#!/bin/sh
#
# Convert ical output to an old-style calendar(1) file.
#	ical2calendar [-calendar <file>] [<no. of days>] > calendar
#
# This script is based on a /bin/sh and awk combination sent to me
# by Nancy Mintz (nlm@usl.com).  I rewrote it to use ical's tcl
# interface because it is simpler this way.
#
# The "kludge" hackery below is based on a posting to comp.lang.tcl by
# Paul Mackerras (paulus@anu.edu.au).
#
# -Sanjay Ghemawat

set kludge { ${1+"$@"}
shift
shift
exec ical -f $0 -nodisplay ${1+"$@"}
}

# Tcl code starts here.

# Parse arguments
proc usage {} {
    puts stderr {Usage: ical2calendar [-calendar <file>] [<no. of days>]}
    exit 1
}
set days 365
if {[llength $argv] > 1} {usage}
if {[llength $argv] == 1} {set days [lindex $argv 0]}
if ![regexp {^[0-9]+$} $days] {usage}

# Set-up arrays for pretty-printing dates
set wday(1)	sun
set wday(2)	mon
set wday(3)	tue
set wday(4)	wed
set wday(5)	thu
set wday(6)	fri
set wday(7)	sat

set mon(1)	jan
set mon(2)	feb
set mon(3)	mar
set mon(4)	apr
set mon(5)	may
set mon(6)	jun
set mon(7)	jul
set mon(8)	aug
set mon(9)	sep
set mon(10)	oct
set mon(11)	nov
set mon(12)	dec

# Generate listing
calendar cal $ical(calendar)

cal listing [date today] [expr [date today]+$days-1] i d {
    set dt [format {%-3s  %2d %-5s }\
	    $mon([date month $d])\
	    [date monthday $d]\
	    $wday([date weekday $d])\
	   ]
    puts -nonewline stdout [item2text $i "$dt - " "$dt   " 50]
}
exit 0