#!/bin/bash

# Scraper/gatherer script by Marc MERLIN <marc_soft@merlins.org>
# sr88 us50 i80

export PATH=/usr/local/sbin:$PATH

set -o nounset

baseurl=http://www.dot.ca.gov/hq/roadinfo

road=${1:-sr88}
ROAD=$(tr 'a-z' 'A-Z' <<< $road)

EMAIL=${EMAIL:-$road@lists.merlins.org}
DATE=$(date "+%Y:%m:%d-%H:%M")
DATE2=$(date "+%Y:%m:%d %H:%M")
SUBJ="Caltrans $ROAD update"

dir=/var/www/html/merlins/roadinfo/$road
mkdir -p $dir/old
lock="$dir/$road.lock"

epoch2date() {
    date -d "1970-01-01 $1 sec UTC" --rfc-3339=seconds
}

# shlock (from inn) does the right thing and grabs a lock for a dead process
# (it checks the PID in the lock file and if it's not there, it
# updates the PID with the value given to -p)
if ! shlock -p $$ -f $lock; then
    echo "$lock held, quitting" >&2
    exit
fi

cd $dir
#gandalfthegrey:~$ set -o pipefail; wget -d http://www.dot.ca.gov/hq/roadinfo/us5 2>&1| grep Last-Modified: | sed "s/Last-Modified: //"
#gandalfthegrey:~$ echo $?
#1
#gandalfthegrey:~$ set -o pipefail; wget -d http://www.dot.ca.gov/hq/roadinfo/us50 2>&1| grep Last-Modified: | sed "s/Last-Modified: //"
#Sat, 19 Nov 2011 14:48:48 GMT
#gandalfthegrey:~$ echo $?
#0
set -o pipefail
rm -f $road # delete in case it was left over.
/var/local/scr/alarm 10 wget -d $baseurl/$road 2>&1| grep Last-Modified: | sed "s/Last-Modified: //" > lastmodified.$road || exit
date -d "$(cat lastmodified.$road)" "+%s" > lastmodified.epoch.$road

oldepoch=$(cat lastmodified.epoch.$road.old)
epoch=$(cat lastmodified.epoch.$road)
if [ "$epoch" -lt "$oldepoch" ]; then
    if [[ $((  $oldepoch - $epoch )) > 60 ]]; then
	echo "Last modified date of new page for $road: $(epoch2date $epoch) is older than last received page ($(epoch2date $oldepoch))" >&2
	echo "Discarding download" >&2
	cat $road >&2
    fi
    rm $road
    exit
fi

mv lastmodified.$road lastmodified.$road.old
mv lastmodified.epoch.$road lastmodified.epoch.$road.old


# Concatenate lines
tail -n +3 $road | tr '\012\015' '| ' | sed "s/| |/@/g" | tr '|@' ' \012' | sed "s/^ *//" > $road.joined
grep -Ei '(SNOW|CLOSED|CHAINS|AVALANCHE|ALTERNATE ROUTE|BEING HELD|REOPENED)' < $road.joined | grep -v 'CONNECTOR' > $road.parsed.new
rm $road


diff -U 0 $road.parsed $road.parsed.new | grep '^[-+][^-+]' > $road.parsed.diff
cp $road.parsed.diff old/$road.$DATE.diff

