev/null} tmp ]} {
		    if [catch {
		        eval exec $startcmd { $xuri & }
		        Exmh_Status "Starting netscape"
                    } err] {
			Exmh_Status "netscape: $err"
		    }
		}
	    }
	    surfit -
	    webedit -
	    webtk {
		set interps [winfo interps]
		if {$uri(viewer) == "surfit" } {
			set dispFunc "surfit_create_window"
		} else {
			set dispFunc "Url_DisplayNew"
		}
		set ix [lsearch -glob $interps $uri(viewer)*]
		if {$ix >= 0} {
		    set interp [lindex $interps $ix]
		} else {
		    Exmh_Status "$uri(viewer) is not running"
		    return
		}
		if [catch {send -async $interp [list $dispFunc $xuri]} err] { 
		    Exmh_Status $err
		} else {
		    Exmh_Status "Viewing URL with $uri(viewer)"
		}
	    }
	    exmh {
		Html_Window $xuri
	    }
	    tclcmd {
		Exmh_Debug [subst $uri(tclCmd)]
		eval $uri(tclCmd)
	    }
	}
    } err] {
	Exmh_Status $err
    }
}

proc URI_OpenSelection {} {
    if [catch {selection get} xuri] {
        return
    }
    URI_StartViewer $xuri
}

proc Hook_MsgShowParseUri {msgPath hmm} {
    global uri exwin mimeHdr

    foreach hdr {x-uri x-url} {
	if {[info exists mimeHdr(0=1,hdr,$hdr)] && $uri(scanForXURIs)} {
	    set temp_uri [MsgParseFrom $mimeHdr(0=1,hdr,$hdr) noaddr]
	}
    }
    if [info exists temp_uri] {
        regsub -all "\[ \t\n\]" $temp_uri {} temp_uri
	set but [Faces_Button [list URI_StartViewer $temp_uri]]
	global exmh
	$but config -bitmap @$exmh(library)/url.bitmap
        if $uri(logOnEnter) {
	    regsub -all % $temp_uri %% temp_uri
	    bind $but <Enter> [list Exmh_Status "X-URL:\t$temp_uri"]
	    bind $but <Leave> [list Exmh_Status "\t$temp_uri"]
	}
    } else {
	Uri_ClearCurrent
    }

    if !$uri(scanForURIs) {
        return
    }
    URI_ScanMsg $exwin(mtext) $uri(scanLimit)
}
proc Uri_ClearCurrent {} {
    Faces_ClearButton
}

proc Hook_MsgClipParseUri {msgPath t} {
    global uri exwin

    if !$uri(scanForURIs) {
        return
    }
    URI_ScanMsg $t $uri(scanLimit)
}

proc URI_ActiveText { w start end URI} {
    global uri
    # Spaces are optional around the edges of the URI in the <a href> context
    set URI [string trim $URI]
    # quote percents in URLs because they appear in binding commands
    regsub -all % $URI %% URI
    set id [TextButtonRange $w $start $end [list URI_StartViewer $URI]]
    if $uri(logOnEnter) {
	$w tag bind $id <Any-Enter> [list +Exmh_Status "X-URL:\t$URI"]
	$w tag bind $id <Any-Leave> [list +Exmh_Status "\t$URI"]
    }
    update idletasks
    return $id
}

proc URI_ScanMsg { {w {}} {limit end} } {
    global uri exwin
    if {$w == {}} {
	set w $exwin(mtext)
    }
    set x [lindex [$w config -cursor] 4]
    $w config -cursor watch

    set grab 0
    set uri(stop) 0
    scan [$w index end] %d lnum
    set limit [string trim $limit]
    if {$limit != "end"} {
	if {$limit > $lnum} {
	    set limit $lnum.0
	} else {
	    set limit $limit.0
	}
    }
    if {$lnum > $uri(scanSoftLimit) && ($uri(scanSoftLimit) < $limit)} {
	set g $w.ustop
	if [winfo exists $g] {
	     destroy $g
	}
	frame $g -bd 4 -relief raised
	set f [frame $g.pad -bd 20]
	set msg [Widget_Message $f msg -text "$lnum Lines to scan" -aspect 1000]
	Widget_AddBut $f stop STOP {set uri(stop) 1}  {top padx 2 pady 2 filly}
	bind $f.stop <Any-Key> {set uri(stop) 1 ; Exmh_Status Stop warn}
	bind $g <Destroy> {set uri(stop) 1 ; Exmh_Status Stop warn}
	pack $f
	Widget_PlaceDialog $w $g
	Visibility_Wait $f.stop
	catch {
	    focus $f.stop
	    grab $f.stop
	}
	set grab 1
    }
    Exmh_Debug "URI_ScanMsg $limit"
    set multiline 0
    set hit 0
    set protocol (ftp|http|https|gopher|nntp|telnet|wais|file|prospero|finger|urn|mailto|news|solo|x500)
    # the following pattern runs extremely slowly if there are long,
    # unbroken character sequences in a message.
#    set protocol {[A-Za-z_]+[-A-Za-z0-9_]*}

    for {set i 0} {[$w compare $i.0 < $limit]} {if {! $hit} {incr i}} {
	if {! $hit} {
	    set begin 0
	    set text [$w get $i.0 "$i.0 lineend"]
	} else {
	    # Look for more on the same line
	    set text [string range $text $begin end]
	}
	set hit 0

	if {$grab && $i && (($i % 20) == 0)} {
	    $msg config -text "Scanned $i of $lnum"
	    update
	}
	if {$uri(stop)} {
	    break
	}
	######
	# In this loop $i is the current line,
	# $text is the remaining part of the line
	# $begin is the offset of $text within the line
	#

