#!/usr/bin/awk -f
################################################################################
# awkiawki - wikiwiki clone written in (n|g|m)awk
# $Id: awki.cgi,v 1.45 2004/07/13 16:34:45 olt Exp $
################################################################################
# Copyright (c) 2002 Oliver Tonnhofer (olt@bogosoft.com)
# See the file `COPYING' for copyright notice.
################################################################################

BEGIN {
	#            --- default options ---
	#    --- use awki.conf to override default settings ---
	#
	#	img_tag: HTML img tag  for picture in page header.
	localconf["img_tag"] = "<img src=\"/awki.png\" width=\"48\" height=\"39\" align=\"left\">"
	#	datadir: Directory for raw pagedata (must be writeable for the script).
	localconf["datadir"] = "./data/"
	#	parser: Parsing script.
	localconf["parser"] = "./parser.awk"
	#   special_parser: Parser for special_* functions.
	localconf["special_parser"] = "./special_parser.awk"
	#	default_page: Name of the default_page.
	localconf["default_page"] = "FrontPage"
	#	show_changes: Number of changes listed by RecentChanges
	localconf["show_changes"] = 10
	#	max_post: Bytes accept by POST requests (to avoid DOS).
	localconf["max_post"] = 100000
	#	write_protection: Regex for write protected files
	#   	e.g.: "*", "PageOne|PageTwo|^.*NonEditable" 
	#		HINT: to edit these protected pages, upload a .htaccess 
	#		      protected awki.cgi script with write_protection = ""
	localconf["write_protection"] = ""
	#   css: HTTP URL for external CSS file.
	localconf["css"] = ""
	#   always_convert_spaces: If true, convert runs of 8 spaces to tab automatical.
	localconf["always_convert_spaces"] = 0
	#	date_cmd: Command for current date.
	localconf["date_cmd"] = "date '+%e %b. %G %R:%S %Z'"
	#	rcs: If true, rcs is used for revisioning.
	localconf["rcs"] = 0
	#	path: add path to PATH environment
	localconf["path"] = ""
	#            --- default options ---

	scriptname = ENVIRON["SCRIPT_NAME"]
	
	if (localconf["path"])
		ENVIRON["PATH"] = localconf["path"] ":" ENVIRON["PATH"]

	#load external configfile
	load_config(scriptname)
	
	# PATH_INFO contains page name
	if (ENVIRON["PATH_INFO"]) {	
		query["page"] = ENVIRON["PATH_INFO"]
	}
	
	if (ENVIRON["REQUEST_METHOD"] == "POST") {
        if (ENVIRON["CONTENT_TYPE"] == "application/x-www-form-urlencoded") {
			if (ENVIRON["CONTENT_LENGTH"] < localconf["max_post"])
				bytes = ENVIRON["CONTENT_LENGTH"]
			else
				bytes = localconf["max_post"]
            cmd = "dd ibs=1 count=" bytes " 2>/dev/null"
            cmd | getline query_str
            close (cmd)
		}
		if (ENVIRON["QUERY_STRING"]) 
			query_str = query_str "&" ENVIRON["QUERY_STRING"]
	} else {
		if (ENVIRON["QUERY_STRING"])	
			query_str = ENVIRON["QUERY_STRING"]
	}
	
	n = split(query_str, querys, "&")
	for (i=1; i<=n; i++) {
		split(querys[i], data, "=")
		query[data[1]] = data[2]
	}

	# (IMPORTANT for security!)
	query["page"] = clear_pagename(query["page"])
	query["revision"] = clear_revision(query["revision"])
	query["revision2"] = clear_revision(query["revision2"])
	query["string"] = clear_str(decode(query["string"]))
	
	if (!localconf["rcs"])
		query["revision"] = 0

	if (query["page"] == "")
		query["page"] = localconf["default_page"]
	
	query["filename"] = localconf["datadir"] query["page"]
	
	#check if page is editable
	special_pages = "FullSearch|PageList|RecentChanges"
	
	if (query["page"] ~ "("special_pages")") {
		special_page = 1
	} else if (!localconf["write_protection"] || query["page"] !~ "("localconf["write_protection"]")") {
		page_editable = 1
	}


	header(query["page"])
	
	if (query["edit"] && page_editable)
		edit(query["page"], query["filename"], query["revision"])
	else if (query["save"] && query["text"] && page_editable)
		save(query["page"], query["text"], query["string"], query["filename"])
	else if (query["page"] ~ "PageList")
		special_index(localconf["datadir"])
	else if (query["page"] ~ "RecentChanges")
		special_changes(localconf["datadir"])
	else if (query["page"] ~ "FullSearch")
		special_search(query["string"],localconf["datadir"])
	else if (query["page"] && query["history"])
		special_history(query["page"], query["filename"])
	else if (query["page"] && query["diff"] && query["revision"])
		special_diff(query["page"], query["filename"], query["revision"], query["revision2"])
	else 
		parse(query["page"], query["filename"], query["revision"])

	footer(query["page"])
	
