aerc/filters/calendar

#!/usr/bin/awk -f
# ex: ft=awk
#
# awk filter for aerc to parse text/calendar mime-types
#
# Based on the ical2org.awk script by Eric S Fraga and updated by Guide Van
# Hoecke. Adapted to aerc by Koni Marti <koni.marti@gmail.com>
#

BEGIN {
	UIDS[0];

	people_attending[0];
	people_partstat[0];
	people_rsvp[0];

	# use a colon to separate the type of data line from the actual contents
	FS = ":";

	method = ""
	prodid = ""

	first = 0
}

/^[ ]/ {
	# assumes continuation lines start with a space
	if (indescription) {
		entry = entry gensub("\r", "", "g", gensub("^[ ]", "", 1, $0));
	} else if (insummary) {
		summary = summary gensub("\r", "", "g", gensub("^[ ]", "", 1, $0))
	} else if (inattendee) {
		attendee = attendee gensub("\r", "", "g", gensub("^[ ]", "", 1, $0))
	} else if (inorganizer) {
		organizer = organizer gensub("\r", "", "g", gensub("^[ ]", "", 1, $0))
	} else if (inlocation) {
		location = location unescape(gensub("\r", "", "g", $0), 0);
	}
}

/^BEGIN:VEVENT/ {
	# start of an event: initialize global values used for each event
	date = "";
	entry = ""
	id = ""

	indescription = 0;
	insummary = 0
	inattendee = 0
	inorganizer = 0
	inlocation = 0
	in_alarm = 0

	location = ""
	status = ""
	summary = ""
	attendee = ""
	organizer = ""

	rrend = ""
	rcount = ""
	intfreq = ""

	delete people_attending;
	delete people_partstat;
	delete people_rsvp;

	if (first == 0) {
		first = 1
		if (method != "")
			print     "  METHOD    " method
		if (prodid != "")
			print     "  PRODID    " prodid
		print ""
	}
}

/^BEGIN:VALARM/ {
	in_alarm = 1
}

/^END:VALARM/ {
	in_alarm = 0
}

/^[A-Z]/ {
	if (attendee != "" && inattendee==1)
		add_attendee(attendee)

	if (organizer != "" && inorganizer==1)
		organizer = find_full_name(organizer)

	indescription = 0;
	insummary = 0;
	inattendee = 0;
	inorganizer = 0;
	inlocation = 0;
}

/^DTSTART;VALUE=DATE/ {
	date = datestring($2);
}

/^DTEND;VALUE=DATE/ {
	end_date = datestring($2);
}

/^DTSTART[:;][^V]/ {
	tz = "";
	match($0, /TZID=([^:]*)/, a)
	{
		tz = a[1];
	}
	date = datetimestring($2, tz);
}

/^DTEND[:;][^V]/ {
	tz = "";
	match($0, /TZID=([^:]*)/, a)
	{
		tz = a[1];
	}
	end_date = datetimestring($2, tz);
}

/^RRULE:FREQ=(DAILY|WEEKLY|MONTHLY|YEARLY)/ {
	# TODO: handle BYDAY values for events that repeat weekly for multiple days
	# (e.g. a "Gym" event)

	# get the d, w, m or y value
	freq = tolower(gensub(/.*FREQ=(.).*/, "\\1", 1, $0))
	# get the interval, and use 1 if none specified
	interval =  $0 ~ /INTERVAL=/ ? gensub(/.*INTERVAL=([0-9]+).*/, "\\1", 1, $0) : 1
	# get the enddate of the rule and use "" if none specified
	rrend = $0 ~ /UNTIL=/ ? datestring(gensub(/.*UNTIL=([0-9]{8}).*/, "\\1", 1, $0)) : ""
	rcount = $0 ~ /COUNT=/ ? gensub(/.*COUNT=([0-9]+).*/, "\\1", 1, $0) : ""
	# build the repetitor value
	intfreq =  " +" interval freq
}

/^DESCRIPTION/ {
	if (!in_alarm) {
		entry = entry gensub("\r", "", "g", gensub($1":", "", 1, $0));
		indescription = 1;
	}
}

