name: Post release topic on Discourse

on:
  release:
    types: [published]
  workflow_run:
    workflows: [Release]
    types: [completed]

permissions:
  contents: read

jobs:
  post:
    if: github.event_name == 'release'
    runs-on: ubuntu-latest
    steps:
      - uses: roots/discourse-topic-github-release-action@557d74ea05b6cc0c47f555c1d5d28a89d904005b # v1.1.0
        with:
          discourse-api-key: ${{ secrets.DISCOURSE_RELEASES_API_KEY }}
          discourse-base-url: https://forum.netbird.io
          discourse-author-username: NetBird
          discourse-category: 17
          discourse-tags: releases

  # goreleaser publishes the release of a pushed tag with GITHUB_TOKEN, and events
  # raised by that token start no workflow, so the release event above never fires.
  post-tag-release:
    if: >-
      github.event_name == 'workflow_run' &&
      github.event.workflow_run.event == 'push' &&
      github.event.workflow_run.conclusion == 'success' &&
      startsWith(github.event.workflow_run.head_branch, 'v') &&
      !contains(github.event.workflow_run.head_branch, '-')
    runs-on: ubuntu-latest
    steps:
      - name: Post the release topic
        env:
          GH_TOKEN: ${{ github.token }}
          TAG: ${{ github.event.workflow_run.head_branch }}
          DISCOURSE_API_KEY: ${{ secrets.DISCOURSE_RELEASES_API_KEY }}
          DISCOURSE_URL: https://forum.netbird.io
          DISCOURSE_USER: NetBird
          DISCOURSE_CATEGORY: "17"
        run: |
          set -euo pipefail

          if ! release=$(gh api "repos/${GITHUB_REPOSITORY}/releases/tags/${TAG}" 2>gh.err); then
            if grep -q 'HTTP 404' gh.err; then
              echo "no release for ${TAG}, nothing to announce"
              exit 0
            fi
            cat gh.err >&2
            exit 1
          fi

          # A release a person published already fired the release event above.
          author=$(jq -r '.author.login' <<<"$release")
          if [ "$author" != "github-actions[bot]" ] || [ "$(jq -r '.draft' <<<"$release")" = "true" ]; then
            echo "${TAG} published by ${author}, announced by the release event"
            exit 0
          fi

          # Same title and body as the action above, so both paths read alike.
          title="${GITHUB_REPOSITORY#*/} ${TAG} released"

          # A re-run of a successful Release run fires this event again. A failed lookup
          # stops the step rather than risk a duplicate topic.
          search=$(curl -fsS --retry 3 --proto '=https' --proto-redir '=https' -G \
            -H "Api-Key: ${DISCOURSE_API_KEY}" \
            -H "Api-Username: ${DISCOURSE_USER}" \
            "${DISCOURSE_URL}/search.json" \
            --data-urlencode "q=\"${title}\" in:title")
          existing=$(jq -r --arg t "$title" --argjson c "$DISCOURSE_CATEGORY" \
            '[(.topics // [])[] | select(.category_id == $c and (.title | ascii_downcase) == ($t | ascii_downcase))] | length' \
            <<<"$search")
          if [ "$existing" != "0" ]; then
            echo "topic '${title}' already exists"
            exit 0
          fi

          # goreleaser leaves the body empty; the notes are written on the release page afterwards.
          url=$(jq -r '.html_url' <<<"$release")
          body=$(jq -r '.body // ""' <<<"$release")
          if [ -z "${body//[[:space:]]/}" ]; then
            body="Release notes and downloads: ${url}"
          fi

          jq -n \
            --arg title "$title" \
            --arg raw "$(printf '[%s](%s)\n\n%s' "$title" "$url" "$body")" \
            --argjson category "$DISCOURSE_CATEGORY" \
            '{title: $title, raw: $raw, category: $category, tags: ["releases"]}' \
            | curl -fsS -X POST "${DISCOURSE_URL}/posts.json" \
                -H "Api-Key: ${DISCOURSE_API_KEY}" \
                -H "Api-Username: ${DISCOURSE_USER}" \
                -H "Content-Type: application/json" \
                --data @- \
            | jq -r '"posted \(env.DISCOURSE_URL)/t/\(.topic_slug)/\(.topic_id)"'