#!/usr/bin/env bash
set -euo pipefail

LLVM_VERSION="${LLVM_VERSION:-22}"
MESON_VERSION="${MESON_VERSION:-latest}"
INSTALL_VULKAN="${INSTALL_VULKAN:-true}"
VULKAN_SOURCE="${VULKAN_SOURCE:-apt}"
LUNARG_SDK_VERSION="${LUNARG_SDK_VERSION:-1.4.309.0}"
MAKE_DEFAULT="${MAKE_DEFAULT:-true}"

log() { printf '\n\033[1;34m==> %s\033[0m\n' "$*"; }
warn() { printf '\n\033[1;33mwarning: %s\033[0m\n' "$*" >&2; }

if command -v sudo >/dev/null 2>&1 && [ "$(id -u)" -ne 0 ]; then
  SUDO=sudo
else
  SUDO=""
fi

export DEBIAN_FRONTEND=noninteractive

apt_install() {
  $SUDO apt-get install -y --no-install-recommends "$@"
}

log "Installing base packages"
$SUDO apt-get update
apt_install \
  ca-certificates \
  curl \
  gnupg \
  lsb-release \
  software-properties-common \
  wget \
  xz-utils \
  build-essential \
  pkg-config \
  git \
  python3 \
  python3-venv \
  python3-pip \
  ninja-build

log "Installing LLVM/Clang ${LLVM_VERSION}"
if ! apt-cache show "clang-${LLVM_VERSION}" >/dev/null 2>&1; then
  warn "clang-${LLVM_VERSION} is not in the current apt sources; adding apt.llvm.org"
  curl -fsSL https://apt.llvm.org/llvm-snapshot.gpg.key | $SUDO gpg --dearmor -o /usr/share/keyrings/llvm-snapshot.gpg
  CODENAME="$(. /etc/os-release && printf '%s' "${VERSION_CODENAME:-}")"
  if [ -z "$CODENAME" ]; then
    CODENAME="$(lsb_release -sc)"
  fi
  echo "deb [signed-by=/usr/share/keyrings/llvm-snapshot.gpg] http://apt.llvm.org/${CODENAME}/ llvm-toolchain-${CODENAME}-${LLVM_VERSION} main" | \
    $SUDO tee "/etc/apt/sources.list.d/llvm-${LLVM_VERSION}.list" >/dev/null
  $SUDO apt-get update
fi

apt_install \
  "clang-${LLVM_VERSION}" \
  "clang-tools-${LLVM_VERSION}" \
  "lld-${LLVM_VERSION}" \
  "lldb-${LLVM_VERSION}" \
  "llvm-${LLVM_VERSION}" \
  "llvm-${LLVM_VERSION}-dev"

if [ "$MAKE_DEFAULT" = "true" ]; then
  log "Making Clang ${LLVM_VERSION} the default compiler for this runner"
  for tool in clang clang++ clang-cpp llvm-ar llvm-ranlib llvm-nm llvm-strip lld lldb; do
    if command -v "${tool}-${LLVM_VERSION}" >/dev/null 2>&1; then
      $SUDO update-alternatives --install "/usr/bin/${tool}" "${tool}" "$(command -v "${tool}-${LLVM_VERSION}")" 100
    fi
  done
fi

log "Installing Meson in an isolated venv"
MESON_VENV="/opt/meson-venv"
$SUDO python3 -m venv "$MESON_VENV"
$SUDO "$MESON_VENV/bin/python" -m pip install --upgrade pip setuptools wheel
if [ "$MESON_VERSION" = "latest" ]; then
  $SUDO "$MESON_VENV/bin/python" -m pip install --upgrade meson
else
  $SUDO "$MESON_VENV/bin/python" -m pip install --upgrade "meson==${MESON_VERSION}"
fi
$SUDO ln -sf "$MESON_VENV/bin/meson" /usr/local/bin/meson

if [ "$INSTALL_VULKAN" = "true" ]; then
  case "$VULKAN_SOURCE" in
    apt)
      log "Installing Vulkan development packages from distro apt repositories"
      apt_install \
        libvulkan-dev \
        vulkan-tools \
        vulkan-validationlayers \
        glslang-tools \
        spirv-tools \
        spirv-headers || {
          warn "Some Vulkan packages were unavailable; retrying minimal Vulkan package set"
          apt_install libvulkan-dev vulkan-tools glslang-tools spirv-tools
        }
      ;;
    lunarg)
      log "Installing Vulkan SDK from LunarG (${LUNARG_SDK_VERSION})"
      . /etc/os-release
      if [ "${ID:-}" != "ubuntu" ]; then
        warn "LunarG apt repo is Ubuntu-oriented. Falling back to distro apt Vulkan packages."
        apt_install libvulkan-dev vulkan-tools glslang-tools spirv-tools
      else
        CODENAME="${VERSION_CODENAME:-$(lsb_release -sc)}"
        curl -fsSL https://packages.lunarg.com/lunarg-signing-key-pub.asc | \
          $SUDO gpg --dearmor -o /usr/share/keyrings/lunarg.gpg
        echo "deb [signed-by=/usr/share/keyrings/lunarg.gpg] https://packages.lunarg.com/vulkan/${LUNARG_SDK_VERSION}/ubuntu ${CODENAME} main" | \
          $SUDO tee /etc/apt/sources.list.d/lunarg-vulkan-sdk.list >/dev/null
        $SUDO apt-get update
        apt_install vulkan-sdk
      fi
      ;;
    *)
      echo "Unsupported VULKAN_SOURCE=${VULKAN_SOURCE}; expected apt or lunarg" >&2
      exit 2
      ;;
  esac
fi

log "Versions"
python3 --version
python3 -m pip --version || true
meson --version
ninja --version
clang --version
if command -v vulkaninfo >/dev/null 2>&1; then
  vulkaninfo --summary || true
fi

log "Build environment ready"