        #######
        # match URIs continued from the previous line (begin is zero)
        if $multiline {
            set right [string first ">" $text]
            if {$right != -1} {
		Exmh_Debug Regexp0 right=$right begin=$begin
                set last $i.$right
                regsub -all "\n" [$w get $mstart $last] {} temp_uri

		URI_ActiveText $w $mstart $last $temp_uri
 
                set begin $right
		set text [string range $text $right end]
	        set multiline 0
		set hit 1
            }
	    # note: we will continue to look until a close is found
	    continue
        }

	# Each regexp clause must set:
	# hit to 1 if it matched
	# start to the index within the text line to begin highlight
	# end to end index within the text line to end highlight
	# temp_uri to the value of the URL.

	if {[regexp -indices "<$protocol:\[^>)\]+>" $text indices] == 1} {

	    # check for URIs like <protocol: > present
	    Exmh_Debug Regexp1 $indices
	    set start [expr [lindex $indices 0] + 1]
	    set end [expr [lindex $indices 1] -1]
	    set hit 1

	} elseif {[regexp -indices -nocase {<a href=([^>]+)>([^<]*)(</a>)?} \
		$text indices i1 i2] == 1} {

	    # match real HTML links
	    Exmh_Debug Regexp2 $indices $i1 $i2
	    set temp_uri [string trim [string range $text [lindex $i1 0] [lindex $i1 1]] {"}]
	    set text [string range $text [lindex $indices 1] end]

	    $w configure -state normal

	    $w delete $i.[expr $begin + [lindex $i2 1] + 1] \
		    $i.[expr $begin + [lindex $indices 1] + 1]
	    $w delete $i.[expr $begin + [lindex $indices 0]] \
		    $i.[expr $begin + [lindex $i2 0]]

	    $w configure -state disabled

	    set start [expr $begin + [lindex $indices 0]]
	    set end [expr $begin + [lindex $indices 0] + [lindex $i2 1] - [lindex $i2 0] + 1]
	    URI_ActiveText $w $i.$start $i.$end $temp_uri

            set begin $end
	    set hit 1

	    # Continue because we have set up begin and text properly
	    continue

        } elseif {[regexp -indices -nocase "<(urn|url|uri)\[: \]\[^>\]+>" $text indices] == 1} {
	    # match URIs wholly contained on one line
	    Exmh_Debug Regexp3 $indices
            set start [expr [lindex $indices 0] + 1]
            set end [expr [lindex $indices 1] - 1]
	    set hit 1

        } elseif {[regexp -indices "$protocol:/+\[^ \n\t\]+\[^ \n\t,\.\)>\'\"\]" \
		$text indices] == 1} {
	    # check for unencapsulated URIs by protocol if no < > present
	    Exmh_Debug Regexp4 $indices
            set start [lindex $indices 0]
            set end [lindex $indices 1]
	    set hit 1

	} elseif {[regexp -indices -nocase \
     "(urn|mailto|news|solo|x500):\[^ \n\t\)\]*\[^ \n\r\)\.\]" \
               $text indices] == 1} {
	    Exmh_Debug Regexp5 $indices
            set start [lindex $indices 0]
            set end [lindex $indices 1]
	    set hit 1

        } elseif {[regexp -indices -nocase "<(urn|url|uri)\[: \]" $text indices] == 1} {
	    # match the start of a URI which is broken over more than one line
	    # must include <URN or <URL
	    Exmh_Debug Regexp6 $indices
            set mstart $i.[expr [lindex $indices 0] + $begin + 1]
            set multiline 1
        }
        if {$hit} {
	    # Found a URL - handle the offset between $text and the text widget line
            set temp_uri [string range $text $start $end]
	    URI_ActiveText $w $i.[expr $begin+$start] $i.[expr $begin+$end] $temp_uri
	    set begin [expr $begin + $end]
	    set text [string range $text $end end]
	}
     }
    if {$grab} {
	catch {grab release $g.stop}
	Exmh_Focus
	destroy $g
    }

     $w config -cursor $x
 }

proc Mime_ShowUri {tkw part} {
    global mimeHdr mime miscRE

    MimeWithDisplayHiding $tkw $part {
	set subtype [file tail $mimeHdr($part,type)]
	Mime_WithTextFile fileIO $tkw $part {
	    set url [read $fileIO]
	    set start [$tkw index insert]
	    $tkw insert insert $url
	    set end [$tkw index insert]
	    $tkw insert insert \n
	    URI_ActiveText $tkw $start $end $url
	}
    }
    return 1
}