}

# print header
function header(page) {
	print "Content-type: text/html\n"
	print "<html>\n<head>\n<title>" page "</title>"
	if (localconf["css"])
		print "<link rel=\"stylesheet\" href=\"" localconf["css"] "\">"
	if (query["save"])
		print "<meta http-equiv=\"refresh\" content=\"2,URL="scriptname"/"page"\">"
	print "</head>\n<body>"
	print "<h1>"localconf["img_tag"]
	print "<a href=\""scriptname"/FullSearch?string="page"\">"page"</a></h1><hr>"
}

# print footer
function footer(page) {
	print "<hr>"
	if (page_editable)
		print "<a href=\""scriptname"?edit=true&amp;page="page"\">Edit "page"</a>"
	print "<a href=\""scriptname"/"localconf["default_page"]"\">"localconf["default_page"]"</a>"
	print "<a href=\""scriptname"/PageList\">PageList</a>"
	print "<a href=\""scriptname"/RecentChanges\">RecentChanges</a>"
	if (localconf["rcs"] && !special_page)
		print "<a href=\""scriptname"/"page"?history=true\">PageHistory</a>"
	print "<form action=\""scriptname"/FullSearch\" method=\"GET\" align=\"right\">"
	print "<input type=\"text\" name=\"string\">"
	print "<input type=\"submit\" value=\"search\">"
	print "</form>\n</body>\n</html>"
}

# send page to parser script
function parse(name, filename, revision) {
	if (system("[ -f "filename" ]") == 0 ) {
		if (revision) {
			print "<em>Displaying old version ("revision") of <a href=\""scriptname"/" name "\">"name"</a>.</em>"
			system("co -q -p'"revision"' " filename " | "localconf["parser"] " -v datadir='"localconf["datadir"] "'")
		} else
			system(localconf["parser"] " -v datadir='"localconf["datadir"] "' " filename)
	}
}

function special_diff(page, filename, revision, revision2,   revisions) {
	if (system("[ -f "filename" ]") == 0) {
		print "<em>Displaying diff between "revision
		if (revision2)
			print " and "revision2
		else
			print " and current version"
		print " of <a href=\""scriptname"/"page "\">"page"</a>.</em>"
		if (revision2)
			revisions = "-r" revision " -r" revision2
		else
			revisions = "-r" revision
		system("rcsdiff "revisions" -u "filename" | " localconf["special_parser"] " -v special_diff='"page"'")
	}
}	

# print edit form
function edit(page, filename, revision,   cmd) {
	if (revision)
		print "<p><small><em>If you save previous versions, you'll overwrite the current page.</em></small>"
	print "<form action=\""scriptname"?save=true&amp;page="page"\" method=\"POST\">"
	print "<textarea name=\"text\" rows=25 cols=80>"
	# insert current page into textarea
	if (revision) {
		cmd = "co -q -p'"revision"' " filename
		while ((cmd | getline) >0)
			print
		close(cmd)
	} else {
		while ((getline < filename) >0)
			print
		close(filename)
	}
	print "</textarea><br />"
	print "<input type=\"submit\" value=\"save\">"
	if (localconf["rcs"])
		print "Comment: <input type=\"text\" name=\"string\" maxlength=80 size=50>"
	if (! localconf["always_convert_spaces"])
		print "<br>Convert runs of 8 spaces to Tab <input type=\"checkbox\" name=\"convertspaces\">"
	print "</form>"
	print "<small><strong>Emphases:</strong> ''<em>italic</em>''; '''<strong>bold</strong>'''; \
'''''<strong><em>bold italic</em></strong>'''''; ''<em>mixed '''<strong>bold</strong>'''\
and italic</em>''<br>\
<strong>Horizontal Rule:</strong> ----<br><strong>Paragraph:</strong> blank line<br>\
<strong>Headings:</strong> -Title 1 ; --Title 2 ; ---Title 3<br>\
<strong>Preformatted Text:</strong> *space*Text<br>\
<strong>Lists:</strong> tab(s) and one of * bullets; 1 numbered items<br>\
<strong>Links:</strong> JoinCapitalizedWords; url (http, https, ftp, gopher, mailto, news)</small>"
}

# save page
function save(page, text, comment, filename,   dtext, date) {
	dtext = decode(text);
	if ( localconf["always_convert_spaces"] || query["convertspaces"] == "on")
		gsub(/        /, "\t", dtext);
	print dtext > filename
	if (localconf["rcs"]) {
		localconf["date_cmd"] | getline date
		system("ci -q -t-"page" -l -m'"ENVIRON["REMOTE_ADDR"] ";;" date ";;"comment"' " filename)
	}
	print "saved <a href=\""scriptname"/"page"\">"page"</a>"
}

