#!/bin/bash
# This shell script produces an email comparing current broken status
# to that of the last run of this script
#
# Copyright (C) Vance Lankhaar  <vance@samba.org>      2005
#
#   This program is free software; you can redistribute it and/or modify
#   it under the terms of the GNU General Public License as published by
#   the Free Software Foundation; either version 2 of the License, or
#   (at your option) any later version.
#   
#   This program is distributed in the hope that it will be useful,
#   but WITHOUT ANY WARRANTY; without even the implied warranty of
#   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#   GNU General Public License for more details.
#   
#   You should have received a copy of the GNU General Public License
#   along with this program; if not, write to the Free Software
#   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

BASEDIR="/home/build/master"
RESULT_CACHE="$BASEDIR/cache/broken_results.txt"
RESULT_URL="http://build.samba.org/?function=Text_Summary"
FULL_RESULT_URL="http://build.samba.org/"

# split into two parts to obfuscate from spam engines
RESULT_EMAIL_USER="samba-cvs"
RESULT_EMAIL_DOMAIN="lists.samba.org"

# End editable variables
##################################################


# exit immediately on failure
set -e

# fail on attempting to use unassigned variable
set -u

# clean up environment a little
PATH="/usr/local/bin:/usr/bin:/bin"
IFS=" 	
"


##################################################
# get the broken report from the build farm
function get_results {
    
    rm -f "$RESULT_CACHE"

    wget --output-file="$RESULT_CACHE".log \
	 --output-document="$RESULT_CACHE" \
         "$RESULT_URL"

    if [ $? -ne 0 ]; then
	echo "Could not retrieve results:" >&2
	cat "$RESULT_CACHE".log >&2
	return 1;
    else
	rm -rf "$RESULT_CACHE".log
    fi
}

##################################################
# compare the results of build 
function compare_results {

    if [ ! -e "$RESULT_CACHE" ]; then
	echo "Could not locate currrent results. $RESULT_CACHE not found" >&2
	return 1
    fi

    if [ ! -e "$RESULT_CACHE".old ]; then
	echo "Could not locate old results. $RESULT_CACHE.old not found" >&2
	return 1
    fi
    
    diff -u "$RESULT_CACHE".old "$RESULT_CACHE" >> "$RESULT_CACHE".report || true
    
    return 0
}

##################################################
# send report to the above-set email address
function send_report {

    if [ ! -e "$RESULT_CACHE".report ]; then
	echo "Results ($RESULT_CACHE.report) not found" >&2
	return 1
    fi

    subject=$1
    if [ x"$subject" = x ]; then 
	subject="Build Farm Status"
    fi

    mail -s "$subject" "$RESULT_EMAIL_USER"@"$RESULT_EMAIL_DOMAIN" < "$RESULT_CACHE".report
}

##################################################
##################################################

if [ $# -gt 0 ]; then
    if [ x"$1" = x"-h" ] || [ x"$1" = x"--help" ]; then
	echo "Usage: broken_report.sh"
	echo
	echo "This shell script produces an email comparing current broken"
	echo "status to that of the last run of this script."
	echo
	echo "The source and destination are configurable within the script."
	exit 1
    fi
fi
    

##################################################
# prepares the report, including subject and "blurb"
rm -f "$RESULT_CACHE".report "$RESULT_CACHE".old

if [ -e "$RESULT_CACHE" ]; then
    mv -f "$RESULT_CACHE" "$RESULT_CACHE".old
else 
    # get results if they don't exist
    get_results
    exit $?
fi
    
get_results

if [ $? -ne 0 ]; then
    echo "Failed to get the results. Bailing." >&2
	
    # remove any new results, as they're almost certainly foul
    rm -f "$RESULT_CACHE"
    mv -f "$RESULT_CACHE".old "$RESULT_CACHE"

    exit 1
fi
    

(
    # set report subject to show updated time
    echo "URL: $FULL_RESULT_URL"
    echo
) > "$RESULT_CACHE".report

compare_results

if [ $? -ne 0 ]; then
    echo "Failed to compare results. Bailing." >&2

    exit 1
fi

subject=$(head -n 1 "$RESULT_CACHE")
send_report "$subject"