name: release

# Publishes an immutable, version-tagged image on ghcr.io.
# Ordinary commits and bare git tag pushes do not publish anything. A published
# GitHub Release runs this workflow directly (same pattern as gosentry / imap-scrub).
# You can also run it manually via workflow_dispatch with an explicit SemVer X.Y.Z.
#
# Native per-architecture builds (see docs/development.md), not qemu: running
# the full Postfix and panel stack under emulation for the e2e gate below is
# impractically slow. Each arch builds, e2e-gates and pushes its own tag on its
# own native runner; a merge job then combines them into the one manifest tag
# documented in deploy/docker-compose.yml. "test, then push" (not push-by-digest
# then test) is deliberate: it means the bytes that get tagged are exactly the
# bytes that passed e2e. The per-arch tags stay in GHCR next to the version
# tag: they are the images the multi-arch manifest points at, and GHCR cannot
# drop a tag without deleting the image behind it.
on:
  release:
    types: [published]
  workflow_dispatch:
    inputs:
      version:
        description: "Image version as X.Y.Z (no v prefix)."
        required: true
        type: string

permissions:
  contents: read
  packages: write

jobs:
  prepare:
    runs-on: ubuntu-latest
    outputs:
      version: ${{ steps.version.outputs.version }}
    steps:
      - name: Derive a SemVer X.Y.Z version
        id: version
        env:
          INPUT_VERSION: ${{ github.event.inputs.version }}
          RELEASE_TAG: ${{ github.event.release.tag_name }}
          EVENT_NAME: ${{ github.event_name }}
        run: |
          set -euo pipefail
          if [ "$EVENT_NAME" = "release" ]; then
            raw="${RELEASE_TAG:-}"
          else
            raw="${INPUT_VERSION:-}"
          fi
          raw="${raw#v}"
          if ! [[ "$raw" =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
            echo "::error::release version is not SemVer X.Y.Z (event=${EVENT_NAME}; tag=${RELEASE_TAG:-} input=${INPUT_VERSION:-}). Refusing to publish ghcr.io/${{ github.repository }}:${raw:-?}"
            exit 1
          fi
          echo "version=${raw}" >> "$GITHUB_OUTPUT"

  build:
    needs: prepare
    strategy:
      fail-fast: false
      matrix:
        include:
          - runner: ubuntu-latest
            arch: amd64
          - runner: ubuntu-24.04-arm
            arch: arm64
    runs-on: ${{ matrix.runner }}
    steps:
      - uses: actions/checkout@v4
        with:
          ref: v${{ needs.prepare.outputs.version }}

      - uses: docker/setup-buildx-action@v3

      - name: Build image (native, loaded locally for the e2e gate)
        uses: docker/build-push-action@v6
        with:
          context: .
          file: build/Dockerfile
          load: true
          provenance: false
          build-args: |
            VERSION=${{ needs.prepare.outputs.version }}
          tags: selfpost:e2e

      - uses: actions/setup-go@v5
        with:
          go-version: "1.26"
          cache-dependency-path: test/e2e/go.sum

      - name: e2e (gates publishing — see docs/development.md)
        # The e2e builds selfpost:e2e again through compose.override.yml, and
        # that rebuild is the image pushed below. Without the version here it
        # was stamped "e2e" (audit 2026-10-12, H1); the suite now checks the
        # stamp against this variable.
        env:
          SELFPOST_E2E_VERSION: ${{ needs.prepare.outputs.version }}
        run: cd test/e2e && go test -v -timeout 20m ./...

      - name: Check the version stamp of the image about to be pushed
        env:
          WANT: ${{ needs.prepare.outputs.version }}
        run: |
          set -euo pipefail
          for bin in panel selfpost-backup; do
            got=$(docker run --rm --entrypoint "$bin" selfpost:e2e -version)
            if [ "$got" != "$WANT" ]; then
              echo "::error::selfpost:e2e $bin -version = '$got', want '$WANT'; refusing to push"
              exit 1
            fi
          done

