#!/bin/sh

# - Syncs mail for all accounts, or a single account given as an argument.
# - Displays a notification showing the number of new mails.
# - Displays a notification for each new mail with its subject displayed.
# - Runs notmuch to index new mail.
# - This script can be set up as a cron job for automated mail syncing.

# There are many arbitrary and ugly features in this script because it is
# inherently difficult to pass environmental variables to cronjobs and other
# issues. It also should at least be compatible with Linux (and maybe BSD) with
# Xorg and MacOS as well.

USAGE="Usage:\n\
$(basename "$0") [-p] [-s <email-sybol>] [-S <mailbox-sybol>] <account> [<account>]\n\
        Arguments:
		account: name of account to sync, can be any number of accounts, including zero (which will lead to\n\
			all accounts being synced).\n\
        Options:
		-p: Force private mode (by default emails will be displayed with sender and title if fewer than 5).\n\
                        This option will display only the mailbox and the number of emails, regardless of how many\n\
			there are.\n\
		-s: Symbol to use for emails (default \`📧\`).\n\
			Change to what you want to see or pass empty string for less eye-candy.\n\
		-S: Symbol to use for mailboxes (default \`📬\`).\n\
			Change to what you want to see or pass empty string for less eye-candy.\n\
                -h: displays help message."

# Read Options:
while getopts ":s:S:ph" flag
do
        case "$flag" in
                s)
                        mailsymbol="$OPTARG"
                        ;;
                S)
                        boxsymbol="$OPTARG"
                        ;;
                p)
                        private_mode="$OPTARG"
                        ;;
                h)
                        echo -e "$USAGE"
                        exit 0
                        ;;
                \?)
                        echo "Invalid option: -$OPTARG" >&2
                        exit 1
                        ;;
                :)
                        echo "Option -$OPTARG requires an argument." >&2
                        exit 1
                        ;;
        esac
done

# Shift pointer to read accounts:
shift $((OPTIND - 1))

# Set default symobols:
if [[ -z ${mailsymbol+.} ]]; then
        mailsymbol="📧"
fi
if [[ -z ${boxsymbol+.} ]]; then
        boxsymbol="📬"
fi

# Run only if not already running in other instance
pgrep mbsync >/dev/null && { echo "mbsync is already running."; exit ;}

# First, we have to get the right variables for the mbsync file, the pass
# archive, notmuch and the GPG home.  This is done by searching common profile
# files for variable assignments. This is ugly, but there are few options that
# will work on the maximum number of machines.
eval "$(grep -h -- \
	"^\s*\(export \)\?\(MBSYNCRC\|MPOPRC\|PASSWORD_STORE_DIR\|PASSWORD_STORE_GPG_OPTS\|NOTMUCH_CONFIG\|GNUPGHOME\|MAILSYNC_MUTE\|XDG_CONFIG_HOME\|XDG_DATA_HOME\)=" \
	"$HOME/.profile" "$HOME/.bash_profile" "$HOME/.zprofile"  "$HOME/.config/zsh/.zprofile" "$HOME/.zshenv" \
	"$HOME/.config/zsh/.zshenv" "$HOME/.bashrc" "$HOME/.zshrc" "$HOME/.config/zsh/.zshrc" \
	"$HOME/.pam_environment" 2>/dev/null)"

export GPG_TTY="$(tty)"

[ -n "$MBSYNCRC" ] && alias mbsync="mbsync -c $MBSYNCRC" || MBSYNCRC="$HOME/.mbsyncrc"
[ -n "$MPOPRC" ] || MPOPRC="$HOME/.config/mpop/config"

lastrun="${XDG_CONFIG_HOME:-$HOME/.config}/mutt/.mailsynclastrun"

