name: Merged Blocking Pull Request Automation

on:
  pull_request:
    types:
      - closed

jobs:
  update_blocked_status:
    name: Update Blocked Status
    runs-on: ubuntu-latest

    if: github.event.pull_request.merged == true

    permissions:
      issues: write
      pull-requests: write
      statuses: write
      checks: write

    steps:
      - name: Gather Dependent PRs
        id: gather_deps
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

        run: |
          owner="${{ github.repository_owner }}"
          owner_repo="${{ github.repository }}"
          repo="${owner_repo#"${owner}/"}"
          blocked_prs=$(
            gh api graphql \
              -f repo="$repo" \
              -f owner="$owner" \
              -f query='
                query($repo: String!, $owner: String!,  $endCursor: String) {
                  repository(name: $repo, owner: $owner) {
                    pullRequests(first: 100, after: $endCursor, states: [OPEN], labels: ["blocked"]) {
                      nodes {
                        number
                        bodyText
                        merged
                      }
                      pageInfo {
                        hasNextPage
                        endCursor
                      }
                    }
                  }
                }
              ' \
              --paginate \
              --slurp \
              | jq --argjson pr "${{ github.event.pull_request.number }}" '
                  [.[].data.repository.pullRequests.nodes[]] | .[] | select(
                    .bodyText |  
                      scan("(?:blocked (?:by|on)|stacked on):? #(?<num>[0-9]+)") |
                      map(tonumber) |
                      any(.[]; . == $pr)
                  )
                '
          )
          echo "deps=$blocked_prs" >> "$GITHUB_OUTPUT"
          echo "numdeps='$(jq -r '. | length' <<< "$blocked_prs")"

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