#!/bin/rc -e
rfork E

# index -- add ids to headings and print index to stderr

flagfmt=s
args='[file ...]'

if(! ifs=() eval `{aux/getflags $*}){
	aux/usage
	exit usage
}

fn source{
	if(! ~ $#* 0)
		cat $*
	if not
		cat
}

source $* | awk '
	/<h[0-9]>.*<\/h[0-9]/ {
		heading($0)
		next
	}
	/<h[0-9]>/ {
		open = 1
		s = $0
		next
	}
	open && /<\/h[0-9]>/ {
		open = 0
		s = s "\n" $0
		heading(s)
		next
	}
	open { s = s " " $0; next }
	{ print }

	function heading(s) {
		i = s
		sub("^.*<h[0-9]>", "", i)
		sub("</h[0-9]>.*$", "", i)
		i = toascii(i)
		sub("^<h[0-9]", "& id=\"" i "\"", s)
		print s
		if (!ENVIRON["flags"]) { # if not silent mode
			sub("^<h", "", s)
			sub(" id=\"", "	", s)
			sub("\">", "	", s)
			sub("<\/h[0-9]>$", "", s)
			print s > "/dev/stderr"
		}
	}

	function toascii(s) {
		s = tolower(s)
		gsub("[ÀÁÂÃÄÅàáâãäå]", "a", s)
		gsub("[Ææ]", "ae", s)
		gsub("[Çç]", "c", s)
		gsub("[Ðð]", "dh", s)
		gsub("[ÈÉÊËèéêë]", "e", s)
		gsub("[ÌÍÎÏìíîï]", "i", s)
		gsub("[Ññ]", "n", s)
		gsub("[ÒÓÔÕÖØòóôõöø]", "o", s)
		gsub("[ß]", "ss", s)
		gsub("[Þþ]", "th", s)
		gsub("[ÙÚÛÜùúûü]", "u", s)
		gsub("[×]", "x", s)
		gsub("[Ýýÿ]", "y", s)
		gsub("[/]", "-", s)
		gsub("[ 	\n]+\\+[ 	\n]+", "+", s)
		gsub("[ 	\n]+=[ 	\n]+", "=", s)
		gsub("[ 	\n]+", "-", s)
		gsub("[^=-+a-z0-9_ 	]", "", s)
		gsub("-+", "-", s)
		return s
	}
'