name: Label PR

on:
  pull_request_target:
    types:
      - opened
    branches:
      - main
      - 2.x

jobs:
  add-pr-labels:
    name: Add PR labels
    runs-on: ubuntu-latest
    permissions:
      pull-requests: write
    if: github.repository == 'nuxt/nuxt'
    steps:
      - uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
        env:
          PULL_REQUEST_TITLE: ${{ github.event.pull_request.title }}
        with:
          script: |
            const labelsToAdd = []

            const pullRequest = {
              baseLabel: '${{ github.event.pull_request.base.label }}',
              number: ${{ github.event.pull_request.number }},
              title: process.env.PULL_REQUEST_TITLE,
              labelsNames: ${{ toJson(github.event.pull_request.labels.*.name) }}
            }

            // Select label based on the branch name
            const branchNameBasedLabelName = {
              'nuxt:main': '3.x',
              'nuxt:2.x': '2.x'
            }[pullRequest.baseLabel]

            if (
              branchNameBasedLabelName &&
              !pullRequest.labelsNames.includes(branchNameBasedLabelName)
            ) {
              labelsToAdd.push(branchNameBasedLabelName)
            }

            // Select label based on the type in PR title
            const eligibleTypesToLabelsNamesMap = {
              chore: 'chore',
              ci: 'chore',
              docs: 'documentation',
              feat: 'enhancement',
              fix: 'bug',
              perf: 'performance',
              refactor: 'refactor',
              test: 'test'
            }

            for (const [eligibleType, labelName] of Object.entries(
              eligibleTypesToLabelsNamesMap
            )) {
              if (
                pullRequest.title.startsWith(eligibleType) &&
                !pullRequest.labelsNames.includes(
                  eligibleTypesToLabelsNamesMap[eligibleType]
                )
              ) {
                labelsToAdd.push(labelName)

                break
              }
            }

            // Add selected labels
            if (labelsToAdd.length > 0) {
              github.rest.issues.addLabels({
                issue_number: pullRequest.number,
                owner: context.repo.owner,
                repo: context.repo.repo,
                labels: labelsToAdd
              })
            }