name: Theme Screenshots

# Screenshots of every template of a new block theme at 1440, 782 and 480px,
# published to https://theme-screenshots.space.fast/<slug>/ for the reviewer.
# Runs on every PR, but only takes screenshots of block theme folders the
# base branch doesn't have yet, whatever the branch is called.
# "Run workflow" on the Actions page takes new screenshots without a push: for
# an open PR (PR number), or for a theme already on trunk (theme folder name).
# Each gallery's Regenerate link goes there.

on:
  pull_request:
    types: [opened, synchronize, reopened]
  workflow_dispatch:
    inputs:
      pr:
        description: 'PR number (an open PR that adds a theme)'
        required: false
      theme:
        description: 'Or a theme folder name on trunk, e.g. solstice (leave the PR number empty)'
        required: false

concurrency:
  group: ${{ github.workflow }}-${{ github.event.pull_request.number || inputs.pr || inputs.theme }}
  cancel-in-progress: true

env:
  # npm, Node and GitHub for the tools; wordpress.org and Playground for WordPress;
  # the apt mirrors for the browser's system libraries;
  # WooCommerce's demo site for the sample product images; Spacefast for publishing.
  SECEX_EGRESS_RULES: registry.npmjs.org,nodejs.org,api.github.com,github.com,codeload.github.com,objects.githubusercontent.com,release-assets.githubusercontent.com,raw.githubusercontent.com,api.wordpress.org,downloads.wordpress.org,wordpress.org,downloads.w.org,playground.wordpress.net,deb.debian.org,security.debian.org,archive.ubuntu.com,security.ubuntu.com,woocommercecore.mystagingwebsite.com,api.spacefast.com,*.space.fast

permissions:
  contents: read
  pull-requests: read

jobs:
  # Finds the PR and the new block themes in it. Most PRs have none, and then
  # the screenshots job is skipped without joining the queue below.
  find:
    runs-on: [self-hosted, secex, gha-runner-2cpu-4gb]
    outputs:
      themes: ${{ steps.themes.outputs.themes || steps.trunk.outputs.themes }}
      number: ${{ steps.pr.outputs.number }}
      sha: ${{ steps.pr.outputs.sha || steps.trunk.outputs.sha }}

    steps:
    # A manual run is for an open PR from a branch in this repo: a fork's code
    # must never run in a job that holds the Spacefast key. With a theme name
    # instead, it takes the theme from the branch the run was started on (trunk).
    - name: Find the PR
      id: pr
      if: ${{ !inputs.theme || inputs.pr }}
      uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6.4.1
      env:
        PR_INPUT: ${{ inputs.pr }}
      with:
        script: |
            const pr = context.payload.pull_request || ( await (async () => {
              if (!/^[0-9]+$/.test(process.env.PR_INPUT || '')) throw new Error('Enter a PR number (digits) or a theme folder name');
              const { data } = await github.rest.pulls.get({ ...context.repo, pull_number: Number(process.env.PR_INPUT) });
              if (data.state !== 'open') throw new Error(`PR #${data.number} is not open`);
              if (data.head.repo?.full_name !== data.base.repo.full_name) throw new Error('PRs from forks are not supported');
              return data;
            })() );
            core.setOutput('number', pr.number);
            core.setOutput('sha', pr.head.sha);
            core.setOutput('base', pr.base.ref);

    - name: Find new block themes
      id: themes
      if: steps.pr.outcome == 'success'
      uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6.4.1
      env:
        PR_NUMBER: ${{ steps.pr.outputs.number }}
        HEAD_SHA: ${{ steps.pr.outputs.sha }}
        BASE_REF: ${{ steps.pr.outputs.base }}
      with:
        script: |
            const { owner, repo } = context.repo;
            const number = Number(process.env.PR_NUMBER);
            const files = await github.paginate(github.rest.pulls.listFiles, { owner, repo, pull_number: number, per_page: 100 });
            const exists = async (path, ref) => {
              try {
                await github.rest.repos.getContent({ owner, repo, path, ref });
                return true;
              } catch (error) {
                if (error.status === 404) return false;
                throw error;
              }
            };

            const folders = new Set(files.map(f => f.filename.split('/')).filter(p => p.length > 1 && !p[0].startsWith('.')).map(p => p[0]));
            const themes = [];
            for (const folder of folders) {
              if (!/^[A-Za-z0-9_-]+$/.test(folder)) continue;
              if (!(await exists(`${folder}/templates/index.html`, process.env.HEAD_SHA))) continue;
              if (!(await exists(`${folder}/style.css`, process.env.BASE_REF))) themes.push(folder);
            }
            core.setOutput('themes', themes.join(' '));
            console.log(`New block themes: ${themes.join(', ') || 'none'}`);

