name: Build and test

# Desktop and Android are built on every push, per the v0.1 decision to carry
# both platforms from the first commit. An Android break is then caught the day
# it lands rather than at a porting milestone.

on:
  push:
    branches: [main, master, develop]
  pull_request:
    branches: [main, master, develop]

jobs:
  # The Android job runs inside an image that this repo builds. Ensure it is in
  # the registry before anything tries to pull it — see android-image.yml for
  # why this is a job rather than a documented manual step. It is a no-op of a
  # few seconds unless docker/android actually changed.
  android-image:
    uses: ./.gitea/workflows/android-image.yml

  desktop:
    runs-on: linux/amd64
    name: Desktop (Linux)
    # actions/checkout and actions/cache are JavaScript actions: the runner
    # executes them with Node from inside this container. The bare runner image
    # has none, so the job failed at checkout before reaching any build step.
    container:
      image: catthehacker/ubuntu:act-latest

    steps:
      - name: Checkout
        # `lfs: true` is load-bearing, not hygiene. `core/dr-segment/models/*.onnx`
        # is tracked in LFS (see .gitattributes), and a checkout without it writes
        # a ~130-byte pointer where the 11 MB model should be. `dr-segment`'s build
        # script detects that and panics by design, so every job that compiles it
        # fails at the build script with a message about git-lfs — which reads like
        # a broken build rather than a missing fetch.
        #
        # It stayed hidden while the Android job built `-p dr-gpu`, which does not
        # reach dr-segment. Building the app crate does.
        uses: actions/checkout@v4
        with:
          lfs: true

      - name: Cache cargo
        uses: actions/cache@v4
        with:
          path: |
            ~/.cargo/registry
            ~/.cargo/git
            target
          key: desktop-${{ runner.os }}-${{ hashFiles('**/Cargo.lock') }}

      # Slint and winit need these at build time; the runner image is minimal.
      - name: Build dependencies
        run: |
          apt-get update -qq
          apt-get install -y -qq pkg-config libfontconfig1-dev libxkbcommon-dev

      # The act image ships Node but no Rust. Pinned to the workspace
      # rust-version so CI, the Android image, and local builds agree — a
      # floating toolchain turns an unrelated push into a mystery failure.
      - name: Install Rust 1.92.0
        run: |
          set -e
          curl -fsSL https://sh.rustup.rs | sh -s -- \
            -y --no-modify-path --profile minimal \
            --default-toolchain 1.92.0 --component rustfmt,clippy
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"

      - name: Format
        run: cargo fmt --all -- --check

      - name: Clippy
        run: cargo clippy --workspace --all-targets -- -D warnings

      # GPU tests skip themselves where no adapter is present rather than
      # failing — CI runners generally have none, and a test that cannot run is
      # not evidence either way.
      - name: Test
        run: cargo test --workspace

      - name: Build
        run: cargo build --workspace --release

  android:
    runs-on: linux/amd64
    name: Android (aarch64)
    # Waits for the image build. Without this the pull races the push and the
    # job dies with "manifest unknown" before its first step, which is the
    # failure mode this ordering exists to remove.
    needs: android-image
    container:
      image: gitea.tourolle.paris/dtourolle/darkroom-android:latest

    steps:
      - name: Checkout
        # `lfs: true` is load-bearing, not hygiene. `core/dr-segment/models/*.onnx`
        # is tracked in LFS (see .gitattributes), and a checkout without it writes
        # a ~130-byte pointer where the 11 MB model should be. `dr-segment`'s build
        # script detects that and panics by design, so every job that compiles it
        # fails at the build script with a message about git-lfs — which reads like
        # a broken build rather than a missing fetch.
        #
        # It stayed hidden while the Android job built `-p dr-gpu`, which does not
        # reach dr-segment. Building the app crate does.
        uses: actions/checkout@v4
        with:
          lfs: true

      - name: Cache cargo
        uses: actions/cache@v4
        with:
          path: |
            /opt/cargo/registry
            target-android
          key: android-${{ hashFiles('**/Cargo.lock') }}

