---
name: Upstream Sync Workflow
'on':
  workflow_call:
    inputs:
      release_series:
        description: 'The OpenStack release series you wish to sync against.'
        required: true
        type: string
      branch_prefix:
        description: 'The prefix of the upstream branch you want to sync against.'
        required: false
        type: string
        default: stable
      fallback_branch_prefix:
        description: 'The fallback prefix of the upstream branch you want to sync against.'
        required: false
        type: string
        default: unmaintained
      upstream:
        description: Upstream repository on GitHub (owner/repo)
        type: string
        required: false
      sync_tags:
        description: 'Whether to synchronize tags from upstream'
        required: false
        type: boolean
        default: true
env:
  GITHUB_TOKEN: ${{github.token}}
  DOWNSTREAM_OWNER: stackhpc
  UPSTREAM_OWNER: openstack
jobs:
  upstream-sync:
    runs-on: ubuntu-latest
    steps:
      - name: Get upstream SHA
        id: get_upstream_sha
        run: |
          set +e

          function get_sha {
            ref=$1
            upstream_repo=$2
            gh api \
            -H "Accept: application/vnd.github.v3+json" \
            "/repos/${upstream_repo}/commits/${ref}" --jq ".sha"
          }

          upstream="${{ inputs.upstream }}"
          if [[ -z "$upstream" ]]; then
            upstream="${{env.UPSTREAM_OWNER}}/$(basename $(pwd))"
          fi
          upstream_ref="${{inputs.branch_prefix}}/${{inputs.release_series}}"
          upstream_sha=$(get_sha $upstream_ref $upstream)
          result=$?
          if [[ $result -ne 0 ]] && [[ -n "${{inputs.fallback_branch_prefix}}" ]]; then
            echo "Failed to get SHA using standard branch prefix. Trying fallback."
            upstream_ref="${{inputs.fallback_branch_prefix}}/${{inputs.release_series}}"
            upstream_sha=$(get_sha $upstream_ref $upstream)
            result=$?
          fi
          if [[ $result -ne 0 ]]; then
            echo "Failed to get SHA using standard or fallback branch prefixes. Checking for EOL tag."
            upstream_ref="${{inputs.release_series}}-eol"
            upstream_sha=$(get_sha $upstream_ref $upstream)
            result=$?
            if [[ $result -ne 0 ]]; then
              echo "Unable to find EOL tag. Trying master branch"
              upstream_ref="master"
              upstream_sha=$(get_sha $upstream_ref $upstream)
              result=$?
              if [[ $result -ne 0 ]]; then
                echo "Unable to find master branch - Failing"
                exit 1
              fi
            fi
          fi
          echo "upstream_ref=$upstream_ref" >> $GITHUB_OUTPUT
          echo "result=$upstream_sha" >> $GITHUB_OUTPUT
      - name: Check if downstream branch exists
        if: steps.get_upstream_sha.outputs.result != ''
        id: check_if_downstream_branch_exists
        run: |
          api_path="/repos/${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))/branches/stackhpc/${{inputs.release_series}}"
          response=$(gh api -H "Accept: application/vnd.github.v3+json" $api_path --silent --include) || true
          if [[ "$response" =~ "HTTP/2.0 200 OK" ]]; then
            echo "result=true" >> $GITHUB_OUTPUT
          elif [[ "$response" =~ "HTTP/2.0 404 Not Found" ]]; then
            echo "result=false" >> $GITHUB_OUTPUT
          else
            exit 1
          fi
      - name: Create missing downstream branch
        if: steps.check_if_downstream_branch_exists.outputs.result == 'false'
        run: |
          gh api \
          --method POST \
          -H "Accept: application/vnd.github.v3+json" \
          "/repos/${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))/git/refs" \
          -f ref='refs/heads/stackhpc/${{inputs.release_series}}' \
          -f sha=${{steps.get_upstream_sha.outputs.result}}
      - name: Check if upstream is ahead of downstream
        if: steps.check_if_downstream_branch_exists.outputs.result == 'true'
        id: check_if_ahead
        run: |
          ahead_by=$(gh api \
          -H "Accept: application/vnd.github.v3+json" \
          "/repos/${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))"\
          "/compare/stackhpc/${{inputs.release_series}}..."\
          "${{env.UPSTREAM_OWNER}}:${{steps.get_upstream_sha.outputs.result}}" --jq '.ahead_by')
          echo "result=$ahead_by" >> $GITHUB_OUTPUT
      - name: Create copy of the upstream branch
        if: steps.check_if_ahead.outputs.result > 0
        run: |
          gh api \
          --method POST \
          -H "Accept: application/vnd.github.v3+json" \
          "/repos/${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))/git/refs" \
          -f ref="refs/heads/upstream/${{inputs.release_series}}-$(date +%F)" \
          -f sha=${{steps.get_upstream_sha.outputs.result}}
      - name: Create a pull request
        if: steps.check_if_ahead.outputs.result > 0
        id: create_pull_request
        run: |
          pull_request_url=$(gh api \
          --method POST \
          -H "Accept: application/vnd.github.v3+json" \
          /repos/${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))/pulls \
          -f title="Synchronise ${{inputs.release_series}} with upstream" \
          -f body="This PR contains a snapshot of ${{inputs.release_series}} from upstream ${{steps.get_upstream_sha.outputs.upstream_ref}}." \
          -f head="${{env.DOWNSTREAM_OWNER}}:upstream/${{inputs.release_series}}-$(date +%F)" \
          -f base="stackhpc/${{inputs.release_series}}" --jq '.url')
          echo "result=$(basename $pull_request_url)" >> $GITHUB_OUTPUT
      - name: Add labels to pull request
        if: steps.check_if_ahead.outputs.result > 0
        run: |
          api_path="https://api.github.com/repos/${{env.DOWNSTREAM_OWNER}}\
          /$(basename $(pwd))/issues/${{steps.create_pull_request.outputs.result}}/labels"
          curl \
          -X POST \
          -H "Authorization: token ${{env.GITHUB_TOKEN}}" \
          -H "Accept: application/vnd.github.v3+json" \
          $api_path \
          -d '{"labels":["automated","synchronisation"]}'
      - name: Sync tags from upstream to downstream
        if: ${{ inputs.sync_tags }}
        run: |
          upstream="${{ inputs.upstream }}"
          if [[ -z "$upstream" ]]; then
            upstream="${{env.UPSTREAM_OWNER}}/$(basename $(pwd))"
          fi
          downstream_repo="${{env.DOWNSTREAM_OWNER}}/$(basename $(pwd))"
          # Get all upstream tags
          gh api --paginate \
            "/repos/${upstream}/git/refs/tags" \
            --jq '.[] | "\(.ref) \(.object.sha)"' | \
          while read -r ref sha; do
            echo "Checking tag: $ref"
            # Check if tag exists in downstream
            if gh api "/repos/${downstream_repo}/git/${ref}" &>/dev/null; then
              echo "Tag already exists, skipping"
            else
              echo "Creating tag: $ref"
              gh api --method POST \
                "/repos/${downstream_repo}/git/refs" \
                -f "ref=$ref" \
                -f "sha=$sha"
            fi
          done