#!/bin/sh
# Tell bunq where to push payment notifications.
#
# Run from a machine whose address the bunq API key permits — the web host is
# not one, which is the whole reason webhooks exist in this setup. The session
# it uses comes from the context file that tools/pull-and-ship-credits.sh
# created, so run that at least once first.
#
#   tools/register-bunq-webhook.sh 'https://catcrafts.net/hooks/bunq/<secret>'
#   tools/register-bunq-webhook.sh --show          # list what is registered
#
# THIS REPLACES THE WHOLE FILTER SET. bunq treats the POST as "here is the
# complete list", so a call that omits an existing filter deletes it. Every
# filter wanted has to be in the one request, which is why --show exists: look
# before overwriting.
#
# The target URL is never echoed: it is a shared secret, and this script's
# output tends to end up pasted into issues and chat logs.
set -eu

cd "$(dirname "$0")/.."

CTX="${CREDITS_LOCAL:-$HOME/.cache/catcrafts}/orders.jsonl.transfer-credits.jsonl.bunq-context.json"
[ -f "$CTX" ] || { echo "$0: no bunq context at $CTX — run tools/pull-and-ship-credits.sh first" >&2; exit 1; }

SESSION=$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1]))["session_token"])' "$CTX")
USERID=$(python3 -c 'import json,sys; print(json.load(open(sys.argv[1]))["user_id"])' "$CTX")
[ -n "$SESSION" ] && [ "$USERID" != "0" ] || { echo "$0: context has no session — run the pull once" >&2; exit 1; }

API="https://api.bunq.com/v1/user/$USERID/notification-filter-url"
HDRS="-H Content-Type:application/json -H X-Bunq-Client-Authentication:$SESSION -H User-Agent:catcrafts.net-register/1.0"

if [ "${1:-}" = "--show" ]; then
    # Redact the secret out of the response before it reaches a terminal.
    # shellcheck disable=SC2086
    curl -s $HDRS "$API" | python3 -c '
import json,sys,re
try: d=json.load(sys.stdin)
except Exception: print("could not parse bunq response"); sys.exit(1)
for item in d.get("Response",[]):
    f=item.get("NotificationFilterUrl") or {}
    t=f.get("notification_target","")
    print("  category=%-22s target=%s" % (f.get("category","?"), re.sub(r"(/hooks/bunq/).*", r"\1<redacted>", t)))
'
    exit 0
fi

TARGET="${1:-}"
case "$TARGET" in
    https://*) ;;
    *) echo "$0: pass the full https:// callback URL (bunq refuses plain http)" >&2; exit 2 ;;
esac

# MUTATION alone: it fires on every balance change and carries the Payment
# object, which is exactly what the handler decodes. Adding PAYMENT as well
# would deliver most events twice, and while the handler deduplicates on the
# payment id, doubling the traffic to buy nothing is not a trade.
BODY=$(python3 -c '
import json,sys
# No notification_delivery_method: bunq rejects it as "Superfluous" on this
# endpoint, because /notification-filter-url already means URL delivery.
print(json.dumps({"notification_filters":[
    {"notification_target":sys.argv[1],
     "category":"MUTATION"}]}))
' "$TARGET")

# shellcheck disable=SC2086
OUT=$(printf '%s' "$BODY" | curl -s -w '\n%{http_code}' $HDRS -X POST --data-binary @- "$API")
CODE=$(printf '%s' "$OUT" | tail -1)
if [ "$CODE" = 200 ]; then
    echo "$0: registered MUTATION callbacks (target not shown)"
    echo "$0: verify with  $0 --show"
else
    # The body can echo the target back, so redact before printing an error.
    printf '%s\n' "$OUT" | sed 's#\(/hooks/bunq/\)[^"]*#\1<redacted>#g' >&2
    echo "$0: bunq refused the registration (HTTP $CODE)" >&2
    exit 1
fi