update-diff.yml

name: Update /diff from hl7-diff

# Manually-triggered workflow that pulls the latest `dist` artifact
# produced by the brianpos/hl7-diff Build workflow and commits its
# contents into source/diff/ on the branch this workflow was run from.
#
# Pick the target branch from the "Run workflow" dropdown in the Actions
# UI (or pass `ref` to the API). The commit lands on whatever branch you
# selected, so you can route updates to `main` or to a feature branch.
#
# Uses only first-party tooling: actions/checkout and the `gh` CLI that
# is preinstalled on GitHub-hosted runners. No third-party actions.

on:
  workflow_dispatch:
    inputs:
      source_run_id:
        description: "hl7-diff workflow run id to pull `dist` from. Leave blank to use the latest successful Build run on hl7-diff `main`."
        required: false
        default: ""

permissions:
  contents: write

jobs:
  update-diff:
    runs-on: ubuntu-latest
    env:
      SOURCE_REPO: brianpos/hl7-diff
      SOURCE_WORKFLOW: build.yml
      SOURCE_BRANCH: main
      ARTIFACT_NAME: dist
      TARGET_DIR: source/diff
      GH_TOKEN: ${{ github.token }}

    steps:
      - name: Checkout target branch
        uses: actions/checkout@v4

      - name: Resolve source run id
        id: resolve
        run: |
          set -euo pipefail
          run_id="${{ inputs.source_run_id }}"
          if [ -z "$run_id" ]; then
            echo "Looking up latest successful '$SOURCE_WORKFLOW' run on $SOURCE_REPO@$SOURCE_BRANCH..."
            run_id=$(gh run list \
              --repo "$SOURCE_REPO" \
              --workflow "$SOURCE_WORKFLOW" \
              --branch "$SOURCE_BRANCH" \
              --status success \
              --limit 1 \
              --json databaseId \
              --jq '.[0].databaseId')
          fi
          if [ -z "$run_id" ] || [ "$run_id" = "null" ]; then
            echo "::error::Could not resolve a source run id."
            exit 1
          fi
          echo "Using source run id: $run_id"
          echo "run_id=$run_id" >> "$GITHUB_OUTPUT"

      - name: Download dist artifact from hl7-diff
        run: |
          set -euo pipefail
          rm -rf /tmp/hl7-diff-dist
          mkdir -p /tmp/hl7-diff-dist
          gh run download "${{ steps.resolve.outputs.run_id }}" \
            --repo "$SOURCE_REPO" \
            --name "$ARTIFACT_NAME" \
            --dir /tmp/hl7-diff-dist
          echo "Downloaded files:"
          ls -la /tmp/hl7-diff-dist

      - name: Replace ${{ env.TARGET_DIR }} with artifact contents
        run: |
          set -euo pipefail
          # Wipe the existing target dir so stale hashed asset filenames
          # are not left behind, then copy the freshly built files in.
          rm -rf "$TARGET_DIR"
          mkdir -p "$TARGET_DIR"
          cp -a /tmp/hl7-diff-dist/. "$TARGET_DIR/"
          echo "New $TARGET_DIR contents:"
          ls -la "$TARGET_DIR"

      - name: Commit and push to ${{ github.ref_name }}
        run: |
          set -euo pipefail
          git config user.name  "github-actions[bot]"
          git config user.email "41898282+github-actions[bot]@users.noreply.github.com"

          git add "$TARGET_DIR"
          if git diff --cached --quiet; then
            echo "No changes to commit; $TARGET_DIR is already up to date."
            exit 0
          fi

          run_url="https://github.com/${SOURCE_REPO}/actions/runs/${{ steps.resolve.outputs.run_id }}"
          git commit -m "Update /diff from hl7-diff run ${{ steps.resolve.outputs.run_id }}" \
                     -m "Source: $run_url"
          git push origin "HEAD:${{ github.ref_name }}"