name: Merged Blocking Pull Request Automation

on:
  pull_request:
    types:
      - closed

jobs:
  update-blocked-status:
    name: Update Blocked Status
    runs-on: ubuntu-latest

    # a pr that was a `blocking:<id>` label was merged.
    # find the open pr's it was blocked by and trigger a refresh of their state
    if: github.event.pull_request.merged == true && contains( join( github.event.pull_request.labels.*.name, ',' ), "blocking:" )

    permissions:
      issues: write
      pull-requests: write
      actions: write

    steps:
      - name: Gather Dependent PRs
        id: gather_deps
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_NUMBER: ${{ github.event.pull_request.number }}
        run: |
          owner=$(echo "${{ github.repository }}" | cut -d '/' -f 1)
          repo=$(echo "${{ github.repository }}" | cut -d '/' -f 2)
          query="
            query(\$repo: String!, \$owner: String!,  \$endCursor: String) {
              repository(name: \$repo, owner: \$owner) {
                pullRequests(first: 100, after: \$endCursor, states: [OPEN], labels: [\"blocked-by:${PR_NUMBER}\"]) {
                  nodes {
                    number
                    bodyText
                    merged
                  }
                  pageInfo {
                    hasNextPage
                    endCursor
                  }
                }
              }
            }
          "
          blocked_prs=$(
            gh api graphql \
              -f repo="$repo" \
              -f owner="$owner" \
              -f query="$query" \
              --paginate \
              --slurp \
              | jq -c --argjson pr "${{ github.event.pull_request.number }}" '
                  reduce ( .[].data.repository.pullRequests.nodes[] | select(
                    .bodyText |  
                      scan("(?:blocked (?:by|on)|stacked on):? #([0-9]+)") |
                      map(tonumber) |
                      any(.[]; . == $pr)
                  )) as $i ([]; . + [$i])
                '
          )
          echo "deps=$blocked_prs" >> "$GITHUB_OUTPUT"
          echo "numdeps=$(jq -r '. | length' <<< "$blocked_prs")" >> "$GITHUB_OUTPUT"

      - name: Trigger Blocked PR Workflows for Dependants
        if: fromJSON(steps.gather_deps.outputs.numdeps) > 0
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          DEPS: ${{ steps.gather_deps.outputs.deps }}
        run: |
          while read -r pr ; do
            gh api \
              --method POST \
              -H "Accept: application/vnd.github+json" \
              -H "X-GitHub-Api-Version: 2022-11-28" \
              "/repos/${{ github.repository }}/actions/workflows/blocked-prs.yml/dispatches" \
              -f "ref=${{ github.ref_name }}" \
              -f "inputs[pr_id]=$pr"
          done < <(jq -c '.[].number' <<< "$DEPS")

  label-cleanup:
    # this pr is closed, no need for these anymore
    name: "Cleanup Related blocking:<id> or blocked-by:<id>  labels"
    runs-on: ubuntu-latest

    permissions:
      issues: write
      pull-requests: write
    
    steps:
      - name: Checkout Default Branch
        uses: actions/checkout@v4
        with:
          ref: ${{ github.event.repository.default_branch }}
      - name: Delete Related Labels
        uses: ./.github/actions/delete-labels
        with:
          repository: ${{ github.repository }}
          gh_token: ${{ secrets.GITHUB_TOKEN }}
          labels: ${{ format('blocking:{0},blocked-by:{0}', github.event.pull_request.number ) }}