# list all pages
function special_index(datadir) {
	system("ls -1 " datadir " | " localconf["special_parser"] " -v special_index=yes")
	
}

# list pages with last modified time (sorted by date)
function special_changes(datadir,   date) {
	localconf["date_cmd"] | getline date
	print "<p>current date:", date "<p>"
	system("ls -tlL "datadir" | " localconf["special_parser"] " -v special_changes=" localconf["show_changes"])
}

function special_search(name,datadir) {
	system("grep -il '"name"' "datadir"* | " localconf["special_parser"] " -v special_search=yes")
}

function special_history(name, filename) {
	print "<p>last changes on <a href=\""scriptname"/" name "\">"name"</a><p>"
	system("rlog " filename " | " localconf["special_parser"] " -v special_history="name)

	print "<p>Show diff between:"
	print "<form action=\""scriptname"/\" method=\"GET\">"
	print "<input type=\"hidden\" name=\"page\" value=\""name"\">"
	print "<input type=\"hidden\" name=\"diff\" value=\"true\">"
	print "<input type=\"text\" name=\"revision\" size=5>"
	print "<input type=\"text\" name=\"revision2\" size=5>"
	print "<input type=\"submit\" value=\"diff\">"
	print "</form></p>"
}

# remove '"` characters from string
# *** !Important for Security! ***
function clear_str(str) {
	gsub(/['`"]/, "", str)
	if (length(str) > 80) 
		return substr(str, 1, 80)
	else
		return str
}

# retrun the pagename
# *** !Important for Security! ***
function clear_pagename(str) {
	if (match(str, /[A-Z][a-z]+[A-Z][A-Za-z]*/))
		return substr(str, RSTART, RLENGTH)
	else
		return ""
}

# return revision numbers
# *** !Important for Security! ***
function clear_revision(str) {
	if (match(str, /[1-9]\.[0-9]+/))
		return substr(str, RSTART, RLENGTH)
	else
		return ""
}

# decode urlencoded string
function decode(text,   hex, i, hextab, decoded, len, c, c1, c2, code) {
	
	split("0 1 2 3 4 5 6 7 8 9 a b c d e f", hex, " ")
	for (i=0; i<16; i++) hextab[hex[i+1]] = i

	# urldecode function from Heiner Steven
	# http://www.shelldorado.com/scripts/cmds/urldecode

	# decode %xx to ASCII char 
	decoded = ""
	i = 1
	len = length(text)
	
	while ( i <= len ) {
	    c = substr (text, i, 1)
		if ( c == "%" ) {
			if ( i+2 <= len ) {
				c1 = tolower(substr(text, i+1, 1))
				c2 = tolower(substr(text, i+2, 1))
				if ( hextab [c1] != "" || hextab [c2] != "" ) {
					if ( (c1 >= 2 && c1 != 7) || (c1 == 7 && c2 != "f") || (c1 == 0 && c2 ~ "[9acd]") ){
						code = 0 + hextab [c1] * 16 + hextab [c2] + 0
						c = sprintf ("%c", code)
					} else {
						c = " "
					}
					i = i + 2
			   }
			}
	    } else if ( c == "+" ) {	# special handling: "+" means " "
	    	c = " "
	    }
	    decoded = decoded c
	    ++i
	}
	
	# change linebreaks to \n
	gsub(/\r\n/, "\n", decoded)
	
	# remove last linebreak
	sub(/[\n\r]*$/,"",decoded)
	
	return decoded
}

#load configfile
function load_config(script,   configfile,key,value) {
	configfile = script
	#remove trailing / ('/awki/awki.cgi/' -> '/awki/awki.cgi')
	sub(/\/$/, "", configfile)
	#remove path ('/awki/awki.cgi' -> 'awki.cgi')
	sub(/^.*\//, "", configfile)
	#remove suffix ('awki.cgi' -> 'awki')
	sub(/\.[^.]*$/,"", configfile)
	# append .conf suffix
	configfile = configfile ".conf"
	
	#read configfile
	while((getline < configfile) >0) {
		if ($0 ~ /^#/) continue #ignore comments
		
		if (match($0,/[ \t]*=[ \t]*/)) {
			key = substr($0, 1, RSTART-1)
			sub(/^[ \t]*/, "", key)
			value = substr($0, RSTART+RLENGTH)
			sub(/[ \t]*$/, "", value)
			if (sub(/^"/, "", value))
				sub(/"$/, "", value) 
			#set localconf variables
			localconf[key] = value
		
		}
	}
}