generate-preview-sample.yml

name: PressMint Preview Sample Generator

on:
  workflow_dispatch:
    inputs:
      pr_number:
        description: "Pull Request number"
        required: true
        type: string
      repo:
        description: "Repository (owner/repo)"
        required: true
        type: string

permissions:
  contents: write
  pull-requests: write

jobs:
  preview:
    if: github.event_name == 'workflow_dispatch'

    runs-on: ubuntu-latest

    steps:
      - name: Load PR metadata
        id: pr
        uses: actions/github-script@v8
        with:
          script: |
            const prNumber = Number('${{ inputs.pr_number }}');
      
            const [owner, repo] = '${{ inputs.repo }}'.split('/');
      
            const { data: pr } = await github.rest.pulls.get({
              owner,
              repo,
              pull_number: prNumber
            });
      
            core.setOutput('number', pr.number);
            core.setOutput('head_sha', pr.head.sha);
            core.setOutput('head_repo', pr.head.repo.full_name);
            core.setOutput('head_ref', pr.head.ref);
      - name: List artifacts
        uses: actions/github-script@v8
        id: artifact
        with:
          script: |
     
            const artifacts =
              await github.rest.actions.listWorkflowRunArtifacts({
                owner: context.repo.owner,
                repo: context.repo.repo
              });
      
            const artifact = artifacts.data.artifacts.find(
              a => a.name === 'pressmint-meta-pr-${{steps.pr.outputs.number}}'
            );
      
            if (!artifact) {
              core.setFailed('Artifact not found');
            }
      
            core.setOutput('artifact_id', artifact.id);
      
      - name: Download artifact
        run: |
          gh api \
            repos/${{ github.repository }}/actions/artifacts/${{ steps.artifact.outputs.artifact_id }}/zip \
            > artifact.zip
      
          unzip artifact.zip
        env:
          GH_TOKEN: ${{ github.token }}

      - name: Load metadata
        id: meta
        run: |
          source pressmint.env
          echo "PRESS_COUNT=$press_count" >> $GITHUB_OUTPUT
          echo "PRESS_CODE=$(echo "$press_process" | jq -r '.[0]')" >> $GITHUB_OUTPUT
      - name: Gate preview
        if: steps.meta.outputs.PRESS_COUNT != '1'
        run: |
          echo "::notice:: Skipping preview generation as ${steps.meta.outputs.PRESS_COUNT} press folders were changed"
          exit 0

      # -----------------------------
      # 1. Checkout PR source safely
      # -----------------------------
      - name: Checkout PR
        uses: actions/checkout@v5
        with:
          repository: ${{ steps.pr.outputs.head_repo }}
          ref: ${{ steps.pr.outputs.head_sha }}
          path: src

      # -----------------------------
      # 2. Run PressMintBuild
      # -----------------------------
      - name: Run PressMintBuild
        uses: ./PressMint/.github/actions/PressMintBuild
        with:
          press: '${{ steps.meta.outputs.PRESS_CODE }}'

      # -----------------------------
      # 3. Prepare preview branch
      # -----------------------------
      - name: Publish preview branch
        env:
          PR_NUMBER: ${{ steps.pr.outputs.number }}
          PRESS_CODE: ${{ steps.meta.outputs.PRESS_CODE }}
          BRANCH: preview-pr-${{ steps.pr.outputs.number }}--${PRESS_CODE,,}
        run: |
          set -e

          echo "Publishing preview branch: $BRANCH"

          git config --global user.name 'Matyáš Kopp (through GitHub Action)'
          git config --global user.email 'matyaskopp@users.noreply.github.com'

          # clone repo with token
          git clone \
            https://x-access-token:${{ secrets.GITHUB_TOKEN }}@github.com/${{ github.repository }}.git \
            repo

          cd repo

          # create or switch to orphan branch
          git checkout --orphan "$BRANCH" || git checkout "$BRANCH"

          # clean branch
          git rm -rf . || true

          # copy only sample output
          mkdir -p sample
          cp -R ../build/sample/* sample/

          # commit only if changes exist
          git add sample

          if git diff --cached --quiet; then
            echo "No changes in sample"
            exit 0
          fi

          git commit -m "PressMint preview for PR #$PR_NUMBER"

          git push origin "$BRANCH" --force

      # -----------------------------
      # 4. Comment on PR (idempotent)
      # -----------------------------
      - name: Find existing comment
        id: find_comment
        uses: peter-evans/find-comment@v4
        with:
          issue-number: ${{ steps.pr.outputs.number }}
          comment-author: "github-actions[bot]"
          body-includes: "<!-- pressmint-preview -->"

      - name: Create or update PR comment
        uses: peter-evans/create-or-update-comment@v5
        with:
          comment-id: ${{ steps.find_comment.outputs.comment-id }}
          issue-number: ${{ steps.pr.outputs.number }}
          edit-mode: replace
          body: |
            <!-- pressmint-preview -->

            ## PressMint Preview

            A sample has been generated for this PR.

            **Preview branch:**
            ```
            preview-pr-${{ steps.pr.outputs.number }}--${{ steps.meta.outputs.PRESS_CODE }}
            ```

            **Sample URL:**
            https://github.com/${{ github.repository }}/tree/preview-pr-${{ steps.pr.outputs.number }}--${{ steps.meta.outputs.PRESS_CODE }}/Sample/PressMint-${{ steps.meta_load.outputs.PRESS_CODE }}

            This preview updates automatically on every push.