      - name: Log in to ghcr.io
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Push per-arch tag
        # GHCR sometimes rejects the final manifest with "unknown blob" after
        # every layer reports Pushed (registry race / overwrite of the same
        # version tag). Retries are idempotent for identical local bytes.
        run: |
          set -euo pipefail
          image="ghcr.io/${{ github.repository }}:${{ needs.prepare.outputs.version }}-${{ matrix.arch }}"
          docker tag selfpost:e2e "$image"
          attempt=1
          max=4
          backoff=15
          while true; do
            set +e
            out=$(docker push "$image" 2>&1)
            rc=$?
            set -e
            if [ "$rc" -eq 0 ]; then
              printf '%s\n' "$out"
              exit 0
            fi
            printf '%s\n' "$out" >&2
            if [ "$attempt" -ge "$max" ] || ! grep -qiE 'unknown blob|blob unknown|blob upload invalid|manifest unknown|received unexpected HTTP status: 5[0-9]{2}|429 Too Many Requests|temporarily unavailable' <<<"$out"; then
              echo "::error::docker push failed for ${image} (attempt ${attempt}/${max}, exit ${rc})" >&2
              exit "$rc"
            fi
            echo "::warning::transient GHCR error pushing ${image} (attempt ${attempt}/${max}); retry in ${backoff}s" >&2
            sleep "$backoff"
            attempt=$((attempt + 1))
            backoff=$((backoff * 2))
          done

  merge:
    needs: [prepare, build]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          ref: v${{ needs.prepare.outputs.version }}

      - uses: docker/setup-buildx-action@v3

      - name: Log in to ghcr.io
        uses: docker/login-action@v3
        with:
          registry: ghcr.io
          username: ${{ github.actor }}
          password: ${{ secrets.GITHUB_TOKEN }}

      - name: Merge per-arch tags into the version manifest
        # Same GHCR "unknown blob" class of failure can hit imagetools create
        # when assembling the multi-arch version tag.
        run: |
          set -euo pipefail
          version_tag="ghcr.io/${{ github.repository }}:${{ needs.prepare.outputs.version }}"
          amd64="ghcr.io/${{ github.repository }}:${{ needs.prepare.outputs.version }}-amd64"
          arm64="ghcr.io/${{ github.repository }}:${{ needs.prepare.outputs.version }}-arm64"
          attempt=1
          max=4
          backoff=15
          while true; do
            set +e
            out=$(docker buildx imagetools create -t "$version_tag" "$amd64" "$arm64" 2>&1)
            rc=$?
            set -e
            if [ "$rc" -eq 0 ]; then
              printf '%s\n' "$out"
              exit 0
            fi
            printf '%s\n' "$out" >&2
            if [ "$attempt" -ge "$max" ] || ! grep -qiE 'unknown blob|blob unknown|blob upload invalid|manifest unknown|received unexpected HTTP status: 5[0-9]{2}|429 Too Many Requests|temporarily unavailable' <<<"$out"; then
              echo "::error::imagetools create failed for ${version_tag} (attempt ${attempt}/${max}, exit ${rc})" >&2
              exit "$rc"
            fi
            echo "::warning::transient GHCR error merging ${version_tag} (attempt ${attempt}/${max}); retry in ${backoff}s" >&2
            sleep "$backoff"
            attempt=$((attempt + 1))
            backoff=$((backoff * 2))
          done

      - name: Remove orphaned untagged versions from GHCR
        # Re-publishing a version moves its tags to new manifests and leaves the
        # old ones behind as untagged "sha256:..." package versions. Delete only
        # those that no tagged manifest references: the images behind a
        # multi-arch tag are package versions too, and deleting one breaks pulls
        # of that tag. Any failed lookup aborts the step before anything is
        # deleted.
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          set -euo pipefail
          image="ghcr.io/${{ github.repository }}"
          owner="${{ github.repository_owner }}"
          pkg="${{ github.event.repository.name }}"
          api="/users/${owner}/packages/container/${pkg}/versions"
          versions=$(gh api "${api}?per_page=100" --paginate \
            --jq '.[] | [.id, .name, (.metadata.container.tags | length)] | @tsv')
          keep=$(mktemp)
          while IFS=$'\t' read -r id digest ntags; do
            [ "$ntags" -gt 0 ] || continue
            echo "$digest" >> "$keep"
            raw=$(docker buildx imagetools inspect --raw "${image}@${digest}")
            jq -r '.manifests[]?.digest' <<<"$raw" >> "$keep"
          done <<<"$versions"
          while IFS=$'\t' read -r id digest ntags; do
            [ "$ntags" -eq 0 ] || continue
            if grep -qxF "$digest" "$keep"; then
              continue
            fi
            echo "deleting orphaned GHCR package version ${id} (${digest})"
            gh api -X DELETE "${api}/${id}"
          done <<<"$versions"