release.yml

name: Release

on:
  workflow_dispatch:
    inputs:
      tag:
        description: 'SemVer tag to release (e.g. v0.1.0)'
        required: true
        type: string
        default: 'v0.1.0'
  # Allows releases when workflow_dispatch is unavailable (e.g. narrow GitHub tokens):
  # create an annotated tag on main and push it — GoReleaser runs for that tag.
  push:
    tags:
      - 'v*.*.*'

permissions:
  contents: read

jobs:
  tag:
    name: Create tag
    if: github.event_name == 'workflow_dispatch'
    runs-on: ubuntu-latest
    permissions:
      contents: write
    outputs:
      tag: ${{ steps.tag.outputs.tag }}
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - name: Require main branch
        run: |
          if [ "${GITHUB_REF}" != "refs/heads/main" ]; then
            echo "Release workflow must be run from main; got ${GITHUB_REF}."
            exit 1
          fi

      - name: Validate version format
        env:
          TAG: ${{ inputs.tag }}
        run: |
          if ! echo "$TAG" | grep -qE '^v(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$'; then
            echo "Invalid tag format: $TAG"
            echo "Expected: vMAJOR.MINOR.PATCH"
            exit 1
          fi

      - name: Ensure tag is reusable or create it
        id: tag
        env:
          TAG: ${{ inputs.tag }}
        run: |
          HEAD_SHA="$(git rev-parse HEAD)"

          if git rev-parse -q --verify "refs/tags/$TAG" >/dev/null; then
            TAG_SHA="$(git rev-list -n1 "$TAG")"
            echo "Tag already exists locally: $TAG ($TAG_SHA)"
            exit 1
          else
            REMOTE_SHA="$(git ls-remote --tags origin "refs/tags/$TAG" | awk '{print $1}' | head -n1)"
            if [ -n "$REMOTE_SHA" ]; then
              echo "Tag already exists on origin: $TAG ($REMOTE_SHA)"
              exit 1
            else
              git config user.name  "github-actions[bot]"
              git config user.email "github-actions[bot]@users.noreply.github.com"
              git tag -a "${TAG}" -m "Release ${TAG}"
              git push origin "refs/tags/${TAG}"
            fi
          fi
          echo "tag=${TAG}" >> $GITHUB_OUTPUT

  goreleaser:
    name: GoReleaser
    needs:
      - tag
    # Run after workflow_dispatch tagging succeeds, or when a release tag was pushed
    # (the tag job is skipped on push; skipped needs require always() so this if is evaluated).
    # always() && !cancelled(): respect workflow cancellation.
    # Push path: only initial tag creation, not delete/force-push.
    if: |
      always() && !cancelled() &&
      (github.event_name != 'push' || (github.event.created && !github.event.deleted && !github.event.forced)) &&
      (needs.tag.result == 'success' ||
        (github.event_name == 'push' && needs.tag.result == 'skipped'))
    runs-on: ubuntu-latest
    permissions:
      contents: write
      id-token: write
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
          ref: >-
            ${{
              github.event_name == 'workflow_dispatch'
              && needs.tag.outputs.tag
              || github.ref
            }}

      - name: Validate pushed tag format
        if: github.event_name == 'push'
        env:
          TAG: ${{ github.ref_name }}
        run: |
          set -euo pipefail
          if ! echo "$TAG" | grep -qE '^v(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)\.(0|[1-9][0-9]*)$'; then
            echo "Invalid tag format: $TAG"
            echo "Expected: vMAJOR.MINOR.PATCH"
            exit 1
          fi

      - name: Determine release tag
        id: release_meta
        env:
          EVENT_NAME: ${{ github.event_name }}
          TAG_WORKFLOW_DISPATCH: ${{ needs.tag.outputs.tag }}
          TAG_PUSH: ${{ github.ref_name }}
        run: |
          set -euo pipefail
          if [ "${EVENT_NAME}" = "workflow_dispatch" ]; then
            TAG="${TAG_WORKFLOW_DISPATCH}"
          else
            TAG="${TAG_PUSH}"
          fi
          echo "release_tag=$TAG" >> "$GITHUB_OUTPUT"

      - name: Require pushed tag to target mainline
        if: github.event_name == 'push'
        run: |
          set -euo pipefail
          TAG_COMMIT="$(git rev-parse HEAD)"
          git fetch origin "refs/heads/main:refs/remotes/origin/main"
          if ! git merge-base --is-ancestor "$TAG_COMMIT" "origin/main"; then
            echo "Release tag must point to a commit reachable from origin/main (not a feature-branch-only SHA)."
            exit 1
          fi

      - uses: actions/setup-go@v5
        with:
          go-version-file: go.mod
          cache: true

      - uses: goreleaser/goreleaser-action@v6
        with:
          distribution: goreleaser
          version: "~> v2"
          args: release --clean --config .goreleaser.stable.yaml
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          HOMEBREW_TAP_TOKEN: ${{ secrets.HOMEBREW_TAP_TOKEN }}

      - name: Verify Homebrew formula publish
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          RELEASE_TAG: ${{ steps.release_meta.outputs.release_tag }}
        run: |
          set -euo pipefail
          RELEASE_VERSION="${RELEASE_TAG#v}"
          for attempt in $(seq 1 18); do
            FORMULA_B64="$(gh api repos/git-fire/homebrew-tap/contents/Formula/git-rain.rb --jq '.content' 2>/dev/null || true)"
            if [ -n "$FORMULA_B64" ]; then
              FORMULA_CONTENT="$(printf '%s' "$FORMULA_B64" | tr -d '\n' | base64 -d)"
              if printf '%s' "$FORMULA_CONTENT" | grep -q "version \"${RELEASE_VERSION}\"" && \
                 printf '%s' "$FORMULA_CONTENT" | grep -q "/download/${RELEASE_TAG}/"; then
                echo "Homebrew formula updated for ${RELEASE_TAG}."
                exit 0
              fi
            fi
            echo "Homebrew formula not updated for ${RELEASE_TAG} yet (attempt ${attempt}/18)."
            sleep 10
          done
          echo "Homebrew formula did not update for ${RELEASE_TAG}; failing release gate."
          exit 1