name: 'Set up libvips'
description: 'Build and cache libvips from source (useful because Ubuntu package is often too old)'
runs:
  using: 'composite'
  steps:
    - name: Get latest libvips version
      id: libvips-version
      shell: bash
      # sometimes this step spuriously fails; just kick it (restart the job) and it should work again
      run: |
        LATEST_VERSION=$(curl -s https://api.github.com/repos/libvips/libvips/releases/latest | grep '"tag_name":' | sed -E 's/.*"v([^"]+)".*/\1/')
        echo "version=$LATEST_VERSION" >> $GITHUB_OUTPUT
        echo "Latest libvips version: $LATEST_VERSION"

    - name: Cache libvips
      id: cache-libvips
      uses: actions/cache@v4
      with:
        path: /opt/libvips
        key: libvips-${{ steps.libvips-version.outputs.version }}-${{ runner.os }}-${{ runner.arch }}

    # The next few steps are derived from instrations at:
    # https://github.com/libvips/libvips/wiki/Build-for-Ubuntu#building-from-source

    - name: Set up build environment
      shell: bash
      run: |
        sudo apt-get update
        sudo apt install -y \
          build-essential \
          pkg-config \
          libglib2.0-dev \
          bc \
          meson \
          ninja-build

    - name: Install libvips dependencies
      shell: bash
      run: |
        sudo apt install -y \
          libcfitsio-dev \
          libexif-dev \
          libexpat1-dev \
          libfftw3-dev \
          libgsf-1-dev \
          libheif-dev \
          libimagequant-dev \
          libjpeg-turbo8-dev \
          liblcms2-dev \
          libmatio-dev \
          libopenexr-dev \
          libopenjp2-7-dev \
          libopenslide-dev \
          liborc-dev \
          libpango1.0-dev \
          libpoppler-glib-dev \
          librsvg2-dev \
          libtiff5-dev \
          libwebp-dev

    # the official instructions refer to a PPA that was archived just a few days
    # ago at time of writing this comment, so build cgif from soure instead
    # (this isn't strictly required, only if rendering animated gifs at runtime)
    - name: Build and install cgif (optional libvips dependency)
      if: steps.cache-libvips.outputs.cache-hit != 'true'
      shell: bash
      run: |
        git clone https://github.com/dloebl/cgif.git
        cd cgif
        meson setup build --prefix=/opt/libvips --buildtype=release
        cd build
        meson compile
        sudo meson install

    - name: Build and install libvips
      if: steps.cache-libvips.outputs.cache-hit != 'true'
      shell: bash
      run: |
        VERSION=${{ steps.libvips-version.outputs.version }}
        wget https://github.com/libvips/libvips/archive/refs/tags/v${VERSION}.tar.gz
        tar xf v${VERSION}.tar.gz
        cd libvips-${VERSION}
        meson setup build --prefix=/opt/libvips --libdir=lib --buildtype=release -Dintrospection=disabled
        cd build
        meson compile
        sudo meson install

    - name: Configure libvips
      shell: bash
      run: |
        echo "PKG_CONFIG_PATH=/opt/libvips/lib/pkgconfig:$PKG_CONFIG_PATH" >> $GITHUB_ENV
        echo "LD_LIBRARY_PATH=/opt/libvips/lib:$LD_LIBRARY_PATH" >> $GITHUB_ENV
        echo "CGO_CFLAGS=-I/opt/libvips/include" >> $GITHUB_ENV
        echo "CGO_LDFLAGS=-L/opt/libvips/lib -Wl,-rpath,/opt/libvips/lib" >> $GITHUB_ENV
        echo "/opt/libvips/bin" >> $GITHUB_PATH
        sudo ldconfig /opt/libvips/lib