name: Auto-label PR

# Sets labels automatically based on:
# - PR size (job: label-size)
# - File categories using .github/labeler config (job: label-category)
# - PR creation date for quarterly tracking (job: label-by-date)
# - Removes "Ready to merge" label on PR update (job: label-remove)

run-name: 'Set labels - PR #${{ github.event.pull_request.number }} ("${{ github.event.pull_request.title }}")'

on: pull_request_target

# Grant required permissions globally
permissions:
  contents: read          # Required for checking changed files
  pull-requests: write    # Required for labeling PRs
  issues: write           # Required for adding/removing labels

jobs:
  label-remove:
    name: "Remove Ready to merge"
    if: ${{ github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'synchronize' }}
    runs-on: ubuntu-latest

    steps:
      - name: Checkout the pull request
        uses: actions/checkout@v6

      - name: Check for label using GH CLI
        id: check
        run: |
          gh pr view ${{ github.event.pull_request.number }} --json labels -q '.labels[].name' | grep -q 'Ready to merge' && echo "has_label=true" >> $GITHUB_OUTPUT || echo "has_label=false" >> $GITHUB_OUTPUT
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}

      - name: Remove "Ready to merge" label
        if: steps.check.outputs.has_label == 'true'
        uses: PauMAVA/add-remove-label-action@v1.0.3
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          add: ""
          remove: "Ready to merge"

  label-category:
    name: "Category Labels"
    runs-on: ubuntu-latest
    if: ${{ github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'synchronize' }}

    steps:
      # Checks out the repository to read files for matching with labeler config
      - uses: actions/checkout@v6

      # Applies labels based on the .github/labeler.yml config
      - uses: actions/labeler@v6
        with:
          repo-token: "${{ secrets.GITHUB_TOKEN }}"

  label-size:
    name: "Size Label"
    runs-on: ubuntu-latest
    if: ${{ github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'synchronize' }}

    steps:
      # Automatically adds size labels based on total changed lines
      - name: Label by size
        uses: pascalgn/size-label-action@v0.5.5
        env:
          GITHUB_TOKEN: "${{ secrets.GITHUB_TOKEN }}"
        with:
          sizes: >
            {
              "0": "small",
              "50": "medium",
              "250": "large"
            }

  label-by-date:
    name: "Date label (Quarters)"
    runs-on: ubuntu-latest
    if: ${{ github.event.action == 'opened' || github.event.action == 'reopened' || github.event.action == 'synchronize' }}

    steps:
      # Determines the label (02, 05, 08, 11) based on PR creation month
      - name: Determine quarter label
        env:
          PR_CREATED_AT: ${{ github.event.pull_request.created_at }}
        run: |
          echo "PR created at: $PR_CREATED_AT"

          # Extract the numeric month (e.g., 04 for April)
          MONTH=$(date -d "$PR_CREATED_AT" +%m | sed 's/^0*//')
          echo "Month extracted: $MONTH"

          # Determine quarter-end label based on month
          if [ "$MONTH" -le 2 ] || [ "$MONTH" -eq 12 ]; then
            LABEL="02"
          elif [ "$MONTH" -le 5 ]; then
            LABEL="05"
          elif [ "$MONTH" -le 8 ]; then
            LABEL="08"
          else
            LABEL="11"
          fi

          # Set as environment variable for next step
          echo "LABEL=${LABEL}" >> $GITHUB_ENV

      # Adds the quarter label to the PR
      - name: Add quarter label
        uses: PauMAVA/add-remove-label-action@v1.0.3
        with:
          github_token: ${{ secrets.GITHUB_TOKEN }}
          add: "${{ env.LABEL }}"