name: Build for Linux

on:
  workflow_call:
    inputs:
      pkg_version:
        description: Build version
        required: true
        type: string

jobs:
  build:
    name: Build for Ubuntu (${{matrix.arch}}, ${{ matrix.configuration }})
    runs-on: ubuntu-22.04${{ matrix.arch == 'aarch64' && '-arm' || '' }}
    strategy:
      matrix:
        arch: [x86_64, aarch64]
        configuration: [debug, release]
    env:
      ARTIFACT_NAME: xemu-ubuntu-${{ matrix.arch }}-${{ matrix.configuration }}
      CCACHE_DIR: /tmp/xemu-ccache
      CCACHE_MAXSIZE: 512M
      LTO_CACHE_DIR: /tmp/xemu-lto-cache
      LTO_CACHE_MAXSIZE: 512m
      DEB_BUILD_MAINT_OPTIONS: optimize=-lto
      DEB_CFLAGS_MAINT_APPEND: -gdwarf-4 -gstrict-dwarf
      DEB_CXXFLAGS_MAINT_APPEND: -gdwarf-4 -gstrict-dwarf
      DEB_LDFLAGS_MAINT_APPEND: -Wl,--build-id=sha1
      CC: ccache clang-21
      CXX: ccache clang++-21
      CC_LD: lld-21
      CXX_LD: lld-21
      AR: llvm-ar-21
      RANLIB: llvm-ranlib-21
      NM: llvm-nm-21
    steps:
    - name: Setup build options
      run: |
        if [[ "${{ matrix.configuration }}" == "debug" ]]; then
          opts=(
            --debug
          )
        else
          opts=(
            --extra-ldflags="-Wl,--thinlto-cache-policy=cache_size_bytes=$LTO_CACHE_MAXSIZE"
            -Db_lto=true
            -Db_lto_mode=thin
            -Db_thinlto_cache=true
            -Db_thinlto_cache_dir="$LTO_CACHE_DIR"
            -Dx86_version=3
          )
          mkdir -p ${LTO_CACHE_DIR}
        fi
        echo "XEMU_BUILD_OPTIONS=${opts[*]}" >> "$GITHUB_ENV"
    - name: Initialize compiler cache
      id: cache
      uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v4
      with:
        path: |
          ${{ env.CCACHE_DIR }}
          ${{ env.LTO_CACHE_DIR }}
        key: cache-${{ runner.os }}-${{ matrix.arch }}-${{ matrix.configuration }}-${{ github.sha }}
        restore-keys: cache-${{ runner.os }}-${{ matrix.arch }}-${{ matrix.configuration }}-
    - name: Download source package
      uses: actions/download-artifact@3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c # v4
      with:
        name: src
    - name: Extract source package
      run: |
        mkdir src
        tar -xf xemu-${{ inputs.pkg_version }}.tar.zst -C src --strip-components=2
    - name: Create debian changelog
      run: |
        pushd src
        echo -e "\
        xemu (1:0.0.0-0) unstable; urgency=medium\n\
          Built from ${{ inputs.pkg_version }})\n\
         -- Matt Borgerson <contact@mborgerson.com>  $(date -R)" > debian/changelog
        popd
    - name: Add LLVM APT repository
      run: |
        sudo install -d /etc/apt/keyrings
        curl -fsSL https://apt.llvm.org/llvm-snapshot.gpg.key \
          | sudo gpg --dearmor -o /etc/apt/keyrings/llvm.gpg
        sudo tee /etc/apt/sources.list.d/llvm.list <<EOF
        deb [signed-by=/etc/apt/keyrings/llvm.gpg] http://apt.llvm.org/jammy/ llvm-toolchain-jammy-21 main
        deb-src [signed-by=/etc/apt/keyrings/llvm.gpg] http://apt.llvm.org/jammy/ llvm-toolchain-jammy-21 main
        EOF
    - name: Install dependencies
      run: |
        sudo apt-get -qy update
        sudo apt-get install ccache libfuse2 libusb-1.0-0-dev #clang-21 lld-21 llvm-21-dev
        pushd src
        sudo apt-get -qy build-dep .
    - name: Install LLVM 21
      shell: bash
      env:
        ARCH: ${{ matrix.arch == 'aarch64' && 'arm64' || 'amd64' }}
        POOL: https://apt.llvm.org/jammy/pool/main/l/llvm-toolchain-21/
      run: |
        set -euxo pipefail

        # Install the newest version that actually exists in the pool.
        # We derive the exact version string from one known package filename.
        HTML="$(curl -fsSL --compressed "$POOL")"
        VER="$(grep -oE 'libllvm21_[0-9][^"]+_${{ env.ARCH }}\.deb' <<<"$HTML" | head -n1 \
          | sed -E 's/^libllvm21_//; s/_${{ env.ARCH }}\.deb$//')"
        echo "Using pool version: $VER"

        mkdir -p /tmp/llvm21 && cd /tmp/llvm21

        fetch() {
          local pkg="$1"
          local file="${pkg}_${VER}_${{ env.ARCH }}.deb"
          curl -fsSLO "${POOL}${file}"
        }

        for pkg in \
          clang-21 clang-tools-21 lld-21 \
          libllvm21 libclang-cpp21 libclang-common-21-dev libclang1-21 libclang-rt-21-dev \
          llvm-21 llvm-21-dev llvm-21-linker-tools llvm-21-runtime llvm-21-tools
        do
          fetch "$pkg"
        done

        # Install the downloaded LLVM debs. apt will resolve any non-LLVM deps from Ubuntu repos.
        sudo apt-get install -y --no-install-recommends ./*.deb
    - name: Setup ccache
      run: |
        echo "PATH=/usr/lib/ccache:$PATH" >> "$GITHUB_ENV"
        mkdir -p ${CCACHE_DIR}
        ccache -z
    - name: Compile
      run: |
        # XXX: dpkg-genbuildinfo takes two minutes on GH runners. Nuke it for now.
        sudo rm /usr/bin/dpkg-genbuildinfo
        sudo ln -s /bin/true /usr/bin/dpkg-genbuildinfo

        pushd src
        dpkg-buildpackage --no-sign -b
        popd

        mkdir -p deb
        mv *.deb *.ddeb deb
    - name: Report ccache stats
      run: ccache -s
    - name: Generate AppImage
      env:
        VERSION: ${{ inputs.pkg_version }}${{ matrix.configuration == 'debug' && '-dbg' || '' }}
      run: |
        wget --no-verbose https://github.com/linuxdeploy/linuxdeploy/releases/latest/download/linuxdeploy-${{ matrix.arch }}.AppImage
        chmod +x linuxdeploy-${{ matrix.arch }}.AppImage

        ar x deb/*.deb
        mkdir appimage
        tar -C appimage -xf data.tar*
        install -DT src/xemu.metainfo.xml appimage/usr/share/metainfo/xemu.metainfo.xml

        ./linuxdeploy-${{ matrix.arch }}.AppImage --output appimage --appdir appimage
    - name: Bundle artifacts
      run: |
        mkdir -p dist
        tar -czvf ./dist/${{ env.ARTIFACT_NAME }}.tgz --transform "s#^dist#${{ env.ARTIFACT_NAME }}#" deb
        mv xemu-*.AppImage dist
    - name: Upload build artifact
      uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a # v4
      with:
        name: ${{ env.ARTIFACT_NAME }}
        path: dist
        compression-level: 0