action.yml

name: "Changelog Check"
description: "Run a changelog check"
author: "Graylog, Inc. <hello@graylog.com>"

inputs:
  gh-token:
    description: "GitHub access token"
    required: false
  cli-version:
    description: "Version of the graylog-project CLI command"
    required: true
    default: "latest"

runs:
  using: "composite"
  steps:
    - name: "Check changelog presence"
      uses: "actions/github-script@v6"
      id: "check-presence"
      with:
        script: |
          const fs = require('node:fs');
          const path = require('node:path');

          const pr = context.payload.pull_request;
          const author = pr.user.login;

          const setSummary = (title, text, files = []) => {
            core.summary.addHeading(title, 2);
            core.summary.addRaw(`<p>${text}</p>`, true);

            if (files.length > 0) {
              core.summary.addRaw(`<p>Files:</p>`);
              core.summary.addList(files.map(f => `<code>${f}</code>`));
            }

            core.summary.write({ overwrite: true });
          };

          if (author.includes('dependabot') || author.includes('github-actions')) {
            setSummary('Changelog Check Skipped', `Check skipped because the PR author is a bot user. (author: ${author})`);
            return;
          }

          const body = pr.body || "";
          if (body.includes('/nocl')) {
            setSummary('Changelog Check Skipped', 'Check skipped because of /nocl flag.');
            return;
          }

          const owner = pr.base.repo.owner.login;
          const repo = pr.base.repo.name;

          const baseRef = `${pr.base.repo.owner.login}:${pr.base.sha}`;
          const headRef = `${pr.head.repo.owner.login}:${pr.head.sha}`;

          console.log(`Getting changed files for ${owner}/${repo}: ${baseRef}...${headRef}`);

          const response = await github.rest.repos.compareCommitsWithBasehead({
            owner: owner,
            repo: repo,
            basehead: `${baseRef}...${headRef}`,
          });

          const clFiles = response.data.files
            .filter(f => f.filename.startsWith('changelog/'))
            .filter(f => f.status !== 'removed')
            .map(f => f.filename);

          if (clFiles.length === 0) {
            const msg = 'The PR does not contain a changelog entry file.';
            setSummary('Failure', msg);
            core.setFailed(msg);
          } else {
            setSummary('Success', 'At least one changelog entry file is present.', clFiles);

            const clFilesPath = path.join(process.env.RUNNER_TEMP, 'changelog-files');

            fs.mkdirSync(clFilesPath, 0o700);

            core.setOutput('changelog_path', clFilesPath);

            clFiles.forEach(async (file) => {
              const outputPath = path.join(clFilesPath, path.basename(file));

              console.log(`Downloading ${file} into ${outputPath}`);

              const response = await github.rest.repos.getContent({
                owner: owner,
                repo: repo,
                path: file,
                ref: pr.head.sha,
              });

              const text = Buffer.from(response.data.content, 'base64').toString('utf-8');

              fs.writeFileSync(outputPath, text, {mode: 0o600});
            });
          }

    - name: "Install graylog-project CLI (version: ${{ inputs.cli-version }})"
      uses: "Graylog2/actions/project-cli@main"
      with:
        cli-version: "${{ inputs.cli-version }}"

    - name: "Run changelog linter"
      if: steps.check-presence.outputs.changelog_path
      shell: "bash"
      run: |
        graylog-project changelog lint --strict ${{ steps.check-presence.outputs.changelog_path }}