#!/bin/sh
# ~/bin/.sh/grepspam

# Call as: grepspam /path/name/of/mail/falsely/identified/with/a/spam/phrase
#	Then it
#	identifies which phrase to remove from lsit of spam phrases $phrases.
#	Analyses a mail file (path name in $1),
#	(that has usually been filed by procmail in ~/mail/spam/phrases/ )
#	to find which phrase[s] in $phrases caused procmail to put it there.
#	Usual use for autopsy, after an innocent mail gets mis-filed as spam.
# Call as grepspam /dev/null
#	Then it ifentifies grep syntax errorsin phrases.

innocent=$1

phrases="$HOME/.DOTS/.procmailrc.spam_shrunk"
#	built from .procmailrc.phrases.src by ~/public_html/dots/Makefile

# phrases="$phrases $HOME/.DOTS/.procmailrc.domains2block.src"
#	.procmailrc.domains2block.src is no longer appended,
#	as also no longer processed into
#	.procmailrc.spam.inc by ~jhs/public_html/dots/Makefile

if [ "$innocent.x" = ".x" ]; then
	echo "Error. Specify a mail file to scan EG ~/mail/spam/phrases/1"
	exit 1
fi

# Ensure ${HOME}/.procmailrc.spam_shrunk is up to date.
(cd $HOME/public_html/dots ; make grepspam_hook ) > /dev/null

for i in $phrases ; do
	if [ \! -r $i ]; then
		echo "Error. Cannot read list of spam phrases: $i"
		exit 1
	fi
	done

# Aggregate all spam phrases, maybe later I will file sepeartely by language,
# or import external lists etc.
cat $phrases > $HOME/tmp/grepspam.$$.tmp

IFS='
'
export IFS

# Show each line from spam phrases list that matches in the mail.
#	Do not enter spam phrases starting with a minus, ie '-',
#	as grep produces an error report.

#	If a syntax error is reported,
#		such as
#			egrep: Unmatched ( or \(
#		To find the error, Uncomment the CheckPhrase: line, Then:
#			script
#			sh -x `which grepspam` /dev/null
#			^D
#			vi typescript

#	 Problem: A spam phrase in list of
#		highest quality of rep\\|ica
#	 with ('for i in') immediately below, shows
#	 false matches on string "ica" in mail with words such as:
#		certificate, helvetica;
#	 although the .procmailrc.spam.inc does the right thing with
#		* highest quality of rep\|ica
#	because ~/public_html/dots/Makefile reducing \\ to \
#	converting from ~/.procmailrc.spam_shrunk to ~/.procmailrc.spam.inc

# for i in `cat $HOME/tmp/grepspam.$$.tmp` ; do
#	# echo "CheckPhrase: $i"
#	egrep -q -i "$i" $innocent && echo "MatchPhrase: $i"
#	# No "&& exit" as we want all matching phrases, not just the first.
#	done

# 	New 'while' below converts \\ to \ so it doesnt cause a false match.

cat $HOME/tmp/grepspam.$$.tmp | while read phrase ; do
	# echo CheckPhrase: $phrase
	egrep -q -i "$phrase" $innocent && echo "MatchPhrase: $phrase"
	done

# JJLATER I should switch the Makefile to use a syntax like 'for'
# further above, rather than 'while read' immediately above, as further
# above does not lose a single backslash, so I would not then need
# double backslash in .procmailrc.phrases.src

rm $HOME/tmp/grepspam.$$.tmp