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

DTK_HOME=${DTK_HOME:-/opt/dtk}
backup_suffix=$(date +%Y%m%d-%H%M%S)

overlay_files=(
  "hip/lib/cmake/hip/hip-config.cmake 0644"
  "hip/lib/cmake/hip/hip-config-amd.cmake 0644"
  "hip/lib/cmake/hip/hip-config-nvidia.cmake 0644"
  "lib/cmake/hiprtc/hiprtc-config.cmake 0644"
)

derived_files=(
  "tools/dtk-amdclang-wrapper llvm/bin/amdclang 0755"
  "tools/dtk-amdclang-wrapper llvm/bin/amdclang++ 0755"
)

backup_and_remove() {
  local dst=$1

  if [ -e "$dst" ] || [ -L "$dst" ]; then
    cp -a "$dst" "$dst.bak.$backup_suffix"
    rm -f "$dst"
  fi
}

for item in "${overlay_files[@]}"; do
  rel=${item% *}
  mode=${item##* }

  src="./$rel"
  dst="$DTK_HOME/$rel"

  if [ ! -f "$src" ]; then
    echo "missing source: $src" >&2
    exit 1
  fi

  backup_and_remove "$dst"

  install -D -m "$mode" "$src" "$dst"
  echo "installed $src -> $dst mode=$mode"
done

for item in "${derived_files[@]}"; do
  read -r src_rel dst_rel mode <<< "$item"

  src="./$src_rel"
  dst="$DTK_HOME/$dst_rel"

  if [ ! -f "$src" ]; then
    echo "missing source: $src" >&2
    exit 1
  fi

  backup_and_remove "$dst"

  install -D -m "$mode" "$src" "$dst"
  echo "installed $src -> $dst mode=$mode"
done