#!/bin/sh

set -eu

export BITMESSAGE_API_USER="${BITMESSAGE_API_USER:-bitmessage_api_user}"
export BITMESSAGE_API_PASSWORD="${BITMESSAGE_API_PASSWORD:-bitmessage_api_password}"
export BITMESSAGE_SEED_ADDRESSES="${BITMESSAGE_SEED_ADDRESSES:-0}"
export BITMESSAGE_API_PORT="${BITMESSAGE_API_PORT:-8442}"
export BITMESSAGE_TTL="${BITMESSAGE_TTL:-172800}"
export BITMESSAGE_STOPRESENDINGAFTERXDAYS="${BITMESSAGE_STOPRESENDINGAFTERXDAYS:-30}"
export BITMESSAGE_APIVARIANT="${BITMESSAGE_APIVARIANT:-legacy}"
export BITMESSAGE_MAXTOTALCONNECTIONS="${BITMESSAGE_MAXTOTALCONNECTIONS:-200}"

# Reject anything but a plain number: this value is written into keys.dat, and
# unlike the credentials below it has no business containing characters that
# esc() would have to neutralise. A typo here would otherwise land in the config
# as a key the daemon silently ignores.
case "$BITMESSAGE_MAXTOTALCONNECTIONS" in
	'' | *[!0-9]*)
		echo "BITMESSAGE_MAXTOTALCONNECTIONS must be a positive integer" >&2
		exit 1
		;;
esac

if [ -z "${BITMESSAGE_SEED_PHRASE:-}" ]
then
  BITMESSAGE_SEED_PHRASE="$(cat /dev/random | tr -dc "a-z" | head -c32)"
  export BITMESSAGE_SEED_PHRASE
fi

# Escape a value for use on the right-hand side of the sed expressions below.
# There, a backslash starts an escape, "&" stands for the whole match, and "|"
# ends the replacement because it is the delimiter. Unescaped, a password
# containing "&" was silently rewritten into something else and one containing
# "|" made sed fail outright.
esc() {
	printf '%s' "$1" | sed -e 's/[\\&|]/\\&/g'
}

# this command must be run as root (for bind mounts to container)
if [ -f keys.dat ]
then
	chown bitmessage:bitmessage keys.dat
	chmod 600 keys.dat
fi

# maxtotalconnections is the only brake on a node whose P2P port (8444) is
# published: it caps inbound sockets at the total minus maxoutboundconnections.
# The substitution below is a no-op when the key is missing, which would ship a
# node that looks capped and is not -- and the PyBitmessage clone in the
# Dockerfile is unpinned, so the stock config is whatever upstream generates
# today. Add the key rather than trust the substitution alone; line 1 is the
# [bitmessagesettings] header the daemon reads it from.
if ! grep -q "^maxtotalconnections = " keys.dat
then
	gosu bitmessage sed -i "1a maxtotalconnections = $BITMESSAGE_MAXTOTALCONNECTIONS" keys.dat
fi

# Set config values. Every expression is anchored to the start of the line and
# names its key in the replacement, so no backreference is involved and nothing
# in another section can match. With set -e a failure here now stops the
# container instead of leaving the daemon on its previous settings unnoticed --
# including the case of a bind mount with no keys.dat at all.
gosu bitmessage sed -i \
	-e "s|^apiinterface = .*|apiinterface = 0.0.0.0|" \
	-e "s|^apivariant = .*|apivariant = $(esc "$BITMESSAGE_APIVARIANT")|" \
	-e "s|^apiusername = .*|apiusername = $(esc "$BITMESSAGE_API_USER")|" \
	-e "s|^apipassword = .*|apipassword = $(esc "$BITMESSAGE_API_PASSWORD")|" \
	-e "s|^apiport = .*|apiport = $(esc "$BITMESSAGE_API_PORT")|" \
	-e "s|^apienabled = .*|apienabled = True|" \
	-e "s|^ttl = .*|ttl = $(esc "$BITMESSAGE_TTL")|" \
	-e "s|^stopresendingafterxdays = .*|stopresendingafterxdays = $(esc "$BITMESSAGE_STOPRESENDINGAFTERXDAYS")|" \
	-e "s|^maxtotalconnections = .*|maxtotalconnections = $BITMESSAGE_MAXTOTALCONNECTIONS|" \
	-e "s|^udp = .*|udp = False|" keys.dat

# generate address from seed
if [ "$BITMESSAGE_SEED_ADDRESSES" -gt 0 ]
then
	# Four attempts, not a bash {1..4}: this runs under dash, where brace
	# expansion is literal and the loop would have run once. The call is
	# idempotent (createDeterministicAddresses returns nothing for an address
	# that already exists), so these are retries while the API comes up.
	for i in 1 2 3 4
	do
		sleep 15
		gosu bitmessage /usr/bin/python /usr/local/bin/seed_addr_gen.py
	done &
fi

exec gosu bitmessage pybitmessage -d