# NOTE: this workflow has never run. Authored 2026-08-25 and not
# executable locally — the first real tag push is its first test.
# Expect to adjust the toolchain step if the pinned OCaml/dune version
# is not available on the runner image.

name: release

# Fires only on a version tag, so nothing is published by an ordinary
# push. `workflow_dispatch` is a DRY RUN: it builds, verifies and reports
# the glibc floor, but skips the tag guard (there is no tag) and skips
# publishing. Use it to rehearse before tagging anything.
on:
  push:
    tags:
      - 'v*'
  workflow_dispatch:

# The ONE line that replaces `gh auth login`: it widens the automatic
# GITHUB_TOKEN so this job may write releases. No PAT, no secret to
# rotate, and the token dies with the job.
permissions:
  contents: write

jobs:
  release:
    # DELIBERATE, not a default. The release binaries link glibc
    # dynamically, so the build host's glibc caps which symbol versions
    # they can import — and that cap becomes the minimum glibc every
    # user needs. Built on 24.04 (glibc 2.39) the floor is 2.39;
    # built here on 22.04 (2.35) it is 2.35, which is the difference
    # between excluding and including Ubuntu 22.04, Debian 12 and
    # RHEL 9. Raise this image only with a reason, and update the
    # supported-systems list in docs/examples/site/install/view.wo in
    # the same change.
    runs-on: ubuntu-22.04

    steps:
      - uses: actions/checkout@v4

      # setup-ocaml gives a compiler and opam. It does NOT give dune —
      # dune is an ordinary opam package, and this project has no .opam
      # file for it to infer one from, so nothing pulls it in. The first
      # run failed here with `dune: command not found`.
      - uses: ocaml/setup-ocaml@v3
        with:
          ocaml-compiler: '4.14'

      # setup-ocaml may already have installed a dune (it uses one for its
      # own cache), in which case asking for an exact older version is a
      # DOWNGRADE the solver refuses — which is how the pinned
      # `dune.3.14.0` failed. So: use whatever is there, and only install
      # if there is nothing. Any dune >= 3.14 satisfies this project's
      # `(lang dune 3.14)`.
      - name: Ensure dune is available
        run: |
          opam exec -- dune --version || opam install -y dune
          echo "dune: $(opam exec -- dune --version)"

      # The tag is the release's identity; VERSION is what the binaries
      # report. If they disagree the download URL would name a version
      # nobody can install. mkdist.sh already guards VERSION against the
      # binaries; this guards the tag against VERSION.
      - name: Tag must match VERSION
        if: github.event_name == 'push'
        run: |
          tag="${GITHUB_REF_NAME#v}"
          ver="$(cat VERSION)"
          [ "$tag" = "$ver" ] || {
            echo "tag $GITHUB_REF_NAME does not match VERSION $ver" >&2
            exit 1
          }

      # `opam exec --` because mkdist.sh calls dune internally; without
      # the opam environment on PATH the script cannot find it.
      - name: Build the tarball
        run: opam exec -- ./scripts/mkdist.sh

      # The site links one exact filename. If mkdist ever changes its
      # naming, the download button 404s for every visitor — so fail
      # here instead.
      - name: Asset name must match what the site links
        run: |
          ver="$(cat VERSION)"
          asset="writeonce-${ver}-linux-amd64.tar.gz"
          test -f "dist/$asset"
          grep -q "$asset" docs/examples/site/install/view.wo || {
            echo "$asset is not the filename /install links" >&2
            exit 1
          }

      - name: Verify the digest
        run: cd dist && sha256sum -c "writeonce-$(cat ../VERSION)-linux-amd64.tar.gz.sha256"

      # Prove the ARTEFACT works, using the binaries inside it rather
      # than the ones just built in the tree. This is what catches a
      # tarball that packaged the wrong thing.
      - name: Smoke-test the extracted toolchain
        run: |
          ver="$(cat VERSION)"
          tmp="$(mktemp -d)"
          tar -C "$tmp" -xzf "dist/writeonce-${ver}-linux-amd64.tar.gz"
          export PATH="$tmp/writeonce/bin:$PATH"
          woc version
          wovm --version
          mkdir -p "$tmp/hello"
          cd "$tmp/hello"
          printf 'name    = "hello"\nversion = "0.1.0"\n\n[runtime]\nwo = ">= 0.1"\n' > wo.toml
          printf 'fn main() -> Int {\n  print("hello, writeonce");\n  return 0;\n}\n' > main.wo
          woc .
          out="$(./target/hello)"
          [ "$out" = "hello, writeonce" ] || { echo "got: $out" >&2; exit 1; }

      # Record the real glibc floor of what is about to ship, so the
      # claim on /install can be checked against a build log rather
      # than trusted.
      - name: Report the glibc floor
        run: |
          ver="$(cat VERSION)"
          tmp="$(mktemp -d)"
          tar -C "$tmp" -xzf "dist/writeonce-${ver}-linux-amd64.tar.gz"
          for b in "$tmp"/writeonce/bin/*; do
            printf '%s needs %s\n' "$(basename "$b")" \
              "$(objdump -T "$b" | grep -oE 'GLIBC_[0-9.]+' | sort -uV | tail -1)"
          done

      # gh is preinstalled on GitHub runners and reads GH_TOKEN from the
      # environment, so there is no `gh auth login` anywhere in this file.
      # Skipped on workflow_dispatch: a dry run must never publish.
      - name: Publish
        if: github.event_name == 'push'
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          ver="$(cat VERSION)"
          gh release create "$GITHUB_REF_NAME" \
            "dist/writeonce-${ver}-linux-amd64.tar.gz" \
            "dist/writeonce-${ver}-linux-amd64.tar.gz.sha256" \
            --title "writeonce ${ver}" \
            --generate-notes