install

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

repo="${OPENKNOWLEDGE_REPO:-openknowledge-sh/openknowledge}"
version="${OPENKNOWLEDGE_VERSION:-latest}"
base_url="${OPENKNOWLEDGE_BASE_URL:-}"
install_dir="${OPENKNOWLEDGE_INSTALL_DIR:-$HOME/.local/bin}"
binary="openknowledge"

need() {
  if ! command -v "$1" >/dev/null 2>&1; then
    echo "openknowledge install: missing required command: $1" >&2
    exit 1
  fi
}

detect_os() {
  case "$(uname -s)" in
    Darwin) echo "darwin" ;;
    Linux) echo "linux" ;;
    *)
      echo "openknowledge install: unsupported OS: $(uname -s)" >&2
      exit 1
      ;;
  esac
}

detect_arch() {
  case "$(uname -m)" in
    x86_64 | amd64) echo "amd64" ;;
    arm64 | aarch64) echo "arm64" ;;
    *)
      echo "openknowledge install: unsupported architecture: $(uname -m)" >&2
      exit 1
      ;;
  esac
}

release_base() {
  if [ -n "$base_url" ]; then
    echo "${base_url%/}"
    return
  fi

  if [ "$version" = "latest" ]; then
    echo "https://github.com/$repo/releases/latest/download"
    return
  fi

  tag="${version#v}"
  echo "https://github.com/$repo/releases/download/v$tag"
}

checksum_line() {
  checksums="$1"
  asset="$2"

  while read -r sum file extra; do
    if [ "$file" = "$asset" ] && [ -z "${extra:-}" ]; then
      printf '%s  %s\n' "$sum" "$file"
      return 0
    fi
  done < "$checksums"

  return 1
}

verify_checksum() {
  checksums="$1"
  archive="$2"
  asset="$3"

  line="$(checksum_line "$checksums" "$asset" || true)"
  if [ -z "$line" ]; then
    echo "openknowledge install: checksum missing for $asset" >&2
    exit 1
  fi

  if command -v sha256sum >/dev/null 2>&1; then
    (cd "$(dirname "$archive")" && printf '%s\n' "$line" | sha256sum -c -)
    return
  fi

  if command -v shasum >/dev/null 2>&1; then
    (cd "$(dirname "$archive")" && printf '%s\n' "$line" | shasum -a 256 -c -)
    return
  fi

  echo "openknowledge install: missing sha256sum or shasum for checksum verification" >&2
  exit 1
}

need curl
need tar

os="$(detect_os)"
arch="$(detect_arch)"
base="$(release_base)"
asset="openknowledge_${os}_${arch}.tar.gz"
tmp="$(mktemp -d)"
trap 'rm -rf "$tmp"' EXIT

archive="$tmp/$asset"
checksums="$tmp/checksums.txt"

echo "Installing openknowledge from $base"
curl -fsSL "$base/$asset" -o "$archive"
curl -fsSL "$base/checksums.txt" -o "$checksums"
verify_checksum "$checksums" "$archive" "$asset"

tar -xzf "$archive" -C "$tmp"

if [ ! -f "$tmp/$binary" ]; then
  echo "openknowledge install: archive did not contain $binary" >&2
  exit 1
fi

mkdir -p "$install_dir"
install -m 0755 "$tmp/$binary" "$install_dir/$binary"

echo "Installed $("$install_dir/$binary" version) to $install_dir/$binary"

case ":$PATH:" in
  *":$install_dir:"*) ;;
  *)
    echo "Add $install_dir to PATH to run openknowledge from any shell."
    ;;
esac