name: 'PR Size Labeler (Batch)'

on:
  workflow_dispatch:
    inputs:
      process_all:
        description: 'Process all PRs (open and closed) or open only'
        required: true
        default: 'false'
        type: 'choice'
        options:
          - 'true'
          - 'false'
      limit:
        description: 'Max number of PRs to fetch and check'
        required: true
        default: '100'
        type: 'string'

permissions:
  pull-requests: 'write'

jobs:
  batch-label:
    runs-on: 'ubuntu-latest'
    steps:
      - name: 'Batch label PRs'
        env:
          GH_TOKEN: '${{ secrets.GITHUB_TOKEN }}'
          GH_REPO: '${{ github.repository }}'
        run: |
          # Determine the state filter
          STATE="open"
          if [ "${{ github.event.inputs.process_all }}" = "true" ]; then
            STATE="all"
          fi

          LIMIT="${{ github.event.inputs.limit }}"
          echo "Batch labeling up to $LIMIT $STATE PRs..."

          # 1. Ensure standard premium size labels exist in the repository (self-healing)
          gh label create "size/XS" --color "7ee081" --description "XS: <10 lines changed" 2>/dev/null || true
          gh label create "size/S"  --color "a6d49f" --description "S: 10-49 lines changed" 2>/dev/null || true
          gh label create "size/M"  --color "f7d070" --description "M: 50-249 lines changed" 2>/dev/null || true
          gh label create "size/L"  --color "f48c06" --description "L: 250-999 lines changed" 2>/dev/null || true
          gh label create "size/XL" --color "dc2f02" --description "XL: >=1000 lines changed" 2>/dev/null || true

          # 2. Query PR list with all required fields in ONE call to prevent N+1 queries
          PR_LIST=$(gh pr list --state "$STATE" --limit "$LIMIT" --json number,additions,deletions,labels)
          if [ -z "$PR_LIST" ] || [ "$PR_LIST" = "[]" ]; then
            echo "ℹ️ No PRs found matching the criteria."
            exit 0
          fi

          # Parse and iterate over PRs
          UPDATED_COUNT=0
          SKIPPED_COUNT=0

          echo "$PR_LIST" | jq -c '.[]' | while read -r PR_JSON; do
            PR_NUMBER=$(echo "$PR_JSON" | jq '.number')
            ADDITIONS=$(echo "$PR_JSON" | jq '.additions')
            DELETIONS=$(echo "$PR_JSON" | jq '.deletions')
            TOTAL=$((ADDITIONS + DELETIONS))

            # Calculate target size
            if [ $TOTAL -lt 10 ]; then
              SIZE="size/XS"
            elif [ $TOTAL -lt 50 ]; then
              SIZE="size/S"
            elif [ $TOTAL -lt 250 ]; then
              SIZE="size/M"
            elif [ $TOTAL -lt 1000 ]; then
              SIZE="size/L"
            else
              SIZE="size/XL"
            fi

            # Inspect existing labels to detect discrepancies
            EXISTING_LABELS=$(echo "$PR_JSON" | jq -r '.labels[].name' 2>/dev/null || echo "")

            LABELS_TO_REMOVE=()
            for L in size/XS size/S size/M size/L size/XL; do
              if echo "$EXISTING_LABELS" | grep -Fq "$L" && [ "$L" != "$SIZE" ]; then
                LABELS_TO_REMOVE+=("--remove-label" "$L")
              fi
            done

            LABEL_TO_ADD=()
            if ! echo "$EXISTING_LABELS" | grep -Fq "$SIZE"; then
              LABEL_TO_ADD+=("--add-label" "$SIZE")
            fi

            # Update labels if there's a difference
            if [ ${#LABELS_TO_REMOVE[@]} -gt 0 ] || [ ${#LABEL_TO_ADD[@]} -gt 0 ]; then
              echo "🔄 PR #$PR_NUMBER (+$ADDITIONS/-$DELETIONS = $TOTAL lines): updating size to $SIZE"
              gh pr edit "$PR_NUMBER" "${LABELS_TO_REMOVE[@]}" "${LABEL_TO_ADD[@]}" 2>/dev/null || true
              UPDATED_COUNT=$((UPDATED_COUNT + 1))
            else
              echo "✅ PR #$PR_NUMBER (+$ADDITIONS/-$DELETIONS = $TOTAL lines): already has correct label ($SIZE). Skipping."
              SKIPPED_COUNT=$((SKIPPED_COUNT + 1))
            fi
          done

          echo "============================================"
          echo "🎉 Batch run completed!"
          echo "Skipped (already correct): $SKIPPED_COUNT"
          echo "Updated: $UPDATED_COUNT"