#!/bin/sh
set -eu

UCI_CONFIG="rmm-agent"
SHELL_CONFIG="/etc/rmm-agent.conf"

uci_get() {
	uci -q get "$UCI_CONFIG.main.$1" 2>/dev/null || true
}

shell_get() {
	key="$1"
	[ -f "$SHELL_CONFIG" ] || return 0
	sed -n "s/^${key}=\"\(.*\)\"$/\1/p" "$SHELL_CONFIG" | tail -n 1
}

escape_value() {
	printf '%s' "$1" | tr -d '\r\n' | sed 's/[\\`"$]/\\&/g'
}

device_id="$(shell_get DEVICE_ID)"
device_token="$(shell_get DEVICE_TOKEN)"
if [ "$(uci_get migration_complete)" != "1" ]; then
	legacy_url="$(shell_get SERVER_URL)"
	if [ -n "$device_id" ] && [ -n "$device_token" ]; then
		[ -z "$legacy_url" ] || uci -q set "$UCI_CONFIG.main.server_url=$legacy_url"
		case "$legacy_url" in http://*) uci -q set "$UCI_CONFIG.main.allow_insecure_http=1" ;; esac
		uci -q set "$UCI_CONFIG.main.enabled=1"
	fi
	uci -q set "$UCI_CONFIG.main.migration_complete=1"
	uci -q commit "$UCI_CONFIG"
fi

server_url="$(uci_get server_url)"
allow_insecure="$(uci_get allow_insecure_http)"
case "$server_url" in
	https://*) ;;
	http://*) [ "$allow_insecure" = "1" ] || exit 1 ;;
	*) exit 1 ;;
esac

if [ "$(uci_get reset_identity)" = "1" ]; then
	device_id=""
	device_token=""
	uci -q set "$UCI_CONFIG.main.reset_identity=0"
	uci -q commit "$UCI_CONFIG"
fi

enrollment_token="$(uci_get enrollment_token)"
if [ -n "$device_id" ] && [ -n "$device_token" ]; then
	enrollment_token=""
	uci -q delete "$UCI_CONFIG.main.enrollment_token"
	uci -q commit "$UCI_CONFIG"
fi

umask 077
temporary="${SHELL_CONFIG}.tmp"
{
	printf 'SERVER_URL="%s"\n' "$(escape_value "$server_url")"
	printf 'ENROLLMENT_TOKEN="%s"\n' "$(escape_value "$enrollment_token")"
	printf 'INTERVAL_SECONDS="%s"\n' "$(escape_value "$(uci_get interval_seconds)")"
	printf 'CHECK_TARGETS="%s"\n' "$(escape_value "$(uci_get check_targets)")"
	printf 'DIRECT_DNS_ENABLED="%s"\n' "$(escape_value "$(uci_get direct_dns_enabled)")"
	printf 'DNS_UPDATE_INTERVAL_SECONDS="%s"\n' "$(escape_value "$(uci_get dns_update_interval_seconds)")"
	printf 'PUBLIC_IPV4_URL="%s"\n' "$(escape_value "$(uci_get public_ipv4_url)")"
	printf 'PUBLIC_IPV6_URL="%s"\n' "$(escape_value "$(uci_get public_ipv6_url)")"
	printf 'TUNNEL_IDENTITY_FILE="%s"\n' "$(escape_value "$(uci_get tunnel_identity_file)")"
	printf 'DEVICE_ID="%s"\n' "$(escape_value "$device_id")"
	printf 'DEVICE_TOKEN="%s"\n' "$(escape_value "$device_token")"
} > "$temporary"
chmod 0600 "$temporary"
mv "$temporary" "$SHELL_CONFIG"