name: VCV Rack plugin (cross-platform)

# Builds the MEMLNaut Rack 2 plugin for all four supported platforms using the
# OFFICIAL VCVRack/rack-plugin-toolchain (the same Docker-based cross-builder the
# VCV Library uses). The toolchain image ships the Linux/MinGW/osxcross cross-
# compilers and the per-platform Rack SDKs, so every .vcvplugin is reproducible on
# a single Linux runner — no per-platform native runners, no Apple hardware.
#
# Outputs: one <slug>-<version>-<platform>.vcvplugin per platform, uploaded as a
# workflow artifact, and attached to a GitHub Release when triggered by a tag push
# (v*). See vcv/DISTRIBUTION.md for the publish-to-/next/vcv flow.

on:
  push:
    branches: [main]
    paths:
      - 'vcv/**'
      - '.github/workflows/vcv-plugin.yml'
    tags:
      - 'v*'
  pull_request:
    paths:
      - 'vcv/**'
      - '.github/workflows/vcv-plugin.yml'
  workflow_dispatch:

env:
  # Pin the official toolchain to a known-good commit (Rack SDK 2.6.6, docker
  # image version 19). Bump deliberately; never float on master.
  TOOLCHAIN_REPO: VCVRack/rack-plugin-toolchain
  TOOLCHAIN_REF: 4fd1318701624051cee54b385343f23d59b4845c
  TOOLCHAIN_IMAGE_VERSION: '19'
  PLUGIN_DIR_REL: vcv

jobs:
  build:
    name: Build ${{ matrix.platform }}
    runs-on: ubuntu-latest
    strategy:
      fail-fast: false
      matrix:
        # lin-x64 + win-x64 cross-build with gcc / mingw (no Apple SDK).
        # mac-x64 + mac-arm64 use osxcross baked into the toolchain image — this
        # is how plugins are cross-built for macOS WITHOUT Apple hardware. The
        # license-restricted macOS SDK is fetched only inside the toolchain image
        # build (never committed to this repo).
        platform: [lin-x64, win-x64, mac-x64, mac-arm64]

    steps:
      - name: Checkout plugin
        uses: actions/checkout@v4
        with:
          submodules: recursive

      - name: Checkout rack-plugin-toolchain (pinned)
        uses: actions/checkout@v4
        with:
          repository: ${{ env.TOOLCHAIN_REPO }}
          ref: ${{ env.TOOLCHAIN_REF }}
          path: toolchain

      - name: Cache toolchain Docker image
        id: img-cache
        uses: actions/cache@v4
        with:
          path: /tmp/rack-toolchain-image
          key: rack-toolchain-${{ env.TOOLCHAIN_REF }}-v${{ env.TOOLCHAIN_IMAGE_VERSION }}

      - name: Fetch per-platform Rack SDKs
        working-directory: toolchain
        run: make rack-sdk-all

      - name: Load or build toolchain image
        working-directory: toolchain
        run: |
          set -euo pipefail
          IMG="rack-plugin-toolchain:${TOOLCHAIN_IMAGE_VERSION}"
          if [ -f /tmp/rack-toolchain-image/image.tar ]; then
            echo "Loading cached toolchain image $IMG"
            docker load -i /tmp/rack-toolchain-image/image.tar
          else
            echo "Building toolchain image $IMG (one-off; cached for later runs)"
            # rack-sdk-all already ran; build the cross-toolchain image (mingw +
            # osxcross). This is the heavy step — cached by TOOLCHAIN_REF.
            docker build --build-arg JOBS=$(nproc) \
              --tag "$IMG" . --progress=plain
            mkdir -p /tmp/rack-toolchain-image
            docker save "$IMG" -o /tmp/rack-toolchain-image/image.tar
          fi

      - name: Build .vcvplugin for ${{ matrix.platform }}
        working-directory: toolchain
        run: |
          set -euo pipefail
          make docker-plugin-build-${{ matrix.platform }} \
            PLUGIN_DIR="${GITHUB_WORKSPACE}/${PLUGIN_DIR_REL}"

      - name: Collect artifact
        run: |
          set -euo pipefail
          mkdir -p out
          cp toolchain/plugin-build/*.vcvplugin out/
          ls -la out

      - name: Upload artifact
        uses: actions/upload-artifact@v4
        with:
          name: MEMLNaut-${{ matrix.platform }}
          path: out/*.vcvplugin
          if-no-files-found: error

  release:
    name: Attach to release
    needs: build
    if: startsWith(github.ref, 'refs/tags/v')
    runs-on: ubuntu-latest
    permissions:
      contents: write
    steps:
      - name: Download all artifacts
        uses: actions/download-artifact@v4
        with:
          path: artifacts
          merge-multiple: true

      - name: Publish release
        uses: softprops/action-gh-release@v2
        with:
          files: artifacts/*.vcvplugin
          generate_release_notes: true