      # A fast gate on the crates most likely to break the cross-compile, run
      # before the expensive part. It is `cargo check`, so it type-checks
      # without linking and returns in a fraction of the time the step below
      # takes.
      #
      # Not a statement that only these crates cross-compile — `darkroom-android`
      # and the whole UI stack beneath it build for aarch64 too, which is what
      # the API-level step below does. This one exists to fail fast and name a
      # smaller suspect when it does.
      - name: Cross-compile core
        env:
          CARGO_TARGET_DIR: target-android
        run: cargo check -p dr-types -p dr-gpu -p dr-sync --target aarch64-linux-android

      # The linker targets MIN_API, not the compile SDK. cargo-ndk otherwise
      # defaults to API 21, far below the Vulkan floor this app needs — and the
      # mismatch is invisible until a device refuses to install.
      #
      # Look under the target triple, and fail on a mismatch. Searching the
      # whole target dir for the first `*.so` found the host proc-macro
      # libraries in target-android/debug/deps instead — x86-64 objects built
      # by the runner's gcc, whose .comment section says nothing about Android
      # and can never contradict the expected API. The step passed regardless
      # of what the linker actually did, which is the one thing it exists to
      # rule out.
      - name: Verify minimum API level
        env:
          CARGO_TARGET_DIR: target-android
        run: |
          set -e
          # `darkroom-android`, not a core crate: this step reads the API level
          # out of a *linked* object, and only that crate produces one. It is
          # the workspace's single `crate-type = ["cdylib"]`; a library crate
          # builds an rlib, which is an archive of object files that no linker
          # has yet touched and that `file` therefore has nothing to say about.
          # Asking for `-p dr-gpu` here could only ever reach the "no aarch64
          # .so was produced" branch below, whatever the linker did.
          #
          # It is also the honest artefact to check: the .so this names is the
          # one that ships in the APK, so the API level verified here is the
          # API level a device will refuse to install against.
          cargo ndk -t arm64-v8a build -p darkroom-android --release
          MIN_API=$(sed -n 's/^ARG MIN_API=\([0-9]*\).*/\1/p' docker/android/Dockerfile)
          # Empty on both sides would compare equal and pass, so neither side
          # is allowed to be the result of a failed parse.
          if [ -z "$MIN_API" ]; then
            echo "no ARG MIN_API= in docker/android/Dockerfile"
            exit 1
          fi
          SO=$(find target-android/aarch64-linux-android/release -maxdepth 1 -name '*.so' | head -1)
          if [ -z "$SO" ]; then
            echo "no aarch64 .so was produced"
            exit 1
          fi
          echo "checking $SO"
          file "$SO"
          API=$(file "$SO" | sed -n 's/.*for Android \([0-9]*\).*/\1/p')
          if [ -z "$API" ] || [ "$API" != "$MIN_API" ]; then
            echo "FAIL: linked for Android '${API:-unknown}', expected $MIN_API"
            exit 1
          fi

  layering:
    runs-on: linux/amd64
    name: Layer separation
    # Node for the JS actions, as above. cargo comes from rustup below.
    container:
      image: catthehacker/ubuntu:act-latest

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      # `cargo tree` resolves the dependency graph, so it needs the registry
      # index but no system libraries — this job builds nothing.
      - name: Install Rust 1.92.0
        run: |
          set -e
          curl -fsSL https://sh.rustup.rs | sh -s -- \
            -y --no-modify-path --profile minimal --default-toolchain 1.92.0
          echo "$HOME/.cargo/bin" >> "$GITHUB_PATH"

      # ARCH §6.5a: no core/ crate may depend on the UI toolkit. One stray
      # `use slint::` costs headless golden-image testing and the
      # one-operation-two-presentations property together, and nothing else
      # would notice.
      - name: Core crates must not depend on the UI
        run: |
          set -e
          FAILED=0
          for crate in dr-types dr-gpu dr-sync; do
            if cargo tree -p "$crate" -e normal 2>/dev/null | grep -qE '\bslint\b|\bi-slint'; then
              echo "FAIL: $crate depends on Slint (ARCH §6.5a)"
              FAILED=1
            else
              echo "ok: $crate"
            fi
          done
          exit $FAILED