#!/bin/bash
#
# Copyright (C) 2026 Danilo M. <danix@danix.xyz>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 as
# published by the Free Software Foundation.
#
# 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.
#
# Waybar custom module in continuous mode: prints one JSON line per notmuch
# commit, forever, and waybar redraws on each line. Waybar owns this process,
# which is why there is no daemon to supervise and no interval to tune.
#
# The count is the total across every account. A per account breakdown is the
# drawer's job; see mail-overview/README.md.

set -u

QUERY='tag:unread and tag:inbox'

# notmuch knows where its own database is, so this follows a moved database
# without an edit here.
db="$(notmuch config get database.path 2>/dev/null)/xapian"

emit() {
    local n
    n="$(notmuch count "$QUERY" 2>/dev/null)"

    # The output is the test, not the exit status. notmuch fails two different
    # ways: a rejected query prints nothing and exits 1, while a query Xapian
    # merely misparses ('tag:unread and ((') returns a plausible wrong number
    # and exits 0. Only the first is detectable, and it is the one that matters
    # here, because empty output would otherwise render as "no new mail". The
    # second is why QUERY is a fixed string and not built from anything.
    if [[ ! "$n" =~ ^[0-9]+$ ]]; then
        printf '{"text":"!","tooltip":"notmuch count failed","class":"error"}\n'
        return
    fi

    if [[ "$n" -eq 0 ]]; then
        printf '{"text":"","class":"empty"}\n'
    else
        printf '{"text":"%s","class":"unread"}\n' "$n"
    fi
}

if [[ ! -d "$db" ]]; then
    printf '{"text":"!","tooltip":"no notmuch database","class":"error"}\n'
    exit 1
fi

emit

while inotifywait -qq -e close_write,moved_to "$db" 2>/dev/null; do
    # One commit touches several files. Without this the module redraws three
    # or four times per sync with intermediate counts.
    sleep 0.3
    emit
done

# Falling out of the loop means inotifywait itself failed. Say so rather than
# exiting silently, which looks like an empty inbox.
printf '{"text":"!","tooltip":"mail watcher stopped","class":"error"}\n'
exit 1