    - name: Find the theme on trunk
      id: trunk
      if: ${{ inputs.theme && !inputs.pr }}
      uses: actions/github-script@d7906e4ad0b1822421a7e6a35d5ca353c962f410 # v6.4.1
      env:
        THEME_INPUT: ${{ inputs.theme }}
      with:
        script: |
            const slug = process.env.THEME_INPUT.trim();
            if (!/^[A-Za-z0-9_-]+$/.test(slug)) throw new Error('Theme must be a folder name, e.g. solstice');
            try {
              await github.rest.repos.getContent({ ...context.repo, path: `${slug}/templates/index.html`, ref: context.sha });
            } catch (error) {
              if (error.status === 404) throw new Error(`${slug} is not a block theme on ${context.ref.replace('refs/heads/', '')}`);
              throw error;
            }
            core.setOutput('themes', slug);
            core.setOutput('sha', context.sha);

  screenshots:
    needs: find
    if: needs.find.outputs.themes != ''
    runs-on: [self-hosted, secex, gha-runner-2cpu-4gb]
    # One screenshot run at a time across all PRs. Each publish rebuilds the
    # whole site from the live galleries, so two at once could undo each other.
    # A run that arrives while another one waits replaces the waiting one.
    concurrency:
      group: theme-screenshots-publish
      cancel-in-progress: false
    env:
      THEMES: ${{ needs.find.outputs.themes }}

    steps:
    # A manual run for a PR checks out the PR merged into the base branch, the
    # same code a push would test. A run for a theme on trunk checks out trunk.
    - name: Checkout code
      uses: actions/checkout@a37ce9120846195fa4ece8f58b268e6043cb2f26 # v3.7.0
      with:
        ref: ${{ github.event_name == 'workflow_dispatch' && needs.find.outputs.number && format('refs/pull/{0}/merge', needs.find.outputs.number) || '' }}

    - name: Setup Node.js
      uses: actions/setup-node@3235b876344d2a9aa001b8d1453c930bba69e610 # v3.9.1
      with:
        node-version: '20'

    - name: Install Playground and Playwright
      if: env.THEMES != ''
      run: |
        npm install -g @wp-playground/cli
        # The runner can't reach Playwright's browser download, so the browser
        # comes from npm instead: @sparticuz/chromium ships Chromium 143, the
        # version Playwright 1.57 drives. `install-deps` only adds system libraries.
        # sharp turns the screenshots into WebP.
        npm install --prefix "$RUNNER_TEMP/pw" playwright@1.57.0 @sparticuz/chromium@143.0.4 sharp@0.34.4
        "$RUNNER_TEMP/pw/node_modules/.bin/playwright" install-deps chromium
        CHROME=$(cd "$RUNNER_TEMP/pw" && node --input-type=module -e "import c from '@sparticuz/chromium'; console.log(await c.executablePath())")
        echo "CHROME_PATH=$CHROME" >> "$GITHUB_ENV"
        echo "PLAYWRIGHT_PATH=$RUNNER_TEMP/pw/node_modules/playwright" >> "$GITHUB_ENV"
        echo "SHARP_PATH=$RUNNER_TEMP/pw/node_modules/sharp" >> "$GITHUB_ENV"

    # The theme's PHP runs in this step, inside Playground. The Spacefast key is
    # not in this step's environment, and Playground is stopped before the next step.
    - name: Take screenshots
      if: env.THEMES != ''
      env:
        PLAYGROUND_CLI: wp-playground-cli
      run: |
        for SLUG in $THEMES; do
          bash .theme-utils/screenshots/capture.sh "$SLUG" "$RUNNER_TEMP/shots/$SLUG"
        done

    - name: Publish to Spacefast
      if: env.THEMES != ''
      env:
        SPACEFAST_TOKEN: ${{ secrets.SPACEFAST_TOKEN }}
        NOTE: "Captured from ${{ needs.find.outputs.sha }} (${{ needs.find.outputs.number && format('PR #{0}', needs.find.outputs.number) || github.ref_name }})"
        PR_NUMBER: ${{ needs.find.outputs.number }}
      run: |
        for SLUG in $THEMES; do
          # Without a PR, the Regenerate link asks for the theme name.
          [ -n "$PR_NUMBER" ] || export REGEN_THEME="$SLUG"
          bash .theme-utils/screenshots/publish.sh "$SLUG" "$RUNNER_TEMP/shots/$SLUG" "$NOTE"
          echo "### $SLUG: https://theme-screenshots.space.fast/$SLUG/" >> "$GITHUB_STEP_SUMMARY"
        done