#!/usr/bin/env sh

VERBOSE=
if [ "$1" = "-v" ]; then
    VERBOSE=1
    shift
fi

mbsync_running()
{
    account_escaped=$(printf '%s\n' "$1" | sed 's/[.[\*^$()+?{|\\]/\\&/g')

    pgrep -f "^mbsync([[:space:]]+[^ ]+)*[[:space:]]+$account_escaped($|[[:space:]])" >/dev/null ||
        pgrep -f "^mbsync([[:space:]]+[^ ]+)*[[:space:]]+-a($|[[:space:]])" >/dev/null
}

# Run only if not already running in other instance
if mbsync_running "$1"; then
    _acc="$([ -z "$1" ] && echo "all" || echo "$1")"
    echo "mbsync ($_acc) is already running."
    exit
fi

notify()
{
    notify-send --app-name="Mail" -- "$1" "$2"
}

MAILDIR="$XDG_DATA_HOME/mail"
lastrun_base="$XDG_CACHE_HOME/.mailsynclastrun"
lastrun="$lastrun_base"
[ -n "$1" ] && {
    lastrun="${lastrun}_$1"
}
time_lastrun="$(stat -c %Y "$lastrun" 2>/dev/null || echo '0')"

[ -f "$lastrun_base" ] || touch "$lastrun_base"
[ -f "$lastrun" ] || touch "$lastrun"

rm_flag=
mbsync_flag="-q"
notmuch_flag="--quiet"
if [ -n "$VERBOSE" ]; then
    rm_flag="-v"
    mbsync_flag="--verbose"
    notmuch_flag="--verbose"
fi

# delete all +deleted messages
notmuch search --format=text0 --output=files tag:deleted | xargs -0 --no-run-if-empty rm $rm_flag

sync_and_notify()
{
    mbsync $mbsync_flag "$1"

    new=$(fd --type f --changed-after "@$time_lastrun" . "$MAILDIR/$1/INBOX/new/" "$MAILDIR/$1/INBOX/cur/" 2>/dev/null)
    newcount=$(echo "$new" | sed '/^\s*$/d' | wc -l)

    case 1 in
    $((newcount > 5)))
        echo "$newcount new mail for $1."
        notify "New Mail!" "$newcount new mail(s)."
        ;;
    $((newcount > 0)))
        echo "$newcount new mail for $1."
        for file in $new; do
            # Extract and decode subject and sender from mail.
            subject=$(awk '/^Subject: / && ++n == 1,/^.*: / && ++i == 2' "$file" | head -n-1 |
                perl -CS -MEncode -ne 'print decode("MIME-Header", $_)' |
                sed 's/^Subject: //' | tr -d '\n\t')
            from="$(sed -n "/^From:/ s|From: *|| p" "$file" |
                perl -CS -MEncode -ne 'print decode("MIME-Header", $_)')"
            from="${from% *}"
            from="${from%\"}"
            from="${from#\"}"
            notify "$from:" "$subject"
        done
        ;;
    *) echo "No new mail for $1." ;;
    esac
}

allaccounts="$(grep -hs "^\(Group\)" "$XDG_CONFIG_HOME/isyncrc")"

IFS='
'
if [ -z "$1" ]; then
    tosync="$allaccounts"
else
    tosync="$(for arg in "$@"; do for availacc in $allaccounts; do
        [ "$arg" = "${availacc##* }" ] && echo "$availacc" && break
    done || echo "error $arg"; done)"
fi

for account in $tosync; do
    case $account in
    Group*) sync_and_notify "${account##* }" & ;;
    error*) echo "ERROR: Account ${account##* } not found." ;;
    esac
done

wait

if pgrep -f 'notmuch new' >/dev/null; then
    notify "Notmuch running" "Notmuch new is running from another sync.\n Please run it again later."
else
    notmuch new $notmuch_flag
fi

#Create a touch file that indicates the time of the last run of mailsync
if [ -z "$1" ]; then
    # if no args are provided, touch all files
    touch "${lastrun_base}"*
else
    touch "$lastrun"
fi