#!/bin/sh -e

echo "== Lua User's Lottery =="
date --utc

OUTDIR=.
NOISE_URL=http://theregister.co.uk/
LOTTERY_URL=http://lua-users.sourceforge.net/wiki/LuaUsersLottery

NOISE_FILE=$OUTDIR/noise.txt
wget -q -O $NOISE_FILE $NOISE_URL
CKSUM_OUT=(`cksum < $NOISE_FILE`)
CHECKSUM=${CKSUM_OUT[0]}

INFO_FILE=$OUTDIR/lottery_info.txt
lynx -dump -nolist -width=160 $LOTTERY_URL > $INFO_FILE

lua <<TEXT1
    readfrom('$INFO_FILE')
    info_text = read('*a')
    participants = gsub(info_text,
        '.-HERE >>>.-\n(.*\n).-<<<.*', '%1')
    participant_list = { }
    -- NOTE: assuming list entries are not multiple lines
    gsub(participants, '%s*%*%s*(.-)\n',
        function (entry)
            tinsert(participant_list, entry)
        end)
    sort(participant_list)
    print('participants:')
    n = getn(participant_list)
    for i = 1, n do
        print('  '..i, participant_list[i])
    end
    print('and the winner is...')
    randomseed($CHECKSUM/2)
    -- ISSUE: random depends on the C library implementation, and so the
    --  lottery result cannot be independently verified
    winner = random(n)
    print('  '..winner, participant_list[winner])
TEXT1