name: Create Internal Release Tag

on:
  workflow_dispatch:
    inputs:
      base_version:
        description: "Base version to iterate on (e.g. 2.6.7). The next internal iteration will be created for this version."
        required: true
      dry_run:
        description: "If true, calculate but do not push tag"
        required: false
        default: "false"

permissions:
  contents: write

jobs:
  create-internal-tag:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout repository
        uses: actions/checkout@v5
        with:
          fetch-depth: 0

      - name: Compute Tag
        id: tag
        run: |
          set -euo pipefail
          BASE='${{ inputs.base_version }}'
          # Find the highest existing internal tag for this base version and increment it.
          EXISTING=$(git tag --list "v${BASE}-internal.*" | sed -E 's/^v.*-internal\.([0-9]+)$/\1/' | sort -n | tail -1 || true)
          if [ -z "$EXISTING" ]; then NEXT=1; else NEXT=$((EXISTING+1)); fi
          FINAL_TAG="v${BASE}-internal.${NEXT}"
          # Check if the tag already exists for some reason (e.g. race condition).
          if git tag --list | grep -q "^${FINAL_TAG}$"; then
            echo "Tag ${FINAL_TAG} already exists." >&2
            exit 1
          fi
          echo "internal_tag=$FINAL_TAG" >> $GITHUB_OUTPUT

      - name: Dry Run Preview
        if: ${{ inputs.dry_run == 'true' }}
        run: |
          echo "DRY RUN: Would create tag ${{ steps.tag.outputs.internal_tag }} pointing to $(git rev-parse HEAD)"
          git log -5 --oneline

      - name: Create and Push Tag
        if: ${{ inputs.dry_run != 'true' }}
        run: |
          TAG='${{ steps.tag.outputs.internal_tag }}'
          MSG="Internal build iteration for ${TAG}"
          git tag -a "$TAG" -m "$MSG"
          git push origin "$TAG"
          echo "Created and pushed $TAG"

      - name: Output Summary
        run: |
          echo "### Internal Tag Created" >> $GITHUB_STEP_SUMMARY
          echo "Tag: ${{ steps.tag.outputs.internal_tag }}" >> $GITHUB_STEP_SUMMARY
          echo "Base Version: ${{ inputs.base_version }}" >> $GITHUB_STEP_SUMMARY
          echo "Dry Run: ${{ inputs.dry_run }}" >> $GITHUB_STEP_SUMMARY