name: Project release on Github

on:
  workflow_dispatch:  # this is useful to re-generate the release page without a new tag being pushed
  push:
    tags:
      - "v2.[0-9]+.[0-9]+*"
      # Ignore release versions tagged with -rc0 suffix
      - "!v2.[0-9]+.[0-9]-rc0"

jobs:
  generate-notes:
    runs-on: ubuntu-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-tags: true
          fetch-depth: 0  # slow but needed by reno

      - name: Parse version
        id: version
        run: |
          echo "current_release=$(awk -F \\- '{print $1}' < VERSION.txt)" >> "$GITHUB_OUTPUT"
          echo "current_pre_release=$(awk -F \\- '{print $2}' < VERSION.txt)" >> "$GITHUB_OUTPUT"

      - name: Install reno
        run: |
          python -m pip install --upgrade pip
          pip install "reno<5"

      - name: Generate release notes for release candidates - minor releases
        if: steps.version.outputs.current_pre_release != '' && endsWith(steps.version.outputs.current_release, '.0')
        env:
          # When generating notes for release candidates of minor versions, pick every vX.Y.Z-rcN but
          # stop when encounter vX.Y.Z-rc0. The -rc0 tag is added automatically when
          # we create the release branch, so we can assume it's always there.
          EARLIEST_VERSION: v${{ steps.version.outputs.current_release }}-rc0
        run: |
          reno report --no-show-source --ignore-cache --earliest-version "$EARLIEST_VERSION" -o relnotes.rst

      - name: Generate release notes for release candidates - bugfix releases
        if: steps.version.outputs.current_pre_release != '' && !endsWith(steps.version.outputs.current_release, '.0')
        env:
          # When generating notes for release candidates of bugfix releases, pick every vX.Y.Z-rcN but
          # stop when encounter vX.Y.Z-rc1.
          # In this case, we don't have the -rc0 tag, because we don't need to go through commits on main,
          # as we cherry-pick them into the release branch.
          EARLIEST_VERSION: v${{ steps.version.outputs.current_release }}-rc1
        run: |
          reno report --no-show-source --ignore-cache --earliest-version "$EARLIEST_VERSION" -o relnotes.rst

      - name: Generate release notes for the final release
        if: steps.version.outputs.current_pre_release == ''
        # When generating notes for the final release vX.Y.Z, we just pass --version and reno
        # will automatically collapse all the vX.Y.Z-rcN.
        run: |
          reno report --no-show-source --ignore-cache --version v${{ steps.version.outputs.current_release }} -o relnotes.rst

      - name: Convert to Markdown
        uses: docker://pandoc/core:3.1
        with:
          args: "--from rst --to markdown_github --no-highlight relnotes.rst -o relnotes.md --wrap=none"

      - name: Debug
        run: |
          cat relnotes.md

      - uses: ncipollo/release-action@v1
        with:
          bodyFile: "relnotes.md"
          prerelease: ${{ steps.version.outputs.current_pre_release }}
          allowUpdates: true