if [ -s $road.parsed.diff ]; then

# some 'CLOSED' messages do not have a 'AT XX:YY', so in order not to miss any,
# closed will be registered twice in those cases.
#
# # some closed messages may not have a matching 'reopened'
# IS CLOSED 2 MI EAST OF TWIN BRIDGES
# IS CLOSED 1.5 MI WEST OF KYBURZ
# IS CLOSED FROM TWIN BRIDGES TO MEYERS
# IS CLOSED TO EASTBOUND TRAFFIC 3 MI EAST OF POLLOCK PINES
# IS CLOSED TO WESTBOUND TRAFFIC AT 4.8 MI WEST OF STRAWBERRY
# IS CLOSED FROM ECHO SUMMIT TO MEYERS
# IS CLOSED TO EASTBOUND TRAFFIC FROM COLFAX (PLACER) TO THE NEVADA STATE LINE
# -> CLOSED.*AT doesn't work.
# REOPENED TO NORMAL TRAFFIC AT THE JCT OF SR 49 /IN JACKSON/ (AMADOR CO)  AT 1725 HRS ON 10/14/11
# -> REOPENED may not always be 'IS REOPENED'
# # traffic held doesn't have a no longer being held matching message
# TRAFFIC IS BEING HELD 1.5 MI WEST OF KYBURZ
# TRAFFIC IS NO LONGER BEING HELD FROM
# grep -v CONNECTOR| EACH | DETOUR.*AVAILABLE
#
    # 88 specific stuff
    if grep -q '^\+.*IS CLOSED.*CARSON SPUR' $road.parsed.diff; then
	date +%s > spur_closed
	echo "$DATE2: Closed" >> spur.txt
	SUBJ="$SUBJ: Carson Spur CLOSED"
    elif grep -q '^\+.*IS CLOSED.*CARSON PASS' $road.parsed.diff; then
	date +%s > pass_closed
	echo "$DATE2: Closed" >> pass.txt
	SUBJ="$SUBJ: Carson Pass CLOSED"
    elif grep -q '^\+.*IS REOPENED.*CARSON SPUR' $road.parsed.diff; then
	diff=$(( ( $(date +%s) - $(cat spur_closed) ) / 60 )) && \
	     diff=" after ${diff}mn" && rm spur_closed
	echo "$DATE2: Reopened$diff" >> spur.txt
	SUBJ="$SUBJ: Carson Spur REOPENED$diff"
    elif grep -q '^\+.*IS REOPENED.*CARSON PASS' $road.parsed.diff; then
	diff=$(( ( $(date +%s) - $(cat pass_closed) ) / 60 )) && \
	     diff=" after ${diff}mn" && rm pass_closed
	echo "$DATE2: Reopened$diff" >> pass.txt
	SUBJ="$SUBJ: Carson Pass REOPENED$diff"

    # common to all roads
    elif grep '^\+.*IS CLOSED ' $road.parsed.diff | grep -qEv '( EACH | DETOUR.*AVAILABLE| TRUCKS )'; then
	date +%s > ${road}_closed
	echo "$DATE2: Closed" >> $road.txt
	SUBJ="$SUBJ: CLOSURE"
    elif grep -q 'REOPENED' $road.parsed.diff; then
	diff=""
	if [ -f "${road}_closed" ]; then
	    diff=$(( ( $(date +%s) - $(cat ${road}_closed) ) / 60 )) && \
		 diff=" after ${diff}mn" && rm ${road}_closed
	fi
	echo "$DATE2: Reopened$diff" >> $road.txt
	SUBJ="$SUBJ: REOPENED$diff"
    elif grep '^\+.*IS BEING HELD ' $road.parsed.diff | grep -qv 'DETOUR.*AVAILABLE'; then
	date +%s > ${road}_held
	echo "$DATE2: Traffic Held" >> $road.txt
	SUBJ="$SUBJ: Traffic HELD"
    elif grep -q '^\+.*NO LONGER BEING HELD ' $road.parsed.diff; then
	diff=""
	if [ -f "${road}_held" ]; then
	    diff=$(( ( $(date +%s) - $(cat ${road}_held) ) / 60 )) && \
		 diff=" after ${diff}mn" && rm ${road}_held
	fi
	echo "$DATE2: Traffic No Longer Held$diff" >> $road.txt
	SUBJ="$SUBJ: Traffic no longer HELD$diff"
    fi

#    cat | Mail -e -s "$SUBJ" marc@merlins.org <<EOF
    cat | Mail -e -s "$SUBJ" $EMAIL <<EOF
Update in http://marc.merlins.org/snow/roadinfo/$road/ : $DATE2

Change since last update http://marc.merlins.org/snow/roadinfo/$road/$road.$DATE.diff :
`cat $road.parsed.diff`

New state from $baseurl/$road saved at http://marc.merlins.org/snow/roadinfo/$road/$road.$DATE
`cat $road.joined`

Main page with google maps of Caltrans reporting points:
http://marc.merlins.org/snow/tahoe_caltrans.shtml
EOF
    mv $road.parsed.diff $road.$DATE.diff
    ln -sf $road.$DATE.diff $road.latest.diff
    cp $road.joined $road.$DATE
    ln -sf $road.$DATE $road.latest
fi

# Get ready for next run
mv $road.parsed.new $road.parsed

cp $road.parsed old/$road.$DATE.parsed
cp $road.joined old/$road.$DATE.orig

rm $lock