version.yml

name: Version Tagger

on:
  workflow_run:
    workflows: ["CI"]
    types: [completed]
  workflow_dispatch:
    inputs:
      bump:
        description: "Version segment to bump"
        required: false
        default: patch
        type: choice
        options:
          - patch
          - minor
          - major
          - revision
      prefix:
        description: "Tag prefix"
        required: false
        default: v
        type: string

concurrency:
  group: version-${{ github.ref }}
  cancel-in-progress: false

permissions:
  actions: write
  contents: write

jobs:
  tag:
    runs-on: ubuntu-latest
    if: >
      github.event_name == 'workflow_dispatch' ||
      (github.event_name == 'workflow_run' &&
       github.event.workflow_run.conclusion == 'success' &&
       github.event.workflow_run.head_branch == 'main')

    steps:
      - name: Checkout
        uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: ${{ github.event_name == 'workflow_run' && github.event.workflow_run.head_sha || github.sha }}

      - name: Fetch tags
        run: git fetch --tags --force

      - name: Detect bump type
        id: bump
        shell: bash
        run: |
          set -euo pipefail

          if [ "${{ github.event_name }}" = "workflow_dispatch" ] && [ -n "${{ github.event.inputs.bump }}" ]; then
            echo "value=${{ github.event.inputs.bump }}" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          prefix="${{ github.event.inputs.prefix || 'v' }}"
          latest=$(git tag --list "${prefix}*" --sort=-v:refname | head -n 1)

          # Auto-mode from commits since latest version tag:
          # major -> BREAKING CHANGE or !: marker, minor -> feat:, else patch.
          if [ -n "$latest" ]; then
            range="${latest}..HEAD"
          else
            range="HEAD"
          fi

          messages=$(git log --format=%B "$range" || true)

          bump="patch"
          if echo "$messages" | grep -Eiq 'BREAKING CHANGE|^[^\n]*!:'; then
            bump="major"
          elif echo "$messages" | grep -Eiq '^feat(\(|:)|^feature(\(|:)'; then
            bump="minor"
          fi

          echo "value=$bump" >> "$GITHUB_OUTPUT"

      - name: Determine next version tag
        id: next
        shell: bash
        run: |
          set -euo pipefail

          prefix="${{ github.event.inputs.prefix || 'v' }}"
          bump="${{ steps.bump.outputs.value }}"

          # If HEAD is already tagged with the configured prefix, do nothing.
          existing_head_tag=$(git tag --points-at HEAD --list "${prefix}*" | head -n 1 || true)
          if [ -n "$existing_head_tag" ]; then
            echo "already_tagged=true" >> "$GITHUB_OUTPUT"
            echo "latest=$existing_head_tag" >> "$GITHUB_OUTPUT"
            echo "tag=$existing_head_tag" >> "$GITHUB_OUTPUT"
            exit 0
          fi

          latest=$(git tag --list "${prefix}*" --sort=-v:refname | head -n 1)
          if [ -z "$latest" ]; then
            latest="${prefix}0.0.0.0"
          fi

          version="${latest#${prefix}}"
          IFS='.' read -r major minor patch revision <<< "$version"
          major=${major:-0}
          minor=${minor:-0}
          patch=${patch:-0}
          revision=${revision:-0}

          case "$bump" in
            major)
              major=$((major + 1)); minor=0; patch=0; revision=0 ;;
            minor)
              minor=$((minor + 1)); patch=0; revision=0 ;;
            patch)
              patch=$((patch + 1)); revision=0 ;;
            revision)
              revision=$((revision + 1)) ;;
            *)
              echo "Unknown bump type: $bump" >&2
              exit 1 ;;
          esac

          new_tag="${prefix}${major}.${minor}.${patch}.${revision}"

          if git rev-parse -q --verify "refs/tags/${new_tag}" >/dev/null; then
            echo "Tag already exists: ${new_tag}" >&2
            exit 1
          fi

          echo "already_tagged=false" >> "$GITHUB_OUTPUT"
          echo "latest=$latest" >> "$GITHUB_OUTPUT"
          echo "tag=$new_tag" >> "$GITHUB_OUTPUT"

      - name: Create and push tag
        if: steps.next.outputs.already_tagged != 'true'
        run: |
          git config user.name "github-actions[bot]"
          git config user.email "github-actions[bot]@users.noreply.github.com"
          git tag "${{ steps.next.outputs.tag }}"
          git push origin "${{ steps.next.outputs.tag }}"

      - name: Trigger Release workflow
        if: steps.next.outputs.already_tagged != 'true'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          gh workflow run release.yml --ref main -f tag_name="${{ steps.next.outputs.tag }}"

      - name: Summary
        run: |
          echo "Bump    : ${{ steps.bump.outputs.value }}"
          echo "Previous: ${{ steps.next.outputs.latest }}"
          echo "Tag     : ${{ steps.next.outputs.tag }}"
          if [ "${{ steps.next.outputs.already_tagged }}" = "true" ]; then
            echo "Result  : skipped (HEAD already tagged)"
          else
            echo "Result  : created"
          fi