#!/usr/bin/env bash
# swap — one-shot installer
#
#   curl -fsSL https://swagg-neon.vercel.app/install.sh | bash
#
# Downloads a prebuilt binary for this OS/arch from the public Vercel
# host (or SWAP_INSTALL_BASE). Binaries live in Vercel Blob and are
# redirected from /cli/* — the git repo can stay private.
# Installs to ~/.local/bin/swap (or SWAP_INSTALL_DIR).
set -euo pipefail

# Public CDN for prebuilt binaries (Vercel Blob). The git repo stays private —
# assets are not served from GitHub. Override with SWAP_INSTALL_BASE if needed.
# install.sh itself is hosted at https://swagg-neon.vercel.app/install.sh
# (and /cli/* on that host redirects here after vercel.json is deployed).
BASE="${SWAP_INSTALL_BASE:-https://jng5l4649ewvi7zy.public.blob.vercel-storage.com/cli}"
INSTALL_DIR="${SWAP_INSTALL_DIR:-$HOME/.local/bin}"
BIN_NAME="swap"

err() { printf 'error: %s\n' "$*" >&2; exit 1; }
info() { printf '%s\n' "$*" >&2; }

need_cmd() {
  command -v "$1" >/dev/null 2>&1 || err "required command not found: $1"
}

detect_asset() {
  local os arch
  os="$(uname -s | tr '[:upper:]' '[:lower:]')"
  arch="$(uname -m)"

  case "$os" in
    darwin|linux) ;;
    msys*|mingw*|cygwin*)
      err "Windows is not supported by this installer yet. Build from source or download a release asset manually."
      ;;
    *)
      err "unsupported OS: $(uname -s). Supported: macOS (darwin), Linux."
      ;;
  esac

  case "$arch" in
    x86_64|amd64) arch="x64" ;;
    arm64|aarch64) arch="arm64" ;;
    *)
      err "unsupported architecture: $arch. Supported: x64, arm64."
      ;;
  esac

  printf '%s\n' "${BIN_NAME}-${os}-${arch}"
}

download() {
  local url="$1" dest="$2"
  if command -v curl >/dev/null 2>&1; then
    if ! curl -fsSL --connect-timeout 30 --max-time 600 -o "$dest" "$url"; then
      return 1
    fi
  elif command -v wget >/dev/null 2>&1; then
    if ! wget -q -O "$dest" "$url"; then
      return 1
    fi
  else
    err "need curl or wget to download the binary"
  fi
  return 0
}

# Global so the EXIT trap can always see it (locals vanish when main returns).
SWAP_TMPDIR=""
cleanup_tmpdir() {
  if [ -n "${SWAP_TMPDIR}" ] && [ -d "${SWAP_TMPDIR}" ]; then
    rm -rf "${SWAP_TMPDIR}"
  fi
}
trap cleanup_tmpdir EXIT INT TERM

main() {
  need_cmd uname
  need_cmd mktemp
  need_cmd mkdir
  need_cmd chmod
  need_cmd mv

  local asset url tmpbin size
  asset="$(detect_asset)"
  url="${BASE%/}/${asset}"

  SWAP_TMPDIR="$(mktemp -d "${TMPDIR:-/tmp}/swap-install.XXXXXX")"
  tmpbin="${SWAP_TMPDIR}/${asset}"

  if ! download "$url" "$tmpbin"; then
    err "failed to download ${asset} from ${url}
  No prebuilt binary for this platform, or the asset is missing from the public CDN.
  Supported prebuilts: swap-darwin-arm64, swap-darwin-x64, swap-linux-arm64, swap-linux-x64
  Build from source (requires repo access + Bun):
    git clone <private-repo> && cd swap-cli && bun install && SWAP_PUBLIC_BUILD=1 ./build
    install dist/swap ${INSTALL_DIR}/swap"
  fi

  if [ ! -s "$tmpbin" ]; then
    err "downloaded file is empty — check ${url}"
  fi
  # Bun-compiled binaries are tens of MB; a few KB almost always means 404 HTML.
  size="$(wc -c <"$tmpbin" | tr -d ' ')"
  if [ "$size" -lt 1000000 ]; then
    err "downloaded file is only ${size} bytes (expected a multi-MB binary). URL may be wrong or the asset missing: ${url}"
  fi

  mkdir -p "$INSTALL_DIR"
  chmod +x "$tmpbin"
  mv -f "$tmpbin" "${INSTALL_DIR}/${BIN_NAME}"

  info ""
  info "installed ${INSTALL_DIR}/${BIN_NAME}"

  case ":$PATH:" in
    *":${INSTALL_DIR}:"*) ;;
    *)
      info ""
      info "note: ${INSTALL_DIR} is not on your PATH."
      info "  add this to your shell profile (~/.zshrc / ~/.bashrc):"
      info "    export PATH=\"${INSTALL_DIR}:\$PATH\""
      info "  then open a new terminal (or: source ~/.zshrc)"
      ;;
  esac

  info ""
  info "try:"
  info "  swap --help"
  info "  swap 100 USDC WETH"
  info ""
  info "first run may prompt for an Alchemy key / RPC URL (saved to ~/.swap)."
  info "re-run this installer anytime to upgrade."
}

main "$@"