# The way this works is the following:
#
# The create-release job runs purely to initialize the GitHub release itself
# and to output upload_url for the following job.
#
# The build-release job runs only once create-release is finished. It gets the
# release upload URL from create-release job outputs, then builds the release
# executables for each supported platform and attaches them as release assets
# to the previously created release.
#
# The key here is that we create the release only once.
#
# Reference:
# https://eugene-babichenko.github.io/blog/2020/05/09/github-actions-cross-platform-auto-releases/

name: release-agent
on:
  push: 
    # Enable when testing release infrastructure on a branch.
    # branches:
    # - test
    tags:
    - "agent-[0-9]+.[0-9]+.[0-9]+"
jobs:
  create-release:
    name: create-release
    runs-on: ubuntu-latest
    # env:
      # Set to force version number, e.g., when no tag exists.
      # AGENT_VERSION: TEST-0.0.0
    outputs:
      upload_url: ${{ steps.release.outputs.upload_url }}
      agent_version: ${{ env.AGENT_VERSION }}
    steps:
      - name: Get the release version from the tag
        shell: bash
        if: env.AGENT_VERSION == ''
        run: |
          # Apparently, this is the right way to get a tag name. Really?
          #
          # See: https://github.community/t5/GitHub-Actions/How-to-get-just-the-tag-name/m-p/32167/highlight/true#M1027
          echo "AGENT_VERSION=${GITHUB_REF#refs/tags/}" >> $GITHUB_ENV
          echo "version is: ${{ env.AGENT_VERSION }}"
      - name: Create GitHub release
        id: release
        uses: actions/create-release@v1
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        with:
          tag_name: ${{ env.AGENT_VERSION }}
          release_name: ${{ env.AGENT_VERSION }}

  build-release:
    name: build-release
    needs: ['create-release']
    runs-on: ${{ matrix.os }}
    env:
      # Emit backtraces on panics.
      RUST_BACKTRACE: 1
    strategy:
      matrix:
        build: [linux, macos, win-msvc]
        include:
        - build: linux
          os: ubuntu-18.04
          rust: nightly
          target: x86_64-unknown-linux-musl
        - build: macos
          os: macos-latest
          rust: nightly
          target: x86_64-apple-darwin
        - build: win-msvc
          os: windows-latest
          rust: nightly
          target: x86_64-pc-windows-msvc

    steps:
    - name: Checkout repository
      uses: actions/checkout@v2
      with:
        fetch-depth: 1

    - name: Install Rust
      uses: actions-rs/toolchain@v1
      with:
        toolchain: ${{ matrix.rust }}
        profile: minimal
        override: true
        target: ${{ matrix.target }}

    - name: Test release binary
      working-directory: agent
      run: cargo test --verbose --release --target ${{ matrix.target }}

    - name: Build release binary
      working-directory: agent
      run: cargo build --verbose --release --target ${{ matrix.target }}

    - name: Strip release binary (linux and macos)
      if: matrix.build == 'linux' || matrix.build == 'macos'
      working-directory: agent
      run: strip "target/${{ matrix.target }}/release/bazelci-agent"

    - name: Build release asset
      shell: bash
      run: |
        staging="bazelci-${{ needs.create-release.outputs.agent_version }}-${{ matrix.target }}"
        if [ "${{ matrix.os }}" = "windows-latest" ]; then
          cp "agent/target/${{ matrix.target }}/release/bazelci-agent.exe" "$staging.exe"
          echo "ASSET=$staging.exe" >> $GITHUB_ENV
        else
          cp "agent/target/${{ matrix.target }}/release/bazelci-agent" "$staging"
          echo "ASSET=$staging" >> $GITHUB_ENV
        fi
    - name: Upload release asset
      uses: actions/upload-release-asset@v1.0.1
      env:
        GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
      with:
        upload_url: ${{ needs.create-release.outputs.upload_url }}
        asset_path: ${{ env.ASSET }}
        asset_name: ${{ env.ASSET }}
        asset_content_type: application/octet-stream