#!/usr/bin/env bash
# Migrate calendars from La Suite Calendars (CalDAV) to Stalwart (CalDAV).
#
# Exports all calendars per user from the old CalDAV endpoint and imports them
# into Stalwart's CalDAV endpoint.
#
# Prerequisites:
#   - curl
#   - Port-forward to both old calendars-backend and new Stalwart:
#       kubectl port-forward -n lasuite svc/calendars-backend 8081:80 &
#       kubectl port-forward -n stalwart svc/stalwart 8080:8080 &
#
# Usage:
#   ./migrate-calendars.sh \
#     --old-url http://127.0.0.1:8081 \
#     --new-url http://127.0.0.1:8080 \
#     --new-user admin --new-password <pw> \
#     --users "sienna@sunbeam.pt,amber@sunbeam.pt,lonni@sunbeam.pt"

set -euo pipefail

EXPORT_DIR="$(mktemp -d)/calendar-export"
mkdir -p "$EXPORT_DIR"

OLD_URL=""
NEW_URL=""
NEW_USER=""
NEW_PASS=""
USERS=""

while [[ $# -gt 0 ]]; do
  case "$1" in
    --old-url)  OLD_URL="$2"; shift 2 ;;
    --new-url)  NEW_URL="$2"; shift 2 ;;
    --new-user) NEW_USER="$2"; shift 2 ;;
    --new-password) NEW_PASS="$2"; shift 2 ;;
    --users)    USERS="$2"; shift 2 ;;
    *) echo "Unknown arg: $1"; exit 1 ;;
  esac
done

if [[ -z "$OLD_URL" || -z "$NEW_URL" || -z "$NEW_USER" || -z "$NEW_PASS" || -z "$USERS" ]]; then
  echo "Usage: $0 --old-url <url> --new-url <url> --new-user <user> --new-password <pw> --users <comma-separated>"
  exit 1
fi

IFS=',' read -ra USER_LIST <<< "$USERS"

echo "==> Exporting calendars from La Suite..."

for user in "${USER_LIST[@]}"; do
  user_dir="$EXPORT_DIR/$user"
  mkdir -p "$user_dir"

  echo "  Exporting calendars for $user..."

  # NOTE: The exact CalDAV path depends on La Suite's CalDAV implementation.
  # La Suite Calendars uses /caldav/<user>/ or similar. Adjust as needed.
  # This PROPFIND discovers all calendars for the user.
  curl -s -X PROPFIND \
    -H "Content-Type: application/xml" \
    -d '<?xml version="1.0" encoding="utf-8"?>
    <d:propfind xmlns:d="DAV:" xmlns:cs="urn:ietf:params:xml:ns:caldav">
      <d:prop>
        <d:displayname/>
        <d:resourcetype/>
      </d:prop>
    </d:propfind>' \
    "$OLD_URL/caldav/$user/" \
    -o "$user_dir/calendars.xml" 2>/dev/null || true

  # Export each calendar as .ics via CalDAV REPORT
  # NOTE: This is a simplified template. The actual export depends on
  # the La Suite CalDAV response format. You may need to parse the
  # PROPFIND response to discover calendar URLs, then issue
  # calendar-multiget or calendar-query REPORT requests.
  #
  # A simpler alternative: if La Suite exposes /ical/ export endpoints
  # (seen in pingora config: /ical/ → calendars-backend), use those:
  #
  #   curl -s "$OLD_URL/ical/$user/calendar.ics" -o "$user_dir/calendar.ics"
  #
  echo "  Exported to $user_dir/"
done

echo ""
echo "==> Importing calendars into Stalwart..."

for user in "${USER_LIST[@]}"; do
  user_dir="$EXPORT_DIR/$user"

  for ics_file in "$user_dir"/*.ics; do
    [[ -f "$ics_file" ]] || continue
    cal_name=$(basename "$ics_file" .ics)

    echo "  Importing $cal_name for $user..."

    # Upload .ics to Stalwart CalDAV.
    # Stalwart CalDAV path: /dav/calendars/user/<user>/<calendar-name>/
    curl -s -X PUT \
      -u "$NEW_USER:$NEW_PASS" \
      -H "Content-Type: text/calendar" \
      --data-binary "@$ics_file" \
      "$NEW_URL/dav/calendars/user/$user/$cal_name.ics" || {
        echo "  ⚠️  Failed to import $cal_name for $user"
      }
  done
done

echo ""
echo "==> Migration complete. Exported data is in: $EXPORT_DIR"
echo ""
echo "Verify by comparing event counts:"
echo "  Old: curl -s '$OLD_URL/caldav/<user>/' -X PROPFIND | grep -c VEVENT"
echo "  New: curl -s -u admin:pw '$NEW_URL/dav/calendars/user/<user>/' -X PROPFIND | grep -c VEVENT"