polybasectl

#!/bin/sh

die() {
	echo "$*" >&2
	exit 1
}

POLYBASE_CONF="${POLYBASE_CONF=/etc/polybase.conf}"
[ -f "$POLYBASE_CONF" ] || die "Can't find configuration file $POLYBASE_CONF"
. "$POLYBASE_CONF"
[ -f "$POLYBASE_DB" ] || die "Database not found"

CURRENT_SEMESTER() {
	if [ $(echo "select julianday('now') between julianday('$(date +%Y)-09-01') and julianday('$(( $(date +%Y) + 1))-01-01');" | sqlite3) -eq 1 ]; then
		echo S1
	else
		echo S2
	fi
}

COMMAND() { sqlite3 "$POLYBASE_DB" "$@"; }

COURSEADD_USAGE="
	$(basename "$0") courseadd <CODE> [-n NAME] [-k KIND] [-P PART] [-p PARTS] [-q QUANTITY] [-t TOTAL] [-S SEMESTER] [-s] [-d]:
	-d: dry run, show SQL commands that would be executed without actually doing them
	-k: overrides default kind of $DEFAULT_KIND
	-n: will be asked interactively if not specified
	-P: overrides current part, default 1; if greater than PARTS, PARTS will be updated to PART across all courses satisfying CODE and KIND
	-p: overrides amount of parts, default 1
	-q: default quantity is 0, can be updated afterwards via Gemini
	-S: override semester, default is $(CURRENT_SEMESTER), based on the current date
	-s: show COURSE publicly immediately
	-t: overrides total quantity, default is QUANTITY
"

COURSEMOD_USAGE="
	$(basename "$0") coursemod <CODE> [-n NAME] [-k KIND] [-P PART|-p PARTS] [-q QUANTITY] [-t TOTAL] [-S SEMESTER] [-s] [-d]:
	-d: dry run, show SQL commands that would be executed without actually doing them
	-k: specify kind if query is ambiguous
	-n: update name
	-P: specify part if query is ambiguous, mutually exclusive with -p
	-p: update amount of parts, mutually exclusive with -P
	-q: update quantity where QUANTITY can be an absolute value or prefixed with +/- to increment/decrement by QUANTITY, can also be updated via Gemini
	-S: update semester
	-s: toggle whether COURSE is shown publicly
	-t: update total quantity
"

USERADD_USAGE="
	$(basename "$0") useradd <USERNAME> <FINGERPRINT>: add user USERNAME with fingerprint FINGERPRINT to Gemini write access
"

USERDEL_USAGE="
	$(basename "$0") userdel <FINGERPRINT>: remove user with FINGERPRINT from users with Gemini write access
"

USERS_USAGE="
	$(basename "$0") users: show all users with Gemini write access
"

database_write() {
	COMMAND 'PRAGMA user_version=0' || die "No write access to database: $POLYBASE_DB, if needed override with the environment variable POLYBASE_DB"
}

add_user() {
	database_write
	COMMAND "INSERT INTO users VALUES ('$1', '$2');"
}

show_users() {
	COMMAND -noheader -tabs "SELECT username, hash FROM users ORDER BY username;"
}

del_user() {
	database_write
	if [ -z "$1" ]; then
		echo -n "Specify fingerprint: "
		read -r 1
	fi
#	COMMAND "SELECT hash FROM users WHERE hash = '$1';" > /dev/null 2>&1 || die "Fingerprint not found" # XXX: invalid fingerprint detection
	echo -n "User "
	COMMAND "SELECT username FROM users WHERE hash = '$1';" | tr -d '\n'
	echo -n " will be deleted. Continue? [y/N]"
	read -r confirmation
	case "$confirmation" in
		y|Y) COMMAND "DELETE FROM users WHERE hash = '$1';" ;;
		*) ;;
	esac
}

add_course() {
	database_write
	if [ -z "$name" ]; then
		echo -n "Specify course name: "
		read -r name
	fi
	COMMAND "INSERT INTO courses VALUES ('$code', '${kind=$DEFAULT_KIND}', ${part=1}, ${parts=1}, '$name', ${quantity=0}, ${total=$quantity}, ${shown=0}, '${semester=$(CURRENT_SEMESTER)}');"
}

