#!/bin/sh
set -eu
: "${BOOK_URL:?}" "${DAV_USER:?}" "${DAV_PASSWORD:?}"
CARD_URL="${BOOK_URL%/}/if-match-delete-probe.vcf"

printf '%s\r\n' \
  'BEGIN:VCARD' 'VERSION:3.0' \
  'UID:if-match-delete-probe' 'FN:Conditional Delete Probe' \
  'N:Probe;Conditional Delete;;;' 'END:VCARD' |
curl --silent --show-error --fail --include \
  --user "$DAV_USER:$DAV_PASSWORD" --request PUT \
  --header 'If-None-Match: *' \
  --header 'Content-Type: text/vcard; charset=utf-8' \
  --data-binary @- "$CARD_URL"

curl --silent --show-error --fail --include \
  --user "$DAV_USER:$DAV_PASSWORD" "$CARD_URL"

curl --silent --show-error --include \
  --user "$DAV_USER:$DAV_PASSWORD" --request DELETE \
  --header 'If-Match: "deliberately-stale-etag"' "$CARD_URL"

curl --silent --show-error --include \
  --user "$DAV_USER:$DAV_PASSWORD" "$CARD_URL"