#!/usr/bin/env bash
# format:
#
# url1 start_regexp1 end_regexp1
#
ntempfiles=0
DEFAULT_SEP="@"
DEFAULT_OUTDIR="${HOME}/.tostracker/output"
DEFAULT_CONFIG="${HOME}/.tostracker/config"
FORMAT="%-32s   %s\n"


function usage() {
    echo "usage:  $0 OPTIONS"
    echo
    echo "OPTIONS:"
    echo "       -c  filename      Use given config file instead of default (./config)"
    echo "       -F  char          Use given character as a field separator in config file instead of default (${SEP})"
    echo "       -gc               After site scrapes, run 'git add' on all files, then 'git commit'"
    echo "       -gp               After site scrapes, run 'git add' on all files, then 'git commit', then 'git push'"
    echo "       -o  dirname       Use given output dir instead of default (.)"
    echo "       -t  sitename      Just output raw content of given site, useful for finding start/end regexps."
    echo "       -T  sitename      Just output content of given site between re_start and re_end regexps."
    echo
    echo ""
}

function newtempfile() {
    local fn
    fn=$(mktemp /tmp/tostracker.XXXXXX)
    if [[ $? -ne 0 ]]; then
        echo "failed to create temp file" >&2
        exit 1
    fi
    tempfile[$ntempfiles]="$fn"
    ntempfiles=$(($ntempfiles + 1))
    echo "$fn"
}

function cleanup() {
    local x
    for x in ${!tempfile[@]}; do
        [[ -e ${tempfile[$x]} ]] && rm -f "${tempfile[$x]}"
    done
}

function addsite() {
    site_name[$nsites]="$1"
    site_url[$nsites]="$2"
    site_re_start[$nsites]="$3"
    site_re_end[$nsites]="$4"
    nsites=$((nsites + 1))
}

function fatal() {
    echo -e "FATAL:  $*" >&2
    exit 1
}

function showsite() { #1=sitename
    local x lookfor="$1" idx=-1
    [[ -z $lookfor ]] && return 1
    for x in ${!site_name[@]}; do
        if [[ ${site_name[$x]} == "$lookfor" ]]; then
            idx=${x}
            break
        fi
    done
    if [[ $idx == -1 ]]; then
        return 1
    fi
    showsite_byidx "$idx"
}

function showsite_byidx() { #1=idx
    local idx="$1"
    printf "$FORMAT" "${site_name[$idx]}" "${site_url[$idx]}"
}

trap cleanup EXIT TERM


# Defaults
OUTDIR="${DEFAULT_OUTDIR}"
CONFIG="${DEFAULT_CONFIG}"
SEP="${DEFAULT_SEP}"
DOGITCOMMIT=0
DOGITPUSH=0
MODE="normal"
TESTSITE=""
TEST_USERES=0

ARGS="hc:F:g:lo:t:T:"
while getopts "$ARGS" i; do
	case "$i" in
		h)
			usage;
                        exit 1;
			;;
		g)
                        if [[ $OPTARG == "c" ]]; then
                            DOGITCOMMIT=1
                            DOGITPUSH=0
                        elif [[ $OPTARG == "p" ]]; then
                            DOGITCOMMIT=1
                            DOGITPUSH=1
                        else
                            fatal "invalid git subargument - must use -gc or -gp"
                        fi
			;;
		l)
                        MODE="list"
			;;
		o)
                        OUTDIR="$OPTARG"
			;;
		c)
                        CONFIG="$OPTARG"
			;;
		F)
                        SEP="$OPTARG"
			;;
		t)
                        MODE="test"
                        TESTSITE="$OPTARG"
                        TEST_USERES=0
			;;
		T)
                        MODE="test"
                        TESTSITE="$OPTARG"
                        TEST_USERES=1
			;;
		*)
                        echo "invalid option '$i'" >&2
			usage;
                        exit 1;
			;;
	esac
done
shift $((OPTIND - 1))

if [[ $# -ne 0 ]]; then
    usage
    exit 1
fi


SED=$(which gsed 2>/dev/null)
[[ $? -ne 0 ]] && SED=$(which sed 2>/dev/null)
[[ -z $SED ]] && fatal "can't find sed in path"

# Read config file
if [[ ! -e ${CONFIG} || ! -f ${CONFIG} ]]; then
    fatal "config file '$CONFIG' doesn't exist or isn't a plaintext file"
fi
wantfields=4
while read line; do
    [[ -z $line ]] && continue
    [[ $line =~ ^# ]] && continue
    nfields=$(echo "1 + $(grep -o @ <<<"$line" | wc -l)" | bc)
    if [[ $nfields -ne $wantfields ]]; then
        fatal "wrong number of fields in config line (want $wantfields, got $nfields):\n$line\n"
    fi

    sitename=$(awk -F "$SEP" '{ print $1 }' <<<"$line")
    url=$(awk -F "$SEP" '{ print $2 }' <<<"$line")
    re_start="$(awk -F "$SEP" '{ print $3 }' <<<"$line")"
    re_end="$(awk -F "$SEP" '{ print $4 }' <<<"$line")"

    addsite "$sitename" "$url" "$re_start" "$re_end"

