#!/bin/bash
PROGNAME=`basename $0`

main()
{
    local MATCH REGEX PART FILE ALLWHATMUSTMATCHONEOFOTHER SUBMATCH

    PART=header
    VERBOSELEVEL=2
    ALLWHATMUSTMATCHONEOFOTHER=regexps
    LOG_FILE=${LOG_FILE:-/dev/null}

    while [ "X$1" != X ]; do
        case $1 in
            -b) PART=body ;;
            -l) ALLWHATMUSTMATCHONEOFOTHER=lines ;;
            *)  break ;;
        esac
        shift
    done

    case $PART in
        header) FILE=$HEADERFILE ;;
        body)   FILE=$BODYFILE ;;
    esac

    debug 80 "meg: PART=$PART, ALLWHATMUSTMATCHONEOFOTHER=$ALLWHATMUSTMATCHONEOFOTHER"

    if [ $ALLWHATMUSTMATCHONEOFOTHER = regexps ]; then
        #  Assume all match until proven otherwise
        MATCH=true
        debug 1000 "meg: start of for loop checking if each regex can be found in file"
        for REGEX in "$@"; do
            debug 80 "meg: checking if regex \"$REGEX\" can be found in file ..."
            ! $EGREP_CMD -- "$REGEX" $FILE > /dev/null && { MATCH=false; debug 80 "meg: it was not found, therefore setting MATCH=$MATCH"; break; }
        done
        debug 80 "meg: end of for loop checking if each regex can be found in file"
    
    elif [ $ALLWHATMUSTMATCHONEOFOTHER = lines ]; then
        #  Assume all lines match one of the regexps until proven otherwise
        MATCH=true
        debug 80 "meg: start of for loop checking if each line can match a regex"
        while IFS= read -r LINE; do 
            debug 80 "meg: checking if line \"$LINE\" can be matched by any regex ..."
            #  Assume each single regex does not match until proven otherwise
            SUBMATCH=false
            for REGEX in "$@"; do
                debug 80 "meg: checking if line \"$LINE\" matches \"$REGEX\" ..."
                echo -E "$LINE" | $EGREP_CMD -- "$REGEX" > /dev/null && { SUBMATCH=true; debug 80 "meg: it matches"; break; }
            done
            [ $SUBMATCH = false ] && { MATCH=false; debug 80 "meg: matching regex was not found, therefore setting MATCH=$MATCH"; break; }
        done < $FILE 
        debug 80 "meg: end of for loop checking if each line can match a regex"
    fi

    debug 80 "meg: returning $MATCH ..."
    $MATCH
}

error()    { [ $VERBOSELEVEL -lt 1  ] || message "$PROGNAME: ERROR: $1";         exit 1; }
internal() { [ $VERBOSELEVEL -lt 0  ] || message "$PROGNAME: INTERNAL ERROR: $1" exit 2; }
warning()  { [ $VERBOSELEVEL -lt 2  ] || message "$PROGNAME: WARNING: $1";               }
info()     { [ $VERBOSELEVEL -lt 3  ] || message "$PROGNAME: INFO: $1";                  }
debug()    { [ $VERBOSELEVEL -lt $1 ] || message "$PROGNAME: DEBUG[$1]: $2";             }

message()
{
    if [ -t 2 ]; then
        echo "$1" >&2
    else
        echo "$(date '+%Y/%m/%d %H:%M:%S'): $1" >> $LOG_FILE
    fi

    return 0
}

main "$@"