name: Deploy Preview

on:
  workflow_run:
    workflows: ["Build Preview"]
    types:
      - completed

jobs:
  deploy-preview:
    runs-on: ubuntu-latest
    if: ${{github.event.workflow_run.event == 'pull_request' && github.event.workflow_run.conclusion == 'success'}}
    steps:
      - uses: actions/setup-node@v2
        with:
          node-version: '16'
      - run: npm install --global netlify-cli@6
      - run: npm install unzipper@0.10

      - name: Get pull request number
        uses: actions/github-script@v5
        id: pull-request-number
        with:
          result-encoding: string
          script: |
            const unzipper = require('unzipper');

            const artifacts = await github.rest.actions.listWorkflowRunArtifacts({
              owner: context.repo.owner,
              repo: context.repo.repo,
              run_id: ${{github.event.workflow_run.id}}
            });

            const artifact = artifacts.data.artifacts.filter(
              artifact => artifact.name === 'pr'
            )[0];

            if (!artifact) {
              throw new Error('No pr artifact found');
            }

            const download = await github.rest.actions.downloadArtifact({
              owner: context.repo.owner,
              repo: context.repo.repo,
              artifact_id: artifact.id,
              archive_format: 'zip'
            });

            const directory = await unzipper.Open.buffer(Buffer.from(download.data));
            const file = directory.files.find(d => d.path === 'number');
            const content = await file.buffer();
            return content.toString();

      - uses: dawidd6/action-download-artifact@v2
        with:
          github_token: ${{secrets.GITHUB_TOKEN}}
          workflow: build-preview.yml
          pr: ${{steps.pull-request-number.outputs.result}}
          name: site
          path: build/site

      - name: Deploy to Netlify
        env:
          NETLIFY_AUTH_TOKEN: ${{secrets.NETLIFY_AUTH_TOKEN}}
          NETLIFY_SITE_ID: ${{secrets.NETLIFY_SITE_ID}}
        run: netlify deploy --dir=build/site --alias=deploy-preview-${{steps.pull-request-number.outputs.result}}

      - name: Add comment to pull request
        uses: actions/github-script@v5
        with:
          script: |
            const pullRequestNumber = parseInt(${{steps.pull-request-number.outputs.result}}, 10);

            const start = ':package:';
            const author = 'github-actions[bot]';

            const comments = await github.rest.issues.listComments({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: pullRequestNumber
            });

            const commentExists = comments.data.some(
              comment => comment.user.login === author && comment.body.startsWith(start)
            );

            if (!commentExists) {
              const body = [
                `${start} Preview the [examples](https://deploy-preview-${pullRequestNumber}--ol-site.netlify.app/examples/) and`,
                `[docs](https://deploy-preview-${pullRequestNumber}--ol-site.netlify.app/apidoc/) from this branch`,
                `here: https://deploy-preview-${pullRequestNumber}--ol-site.netlify.app/.`
              ].join(' ');

              await github.rest.issues.createComment({
                owner: context.repo.owner,
                repo: context.repo.repo,
                issue_number: pullRequestNumber,
                body: body
              });
            } else {
              console.log(`Preview URL comment already added to PR #${pullRequestNumber}`);
            }