    #echo "sitename:   [$sitename]"
    #echo "url:   [$url]"
    #echo "start: [$re_start]"
    #echo "end:   [$re_end]"
done < ${CONFIG}


if [[ $MODE == "list" ]]; then
    printf "$FORMAT" "Site Name" "URL"
    for x in ${!site_name[@]}; do
        showsite_byidx "$x"
    done
    exit 0
elif [[ $MODE == "test" ]]; then
    if [[ -n $TESTSITE ]]; then
        idx=-1
        for x in ${!site_name[@]}; do
            if [[ ${site_name[$x]} == $TESTSITE ]]; then
                idx="$x"
                break
            fi
        done
        if [[ $idx == -1 ]]; then
            fatal "Requested site '$TESTSITE' not found in config file ($CONFIG)."
        fi
        url="${site_url[$idx]}"

        temp=$(newtempfile)

        curl -sL "$url" | ${SED} 's/>/>\n/g;s/</\n</g;' | awk NF | egrep -v "^<.*>$" > ${temp}
        if [[ $TEST_USERES -eq 1 ]]; then
            sedcmd="/${site_re_start[$idx]}/,/${site_re_end[$idx]}/p"
            cat "$temp" | ${SED} -n "$sedcmd"
        else
            cat "$temp"
        fi
        rm -f "$temp"
        exit $?
    else
        fatal "Test mode in use, but \$TESTSITE is empty."
    fi
fi

# confirm output dir
if [[ -e ${OUTPUT} ]]; then
    if [[ ! -d ${OUTDIR} ]]; then
        fatal "output directory '$OUTDIR' already exists but is not a directory"
    fi
else
    mkdir -p "${OUTDIR}"
fi

if [[ $DOGITPUSH -eq 1 && $DOGITCOMMIT -ne 1 ]]; then
    fatal "git push option cannot be used without git commit option"
fi

if [[ $DOGITCOMMIT -eq 1 ]]; then
    if [[ ! -d ${OUTDIR}/.git ]]; then
        fatal "error - git commit option used, but output directory '$OUTDIR' doesn't seem to be a git repo"
    fi
fi

if [[ $DOGITPUSH -eq 1 ]]; then
    grep -q "\[remote" ${OUTDIR}/.git/config 2>/dev/null
    if [[ $? -ne 0 ]]; then
        fatal "git push option used, but output git repo '$OUTDIR' doesn't have any remotes"
    fi
fi

filesdone=""
sitesdone=""
summary=""
for x in ${!site_name[@]}; do
    sitename="${site_name[$x]}"
    url="${site_url[$x]}"
    re_start="${site_re_start[$x]}"
    re_end="${site_re_end[$x]}"

    if [[ -z $re_start || -z $re_end ]]; then
        # skip processing
        continue
    fi

    thisfile="${sitename}.txt"
    outfile="${OUTDIR}/${thisfile}"
    temp=$(newtempfile)
    temp2=$(newtempfile)
    curl -sL "$url" | ${SED} 's/>/>\n/g;s/</\n</g;' | awk NF | egrep -v "^<.*>$" > "${temp}"
    sedcmd="/${re_start}/,/${re_end}/p"

    echo -e "SITE:  ${sitename}\nURL:   $url\n\n" >${temp2}
    cat "$temp" | ${SED} -n "$sedcmd" >> ${temp2}

    if [[ -e ${outfile} ]]; then
        # has it changed?
        diff "$temp2" "$outfile" &>/dev/null
        [[ $? -eq 0 ]] && changed=0 || changed=1
    else
        changed=1
    fi

    if [[ $changed -eq 1 ]]; then
        text="UPDATES FOUND"
    else
        text="no change"

    fi
    cp -a "${temp2}" "${outfile}"
    echo "Scraped '${sitename}' to '${outfile}' ($text)"
    rm -f "${temp}" "${temp2}"

    if [[ $changed -eq 1 ]]; then
        sitesdone="$sitesdone $sitename"
        filesdone="$filesdone $thisfile"
        if [[ -z $summary ]]; then
            summary="$(showsite $sitename)"
        else
            summary=$(echo -e "$summary\n$(showsite $sitename)")
        fi
    fi
done

if [[ $DOGITCOMMIT -eq 1 ]]; then
    if [[ -n $filesdone ]]; then
        echo -n "Doing git add..." >&2

        msg="Policies have been updated for the following sites:"
        msg=$(echo -e "Policies have been updated for the following sites:\n$summary")

        pushd "${OUTDIR}" &>/dev/null

        fd=( $filesdone  )
        res=$(git add ${fd[@]} 2>&1)
        [[ $? -eq 0 ]] && echo "ok" >&2 || { echo "failed" >&2; fatal "git add failed:\n$res\n"; }

        echo -n "Doing git commit..." >&2
        res=$(git commit -m "$msg" 2>&1)
        if [[ $? -eq 0 ]]; then
            echo "ok" >&2
        elif [[ $res == *"othing to commit"* ]]; then
            echo "ok (no changes)" >&2
        else
            echo "failed" >&2
            fatal "git commit failed:\n$res\n"
        fi

        if [[ $DOGITPUSH -eq 1 ]]; then
            echo -n "Doing git push..." >&2
            res=$(git push 2>&1)
            [[ $? -eq 0 ]] && echo "ok" >&2 || { echo "failed" >&2; fatal "git push failed:\n$res\n"; }
        fi
        popd &>/dev/null
    fi
fi

exit 0