mod_course() {
	database_write
	query=$(COMMAND "SELECT code,kind,part,parts,name FROM courses WHERE code = '$code'${kind:+ AND kind = '$kind'}${part:+ AND part = $part};")
	case "$quantity" in
		'+'*|'-'*) quantity="quantity$quantity" ;;
		*) ;;
	esac
	{ [ $(echo "$query" | wc -l) -gt 1 ] && [ -z "$total" ]; } && die "Ambiguous query, please refine with -k and/or -P:\n$query"
	COMMAND "UPDATE courses SET code = '$code'${quantity:+, quantity = $quantity}${name:+, name = '$name'}${parts:+, parts = $parts}${total:+, total = $total}${shown:+, shown = NOT shown}${semester:+, semester = '$semester'} WHERE code = '$code'${kind:+ AND kind = '$kind'}${part:+ AND part = $part};"
}

case "$1" in
	courseadd)
		code="$2"
		shift 2
		while getopts "hdk:n:P:p:q:S:st:" opt; do
			case "$opt" in
				h) echo "Usage for courseadd:$COURSEADD_USAGE" && exit ;;
				d) COMMAND() { echo "$@"; } ;;
				k) kind="$OPTARG" ;;
				n) name="$OPTARG" ;;
				P) [ "$OPTARG" -gt 0 ] && part="$OPTARG" || die "Part must be a positive integer$COURSEADD_USAGE" ;;
				p) [ "$OPTARG" -gt 0 ] && parts="$OPTARG" || die "Parts must be a positive integer$COURSEADD_USAGE" ;;
				q) [ "$OPTARG" -gt 0 ] && quantity="$OPTARG" || die "Quantity must be a positive integer$COURSEADD_USAGE" ;;
				S) semester="$OPTARG" ;;
				s) shown=1 ;;
				t) [ "$OPTARG" -gt 0 ] && total="$OPTARG" || die "Total must be a positive integer$COURSEADD_USAGE" ;;
				*) die "Usage for courseadd:$COURSEADD_USAGE" ;;
			esac
		done
		[ $OPTIND -ne 1 ] && add_course || die "Usage for courseadd:$COURSEADD_USAGE" ;;

	coursemod)
		code="$2"
		shift 2
		while getopts "hdk:n:P:p:q:S:st:" opt; do
			case "$opt" in
				h) echo "Usage for coursemod:$COURSEMOD_USAGE" && exit ;;
				d) COMMAND() { echo "$@"; } ;;
				k) kind="$OPTARG" ;;
				n) name="$OPTARG" ;;
				P) ( [ "$OPTARG" -gt 0 ] && [ -z "$parts" ] ) && part="$OPTARG" || die "Part must be a positive integer and -p must not be set$COURSEMOD_USAGE" ;;
				p) ( [ "$OPTARG" -gt 0 ] && [ -z "$part" ] ) && parts="$OPTARG" || die "Parts must be a positive integer and -P must not be set$COURSEMOD_USAGE" ;;
				q) case "$OPTARG" in
					*[!0123456789+-]*|-|?*-*|0?*|-0|'') die "Quantity must be an integer or increment/decrement value$COURSEMOD_USAGE" ;;
					*) quantity="$OPTARG" ;;
				esac ;;
				S) semester="$OPTARG" ;;
				s) shown=1 ;;
				t) [ "$OPTARG" -gt 0 ] && total="$OPTARG" || die "Total must be a positive integer$COURSEMOD_USAGE" ;;
				*) die "Usage for coursemod:$COURSEMOD_USAGE" ;;
			esac
		done
		[ $OPTIND -ne 1 ] && mod_course || die "Usage for coursemod:$COURSEMOD_USAGE" ;;

	useradd)
		shift
		[ "$#" -eq 2 ] && add_user "$1" "$2" || die "Usage for useradd:$USERADD_USAGE" ;;

	userdel)
		shift
		[ "$#" -eq 1 ] && del_user "$1" || die "Usage for userdel:$USERDEL_USAGE" ;;

	users)
		shift
		show_users ;;

	-h|help)
		echo "Usage:$COURSEADD_USAGE$COURSEMOD_USAGE$USERADD_USAGE$USERDEL_USAGE$USERS_USAGE" ;;

	*)
		die "Usage:$COURSEADD_USAGE$COURSEMOD_USAGE$USERADD_USAGE$USERDEL_USAGE$USERS_USAGE" ;;
esac