# This workflow checks that there is either a 'pr/no-changelog' label applied to a PR
# or there is a changelog/<pr number>.txt file associated with a PR for a changelog entry

name: Check Changelog

on:
  pull_request:
    types: [opened, synchronize, labeled, unlabeled]
    # Runs on PRs to main
    branches:
      - main

jobs:
  # checks that a changelog entry is present for a PR
  changelog-check:
    # If there  a `pr/no-changelog` label we ignore this check
    if: "!contains(github.event.pull_request.labels.*.name, 'pr/no-changelog')"
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@c85c95e3d7251135ab7dc9ce3241c5835cc595a9 # v3.5.3
        with:
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0 # by default the checkout action doesn't checkout all branches
      - name: Check for changelog entry in diff
        run: |
          # Check if there is a diff in the changelog directory.
          #
          # Try to identify the expected changelog file name based on PR
          # number. This won't work for Go version updates though.
          if [ ${{ github.event.repository.name }} == "vault-enterprise" ]; then
            expected_changelog_file=changelog/_${{ github.event.pull_request.number }}.txt
          else
            expected_changelog_file=changelog/${{ github.event.pull_request.number }}.txt
          fi

          echo "looking for changelog file ${expected_changelog_file}"
          changelog_files=$(git --no-pager diff --name-only HEAD "$(git merge-base HEAD "origin/${{ github.event.pull_request.base.ref }}")" -- ${expected_changelog_file})

          if [ -z "$changelog_files" ]; then
            echo "Not found."
            echo "looking for changelog file matching changelog/_go-ver-*.txt"
            # If we do not find a file matching the PR # in changelog/, we fail the check
            # unless we did a Go toolchain version update, in which case we check the
            # alternative name.
            toolchain_files=$(git --no-pager diff --name-only HEAD "$(git merge-base HEAD "origin/${{ github.event.pull_request.base.ref }}")" -- 'changelog/_go-ver-*.txt')
            if [ -z "$toolchain_files" ]; then
              echo "Not found."
              echo ""
              echo "Did not find a changelog entry named ${expected_changelog_file}"
              echo "If your changelog file is correct, skip this check with the 'pr/no-changelog' label"
              echo "Reference - https://github.com/hashicorp/vault/pull/10363 and https://github.com/hashicorp/vault/pull/11894"
              exit 1
            fi

            # Else, we found some toolchain files. Let's make sure the contents are correct.
            if ! grep -q 'release-note:change' "$toolchain_files" || ! grep -q '^core: Bump Go version to' "$toolchain_files"; then
              echo "Invalid format for changelog. Expected format:"
              echo '```release-note:change'
              echo "core: Bump Go version to x.y.z."
              echo '```'
              exit 1
            else
              echo "Found Go toolchain changelog entry in PR!"
            fi
          elif grep -q ':enhancement$' "$changelog_files"; then
            # "Enhancement is not a valid type of changelog entry, but it's a common mistake.
            echo "Found invalid type (enhancement) in changelog - did you mean improvement?"
            exit 1
          elif grep -q ':changes$' "$changelog_files"; then
            echo "Found invalid type (changes) in changelog - did you mean change?"
            exit 1
          elif grep -q ':bugs$' "$changelog_files"; then
            echo "Found invalid type (bugs) in changelog - did you mean bug?"
            exit 1
          elif grep -q ':fix$' "$changelog_files"; then
            echo "Found invalid type (fix) in changelog - did you mean bug?"
            exit 1
          elif ! grep -q '```release-note:' "$changelog_files"; then
            # People often make changelog files like ```changelog:, which is incorrect.
            echo "Changelog file did not contain 'release-note' heading - check formatting."
            exit 1
          elif grep -q '^core: Bump Go version' "$changelog_files"; then
            echo "Don't use PR numbered changelog entries for Go version bumps!"
            echo "Please use the format changelog/_go-ver-<VAULT_VERSION_WITHOUT_DOTS>.txt instead."
            echo "Example: _go-ver-1110.txt for Vault 1.11.0"
            exit 1
          else
            echo "Found changelog entry in PR!"
          fi