#!/bin/sh
set -e

DOWNLOAD_BASE="https://download.astropods.ai/latest"
PREFIX="ast"

OS="$(uname -s | tr '[:upper:]' '[:lower:]')"
ARCH="$(uname -m)"
case "$ARCH" in
  x86_64|amd64) ARCH="amd64" ;;
  arm64|aarch64) ARCH="arm64" ;;
  *) echo "Unsupported architecture: $ARCH" >&2; exit 1 ;;
esac

INSTALL_DIR="${HOME}/.ast/bin"
mkdir -p "$INSTALL_DIR"

VERSION="$(curl -fsSL "${DOWNLOAD_BASE}/VERSION" | tr -d '[:space:]')"
if [ -z "$VERSION" ]; then
  echo "Failed to fetch version from ${DOWNLOAD_BASE}/VERSION" >&2
  exit 1
fi

BINARY_NAME="${PREFIX}-${OS}-${ARCH}"
URL="${DOWNLOAD_BASE}/${BINARY_NAME}"

echo "Downloading ${PREFIX} ${VERSION} for ${OS}/${ARCH}..."
curl -fsSL "$URL" -o "$INSTALL_DIR/${PREFIX}.tmp"

echo "Verifying checksum..."
CHECKSUMS="$(curl -fsSL "${DOWNLOAD_BASE}/checksums.txt")"
EXPECTED="$(echo "$CHECKSUMS" | grep "$BINARY_NAME" | awk '{print $1}')"
if [ -n "$EXPECTED" ]; then
  # Use shasum on macOS, sha256sum on Linux
  if command -v shasum >/dev/null 2>&1; then
    ACTUAL="$(shasum -a 256 "$INSTALL_DIR/${PREFIX}.tmp" | awk '{print $1}')"
  else
    ACTUAL="$(sha256sum "$INSTALL_DIR/${PREFIX}.tmp" | awk '{print $1}')"
  fi
  if [ "$ACTUAL" != "$EXPECTED" ]; then
    rm -f "$INSTALL_DIR/${PREFIX}.tmp"
    echo "Checksum verification failed!" >&2
    echo "  Expected: $EXPECTED" >&2
    echo "  Got:      $ACTUAL" >&2
    exit 1
  fi
  echo "Checksum OK"
fi

chmod +x "$INSTALL_DIR/${PREFIX}.tmp"
mv "$INSTALL_DIR/${PREFIX}.tmp" "$INSTALL_DIR/${PREFIX}-${VERSION}"
ln -sf "${PREFIX}-${VERSION}" "$INSTALL_DIR/${PREFIX}"

# Remove old versioned binaries (keep only the new one)
for f in "$INSTALL_DIR/${PREFIX}"-*; do
  case "$(basename "$f")" in
    "${PREFIX}-${VERSION}") ;;
    "${PREFIX}"-[0-9]*) rm -f "$f" ;;
  esac
done

echo "Installed ${PREFIX} ${VERSION} to ${INSTALL_DIR}"

# Check if INSTALL_DIR is on PATH
case ":${PATH}:" in
  *":${INSTALL_DIR}:"*) ;;
  *)
    echo ""
    echo "Add this to your shell profile:"
    echo "  export PATH=\"\$HOME/.ast/bin:\$PATH\""
    ;;
esac