# Settings are different for MacOS (Darwin) systems.
case "$(uname)" in
	Darwin)
		notify() { osascript -e "display notification \"$2 in $1\" with title \"Account: $account\" subtitle \"$2 new mail(s)\"" && sleep 2 ;}
		messageinfo() { osascript -e "display notification with title \"$mailsymbol$from [$account]\" subtitle \"$subject\"" ;}
		;;
	*)
		case "$(readlink -f /sbin/init)" in
			*systemd*|*openrc*) export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$(id -u)/bus ;;
		esac
		# remember if a display server is running since `ps` doesn't always contain a display
		pgrepoutput="$(pgrep -ax X\(\|org\|wayland\))"
		[ -z $displays ] && [ -d /tmp/.X11-unix ] && displays=$(cd /tmp/.X11-unix && for x in X*; do echo ":${x#X}"; done)

		notify() { [ -n "$pgrepoutput" ] && for x in ${displays:-0:}; do
				export DISPLAY=$x
				notify-send --app-name="mutt-wizard" "Account: $1" "$boxsymbol $2 new mail(s)."
			done ;}
		messageinfo() { [ -n "$pgrepoutput" ] && for x in ${displays:-0:}; do
				export DISPLAY=$x
				notify-send --app-name="mutt-wizard" "$mailsymbol$from [$account]" "$subject"
			done ;}
		;;
esac

# Check account for new mail. Notify if there is new content.
syncandnotify() {
	acc="$(echo "$account" | sed "s/.*\///")"
	if [ "$1" = "pop" ]; then
		# Handle POP
		mpop "$acc"
	else
		# Handle IMAP
		if [ -z "$opts" ]; then mbsync "$acc"; else mbsync "$opts" "$acc"; fi
	fi
	new=$(find\
		"$HOME/.local/share/mail/$acc/"[Ii][Nn][Bb][Oo][Xx]/new/ \
		"$HOME/.local/share/mail/$acc/"[Ii][Nn][Bb][Oo][Xx]/cur/ \
		-type f -newer "$lastrun" 2> /dev/null)
	newcount=$(echo "$new" | sed '/^\s*$/d' | wc -l)
	[ -z "$MAILSYNC_MUTE" ] && case 1 in
		$((newcount > 5)) ) notify "$acc" "$newcount" ;;
			$((newcount > 0)) ) for file in $new; do
				# Extract subject and sender from mail.
				from=$(awk '/^From: / && ++n ==1,/^\<.*\>:/' "$file" | perl -CS -MEncode -ne 'print decode("MIME-Header", $_)' | awk '{ $1=""; if (NF>=3)$NF=""; print $0 }' | sed 's/^[[:blank:]]*[\"'\''\<]*//;s/[\"'\''\>]*[[:blank:]]*$//')
				subject=$(awk '/^Subject: / && ++n == 1,/^\<.*\>: / && ++i == 2' "$file" | head -n 1 | perl -CS -MEncode -ne 'print decode("MIME-Header", $_)' | sed 's/^Subject: //' | sed 's/^{[[:blank:]]*[\"'\''\<]*//;s/[\"'\''\>]*[[:blank:]]*$//' | tr -d '\n')
				messageinfo &
			done ;;
	esac
}

# Sync accounts passed as argument or all.
if [ "$#" -gt "0" ]; then
	for arg in "$@"; do
		[ "${arg%${arg#?}}" = '-' ] && opts="${opts:+${opts} }${arg}" && shift 1
	done
	accounts=$*
fi
[ -z "$imap_accounts" ] && [ -r "$MBSYNCRC" ] && imap_accounts="$(awk '/^Channel/ {print $2}' "$MBSYNCRC" 2>/dev/null)"
[ -z "$pop_accounts" ] && [ -r "$MPOPRC" ] && pop_accounts="$(awk '/^account/ {print $2}' "$MPOPRC" 2>/dev/null)"

# Parallelize multiple accounts
for account in $imap_accounts; do
	if [ -n "$accounts" ]; then
		for tmp_ac in $accounts; do
			[ "$tmp_ac" = "$account" ] && syncandnotify "imap" &
		done
		continue
	fi
	syncandnotify "imap" &
done

for account in $pop_accounts; do
	if [ -n "$accounts" ]; then
		for tmp_ac in $accounts; do
			[ "$tmp_ac" = "$account" ] && syncandnotify "pop" &
		done
		continue
	fi
	syncandnotify "pop" &
done

wait

notmuch new --quiet

#Create a touch file that indicates the time of the last run of mailsync
touch "$lastrun"