/^SUMMARY/ {
	if (!in_alarm) {
		summary = gensub("\r", "", "g", gensub($1":", "", 1, $0));
		insummary = 1;
	}
}

/^UID/ {
	if (!in_alarm) {
		id = gensub("\r", "", "g", $2);
	}
}

/^METHOD/ {
	method = gensub("\r", "", "g", $2);
}

/^PRODID/ {
	prodid = gensub("\r", "", "g", $2);
}

/^ORGANIZER/ {
	organizer = gensub("\r", "", "g", $0);
	inorganizer = 1;
}

/^LOCATION/ {
	location = unescape(gensub("\r", "", "g", $2), 0);
	inlocation = 1;
}

/^STATUS/ {
	status = gensub("\r", "", "g", $2);
}

/^ATTENDEE/ {
	attendee = gensub("\r", "", "g", $0);
	inattendee = 1;
}

/^END:VEVENT/ {
	#output event
	is_duplicate = (id in UIDS);
	if(is_duplicate == 0) {
		print "* SUMMARY   " gensub("^[ ]+", "", "g", unescape(summary, 0))
		if(length(location))
			print "  LOCATION  " location
		if(organizer != "")
			print "  ORGANIZER " organizer
		for (cn in people_attending) {
			print "  ATTENDEE  " cn
			partstat = people_partstat[cn]
			if (partstat != "") {
				print "            STATUS " partstat
			}
			rsvp = people_rsvp[cn]
			if (rsvp != "") {
				print "            RSVP   " rsvp
			}
		}
		print "  START     " date
		print "  END       " end_date

		if (intfreq != "") {
			print ""
			print         "  RECURRENCE  " intfreq
			if (rcount != "")
				print "    COUNTS    " rcount
			if (rrend != "")
				print "    END DATE  " rrend

		}

		print ""
		if(length(entry)>1)
			print gensub("^[ ]+", "", "g", unescape(entry, 1));
		UIDS[id] = 1;
	}
}


function unescape(input, preserve_newlines)
{
	ret = gensub("\\\\,", ",", "g",
		     gensub("\\\\;", ";", "g", input))
	if (preserve_newlines)
		ret = gensub("\\\\n", "\n", "g", ret)
	else
		ret = gensub("\\\\n", " ", "g", ret)
	return ret
}


function datetimestring(input, tz)
{
	spec  = match(input, "([0-9]{4})([0-9]{2})([0-9]{2})T([0-9]{2})([0-9]{2})([0-9]{2}).*[\r]*", a);
	year = a[1]
	month = a[2]
	day = a[3]
	hour = a[4]
	min = a[5]
	sec = a[6]

	stamp = mktime(year" "month" "day" "hour" "min" "sec);

	if (input ~ /[0-9]{8}T[0-9]{6}Z/ ) {
		tz = "UTC"
	}

	return strftime("%Y-%m-%d %a %H:%M", stamp)" "tz;
}


function datestring(input)
{
	spec = gensub("([0-9]{4})([0-9]{2})([0-9]{2}).*[\r]*", "\\1 \\2 \\3 00 00 00", "g", input);

	stamp = mktime(spec);

	return strftime("%Y-%m-%d %a", stamp);
}

function add_attendee(attendee)
{
	CN = find_full_name(attendee)
	if (CN != "")
		people_attending[CN] = 1;

	if (CN != "") {
		match(attendee, /PARTSTAT=([^;]+)/, m)
		{
			people_partstat[CN] = m[1]
		}
		match(attendee, /RSVP=([^;]+)/, m)
		{
			people_rsvp[CN] = m[1]
		}
	}
}

function extract_email(line)
{
	email = ""
	match(line,/:[ ]*(mailto|MAILTO):([^;]+)/, m)
	{
		email = m[2]
	}
	return email
}

function extract_name(line)
{
	name = ""
	match(line,/CN="?([^;:"]+)/, m)
	{
		name = m[1]
	}
	return name
}

function find_full_name(line)
{
	name = extract_name(line)
	email = extract_email(line)

	if (name == "") {
		if (email == "") {
			return ""
		} else {
			return name
		}
	}

	if (email == "")
		return name

	if (email == name)
		return "<"email">"

	return name" <"email">"
}