backfill-milestones.yml

name: Backfill milestones on issues

on:
    workflow_dispatch:
        inputs:
            dry_run:
                description: "Dry run (true/false)"
                required: false
                default: "true"

permissions:
    issues: write

jobs:
    backfill:
        runs-on: ubuntu-latest
        env:
            DRY_RUN: ${{ inputs.dry_run }}
        steps:
            - name: Checkout
              uses: actions/checkout@v4

            - name: Install jq
              run: sudo apt-get update && sudo apt-get install -y jq

            - name: Map labels to milestones and apply
              env:
                  GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
                  REPO: ${{ github.repository }}
              run: |
                  set -euo pipefail
                  # Milestone mapping rules by label prefixes
                  map_milestone() {
                    title="$1"
                    labels="$2"
                    if echo "$labels" | grep -qi 'type: docs\|docs'; then echo 'Documentation & Testing'; return; fi
                    if echo "$labels" | grep -qi 'type: bug\|status: bug\|bug'; then echo 'Stabilization & Cleanup'; return; fi
                    if echo "$labels" | grep -qi 'area: worker\|area: pipeline\|area: api'; then echo 'Feature Completion'; return; fi
                    if echo "$labels" | grep -qi 'area: infra\|area: devops\|opensearch\|performance\|scale'; then echo 'Optimization & Scalability'; return; fi
                    if echo "$labels" | grep -qi 'release\|v1'; then echo 'Professional Release v1.0'; return; fi
                    # default fallback
                    echo 'Feature Completion'
                  }

                  issues_json=$(gh issue list --repo "$REPO" --state open --limit 200 --json number,title,labels,milestone)
                  echo "$issues_json" | jq -c '.[]' | while read -r issue; do
                    number=$(echo "$issue" | jq -r '.number')
                    title=$(echo "$issue" | jq -r '.title')
                    current_ms=$(echo "$issue" | jq -r '.milestone.title // ""')
                    labels=$(echo "$issue" | jq -r '[.labels[].name] | join(", ")')
                    target_ms=$(map_milestone "$title" "$labels")
                    if [ -n "$current_ms" ] && [ "$current_ms" != "null" ]; then
                      echo "#${number} already has milestone '$current_ms' — skipping"
                      continue
                    fi
                    echo "#${number} => '$target_ms' (labels: $labels)"
                    if [ "$DRY_RUN" = "true" ]; then
                      continue
                    fi
                    gh issue edit "$number" --repo "$REPO" --milestone "$target_ms"
                  done